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@@ -1,549 +1,554 b'' | |||
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1 | 1 | from __future__ import print_function |
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2 | 2 | |
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3 | 3 | # Standard library imports |
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4 | 4 | from collections import namedtuple |
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5 | 5 | import sys |
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6 | 6 | |
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7 | 7 | # System library imports |
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8 | 8 | from pygments.lexers import PythonLexer |
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9 | 9 | from PyQt4 import QtCore, QtGui |
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10 | 10 | |
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11 | 11 | # Local imports |
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12 | 12 | from IPython.core.inputsplitter import InputSplitter, transform_classic_prompt |
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13 | 13 | from IPython.frontend.qt.base_frontend_mixin import BaseFrontendMixin |
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14 | 14 | from IPython.utils.traitlets import Bool |
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15 | 15 | from bracket_matcher import BracketMatcher |
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16 | 16 | from call_tip_widget import CallTipWidget |
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17 | 17 | from completion_lexer import CompletionLexer |
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18 | 18 | from history_console_widget import HistoryConsoleWidget |
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19 | 19 | from pygments_highlighter import PygmentsHighlighter |
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20 | 20 | |
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21 | 21 | |
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22 | 22 | class FrontendHighlighter(PygmentsHighlighter): |
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23 | 23 | """ A PygmentsHighlighter that can be turned on and off and that ignores |
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24 | 24 | prompts. |
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25 | 25 | """ |
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26 | 26 | |
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27 | 27 | def __init__(self, frontend): |
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28 | 28 | super(FrontendHighlighter, self).__init__(frontend._control.document()) |
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29 | 29 | self._current_offset = 0 |
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30 | 30 | self._frontend = frontend |
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31 | 31 | self.highlighting_on = False |
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32 | 32 | |
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33 | 33 | def highlightBlock(self, qstring): |
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34 | 34 | """ Highlight a block of text. Reimplemented to highlight selectively. |
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35 | 35 | """ |
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36 | 36 | if not self.highlighting_on: |
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37 | 37 | return |
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38 | 38 | |
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39 | 39 | # The input to this function is unicode string that may contain |
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40 | 40 | # paragraph break characters, non-breaking spaces, etc. Here we acquire |
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41 | 41 | # the string as plain text so we can compare it. |
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42 | 42 | current_block = self.currentBlock() |
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43 | 43 | string = self._frontend._get_block_plain_text(current_block) |
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44 | 44 | |
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45 | 45 | # Decide whether to check for the regular or continuation prompt. |
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46 | 46 | if current_block.contains(self._frontend._prompt_pos): |
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47 | 47 | prompt = self._frontend._prompt |
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48 | 48 | else: |
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49 | 49 | prompt = self._frontend._continuation_prompt |
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50 | 50 | |
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51 | 51 | # Don't highlight the part of the string that contains the prompt. |
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52 | 52 | if string.startswith(prompt): |
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53 | 53 | self._current_offset = len(prompt) |
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54 | 54 | qstring.remove(0, len(prompt)) |
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55 | 55 | else: |
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56 | 56 | self._current_offset = 0 |
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57 | 57 | |
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58 | 58 | PygmentsHighlighter.highlightBlock(self, qstring) |
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59 | 59 | |
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60 | 60 | def rehighlightBlock(self, block): |
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61 | 61 | """ Reimplemented to temporarily enable highlighting if disabled. |
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62 | 62 | """ |
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63 | 63 | old = self.highlighting_on |
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64 | 64 | self.highlighting_on = True |
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65 | 65 | super(FrontendHighlighter, self).rehighlightBlock(block) |
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66 | 66 | self.highlighting_on = old |
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67 | 67 | |
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68 | 68 | def setFormat(self, start, count, format): |
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69 | 69 | """ Reimplemented to highlight selectively. |
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70 | 70 | """ |
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71 | 71 | start += self._current_offset |
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72 | 72 | PygmentsHighlighter.setFormat(self, start, count, format) |
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73 | 73 | |
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74 | 74 | |
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75 | 75 | class FrontendWidget(HistoryConsoleWidget, BaseFrontendMixin): |
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76 | 76 | """ A Qt frontend for a generic Python kernel. |
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77 | 77 | """ |
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78 | 78 | |
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79 | 79 | # An option and corresponding signal for overriding the default kernel |
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80 | 80 | # interrupt behavior. |
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81 | 81 | custom_interrupt = Bool(False) |
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82 | 82 | custom_interrupt_requested = QtCore.pyqtSignal() |
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83 | 83 | |
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84 | 84 | # An option and corresponding signals for overriding the default kernel |
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85 | 85 | # restart behavior. |
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86 | 86 | custom_restart = Bool(False) |
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87 | 87 | custom_restart_kernel_died = QtCore.pyqtSignal(float) |
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88 | 88 | custom_restart_requested = QtCore.pyqtSignal() |
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89 | 89 | |
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90 | 90 | # Emitted when an 'execute_reply' has been received from the kernel and |
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91 | 91 | # processed by the FrontendWidget. |
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92 | 92 | executed = QtCore.pyqtSignal(object) |
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93 | 93 | |
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94 | 94 | # Emitted when an exit request has been received from the kernel. |
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95 | 95 | exit_requested = QtCore.pyqtSignal() |
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96 | 96 | |
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97 | 97 | # Protected class variables. |
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98 | 98 | _CallTipRequest = namedtuple('_CallTipRequest', ['id', 'pos']) |
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99 | 99 | _CompletionRequest = namedtuple('_CompletionRequest', ['id', 'pos']) |
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100 | 100 | _ExecutionRequest = namedtuple('_ExecutionRequest', ['id', 'kind']) |
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101 | 101 | _input_splitter_class = InputSplitter |
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102 | 102 | |
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103 | 103 | #--------------------------------------------------------------------------- |
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104 | 104 | # 'object' interface |
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105 | 105 | #--------------------------------------------------------------------------- |
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106 | 106 | |
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107 | 107 | def __init__(self, *args, **kw): |
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108 | 108 | super(FrontendWidget, self).__init__(*args, **kw) |
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109 | 109 | |
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110 | 110 | # FrontendWidget protected variables. |
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111 | 111 | self._bracket_matcher = BracketMatcher(self._control) |
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112 | 112 | self._call_tip_widget = CallTipWidget(self._control) |
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113 | 113 | self._completion_lexer = CompletionLexer(PythonLexer()) |
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114 | 114 | self._copy_raw_action = QtGui.QAction('Copy (Raw Text)', None) |
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115 | 115 | self._hidden = False |
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116 | 116 | self._highlighter = FrontendHighlighter(self) |
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117 | 117 | self._input_splitter = self._input_splitter_class(input_mode='cell') |
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118 | 118 | self._kernel_manager = None |
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119 | 119 | self._request_info = {} |
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120 | 120 | |
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121 | 121 | # Configure the ConsoleWidget. |
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122 | 122 | self.tab_width = 4 |
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123 | 123 | self._set_continuation_prompt('... ') |
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124 | 124 | |
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125 | 125 | # Configure the CallTipWidget. |
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126 | 126 | self._call_tip_widget.setFont(self.font) |
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127 | 127 | self.font_changed.connect(self._call_tip_widget.setFont) |
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128 | 128 | |
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129 | 129 | # Configure actions. |
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130 | 130 | action = self._copy_raw_action |
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131 | 131 | key = QtCore.Qt.CTRL | QtCore.Qt.SHIFT | QtCore.Qt.Key_C |
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132 | 132 | action.setEnabled(False) |
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133 | 133 | action.setShortcut(QtGui.QKeySequence(key)) |
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134 | 134 | action.setShortcutContext(QtCore.Qt.WidgetWithChildrenShortcut) |
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135 | 135 | action.triggered.connect(self.copy_raw) |
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136 | 136 | self.copy_available.connect(action.setEnabled) |
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137 | 137 | self.addAction(action) |
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138 | 138 | |
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139 | 139 | # Connect signal handlers. |
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140 | 140 | document = self._control.document() |
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141 | 141 | document.contentsChange.connect(self._document_contents_change) |
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142 | 142 | |
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143 | 143 | #--------------------------------------------------------------------------- |
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144 | 144 | # 'ConsoleWidget' public interface |
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145 | 145 | #--------------------------------------------------------------------------- |
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146 | 146 | |
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147 | 147 | def copy(self): |
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148 | 148 | """ Copy the currently selected text to the clipboard, removing prompts. |
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149 | 149 | """ |
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150 | 150 | text = unicode(self._control.textCursor().selection().toPlainText()) |
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151 | 151 | if text: |
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152 | 152 | lines = map(transform_classic_prompt, text.splitlines()) |
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153 | 153 | text = '\n'.join(lines) |
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154 | 154 | QtGui.QApplication.clipboard().setText(text) |
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155 | 155 | |
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156 | 156 | #--------------------------------------------------------------------------- |
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157 | 157 | # 'ConsoleWidget' abstract interface |
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158 | 158 | #--------------------------------------------------------------------------- |
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159 | 159 | |
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160 | 160 | def _is_complete(self, source, interactive): |
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161 | 161 | """ Returns whether 'source' can be completely processed and a new |
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162 | 162 | prompt created. When triggered by an Enter/Return key press, |
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163 | 163 | 'interactive' is True; otherwise, it is False. |
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164 | 164 | """ |
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165 | 165 | complete = self._input_splitter.push(source) |
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166 | 166 | if interactive: |
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167 | 167 | complete = not self._input_splitter.push_accepts_more() |
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168 | 168 | return complete |
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169 | 169 | |
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170 | 170 | def _execute(self, source, hidden): |
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171 | 171 | """ Execute 'source'. If 'hidden', do not show any output. |
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172 | 172 | |
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173 | 173 | See parent class :meth:`execute` docstring for full details. |
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174 | 174 | """ |
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175 | 175 | msg_id = self.kernel_manager.xreq_channel.execute(source, hidden) |
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176 | 176 | self._request_info['execute'] = self._ExecutionRequest(msg_id, 'user') |
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177 | 177 | self._hidden = hidden |
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178 | 178 | |
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179 | 179 | def _prompt_started_hook(self): |
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180 | 180 | """ Called immediately after a new prompt is displayed. |
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181 | 181 | """ |
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182 | 182 | if not self._reading: |
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183 | 183 | self._highlighter.highlighting_on = True |
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184 | 184 | |
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185 | 185 | def _prompt_finished_hook(self): |
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186 | 186 | """ Called immediately after a prompt is finished, i.e. when some input |
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187 | 187 | will be processed and a new prompt displayed. |
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188 | 188 | """ |
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189 | 189 | if not self._reading: |
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190 | 190 | self._highlighter.highlighting_on = False |
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191 | 191 | |
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192 | 192 | def _tab_pressed(self): |
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193 | 193 | """ Called when the tab key is pressed. Returns whether to continue |
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194 | 194 | processing the event. |
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195 | 195 | """ |
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196 | 196 | # Perform tab completion if: |
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197 | 197 | # 1) The cursor is in the input buffer. |
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198 | 198 | # 2) There is a non-whitespace character before the cursor. |
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199 | 199 | text = self._get_input_buffer_cursor_line() |
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200 | 200 | if text is None: |
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201 | 201 | return False |
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202 | 202 | complete = bool(text[:self._get_input_buffer_cursor_column()].strip()) |
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203 | 203 | if complete: |
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204 | 204 | self._complete() |
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205 | 205 | return not complete |
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206 | 206 | |
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207 | 207 | #--------------------------------------------------------------------------- |
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208 | 208 | # 'ConsoleWidget' protected interface |
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209 | 209 | #--------------------------------------------------------------------------- |
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210 | 210 | |
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211 | 211 | def _context_menu_make(self, pos): |
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212 | 212 | """ Reimplemented to add an action for raw copy. |
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213 | 213 | """ |
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214 | 214 | menu = super(FrontendWidget, self)._context_menu_make(pos) |
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215 | 215 | for before_action in menu.actions(): |
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216 | 216 | if before_action.shortcut().matches(QtGui.QKeySequence.Paste) == \ |
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217 | 217 | QtGui.QKeySequence.ExactMatch: |
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218 | 218 | menu.insertAction(before_action, self._copy_raw_action) |
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219 | 219 | break |
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220 | 220 | return menu |
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221 | 221 | |
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222 | 222 | def _event_filter_console_keypress(self, event): |
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223 | 223 | """ Reimplemented for execution interruption and smart backspace. |
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224 | 224 | """ |
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225 | 225 | key = event.key() |
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226 | 226 | if self._control_key_down(event.modifiers(), include_command=False): |
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227 | 227 | |
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228 | 228 | if key == QtCore.Qt.Key_C and self._executing: |
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229 | 229 | self.interrupt_kernel() |
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230 | 230 | return True |
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231 | 231 | |
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232 | 232 | elif key == QtCore.Qt.Key_Period: |
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233 | 233 | message = 'Are you sure you want to restart the kernel?' |
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234 | 234 | self.restart_kernel(message, now=False) |
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235 | 235 | return True |
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236 | 236 | |
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237 | 237 | elif not event.modifiers() & QtCore.Qt.AltModifier: |
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238 | 238 | |
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239 | 239 | # Smart backspace: remove four characters in one backspace if: |
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240 | 240 | # 1) everything left of the cursor is whitespace |
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241 | 241 | # 2) the four characters immediately left of the cursor are spaces |
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242 | 242 | if key == QtCore.Qt.Key_Backspace: |
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243 | 243 | col = self._get_input_buffer_cursor_column() |
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244 | 244 | cursor = self._control.textCursor() |
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245 | 245 | if col > 3 and not cursor.hasSelection(): |
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246 | 246 | text = self._get_input_buffer_cursor_line()[:col] |
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247 | 247 | if text.endswith(' ') and not text.strip(): |
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248 | 248 | cursor.movePosition(QtGui.QTextCursor.Left, |
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249 | 249 | QtGui.QTextCursor.KeepAnchor, 4) |
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250 | 250 | cursor.removeSelectedText() |
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251 | 251 | return True |
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252 | 252 | |
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253 | 253 | return super(FrontendWidget, self)._event_filter_console_keypress(event) |
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254 | 254 | |
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255 | 255 | def _insert_continuation_prompt(self, cursor): |
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256 | 256 | """ Reimplemented for auto-indentation. |
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257 | 257 | """ |
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258 | 258 | super(FrontendWidget, self)._insert_continuation_prompt(cursor) |
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259 | 259 | cursor.insertText(' ' * self._input_splitter.indent_spaces) |
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260 | 260 | |
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261 | 261 | #--------------------------------------------------------------------------- |
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262 | 262 | # 'BaseFrontendMixin' abstract interface |
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263 | 263 | #--------------------------------------------------------------------------- |
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264 | 264 | |
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265 | 265 | def _handle_complete_reply(self, rep): |
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266 | 266 | """ Handle replies for tab completion. |
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267 | 267 | """ |
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268 | 268 | cursor = self._get_cursor() |
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269 | 269 | info = self._request_info.get('complete') |
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270 | 270 | if info and info.id == rep['parent_header']['msg_id'] and \ |
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271 | 271 | info.pos == cursor.position(): |
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272 | 272 | text = '.'.join(self._get_context()) |
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273 | 273 | cursor.movePosition(QtGui.QTextCursor.Left, n=len(text)) |
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274 | 274 | self._complete_with_items(cursor, rep['content']['matches']) |
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275 | 275 | |
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276 | 276 | def _handle_execute_reply(self, msg): |
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277 | 277 | """ Handles replies for code execution. |
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278 | 278 | """ |
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279 | 279 | info = self._request_info.get('execute') |
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280 | 280 | if info and info.id == msg['parent_header']['msg_id'] and \ |
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281 | 281 | info.kind == 'user' and not self._hidden: |
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282 | 282 | # Make sure that all output from the SUB channel has been processed |
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283 | 283 | # before writing a new prompt. |
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284 | 284 | self.kernel_manager.sub_channel.flush() |
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285 | 285 | |
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286 | 286 | # Reset the ANSI style information to prevent bad text in stdout |
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287 | 287 | # from messing up our colors. We're not a true terminal so we're |
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288 | 288 | # allowed to do this. |
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289 | 289 | if self.ansi_codes: |
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290 | 290 | self._ansi_processor.reset_sgr() |
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291 | 291 | |
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292 | 292 | content = msg['content'] |
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293 | 293 | status = content['status'] |
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294 | 294 | if status == 'ok': |
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295 | 295 | self._process_execute_ok(msg) |
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296 | 296 | elif status == 'error': |
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297 | 297 | self._process_execute_error(msg) |
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298 | 298 | elif status == 'abort': |
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299 | 299 | self._process_execute_abort(msg) |
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300 | 300 | |
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301 | 301 | self._show_interpreter_prompt_for_reply(msg) |
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302 | 302 | self.executed.emit(msg) |
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303 | 303 | |
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304 | 304 | def _handle_input_request(self, msg): |
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305 | 305 | """ Handle requests for raw_input. |
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306 | 306 | """ |
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307 | 307 | if self._hidden: |
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308 | 308 | raise RuntimeError('Request for raw input during hidden execution.') |
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309 | 309 | |
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310 | 310 | # Make sure that all output from the SUB channel has been processed |
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311 | 311 | # before entering readline mode. |
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312 | 312 | self.kernel_manager.sub_channel.flush() |
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313 | 313 | |
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314 | 314 | def callback(line): |
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315 | 315 | self.kernel_manager.rep_channel.input(line) |
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316 | 316 | self._readline(msg['content']['prompt'], callback=callback) |
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317 | 317 | |
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318 | 318 | def _handle_kernel_died(self, since_last_heartbeat): |
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319 | 319 | """ Handle the kernel's death by asking if the user wants to restart. |
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320 | 320 | """ |
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321 | 321 | if self.custom_restart: |
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322 | 322 | self.custom_restart_kernel_died.emit(since_last_heartbeat) |
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323 | 323 | else: |
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324 | 324 | message = 'The kernel heartbeat has been inactive for %.2f ' \ |
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325 | 325 | 'seconds. Do you want to restart the kernel? You may ' \ |
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326 | 326 | 'first want to check the network connection.' % \ |
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327 | 327 | since_last_heartbeat |
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328 | 328 | self.restart_kernel(message, now=True) |
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329 | 329 | |
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330 | 330 | def _handle_object_info_reply(self, rep): |
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331 | 331 | """ Handle replies for call tips. |
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332 | 332 | """ |
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333 | 333 | cursor = self._get_cursor() |
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334 | 334 | info = self._request_info.get('call_tip') |
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335 | 335 | if info and info.id == rep['parent_header']['msg_id'] and \ |
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336 | 336 | info.pos == cursor.position(): |
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337 | 337 | doc = rep['content']['docstring'] |
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338 | 338 | if doc: |
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339 | 339 | self._call_tip_widget.show_docstring(doc) |
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340 | 340 | |
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341 | 341 | def _handle_pyout(self, msg): |
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342 | 342 | """ Handle display hook output. |
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343 | 343 | """ |
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344 | 344 | if not self._hidden and self._is_from_this_session(msg): |
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345 | 345 | self._append_plain_text(msg['content']['data'] + '\n') |
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346 | 346 | |
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347 | 347 | def _handle_stream(self, msg): |
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348 | 348 | """ Handle stdout, stderr, and stdin. |
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349 | 349 | """ |
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350 | 350 | if not self._hidden and self._is_from_this_session(msg): |
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351 | 351 | # Most consoles treat tabs as being 8 space characters. Convert tabs |
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352 | 352 | # to spaces so that output looks as expected regardless of this |
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353 | 353 | # widget's tab width. |
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354 | 354 | text = msg['content']['data'].expandtabs(8) |
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355 | 355 | |
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356 | 356 | self._append_plain_text(text) |
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357 | 357 | self._control.moveCursor(QtGui.QTextCursor.End) |
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358 | ||
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358 | ||
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359 | def _handle_status(self, msg): | |
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360 | """ Handle kernel status messages. | |
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361 | """ | |
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362 | pass | |
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363 | ||
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359 | 364 | def _started_channels(self): |
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360 | 365 | """ Called when the KernelManager channels have started listening or |
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361 | 366 | when the frontend is assigned an already listening KernelManager. |
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362 | 367 | """ |
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363 | 368 | self.reset() |
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364 | 369 | |
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365 | 370 | #--------------------------------------------------------------------------- |
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366 | 371 | # 'FrontendWidget' public interface |
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367 | 372 | #--------------------------------------------------------------------------- |
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368 | 373 | |
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369 | 374 | def copy_raw(self): |
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370 | 375 | """ Copy the currently selected text to the clipboard without attempting |
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371 | 376 | to remove prompts or otherwise alter the text. |
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372 | 377 | """ |
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373 | 378 | self._control.copy() |
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374 | 379 | |
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375 | 380 | def execute_file(self, path, hidden=False): |
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376 | 381 | """ Attempts to execute file with 'path'. If 'hidden', no output is |
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377 | 382 | shown. |
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378 | 383 | """ |
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379 | 384 | self.execute('execfile("%s")' % path, hidden=hidden) |
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380 | 385 | |
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381 | 386 | def interrupt_kernel(self): |
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382 | 387 | """ Attempts to interrupt the running kernel. |
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383 | 388 | """ |
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384 | 389 | if self.custom_interrupt: |
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385 | 390 | self.custom_interrupt_requested.emit() |
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386 | 391 | elif self.kernel_manager.has_kernel: |
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387 | 392 | self.kernel_manager.interrupt_kernel() |
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388 | 393 | else: |
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389 | 394 | self._append_plain_text('Kernel process is either remote or ' |
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390 | 395 | 'unspecified. Cannot interrupt.\n') |
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391 | 396 | |
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392 | 397 | def reset(self): |
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393 | 398 | """ Resets the widget to its initial state. Similar to ``clear``, but |
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394 | 399 | also re-writes the banner and aborts execution if necessary. |
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395 | 400 | """ |
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396 | 401 | if self._executing: |
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397 | 402 | self._executing = False |
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398 | 403 | self._request_info['execute'] = None |
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399 | 404 | self._reading = False |
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400 | 405 | self._highlighter.highlighting_on = False |
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401 | 406 | |
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402 | 407 | self._control.clear() |
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403 | 408 | self._append_plain_text(self._get_banner()) |
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404 | 409 | self._show_interpreter_prompt() |
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405 | 410 | |
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406 | 411 | def restart_kernel(self, message, now=False): |
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407 | 412 | """ Attempts to restart the running kernel. |
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408 | 413 | """ |
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409 | 414 | # FIXME: now should be configurable via a checkbox in the dialog. Right |
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410 | 415 | # now at least the heartbeat path sets it to True and the manual restart |
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411 | 416 | # to False. But those should just be the pre-selected states of a |
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412 | 417 | # checkbox that the user could override if so desired. But I don't know |
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413 | 418 | # enough Qt to go implementing the checkbox now. |
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414 | 419 | |
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415 | 420 | if self.custom_restart: |
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416 | 421 | self.custom_restart_requested.emit() |
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417 | 422 | |
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418 | 423 | elif self.kernel_manager.has_kernel: |
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419 | 424 | # Pause the heart beat channel to prevent further warnings. |
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420 | 425 | self.kernel_manager.hb_channel.pause() |
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421 | 426 | |
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422 | 427 | # Prompt the user to restart the kernel. Un-pause the heartbeat if |
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423 | 428 | # they decline. (If they accept, the heartbeat will be un-paused |
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424 | 429 | # automatically when the kernel is restarted.) |
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425 | 430 | buttons = QtGui.QMessageBox.Yes | QtGui.QMessageBox.No |
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426 | 431 | result = QtGui.QMessageBox.question(self, 'Restart kernel?', |
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427 | 432 | message, buttons) |
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428 | 433 | if result == QtGui.QMessageBox.Yes: |
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429 | 434 | try: |
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430 | 435 | self.kernel_manager.restart_kernel(now=now) |
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431 | 436 | except RuntimeError: |
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432 | 437 | self._append_plain_text('Kernel started externally. ' |
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433 | 438 | 'Cannot restart.\n') |
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434 | 439 | else: |
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435 | 440 | self.reset() |
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436 | 441 | else: |
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437 | 442 | self.kernel_manager.hb_channel.unpause() |
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438 | 443 | |
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439 | 444 | else: |
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440 | 445 | self._append_plain_text('Kernel process is either remote or ' |
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441 | 446 | 'unspecified. Cannot restart.\n') |
|
442 | 447 | |
|
443 | 448 | #--------------------------------------------------------------------------- |
|
444 | 449 | # 'FrontendWidget' protected interface |
|
445 | 450 | #--------------------------------------------------------------------------- |
|
446 | 451 | |
|
447 | 452 | def _call_tip(self): |
|
448 | 453 | """ Shows a call tip, if appropriate, at the current cursor location. |
|
449 | 454 | """ |
|
450 | 455 | # Decide if it makes sense to show a call tip |
|
451 | 456 | cursor = self._get_cursor() |
|
452 | 457 | cursor.movePosition(QtGui.QTextCursor.Left) |
|
453 | 458 | if cursor.document().characterAt(cursor.position()).toAscii() != '(': |
|
454 | 459 | return False |
|
455 | 460 | context = self._get_context(cursor) |
|
456 | 461 | if not context: |
|
457 | 462 | return False |
|
458 | 463 | |
|
459 | 464 | # Send the metadata request to the kernel |
|
460 | 465 | name = '.'.join(context) |
|
461 | 466 | msg_id = self.kernel_manager.xreq_channel.object_info(name) |
|
462 | 467 | pos = self._get_cursor().position() |
|
463 | 468 | self._request_info['call_tip'] = self._CallTipRequest(msg_id, pos) |
|
464 | 469 | return True |
|
465 | 470 | |
|
466 | 471 | def _complete(self): |
|
467 | 472 | """ Performs completion at the current cursor location. |
|
468 | 473 | """ |
|
469 | 474 | context = self._get_context() |
|
470 | 475 | if context: |
|
471 | 476 | # Send the completion request to the kernel |
|
472 | 477 | msg_id = self.kernel_manager.xreq_channel.complete( |
|
473 | 478 | '.'.join(context), # text |
|
474 | 479 | self._get_input_buffer_cursor_line(), # line |
|
475 | 480 | self._get_input_buffer_cursor_column(), # cursor_pos |
|
476 | 481 | self.input_buffer) # block |
|
477 | 482 | pos = self._get_cursor().position() |
|
478 | 483 | info = self._CompletionRequest(msg_id, pos) |
|
479 | 484 | self._request_info['complete'] = info |
|
480 | 485 | |
|
481 | 486 | def _get_banner(self): |
|
482 | 487 | """ Gets a banner to display at the beginning of a session. |
|
483 | 488 | """ |
|
484 | 489 | banner = 'Python %s on %s\nType "help", "copyright", "credits" or ' \ |
|
485 | 490 | '"license" for more information.' |
|
486 | 491 | return banner % (sys.version, sys.platform) |
|
487 | 492 | |
|
488 | 493 | def _get_context(self, cursor=None): |
|
489 | 494 | """ Gets the context for the specified cursor (or the current cursor |
|
490 | 495 | if none is specified). |
|
491 | 496 | """ |
|
492 | 497 | if cursor is None: |
|
493 | 498 | cursor = self._get_cursor() |
|
494 | 499 | cursor.movePosition(QtGui.QTextCursor.StartOfBlock, |
|
495 | 500 | QtGui.QTextCursor.KeepAnchor) |
|
496 | 501 | text = unicode(cursor.selection().toPlainText()) |
|
497 | 502 | return self._completion_lexer.get_context(text) |
|
498 | 503 | |
|
499 | 504 | def _process_execute_abort(self, msg): |
|
500 | 505 | """ Process a reply for an aborted execution request. |
|
501 | 506 | """ |
|
502 | 507 | self._append_plain_text("ERROR: execution aborted\n") |
|
503 | 508 | |
|
504 | 509 | def _process_execute_error(self, msg): |
|
505 | 510 | """ Process a reply for an execution request that resulted in an error. |
|
506 | 511 | """ |
|
507 | 512 | content = msg['content'] |
|
508 | 513 | traceback = ''.join(content['traceback']) |
|
509 | 514 | self._append_plain_text(traceback) |
|
510 | 515 | |
|
511 | 516 | def _process_execute_ok(self, msg): |
|
512 | 517 | """ Process a reply for a successful execution equest. |
|
513 | 518 | """ |
|
514 | 519 | payload = msg['content']['payload'] |
|
515 | 520 | for item in payload: |
|
516 | 521 | if not self._process_execute_payload(item): |
|
517 | 522 | warning = 'Warning: received unknown payload of type %s' |
|
518 | 523 | print(warning % repr(item['source'])) |
|
519 | 524 | |
|
520 | 525 | def _process_execute_payload(self, item): |
|
521 | 526 | """ Process a single payload item from the list of payload items in an |
|
522 | 527 | execution reply. Returns whether the payload was handled. |
|
523 | 528 | """ |
|
524 | 529 | # The basic FrontendWidget doesn't handle payloads, as they are a |
|
525 | 530 | # mechanism for going beyond the standard Python interpreter model. |
|
526 | 531 | return False |
|
527 | 532 | |
|
528 | 533 | def _show_interpreter_prompt(self): |
|
529 | 534 | """ Shows a prompt for the interpreter. |
|
530 | 535 | """ |
|
531 | 536 | self._show_prompt('>>> ') |
|
532 | 537 | |
|
533 | 538 | def _show_interpreter_prompt_for_reply(self, msg): |
|
534 | 539 | """ Shows a prompt for the interpreter given an 'execute_reply' message. |
|
535 | 540 | """ |
|
536 | 541 | self._show_interpreter_prompt() |
|
537 | 542 | |
|
538 | 543 | #------ Signal handlers ---------------------------------------------------- |
|
539 | 544 | |
|
540 | 545 | def _document_contents_change(self, position, removed, added): |
|
541 | 546 | """ Called whenever the document's content changes. Display a call tip |
|
542 | 547 | if appropriate. |
|
543 | 548 | """ |
|
544 | 549 | # Calculate where the cursor should be *after* the change: |
|
545 | 550 | position += added |
|
546 | 551 | |
|
547 | 552 | document = self._control.document() |
|
548 | 553 | if position == self._get_cursor().position(): |
|
549 | 554 | self._call_tip() |
@@ -1,612 +1,627 b'' | |||
|
1 | 1 | #!/usr/bin/env python |
|
2 | 2 | """A simple interactive kernel that talks to a frontend over 0MQ. |
|
3 | 3 | |
|
4 | 4 | Things to do: |
|
5 | 5 | |
|
6 | 6 | * Implement `set_parent` logic. Right before doing exec, the Kernel should |
|
7 | 7 | call set_parent on all the PUB objects with the message about to be executed. |
|
8 | 8 | * Implement random port and security key logic. |
|
9 | 9 | * Implement control messages. |
|
10 | 10 | * Implement event loop and poll version. |
|
11 | 11 | """ |
|
12 | 12 | |
|
13 | 13 | #----------------------------------------------------------------------------- |
|
14 | 14 | # Imports |
|
15 | 15 | #----------------------------------------------------------------------------- |
|
16 | 16 | from __future__ import print_function |
|
17 | 17 | |
|
18 | 18 | # Standard library imports. |
|
19 | 19 | import __builtin__ |
|
20 | 20 | import atexit |
|
21 | 21 | import sys |
|
22 | 22 | import time |
|
23 | 23 | import traceback |
|
24 | 24 | |
|
25 | 25 | # System library imports. |
|
26 | 26 | import zmq |
|
27 | 27 | |
|
28 | 28 | # Local imports. |
|
29 | 29 | from IPython.config.configurable import Configurable |
|
30 | 30 | from IPython.utils import io |
|
31 | 31 | from IPython.utils.jsonutil import json_clean |
|
32 | 32 | from IPython.lib import pylabtools |
|
33 | 33 | from IPython.utils.traitlets import Instance, Float |
|
34 | 34 | from entry_point import (base_launch_kernel, make_argument_parser, make_kernel, |
|
35 | 35 | start_kernel) |
|
36 | 36 | from iostream import OutStream |
|
37 | 37 | from session import Session, Message |
|
38 | 38 | from zmqshell import ZMQInteractiveShell |
|
39 | 39 | |
|
40 | 40 | #----------------------------------------------------------------------------- |
|
41 | 41 | # Main kernel class |
|
42 | 42 | #----------------------------------------------------------------------------- |
|
43 | 43 | |
|
44 | 44 | class Kernel(Configurable): |
|
45 | 45 | |
|
46 | 46 | #--------------------------------------------------------------------------- |
|
47 | 47 | # Kernel interface |
|
48 | 48 | #--------------------------------------------------------------------------- |
|
49 | 49 | |
|
50 | 50 | shell = Instance('IPython.core.interactiveshell.InteractiveShellABC') |
|
51 | 51 | session = Instance(Session) |
|
52 | 52 | reply_socket = Instance('zmq.Socket') |
|
53 | 53 | pub_socket = Instance('zmq.Socket') |
|
54 | 54 | req_socket = Instance('zmq.Socket') |
|
55 | 55 | |
|
56 | 56 | # Private interface |
|
57 | 57 | |
|
58 | 58 | # Time to sleep after flushing the stdout/err buffers in each execute |
|
59 | 59 | # cycle. While this introduces a hard limit on the minimal latency of the |
|
60 | 60 | # execute cycle, it helps prevent output synchronization problems for |
|
61 | 61 | # clients. |
|
62 | 62 | # Units are in seconds. The minimum zmq latency on local host is probably |
|
63 | 63 | # ~150 microseconds, set this to 500us for now. We may need to increase it |
|
64 | 64 | # a little if it's not enough after more interactive testing. |
|
65 | 65 | _execute_sleep = Float(0.0005, config=True) |
|
66 | 66 | |
|
67 | 67 | # Frequency of the kernel's event loop. |
|
68 | 68 | # Units are in seconds, kernel subclasses for GUI toolkits may need to |
|
69 | 69 | # adapt to milliseconds. |
|
70 | 70 | _poll_interval = Float(0.05, config=True) |
|
71 | 71 | |
|
72 | 72 | # If the shutdown was requested over the network, we leave here the |
|
73 | 73 | # necessary reply message so it can be sent by our registered atexit |
|
74 | 74 | # handler. This ensures that the reply is only sent to clients truly at |
|
75 | 75 | # the end of our shutdown process (which happens after the underlying |
|
76 | 76 | # IPython shell's own shutdown). |
|
77 | 77 | _shutdown_message = None |
|
78 | 78 | |
|
79 | 79 | # This is a dict of port number that the kernel is listening on. It is set |
|
80 | 80 | # by record_ports and used by connect_request. |
|
81 | 81 | _recorded_ports = None |
|
82 | 82 | |
|
83 | 83 | def __init__(self, **kwargs): |
|
84 | 84 | super(Kernel, self).__init__(**kwargs) |
|
85 | 85 | |
|
86 | 86 | # Before we even start up the shell, register *first* our exit handlers |
|
87 | 87 | # so they come before the shell's |
|
88 | 88 | atexit.register(self._at_shutdown) |
|
89 | 89 | |
|
90 | 90 | # Initialize the InteractiveShell subclass |
|
91 | 91 | self.shell = ZMQInteractiveShell.instance() |
|
92 | 92 | self.shell.displayhook.session = self.session |
|
93 | 93 | self.shell.displayhook.pub_socket = self.pub_socket |
|
94 | 94 | |
|
95 | 95 | # TMP - hack while developing |
|
96 | 96 | self.shell._reply_content = None |
|
97 | 97 | |
|
98 | 98 | # Build dict of handlers for message types |
|
99 | 99 | msg_types = [ 'execute_request', 'complete_request', |
|
100 | 100 | 'object_info_request', 'history_request', |
|
101 | 101 | 'connect_request', 'shutdown_request'] |
|
102 | 102 | self.handlers = {} |
|
103 | 103 | for msg_type in msg_types: |
|
104 | 104 | self.handlers[msg_type] = getattr(self, msg_type) |
|
105 | 105 | |
|
106 | 106 | def do_one_iteration(self): |
|
107 | 107 | """Do one iteration of the kernel's evaluation loop. |
|
108 | 108 | """ |
|
109 | 109 | try: |
|
110 | 110 | ident = self.reply_socket.recv(zmq.NOBLOCK) |
|
111 | 111 | except zmq.ZMQError, e: |
|
112 | 112 | if e.errno == zmq.EAGAIN: |
|
113 | 113 | return |
|
114 | 114 | else: |
|
115 | 115 | raise |
|
116 | 116 | # FIXME: Bug in pyzmq/zmq? |
|
117 | 117 | # assert self.reply_socket.rcvmore(), "Missing message part." |
|
118 | 118 | msg = self.reply_socket.recv_json() |
|
119 | 119 | |
|
120 | 120 | # Print some info about this message and leave a '--->' marker, so it's |
|
121 | 121 | # easier to trace visually the message chain when debugging. Each |
|
122 | 122 | # handler prints its message at the end. |
|
123 | 123 | # Eventually we'll move these from stdout to a logger. |
|
124 | 124 | io.raw_print('\n*** MESSAGE TYPE:', msg['msg_type'], '***') |
|
125 | 125 | io.raw_print(' Content: ', msg['content'], |
|
126 | 126 | '\n --->\n ', sep='', end='') |
|
127 | 127 | |
|
128 | 128 | # Find and call actual handler for message |
|
129 | 129 | handler = self.handlers.get(msg['msg_type'], None) |
|
130 | 130 | if handler is None: |
|
131 | 131 | io.raw_print_err("UNKNOWN MESSAGE TYPE:", msg) |
|
132 | 132 | else: |
|
133 | 133 | handler(ident, msg) |
|
134 | 134 | |
|
135 | 135 | # Check whether we should exit, in case the incoming message set the |
|
136 | 136 | # exit flag on |
|
137 | 137 | if self.shell.exit_now: |
|
138 | 138 | io.raw_print('\nExiting IPython kernel...') |
|
139 | 139 | # We do a normal, clean exit, which allows any actions registered |
|
140 | 140 | # via atexit (such as history saving) to take place. |
|
141 | 141 | sys.exit(0) |
|
142 | 142 | |
|
143 | 143 | |
|
144 | 144 | def start(self): |
|
145 | 145 | """ Start the kernel main loop. |
|
146 | 146 | """ |
|
147 | 147 | while True: |
|
148 | 148 | time.sleep(self._poll_interval) |
|
149 | 149 | self.do_one_iteration() |
|
150 | 150 | |
|
151 | 151 | def record_ports(self, xrep_port, pub_port, req_port, hb_port): |
|
152 | 152 | """Record the ports that this kernel is using. |
|
153 | 153 | |
|
154 | 154 | The creator of the Kernel instance must call this methods if they |
|
155 | 155 | want the :meth:`connect_request` method to return the port numbers. |
|
156 | 156 | """ |
|
157 | 157 | self._recorded_ports = { |
|
158 | 158 | 'xrep_port' : xrep_port, |
|
159 | 159 | 'pub_port' : pub_port, |
|
160 | 160 | 'req_port' : req_port, |
|
161 | 161 | 'hb_port' : hb_port |
|
162 | 162 | } |
|
163 | 163 | |
|
164 | 164 | #--------------------------------------------------------------------------- |
|
165 | 165 | # Kernel request handlers |
|
166 | 166 | #--------------------------------------------------------------------------- |
|
167 | 167 | |
|
168 | 168 | def _publish_pyin(self, code, parent): |
|
169 | 169 | """Publish the code request on the pyin stream.""" |
|
170 | 170 | |
|
171 | 171 | pyin_msg = self.session.msg(u'pyin',{u'code':code}, parent=parent) |
|
172 | 172 | self.pub_socket.send_json(pyin_msg) |
|
173 | 173 | |
|
174 | 174 | def execute_request(self, ident, parent): |
|
175 | ||
|
176 | status_msg = self.session.msg( | |
|
177 | u'status', | |
|
178 | {u'execution_state':u'busy'}, | |
|
179 | parent=parent | |
|
180 | ) | |
|
181 | self.pub_socket.send_json(status_msg) | |
|
182 | ||
|
175 | 183 | try: |
|
176 | 184 | content = parent[u'content'] |
|
177 | 185 | code = content[u'code'] |
|
178 | 186 | silent = content[u'silent'] |
|
179 | 187 | except: |
|
180 | 188 | io.raw_print_err("Got bad msg: ") |
|
181 | 189 | io.raw_print_err(Message(parent)) |
|
182 | 190 | return |
|
183 | 191 | |
|
184 | 192 | shell = self.shell # we'll need this a lot here |
|
185 | 193 | |
|
186 | 194 | # Replace raw_input. Note that is not sufficient to replace |
|
187 | 195 | # raw_input in the user namespace. |
|
188 | 196 | raw_input = lambda prompt='': self._raw_input(prompt, ident, parent) |
|
189 | 197 | __builtin__.raw_input = raw_input |
|
190 | 198 | |
|
191 | 199 | # Set the parent message of the display hook and out streams. |
|
192 | 200 | shell.displayhook.set_parent(parent) |
|
193 | 201 | sys.stdout.set_parent(parent) |
|
194 | 202 | sys.stderr.set_parent(parent) |
|
195 | 203 | |
|
196 | 204 | # Re-broadcast our input for the benefit of listening clients, and |
|
197 | 205 | # start computing output |
|
198 | 206 | if not silent: |
|
199 | 207 | self._publish_pyin(code, parent) |
|
200 | 208 | |
|
201 | 209 | reply_content = {} |
|
202 | 210 | try: |
|
203 | 211 | if silent: |
|
204 | 212 | # runcode uses 'exec' mode, so no displayhook will fire, and it |
|
205 | 213 | # doesn't call logging or history manipulations. Print |
|
206 | 214 | # statements in that code will obviously still execute. |
|
207 | 215 | shell.runcode(code) |
|
208 | 216 | else: |
|
209 | 217 | # FIXME: runlines calls the exception handler itself. |
|
210 | 218 | shell._reply_content = None |
|
211 | 219 | |
|
212 | 220 | # For now leave this here until we're sure we can stop using it |
|
213 | 221 | #shell.runlines(code) |
|
214 | 222 | |
|
215 | 223 | # Experimental: cell mode! Test more before turning into |
|
216 | 224 | # default and removing the hacks around runlines. |
|
217 | 225 | shell.run_cell(code) |
|
218 | 226 | except: |
|
219 | 227 | status = u'error' |
|
220 | 228 | # FIXME: this code right now isn't being used yet by default, |
|
221 | 229 | # because the runlines() call above directly fires off exception |
|
222 | 230 | # reporting. This code, therefore, is only active in the scenario |
|
223 | 231 | # where runlines itself has an unhandled exception. We need to |
|
224 | 232 | # uniformize this, for all exception construction to come from a |
|
225 | 233 | # single location in the codbase. |
|
226 | 234 | etype, evalue, tb = sys.exc_info() |
|
227 | 235 | tb_list = traceback.format_exception(etype, evalue, tb) |
|
228 | 236 | reply_content.update(shell._showtraceback(etype, evalue, tb_list)) |
|
229 | 237 | else: |
|
230 | 238 | status = u'ok' |
|
231 | 239 | |
|
232 | 240 | reply_content[u'status'] = status |
|
233 | 241 | # Compute the execution counter so clients can display prompts |
|
234 | 242 | reply_content['execution_count'] = shell.displayhook.prompt_count |
|
235 | 243 | |
|
236 | 244 | # FIXME - fish exception info out of shell, possibly left there by |
|
237 | 245 | # runlines. We'll need to clean up this logic later. |
|
238 | 246 | if shell._reply_content is not None: |
|
239 | 247 | reply_content.update(shell._reply_content) |
|
240 | 248 | |
|
241 | 249 | # At this point, we can tell whether the main code execution succeeded |
|
242 | 250 | # or not. If it did, we proceed to evaluate user_variables/expressions |
|
243 | 251 | if reply_content['status'] == 'ok': |
|
244 | 252 | reply_content[u'user_variables'] = \ |
|
245 | 253 | shell.get_user_variables(content[u'user_variables']) |
|
246 | 254 | reply_content[u'user_expressions'] = \ |
|
247 | 255 | shell.eval_expressions(content[u'user_expressions']) |
|
248 | 256 | else: |
|
249 | 257 | # If there was an error, don't even try to compute variables or |
|
250 | 258 | # expressions |
|
251 | 259 | reply_content[u'user_variables'] = {} |
|
252 | 260 | reply_content[u'user_expressions'] = {} |
|
253 | 261 | |
|
254 | 262 | # Payloads should be retrieved regardless of outcome, so we can both |
|
255 | 263 | # recover partial output (that could have been generated early in a |
|
256 | 264 | # block, before an error) and clear the payload system always. |
|
257 | 265 | reply_content[u'payload'] = shell.payload_manager.read_payload() |
|
258 | 266 | # Be agressive about clearing the payload because we don't want |
|
259 | 267 | # it to sit in memory until the next execute_request comes in. |
|
260 | 268 | shell.payload_manager.clear_payload() |
|
261 | 269 | |
|
262 | 270 | # Send the reply. |
|
263 | 271 | reply_msg = self.session.msg(u'execute_reply', reply_content, parent) |
|
264 | 272 | io.raw_print(reply_msg) |
|
265 | 273 | |
|
266 | 274 | # Flush output before sending the reply. |
|
267 | 275 | sys.stdout.flush() |
|
268 | 276 | sys.stderr.flush() |
|
269 | 277 | # FIXME: on rare occasions, the flush doesn't seem to make it to the |
|
270 | 278 | # clients... This seems to mitigate the problem, but we definitely need |
|
271 | 279 | # to better understand what's going on. |
|
272 | 280 | if self._execute_sleep: |
|
273 | 281 | time.sleep(self._execute_sleep) |
|
274 | 282 | |
|
275 | 283 | self.reply_socket.send(ident, zmq.SNDMORE) |
|
276 | 284 | self.reply_socket.send_json(reply_msg) |
|
277 | 285 | if reply_msg['content']['status'] == u'error': |
|
278 | 286 | self._abort_queue() |
|
279 | 287 | |
|
288 | status_msg = self.session.msg( | |
|
289 | u'status', | |
|
290 | {u'execution_state':u'idle'}, | |
|
291 | parent=parent | |
|
292 | ) | |
|
293 | self.pub_socket.send_json(status_msg) | |
|
294 | ||
|
280 | 295 | def complete_request(self, ident, parent): |
|
281 | 296 | txt, matches = self._complete(parent) |
|
282 | 297 | matches = {'matches' : matches, |
|
283 | 298 | 'matched_text' : txt, |
|
284 | 299 | 'status' : 'ok'} |
|
285 | 300 | completion_msg = self.session.send(self.reply_socket, 'complete_reply', |
|
286 | 301 | matches, parent, ident) |
|
287 | 302 | io.raw_print(completion_msg) |
|
288 | 303 | |
|
289 | 304 | def object_info_request(self, ident, parent): |
|
290 | 305 | object_info = self.shell.object_inspect(parent['content']['oname']) |
|
291 | 306 | # Before we send this object over, we turn it into a dict and we scrub |
|
292 | 307 | # it for JSON usage |
|
293 | 308 | oinfo = json_clean(object_info._asdict()) |
|
294 | 309 | msg = self.session.send(self.reply_socket, 'object_info_reply', |
|
295 | 310 | oinfo, parent, ident) |
|
296 | 311 | io.raw_print(msg) |
|
297 | 312 | |
|
298 | 313 | def history_request(self, ident, parent): |
|
299 | 314 | output = parent['content']['output'] |
|
300 | 315 | index = parent['content']['index'] |
|
301 | 316 | raw = parent['content']['raw'] |
|
302 | 317 | hist = self.shell.get_history(index=index, raw=raw, output=output) |
|
303 | 318 | content = {'history' : hist} |
|
304 | 319 | msg = self.session.send(self.reply_socket, 'history_reply', |
|
305 | 320 | content, parent, ident) |
|
306 | 321 | io.raw_print(msg) |
|
307 | 322 | |
|
308 | 323 | def connect_request(self, ident, parent): |
|
309 | 324 | if self._recorded_ports is not None: |
|
310 | 325 | content = self._recorded_ports.copy() |
|
311 | 326 | else: |
|
312 | 327 | content = {} |
|
313 | 328 | msg = self.session.send(self.reply_socket, 'connect_reply', |
|
314 | 329 | content, parent, ident) |
|
315 | 330 | io.raw_print(msg) |
|
316 | 331 | |
|
317 | 332 | def shutdown_request(self, ident, parent): |
|
318 | 333 | self.shell.exit_now = True |
|
319 | 334 | self._shutdown_message = self.session.msg(u'shutdown_reply', {}, parent) |
|
320 | 335 | sys.exit(0) |
|
321 | 336 | |
|
322 | 337 | #--------------------------------------------------------------------------- |
|
323 | 338 | # Protected interface |
|
324 | 339 | #--------------------------------------------------------------------------- |
|
325 | 340 | |
|
326 | 341 | def _abort_queue(self): |
|
327 | 342 | while True: |
|
328 | 343 | try: |
|
329 | 344 | ident = self.reply_socket.recv(zmq.NOBLOCK) |
|
330 | 345 | except zmq.ZMQError, e: |
|
331 | 346 | if e.errno == zmq.EAGAIN: |
|
332 | 347 | break |
|
333 | 348 | else: |
|
334 | 349 | assert self.reply_socket.rcvmore(), \ |
|
335 | 350 | "Unexpected missing message part." |
|
336 | 351 | msg = self.reply_socket.recv_json() |
|
337 | 352 | io.raw_print("Aborting:\n", Message(msg)) |
|
338 | 353 | msg_type = msg['msg_type'] |
|
339 | 354 | reply_type = msg_type.split('_')[0] + '_reply' |
|
340 | 355 | reply_msg = self.session.msg(reply_type, {'status' : 'aborted'}, msg) |
|
341 | 356 | io.raw_print(reply_msg) |
|
342 | 357 | self.reply_socket.send(ident,zmq.SNDMORE) |
|
343 | 358 | self.reply_socket.send_json(reply_msg) |
|
344 | 359 | # We need to wait a bit for requests to come in. This can probably |
|
345 | 360 | # be set shorter for true asynchronous clients. |
|
346 | 361 | time.sleep(0.1) |
|
347 | 362 | |
|
348 | 363 | def _raw_input(self, prompt, ident, parent): |
|
349 | 364 | # Flush output before making the request. |
|
350 | 365 | sys.stderr.flush() |
|
351 | 366 | sys.stdout.flush() |
|
352 | 367 | |
|
353 | 368 | # Send the input request. |
|
354 | 369 | content = dict(prompt=prompt) |
|
355 | 370 | msg = self.session.msg(u'input_request', content, parent) |
|
356 | 371 | self.req_socket.send_json(msg) |
|
357 | 372 | |
|
358 | 373 | # Await a response. |
|
359 | 374 | reply = self.req_socket.recv_json() |
|
360 | 375 | try: |
|
361 | 376 | value = reply['content']['value'] |
|
362 | 377 | except: |
|
363 | 378 | io.raw_print_err("Got bad raw_input reply: ") |
|
364 | 379 | io.raw_print_err(Message(parent)) |
|
365 | 380 | value = '' |
|
366 | 381 | return value |
|
367 | 382 | |
|
368 | 383 | def _complete(self, msg): |
|
369 | 384 | c = msg['content'] |
|
370 | 385 | try: |
|
371 | 386 | cpos = int(c['cursor_pos']) |
|
372 | 387 | except: |
|
373 | 388 | # If we don't get something that we can convert to an integer, at |
|
374 | 389 | # least attempt the completion guessing the cursor is at the end of |
|
375 | 390 | # the text, if there's any, and otherwise of the line |
|
376 | 391 | cpos = len(c['text']) |
|
377 | 392 | if cpos==0: |
|
378 | 393 | cpos = len(c['line']) |
|
379 | 394 | return self.shell.complete(c['text'], c['line'], cpos) |
|
380 | 395 | |
|
381 | 396 | def _object_info(self, context): |
|
382 | 397 | symbol, leftover = self._symbol_from_context(context) |
|
383 | 398 | if symbol is not None and not leftover: |
|
384 | 399 | doc = getattr(symbol, '__doc__', '') |
|
385 | 400 | else: |
|
386 | 401 | doc = '' |
|
387 | 402 | object_info = dict(docstring = doc) |
|
388 | 403 | return object_info |
|
389 | 404 | |
|
390 | 405 | def _symbol_from_context(self, context): |
|
391 | 406 | if not context: |
|
392 | 407 | return None, context |
|
393 | 408 | |
|
394 | 409 | base_symbol_string = context[0] |
|
395 | 410 | symbol = self.shell.user_ns.get(base_symbol_string, None) |
|
396 | 411 | if symbol is None: |
|
397 | 412 | symbol = __builtin__.__dict__.get(base_symbol_string, None) |
|
398 | 413 | if symbol is None: |
|
399 | 414 | return None, context |
|
400 | 415 | |
|
401 | 416 | context = context[1:] |
|
402 | 417 | for i, name in enumerate(context): |
|
403 | 418 | new_symbol = getattr(symbol, name, None) |
|
404 | 419 | if new_symbol is None: |
|
405 | 420 | return symbol, context[i:] |
|
406 | 421 | else: |
|
407 | 422 | symbol = new_symbol |
|
408 | 423 | |
|
409 | 424 | return symbol, [] |
|
410 | 425 | |
|
411 | 426 | def _at_shutdown(self): |
|
412 | 427 | """Actions taken at shutdown by the kernel, called by python's atexit. |
|
413 | 428 | """ |
|
414 | 429 | # io.rprint("Kernel at_shutdown") # dbg |
|
415 | 430 | if self._shutdown_message is not None: |
|
416 | 431 | self.reply_socket.send_json(self._shutdown_message) |
|
417 | 432 | io.raw_print(self._shutdown_message) |
|
418 | 433 | # A very short sleep to give zmq time to flush its message buffers |
|
419 | 434 | # before Python truly shuts down. |
|
420 | 435 | time.sleep(0.01) |
|
421 | 436 | |
|
422 | 437 | |
|
423 | 438 | class QtKernel(Kernel): |
|
424 | 439 | """A Kernel subclass with Qt support.""" |
|
425 | 440 | |
|
426 | 441 | def start(self): |
|
427 | 442 | """Start a kernel with QtPy4 event loop integration.""" |
|
428 | 443 | |
|
429 | 444 | from PyQt4 import QtCore |
|
430 | 445 | from IPython.lib.guisupport import get_app_qt4, start_event_loop_qt4 |
|
431 | 446 | |
|
432 | 447 | self.app = get_app_qt4([" "]) |
|
433 | 448 | self.app.setQuitOnLastWindowClosed(False) |
|
434 | 449 | self.timer = QtCore.QTimer() |
|
435 | 450 | self.timer.timeout.connect(self.do_one_iteration) |
|
436 | 451 | # Units for the timer are in milliseconds |
|
437 | 452 | self.timer.start(1000*self._poll_interval) |
|
438 | 453 | start_event_loop_qt4(self.app) |
|
439 | 454 | |
|
440 | 455 | |
|
441 | 456 | class WxKernel(Kernel): |
|
442 | 457 | """A Kernel subclass with Wx support.""" |
|
443 | 458 | |
|
444 | 459 | def start(self): |
|
445 | 460 | """Start a kernel with wx event loop support.""" |
|
446 | 461 | |
|
447 | 462 | import wx |
|
448 | 463 | from IPython.lib.guisupport import start_event_loop_wx |
|
449 | 464 | |
|
450 | 465 | doi = self.do_one_iteration |
|
451 | 466 | # Wx uses milliseconds |
|
452 | 467 | poll_interval = int(1000*self._poll_interval) |
|
453 | 468 | |
|
454 | 469 | # We have to put the wx.Timer in a wx.Frame for it to fire properly. |
|
455 | 470 | # We make the Frame hidden when we create it in the main app below. |
|
456 | 471 | class TimerFrame(wx.Frame): |
|
457 | 472 | def __init__(self, func): |
|
458 | 473 | wx.Frame.__init__(self, None, -1) |
|
459 | 474 | self.timer = wx.Timer(self) |
|
460 | 475 | # Units for the timer are in milliseconds |
|
461 | 476 | self.timer.Start(poll_interval) |
|
462 | 477 | self.Bind(wx.EVT_TIMER, self.on_timer) |
|
463 | 478 | self.func = func |
|
464 | 479 | |
|
465 | 480 | def on_timer(self, event): |
|
466 | 481 | self.func() |
|
467 | 482 | |
|
468 | 483 | # We need a custom wx.App to create our Frame subclass that has the |
|
469 | 484 | # wx.Timer to drive the ZMQ event loop. |
|
470 | 485 | class IPWxApp(wx.App): |
|
471 | 486 | def OnInit(self): |
|
472 | 487 | self.frame = TimerFrame(doi) |
|
473 | 488 | self.frame.Show(False) |
|
474 | 489 | return True |
|
475 | 490 | |
|
476 | 491 | # The redirect=False here makes sure that wx doesn't replace |
|
477 | 492 | # sys.stdout/stderr with its own classes. |
|
478 | 493 | self.app = IPWxApp(redirect=False) |
|
479 | 494 | start_event_loop_wx(self.app) |
|
480 | 495 | |
|
481 | 496 | |
|
482 | 497 | class TkKernel(Kernel): |
|
483 | 498 | """A Kernel subclass with Tk support.""" |
|
484 | 499 | |
|
485 | 500 | def start(self): |
|
486 | 501 | """Start a Tk enabled event loop.""" |
|
487 | 502 | |
|
488 | 503 | import Tkinter |
|
489 | 504 | doi = self.do_one_iteration |
|
490 | 505 | # Tk uses milliseconds |
|
491 | 506 | poll_interval = int(1000*self._poll_interval) |
|
492 | 507 | # For Tkinter, we create a Tk object and call its withdraw method. |
|
493 | 508 | class Timer(object): |
|
494 | 509 | def __init__(self, func): |
|
495 | 510 | self.app = Tkinter.Tk() |
|
496 | 511 | self.app.withdraw() |
|
497 | 512 | self.func = func |
|
498 | 513 | |
|
499 | 514 | def on_timer(self): |
|
500 | 515 | self.func() |
|
501 | 516 | self.app.after(poll_interval, self.on_timer) |
|
502 | 517 | |
|
503 | 518 | def start(self): |
|
504 | 519 | self.on_timer() # Call it once to get things going. |
|
505 | 520 | self.app.mainloop() |
|
506 | 521 | |
|
507 | 522 | self.timer = Timer(doi) |
|
508 | 523 | self.timer.start() |
|
509 | 524 | |
|
510 | 525 | |
|
511 | 526 | class GTKKernel(Kernel): |
|
512 | 527 | """A Kernel subclass with GTK support.""" |
|
513 | 528 | |
|
514 | 529 | def start(self): |
|
515 | 530 | """Start the kernel, coordinating with the GTK event loop""" |
|
516 | 531 | from .gui.gtkembed import GTKEmbed |
|
517 | 532 | |
|
518 | 533 | gtk_kernel = GTKEmbed(self) |
|
519 | 534 | gtk_kernel.start() |
|
520 | 535 | |
|
521 | 536 | |
|
522 | 537 | #----------------------------------------------------------------------------- |
|
523 | 538 | # Kernel main and launch functions |
|
524 | 539 | #----------------------------------------------------------------------------- |
|
525 | 540 | |
|
526 | 541 | def launch_kernel(xrep_port=0, pub_port=0, req_port=0, hb_port=0, |
|
527 | 542 | independent=False, pylab=False): |
|
528 | 543 | """Launches a localhost kernel, binding to the specified ports. |
|
529 | 544 | |
|
530 | 545 | Parameters |
|
531 | 546 | ---------- |
|
532 | 547 | xrep_port : int, optional |
|
533 | 548 | The port to use for XREP channel. |
|
534 | 549 | |
|
535 | 550 | pub_port : int, optional |
|
536 | 551 | The port to use for the SUB channel. |
|
537 | 552 | |
|
538 | 553 | req_port : int, optional |
|
539 | 554 | The port to use for the REQ (raw input) channel. |
|
540 | 555 | |
|
541 | 556 | hb_port : int, optional |
|
542 | 557 | The port to use for the hearbeat REP channel. |
|
543 | 558 | |
|
544 | 559 | independent : bool, optional (default False) |
|
545 | 560 | If set, the kernel process is guaranteed to survive if this process |
|
546 | 561 | dies. If not set, an effort is made to ensure that the kernel is killed |
|
547 | 562 | when this process dies. Note that in this case it is still good practice |
|
548 | 563 | to kill kernels manually before exiting. |
|
549 | 564 | |
|
550 | 565 | pylab : bool or string, optional (default False) |
|
551 | 566 | If not False, the kernel will be launched with pylab enabled. If a |
|
552 | 567 | string is passed, matplotlib will use the specified backend. Otherwise, |
|
553 | 568 | matplotlib's default backend will be used. |
|
554 | 569 | |
|
555 | 570 | Returns |
|
556 | 571 | ------- |
|
557 | 572 | A tuple of form: |
|
558 | 573 | (kernel_process, xrep_port, pub_port, req_port) |
|
559 | 574 | where kernel_process is a Popen object and the ports are integers. |
|
560 | 575 | """ |
|
561 | 576 | extra_arguments = [] |
|
562 | 577 | if pylab: |
|
563 | 578 | extra_arguments.append('--pylab') |
|
564 | 579 | if isinstance(pylab, basestring): |
|
565 | 580 | extra_arguments.append(pylab) |
|
566 | 581 | return base_launch_kernel('from IPython.zmq.ipkernel import main; main()', |
|
567 | 582 | xrep_port, pub_port, req_port, hb_port, |
|
568 | 583 | independent, extra_arguments) |
|
569 | 584 | |
|
570 | 585 | |
|
571 | 586 | def main(): |
|
572 | 587 | """ The IPython kernel main entry point. |
|
573 | 588 | """ |
|
574 | 589 | parser = make_argument_parser() |
|
575 | 590 | parser.add_argument('--pylab', type=str, metavar='GUI', nargs='?', |
|
576 | 591 | const='auto', help = \ |
|
577 | 592 | "Pre-load matplotlib and numpy for interactive use. If GUI is not \ |
|
578 | 593 | given, the GUI backend is matplotlib's, otherwise use one of: \ |
|
579 | 594 | ['tk', 'gtk', 'qt', 'wx', 'inline'].") |
|
580 | 595 | namespace = parser.parse_args() |
|
581 | 596 | |
|
582 | 597 | kernel_class = Kernel |
|
583 | 598 | |
|
584 | 599 | kernel_classes = { |
|
585 | 600 | 'qt' : QtKernel, |
|
586 | 601 | 'qt4': QtKernel, |
|
587 | 602 | 'inline': Kernel, |
|
588 | 603 | 'wx' : WxKernel, |
|
589 | 604 | 'tk' : TkKernel, |
|
590 | 605 | 'gtk': GTKKernel, |
|
591 | 606 | } |
|
592 | 607 | if namespace.pylab: |
|
593 | 608 | if namespace.pylab == 'auto': |
|
594 | 609 | gui, backend = pylabtools.find_gui_and_backend() |
|
595 | 610 | else: |
|
596 | 611 | gui, backend = pylabtools.find_gui_and_backend(namespace.pylab) |
|
597 | 612 | kernel_class = kernel_classes.get(gui) |
|
598 | 613 | if kernel_class is None: |
|
599 | 614 | raise ValueError('GUI is not supported: %r' % gui) |
|
600 | 615 | pylabtools.activate_matplotlib(backend) |
|
601 | 616 | |
|
602 | 617 | kernel = make_kernel(namespace, kernel_class, OutStream) |
|
603 | 618 | |
|
604 | 619 | if namespace.pylab: |
|
605 | 620 | pylabtools.import_pylab(kernel.shell.user_ns, backend, |
|
606 | 621 | shell=kernel.shell) |
|
607 | 622 | |
|
608 | 623 | start_kernel(namespace, kernel) |
|
609 | 624 | |
|
610 | 625 | |
|
611 | 626 | if __name__ == '__main__': |
|
612 | 627 | main() |
@@ -1,782 +1,795 b'' | |||
|
1 | 1 | .. _messaging: |
|
2 | 2 | |
|
3 | 3 | ====================== |
|
4 | 4 | Messaging in IPython |
|
5 | 5 | ====================== |
|
6 | 6 | |
|
7 | 7 | |
|
8 | 8 | Introduction |
|
9 | 9 | ============ |
|
10 | 10 | |
|
11 | 11 | This document explains the basic communications design and messaging |
|
12 | 12 | specification for how the various IPython objects interact over a network |
|
13 | 13 | transport. The current implementation uses the ZeroMQ_ library for messaging |
|
14 | 14 | within and between hosts. |
|
15 | 15 | |
|
16 | 16 | .. Note:: |
|
17 | 17 | |
|
18 | 18 | This document should be considered the authoritative description of the |
|
19 | 19 | IPython messaging protocol, and all developers are strongly encouraged to |
|
20 | 20 | keep it updated as the implementation evolves, so that we have a single |
|
21 | 21 | common reference for all protocol details. |
|
22 | 22 | |
|
23 | 23 | The basic design is explained in the following diagram: |
|
24 | 24 | |
|
25 | 25 | .. image:: frontend-kernel.png |
|
26 | 26 | :width: 450px |
|
27 | 27 | :alt: IPython kernel/frontend messaging architecture. |
|
28 | 28 | :align: center |
|
29 | 29 | :target: ../_images/frontend-kernel.png |
|
30 | 30 | |
|
31 | 31 | A single kernel can be simultaneously connected to one or more frontends. The |
|
32 | 32 | kernel has three sockets that serve the following functions: |
|
33 | 33 | |
|
34 | 34 | 1. REQ: this socket is connected to a *single* frontend at a time, and it allows |
|
35 | 35 | the kernel to request input from a frontend when :func:`raw_input` is called. |
|
36 | 36 | The frontend holding the matching REP socket acts as a 'virtual keyboard' |
|
37 | 37 | for the kernel while this communication is happening (illustrated in the |
|
38 | 38 | figure by the black outline around the central keyboard). In practice, |
|
39 | 39 | frontends may display such kernel requests using a special input widget or |
|
40 | 40 | otherwise indicating that the user is to type input for the kernel instead |
|
41 | 41 | of normal commands in the frontend. |
|
42 | 42 | |
|
43 | 43 | 2. XREP: this single sockets allows multiple incoming connections from |
|
44 | 44 | frontends, and this is the socket where requests for code execution, object |
|
45 | 45 | information, prompts, etc. are made to the kernel by any frontend. The |
|
46 | 46 | communication on this socket is a sequence of request/reply actions from |
|
47 | 47 | each frontend and the kernel. |
|
48 | 48 | |
|
49 | 49 | 3. PUB: this socket is the 'broadcast channel' where the kernel publishes all |
|
50 | 50 | side effects (stdout, stderr, etc.) as well as the requests coming from any |
|
51 | 51 | client over the XREP socket and its own requests on the REP socket. There |
|
52 | 52 | are a number of actions in Python which generate side effects: :func:`print` |
|
53 | 53 | writes to ``sys.stdout``, errors generate tracebacks, etc. Additionally, in |
|
54 | 54 | a multi-client scenario, we want all frontends to be able to know what each |
|
55 | 55 | other has sent to the kernel (this can be useful in collaborative scenarios, |
|
56 | 56 | for example). This socket allows both side effects and the information |
|
57 | 57 | about communications taking place with one client over the XREQ/XREP channel |
|
58 | 58 | to be made available to all clients in a uniform manner. |
|
59 | 59 | |
|
60 | 60 | All messages are tagged with enough information (details below) for clients |
|
61 | 61 | to know which messages come from their own interaction with the kernel and |
|
62 | 62 | which ones are from other clients, so they can display each type |
|
63 | 63 | appropriately. |
|
64 | 64 | |
|
65 | 65 | The actual format of the messages allowed on each of these channels is |
|
66 | 66 | specified below. Messages are dicts of dicts with string keys and values that |
|
67 | 67 | are reasonably representable in JSON. Our current implementation uses JSON |
|
68 | 68 | explicitly as its message format, but this shouldn't be considered a permanent |
|
69 | 69 | feature. As we've discovered that JSON has non-trivial performance issues due |
|
70 | 70 | to excessive copying, we may in the future move to a pure pickle-based raw |
|
71 | 71 | message format. However, it should be possible to easily convert from the raw |
|
72 | 72 | objects to JSON, since we may have non-python clients (e.g. a web frontend). |
|
73 | 73 | As long as it's easy to make a JSON version of the objects that is a faithful |
|
74 | 74 | representation of all the data, we can communicate with such clients. |
|
75 | 75 | |
|
76 | 76 | .. Note:: |
|
77 | 77 | |
|
78 | 78 | Not all of these have yet been fully fleshed out, but the key ones are, see |
|
79 | 79 | kernel and frontend files for actual implementation details. |
|
80 | 80 | |
|
81 | 81 | |
|
82 | 82 | Python functional API |
|
83 | 83 | ===================== |
|
84 | 84 | |
|
85 | 85 | As messages are dicts, they map naturally to a ``func(**kw)`` call form. We |
|
86 | 86 | should develop, at a few key points, functional forms of all the requests that |
|
87 | 87 | take arguments in this manner and automatically construct the necessary dict |
|
88 | 88 | for sending. |
|
89 | 89 | |
|
90 | 90 | |
|
91 | 91 | General Message Format |
|
92 | 92 | ====================== |
|
93 | 93 | |
|
94 | 94 | All messages send or received by any IPython process should have the following |
|
95 | 95 | generic structure:: |
|
96 | 96 | |
|
97 | 97 | { |
|
98 | 98 | # The message header contains a pair of unique identifiers for the |
|
99 | 99 | # originating session and the actual message id, in addition to the |
|
100 | 100 | # username for the process that generated the message. This is useful in |
|
101 | 101 | # collaborative settings where multiple users may be interacting with the |
|
102 | 102 | # same kernel simultaneously, so that frontends can label the various |
|
103 | 103 | # messages in a meaningful way. |
|
104 | 104 | 'header' : { 'msg_id' : uuid, |
|
105 | 105 | 'username' : str, |
|
106 | 106 | 'session' : uuid |
|
107 | 107 | }, |
|
108 | 108 | |
|
109 | 109 | # In a chain of messages, the header from the parent is copied so that |
|
110 | 110 | # clients can track where messages come from. |
|
111 | 111 | 'parent_header' : dict, |
|
112 | 112 | |
|
113 | 113 | # All recognized message type strings are listed below. |
|
114 | 114 | 'msg_type' : str, |
|
115 | 115 | |
|
116 | 116 | # The actual content of the message must be a dict, whose structure |
|
117 | 117 | # depends on the message type.x |
|
118 | 118 | 'content' : dict, |
|
119 | 119 | } |
|
120 | 120 | |
|
121 | 121 | For each message type, the actual content will differ and all existing message |
|
122 | 122 | types are specified in what follows of this document. |
|
123 | 123 | |
|
124 | 124 | |
|
125 | 125 | Messages on the XREP/XREQ socket |
|
126 | 126 | ================================ |
|
127 | 127 | |
|
128 | 128 | .. _execute: |
|
129 | 129 | |
|
130 | 130 | Execute |
|
131 | 131 | ------- |
|
132 | 132 | |
|
133 | 133 | This message type is used by frontends to ask the kernel to execute code on |
|
134 | 134 | behalf of the user, in a namespace reserved to the user's variables (and thus |
|
135 | 135 | separate from the kernel's own internal code and variables). |
|
136 | 136 | |
|
137 | 137 | Message type: ``execute_request``:: |
|
138 | 138 | |
|
139 | 139 | content = { |
|
140 | 140 | # Source code to be executed by the kernel, one or more lines. |
|
141 | 141 | 'code' : str, |
|
142 | 142 | |
|
143 | 143 | # A boolean flag which, if True, signals the kernel to execute this |
|
144 | 144 | # code as quietly as possible. This means that the kernel will compile |
|
145 | 145 | # the code witIPython/core/tests/h 'exec' instead of 'single' (so |
|
146 | 146 | # sys.displayhook will not fire), and will *not*: |
|
147 | 147 | # - broadcast exceptions on the PUB socket |
|
148 | 148 | # - do any logging |
|
149 | 149 | # - populate any history |
|
150 | 150 | # |
|
151 | 151 | # The default is False. |
|
152 | 152 | 'silent' : bool, |
|
153 | 153 | |
|
154 | 154 | # A list of variable names from the user's namespace to be retrieved. What |
|
155 | 155 | # returns is a JSON string of the variable's repr(), not a python object. |
|
156 | 156 | 'user_variables' : list, |
|
157 | 157 | |
|
158 | 158 | # Similarly, a dict mapping names to expressions to be evaluated in the |
|
159 | 159 | # user's dict. |
|
160 | 160 | 'user_expressions' : dict, |
|
161 | 161 | } |
|
162 | 162 | |
|
163 | 163 | The ``code`` field contains a single string, but this may be a multiline |
|
164 | 164 | string. The kernel is responsible for splitting this into possibly more than |
|
165 | 165 | one block and deciding whether to compile these in 'single' or 'exec' mode. |
|
166 | 166 | We're still sorting out this policy. The current inputsplitter is capable of |
|
167 | 167 | splitting the input for blocks that can all be run as 'single', but in the long |
|
168 | 168 | run it may prove cleaner to only use 'single' mode for truly single-line |
|
169 | 169 | inputs, and run all multiline input in 'exec' mode. This would preserve the |
|
170 | 170 | natural behavior of single-line inputs while allowing long cells to behave more |
|
171 | 171 | likea a script. This design will be refined as we complete the implementation. |
|
172 | 172 | |
|
173 | 173 | The ``user_`` fields deserve a detailed explanation. In the past, IPython had |
|
174 | 174 | the notion of a prompt string that allowed arbitrary code to be evaluated, and |
|
175 | 175 | this was put to good use by many in creating prompts that displayed system |
|
176 | 176 | status, path information, and even more esoteric uses like remote instrument |
|
177 | 177 | status aqcuired over the network. But now that IPython has a clean separation |
|
178 | 178 | between the kernel and the clients, the notion of embedding 'prompt' |
|
179 | 179 | maninpulations into the kernel itself feels awkward. Prompts should be a |
|
180 | 180 | frontend-side feature, and it should be even possible for different frontends |
|
181 | 181 | to display different prompts while interacting with the same kernel. |
|
182 | 182 | |
|
183 | 183 | We have therefore abandoned the idea of a 'prompt string' to be evaluated by |
|
184 | 184 | the kernel, and instead provide the ability to retrieve from the user's |
|
185 | 185 | namespace information after the execution of the main ``code``, with two fields |
|
186 | 186 | of the execution request: |
|
187 | 187 | |
|
188 | 188 | - ``user_variables``: If only variables from the user's namespace are needed, a |
|
189 | 189 | list of variable names can be passed and a dict with these names as keys and |
|
190 | 190 | their :func:`repr()` as values will be returned. |
|
191 | 191 | |
|
192 | 192 | - ``user_expressions``: For more complex expressions that require function |
|
193 | 193 | evaluations, a dict can be provided with string keys and arbitrary python |
|
194 | 194 | expressions as values. The return message will contain also a dict with the |
|
195 | 195 | same keys and the :func:`repr()` of the evaluated expressions as value. |
|
196 | 196 | |
|
197 | 197 | With this information, frontends can display any status information they wish |
|
198 | 198 | in the form that best suits each frontend (a status line, a popup, inline for a |
|
199 | 199 | terminal, etc). |
|
200 | 200 | |
|
201 | 201 | .. Note:: |
|
202 | 202 | |
|
203 | 203 | In order to obtain the current execution counter for the purposes of |
|
204 | 204 | displaying input prompts, frontends simply make an execution request with an |
|
205 | 205 | empty code string and ``silent=True``. |
|
206 | 206 | |
|
207 | 207 | Execution semantics |
|
208 | 208 | Upon completion of the execution request, the kernel *always* sends a |
|
209 | 209 | reply, with a status code indicating what happened and additional data |
|
210 | 210 | depending on the outcome. |
|
211 | 211 | |
|
212 | 212 | The ``code`` field is executed first, and then the ``user_variables`` and |
|
213 | 213 | ``user_expressions`` are computed. This ensures that any error in the |
|
214 | 214 | latter don't harm the main code execution. |
|
215 | 215 | |
|
216 | 216 | Any error in retrieving the ``user_variables`` or evaluating the |
|
217 | 217 | ``user_expressions`` will result in a simple error message in the return |
|
218 | 218 | fields of the form:: |
|
219 | 219 | |
|
220 | 220 | [ERROR] ExceptionType: Exception message |
|
221 | 221 | |
|
222 | 222 | The user can simply send the same variable name or expression for |
|
223 | 223 | evaluation to see a regular traceback. |
|
224 | 224 | |
|
225 | 225 | Execution counter (old prompt number) |
|
226 | 226 | The kernel has a single, monotonically increasing counter of all execution |
|
227 | 227 | requests that are made with ``silent=False``. This counter is used to |
|
228 | 228 | populate the ``In[n]``, ``Out[n]`` and ``_n`` variables, so clients will |
|
229 | 229 | likely want to display it in some form to the user, which will typically |
|
230 | 230 | (but not necessarily) be done in the prompts. The value of this counter |
|
231 | 231 | will be returned as the ``execution_count`` field of all ``execute_reply``` |
|
232 | 232 | messages. |
|
233 | 233 | |
|
234 | 234 | Message type: ``execute_reply``:: |
|
235 | 235 | |
|
236 | 236 | content = { |
|
237 | 237 | # One of: 'ok' OR 'error' OR 'abort' |
|
238 | 238 | 'status' : str, |
|
239 | 239 | |
|
240 | 240 | # The global kernel counter that increases by one with each non-silent |
|
241 | 241 | # executed request. This will typically be used by clients to display |
|
242 | 242 | # prompt numbers to the user. If the request was a silent one, this will |
|
243 | 243 | # be the current value of the counter in the kernel. |
|
244 | 244 | 'execution_count' : int, |
|
245 | 245 | } |
|
246 | 246 | |
|
247 | 247 | When status is 'ok', the following extra fields are present:: |
|
248 | 248 | |
|
249 | 249 | { |
|
250 | 250 | # The execution payload is a dict with string keys that may have been |
|
251 | 251 | # produced by the code being executed. It is retrieved by the kernel at |
|
252 | 252 | # the end of the execution and sent back to the front end, which can take |
|
253 | 253 | # action on it as needed. See main text for further details. |
|
254 | 254 | 'payload' : dict, |
|
255 | 255 | |
|
256 | 256 | # Results for the user_variables and user_expressions. |
|
257 | 257 | 'user_variables' : dict, |
|
258 | 258 | 'user_expressions' : dict, |
|
259 | 259 | |
|
260 | 260 | # The kernel will often transform the input provided to it. If the |
|
261 | 261 | # '---->' transform had been applied, this is filled, otherwise it's the |
|
262 | 262 | # empty string. So transformations like magics don't appear here, only |
|
263 | 263 | # autocall ones. |
|
264 | 264 | 'transformed_code' : str, |
|
265 | 265 | } |
|
266 | 266 | |
|
267 | 267 | .. admonition:: Execution payloads |
|
268 | 268 | |
|
269 | 269 | The notion of an 'execution payload' is different from a return value of a |
|
270 | 270 | given set of code, which normally is just displayed on the pyout stream |
|
271 | 271 | through the PUB socket. The idea of a payload is to allow special types of |
|
272 | 272 | code, typically magics, to populate a data container in the IPython kernel |
|
273 | 273 | that will be shipped back to the caller via this channel. The kernel will |
|
274 | 274 | have an API for this, probably something along the lines of:: |
|
275 | 275 | |
|
276 | 276 | ip.exec_payload_add(key, value) |
|
277 | 277 | |
|
278 | 278 | though this API is still in the design stages. The data returned in this |
|
279 | 279 | payload will allow frontends to present special views of what just happened. |
|
280 | 280 | |
|
281 | 281 | |
|
282 | 282 | When status is 'error', the following extra fields are present:: |
|
283 | 283 | |
|
284 | 284 | { |
|
285 | 285 | 'exc_name' : str, # Exception name, as a string |
|
286 | 286 | 'exc_value' : str, # Exception value, as a string |
|
287 | 287 | |
|
288 | 288 | # The traceback will contain a list of frames, represented each as a |
|
289 | 289 | # string. For now we'll stick to the existing design of ultraTB, which |
|
290 | 290 | # controls exception level of detail statefully. But eventually we'll |
|
291 | 291 | # want to grow into a model where more information is collected and |
|
292 | 292 | # packed into the traceback object, with clients deciding how little or |
|
293 | 293 | # how much of it to unpack. But for now, let's start with a simple list |
|
294 | 294 | # of strings, since that requires only minimal changes to ultratb as |
|
295 | 295 | # written. |
|
296 | 296 | 'traceback' : list, |
|
297 | 297 | } |
|
298 | 298 | |
|
299 | 299 | |
|
300 | 300 | When status is 'abort', there are for now no additional data fields. This |
|
301 | 301 | happens when the kernel was interrupted by a signal. |
|
302 | 302 | |
|
303 | 303 | Kernel attribute access |
|
304 | 304 | ----------------------- |
|
305 | 305 | |
|
306 | 306 | While this protocol does not specify full RPC access to arbitrary methods of |
|
307 | 307 | the kernel object, the kernel does allow read (and in some cases write) access |
|
308 | 308 | to certain attributes. |
|
309 | 309 | |
|
310 | 310 | The policy for which attributes can be read is: any attribute of the kernel, or |
|
311 | 311 | its sub-objects, that belongs to a :class:`Configurable` object and has been |
|
312 | 312 | declared at the class-level with Traits validation, is in principle accessible |
|
313 | 313 | as long as its name does not begin with a leading underscore. The attribute |
|
314 | 314 | itself will have metadata indicating whether it allows remote read and/or write |
|
315 | 315 | access. The message spec follows for attribute read and write requests. |
|
316 | 316 | |
|
317 | 317 | Message type: ``getattr_request``:: |
|
318 | 318 | |
|
319 | 319 | content = { |
|
320 | 320 | # The (possibly dotted) name of the attribute |
|
321 | 321 | 'name' : str, |
|
322 | 322 | } |
|
323 | 323 | |
|
324 | 324 | When a ``getattr_request`` fails, there are two possible error types: |
|
325 | 325 | |
|
326 | 326 | - AttributeError: this type of error was raised when trying to access the |
|
327 | 327 | given name by the kernel itself. This means that the attribute likely |
|
328 | 328 | doesn't exist. |
|
329 | 329 | |
|
330 | 330 | - AccessError: the attribute exists but its value is not readable remotely. |
|
331 | 331 | |
|
332 | 332 | |
|
333 | 333 | Message type: ``getattr_reply``:: |
|
334 | 334 | |
|
335 | 335 | content = { |
|
336 | 336 | # One of ['ok', 'AttributeError', 'AccessError']. |
|
337 | 337 | 'status' : str, |
|
338 | 338 | # If status is 'ok', a JSON object. |
|
339 | 339 | 'value' : object, |
|
340 | 340 | } |
|
341 | 341 | |
|
342 | 342 | Message type: ``setattr_request``:: |
|
343 | 343 | |
|
344 | 344 | content = { |
|
345 | 345 | # The (possibly dotted) name of the attribute |
|
346 | 346 | 'name' : str, |
|
347 | 347 | |
|
348 | 348 | # A JSON-encoded object, that will be validated by the Traits |
|
349 | 349 | # information in the kernel |
|
350 | 350 | 'value' : object, |
|
351 | 351 | } |
|
352 | 352 | |
|
353 | 353 | When a ``setattr_request`` fails, there are also two possible error types with |
|
354 | 354 | similar meanings as those of the ``getattr_request`` case, but for writing. |
|
355 | 355 | |
|
356 | 356 | Message type: ``setattr_reply``:: |
|
357 | 357 | |
|
358 | 358 | content = { |
|
359 | 359 | # One of ['ok', 'AttributeError', 'AccessError']. |
|
360 | 360 | 'status' : str, |
|
361 | 361 | } |
|
362 | 362 | |
|
363 | 363 | |
|
364 | 364 | Object information |
|
365 | 365 | ------------------ |
|
366 | 366 | |
|
367 | 367 | One of IPython's most used capabilities is the introspection of Python objects |
|
368 | 368 | in the user's namespace, typically invoked via the ``?`` and ``??`` characters |
|
369 | 369 | (which in reality are shorthands for the ``%pinfo`` magic). This is used often |
|
370 | 370 | enough that it warrants an explicit message type, especially because frontends |
|
371 | 371 | may want to get object information in response to user keystrokes (like Tab or |
|
372 | 372 | F1) besides from the user explicitly typing code like ``x??``. |
|
373 | 373 | |
|
374 | 374 | Message type: ``object_info_request``:: |
|
375 | 375 | |
|
376 | 376 | content = { |
|
377 | 377 | # The (possibly dotted) name of the object to be searched in all |
|
378 | 378 | # relevant namespaces |
|
379 | 379 | 'name' : str, |
|
380 | 380 | |
|
381 | 381 | # The level of detail desired. The default (0) is equivalent to typing |
|
382 | 382 | # 'x?' at the prompt, 1 is equivalent to 'x??'. |
|
383 | 383 | 'detail_level' : int, |
|
384 | 384 | } |
|
385 | 385 | |
|
386 | 386 | The returned information will be a dictionary with keys very similar to the |
|
387 | 387 | field names that IPython prints at the terminal. |
|
388 | 388 | |
|
389 | 389 | Message type: ``object_info_reply``:: |
|
390 | 390 | |
|
391 | 391 | content = { |
|
392 | 392 | # Boolean flag indicating whether the named object was found or not. If |
|
393 | 393 | # it's false, all other fields will be empty. |
|
394 | 394 | 'found' : bool, |
|
395 | 395 | |
|
396 | 396 | # Flags for magics and system aliases |
|
397 | 397 | 'ismagic' : bool, |
|
398 | 398 | 'isalias' : bool, |
|
399 | 399 | |
|
400 | 400 | # The name of the namespace where the object was found ('builtin', |
|
401 | 401 | # 'magics', 'alias', 'interactive', etc.) |
|
402 | 402 | 'namespace' : str, |
|
403 | 403 | |
|
404 | 404 | # The type name will be type.__name__ for normal Python objects, but it |
|
405 | 405 | # can also be a string like 'Magic function' or 'System alias' |
|
406 | 406 | 'type_name' : str, |
|
407 | 407 | |
|
408 | 408 | 'string_form' : str, |
|
409 | 409 | |
|
410 | 410 | # For objects with a __class__ attribute this will be set |
|
411 | 411 | 'base_class' : str, |
|
412 | 412 | |
|
413 | 413 | # For objects with a __len__ attribute this will be set |
|
414 | 414 | 'length' : int, |
|
415 | 415 | |
|
416 | 416 | # If the object is a function, class or method whose file we can find, |
|
417 | 417 | # we give its full path |
|
418 | 418 | 'file' : str, |
|
419 | 419 | |
|
420 | 420 | # For pure Python callable objects, we can reconstruct the object |
|
421 | 421 | # definition line which provides its call signature. For convenience this |
|
422 | 422 | # is returned as a single 'definition' field, but below the raw parts that |
|
423 | 423 | # compose it are also returned as the argspec field. |
|
424 | 424 | 'definition' : str, |
|
425 | 425 | |
|
426 | 426 | # The individual parts that together form the definition string. Clients |
|
427 | 427 | # with rich display capabilities may use this to provide a richer and more |
|
428 | 428 | # precise representation of the definition line (e.g. by highlighting |
|
429 | 429 | # arguments based on the user's cursor position). For non-callable |
|
430 | 430 | # objects, this field is empty. |
|
431 | 431 | 'argspec' : { # The names of all the arguments |
|
432 | 432 | args : list, |
|
433 | 433 | # The name of the varargs (*args), if any |
|
434 | 434 | varargs : str, |
|
435 | 435 | # The name of the varkw (**kw), if any |
|
436 | 436 | varkw : str, |
|
437 | 437 | # The values (as strings) of all default arguments. Note |
|
438 | 438 | # that these must be matched *in reverse* with the 'args' |
|
439 | 439 | # list above, since the first positional args have no default |
|
440 | 440 | # value at all. |
|
441 | 441 | func_defaults : list, |
|
442 | 442 | }, |
|
443 | 443 | |
|
444 | 444 | # For instances, provide the constructor signature (the definition of |
|
445 | 445 | # the __init__ method): |
|
446 | 446 | 'init_definition' : str, |
|
447 | 447 | |
|
448 | 448 | # Docstrings: for any object (function, method, module, package) with a |
|
449 | 449 | # docstring, we show it. But in addition, we may provide additional |
|
450 | 450 | # docstrings. For example, for instances we will show the constructor |
|
451 | 451 | # and class docstrings as well, if available. |
|
452 | 452 | 'docstring' : str, |
|
453 | 453 | |
|
454 | 454 | # For instances, provide the constructor and class docstrings |
|
455 | 455 | 'init_docstring' : str, |
|
456 | 456 | 'class_docstring' : str, |
|
457 | 457 | |
|
458 | 458 | # If it's a callable object whose call method has a separate docstring and |
|
459 | 459 | # definition line: |
|
460 | 460 | 'call_def' : str, |
|
461 | 461 | 'call_docstring' : str, |
|
462 | 462 | |
|
463 | 463 | # If detail_level was 1, we also try to find the source code that |
|
464 | 464 | # defines the object, if possible. The string 'None' will indicate |
|
465 | 465 | # that no source was found. |
|
466 | 466 | 'source' : str, |
|
467 | 467 | } |
|
468 | 468 | ' |
|
469 | 469 | |
|
470 | 470 | Complete |
|
471 | 471 | -------- |
|
472 | 472 | |
|
473 | 473 | Message type: ``complete_request``:: |
|
474 | 474 | |
|
475 | 475 | content = { |
|
476 | 476 | # The text to be completed, such as 'a.is' |
|
477 | 477 | 'text' : str, |
|
478 | 478 | |
|
479 | 479 | # The full line, such as 'print a.is'. This allows completers to |
|
480 | 480 | # make decisions that may require information about more than just the |
|
481 | 481 | # current word. |
|
482 | 482 | 'line' : str, |
|
483 | 483 | |
|
484 | 484 | # The entire block of text where the line is. This may be useful in the |
|
485 | 485 | # case of multiline completions where more context may be needed. Note: if |
|
486 | 486 | # in practice this field proves unnecessary, remove it to lighten the |
|
487 | 487 | # messages. |
|
488 | 488 | |
|
489 | 489 | 'block' : str, |
|
490 | 490 | |
|
491 | 491 | # The position of the cursor where the user hit 'TAB' on the line. |
|
492 | 492 | 'cursor_pos' : int, |
|
493 | 493 | } |
|
494 | 494 | |
|
495 | 495 | Message type: ``complete_reply``:: |
|
496 | 496 | |
|
497 | 497 | content = { |
|
498 | 498 | # The list of all matches to the completion request, such as |
|
499 | 499 | # ['a.isalnum', 'a.isalpha'] for the above example. |
|
500 | 500 | 'matches' : list |
|
501 | 501 | } |
|
502 | 502 | |
|
503 | 503 | |
|
504 | 504 | History |
|
505 | 505 | ------- |
|
506 | 506 | |
|
507 | 507 | For clients to explicitly request history from a kernel. The kernel has all |
|
508 | 508 | the actual execution history stored in a single location, so clients can |
|
509 | 509 | request it from the kernel when needed. |
|
510 | 510 | |
|
511 | 511 | Message type: ``history_request``:: |
|
512 | 512 | |
|
513 | 513 | content = { |
|
514 | 514 | |
|
515 | 515 | # If True, also return output history in the resulting dict. |
|
516 | 516 | 'output' : bool, |
|
517 | 517 | |
|
518 | 518 | # If True, return the raw input history, else the transformed input. |
|
519 | 519 | 'raw' : bool, |
|
520 | 520 | |
|
521 | 521 | # This parameter can be one of: A number, a pair of numbers, None |
|
522 | 522 | # If not given, last 40 are returned. |
|
523 | 523 | # - number n: return the last n entries. |
|
524 | 524 | # - pair n1, n2: return entries in the range(n1, n2). |
|
525 | 525 | # - None: return all history |
|
526 | 526 | 'index' : n or (n1, n2) or None, |
|
527 | 527 | } |
|
528 | 528 | |
|
529 | 529 | Message type: ``history_reply``:: |
|
530 | 530 | |
|
531 | 531 | content = { |
|
532 | 532 | # A dict with prompt numbers as keys and either (input, output) or input |
|
533 | 533 | # as the value depending on whether output was True or False, |
|
534 | 534 | # respectively. |
|
535 | 535 | 'history' : dict, |
|
536 | 536 | } |
|
537 | 537 | |
|
538 | 538 | |
|
539 | 539 | Connect |
|
540 | 540 | ------- |
|
541 | 541 | |
|
542 | 542 | When a client connects to the request/reply socket of the kernel, it can issue |
|
543 | 543 | a connect request to get basic information about the kernel, such as the ports |
|
544 | 544 | the other ZeroMQ sockets are listening on. This allows clients to only have |
|
545 | 545 | to know about a single port (the XREQ/XREP channel) to connect to a kernel. |
|
546 | 546 | |
|
547 | 547 | Message type: ``connect_request``:: |
|
548 | 548 | |
|
549 | 549 | content = { |
|
550 | 550 | } |
|
551 | 551 | |
|
552 | 552 | Message type: ``connect_reply``:: |
|
553 | 553 | |
|
554 | 554 | content = { |
|
555 | 555 | 'xrep_port' : int # The port the XREP socket is listening on. |
|
556 | 556 | 'pub_port' : int # The port the PUB socket is listening on. |
|
557 | 557 | 'req_port' : int # The port the REQ socket is listening on. |
|
558 | 558 | 'hb_port' : int # The port the heartbeat socket is listening on. |
|
559 | 559 | } |
|
560 | 560 | |
|
561 | 561 | |
|
562 | 562 | |
|
563 | 563 | Kernel shutdown |
|
564 | 564 | --------------- |
|
565 | 565 | |
|
566 | 566 | The clients can request the kernel to shut itself down; this is used in |
|
567 | 567 | multiple cases: |
|
568 | 568 | |
|
569 | 569 | - when the user chooses to close the client application via a menu or window |
|
570 | 570 | control. |
|
571 | 571 | - when the user types 'exit' or 'quit' (or their uppercase magic equivalents). |
|
572 | 572 | - when the user chooses a GUI method (like the 'Ctrl-C' shortcut in the |
|
573 | 573 | IPythonQt client) to force a kernel restart to get a clean kernel without |
|
574 | 574 | losing client-side state like history or inlined figures. |
|
575 | 575 | |
|
576 | 576 | The client sends a shutdown request to the kernel, and once it receives the |
|
577 | 577 | reply message (which is otherwise empty), it can assume that the kernel has |
|
578 | 578 | completed shutdown safely. |
|
579 | 579 | |
|
580 | 580 | Upon their own shutdown, client applications will typically execute a last |
|
581 | 581 | minute sanity check and forcefully terminate any kernel that is still alive, to |
|
582 | 582 | avoid leaving stray processes in the user's machine. |
|
583 | 583 | |
|
584 | 584 | For both shutdown request and reply, there is no actual content that needs to |
|
585 | 585 | be sent, so the content dict is empty. |
|
586 | 586 | |
|
587 | 587 | Message type: ``shutdown_request``:: |
|
588 | 588 | |
|
589 | 589 | content = { |
|
590 | 590 | } |
|
591 | 591 | |
|
592 | 592 | Message type: ``shutdown_reply``:: |
|
593 | 593 | |
|
594 | 594 | content = { |
|
595 | 595 | } |
|
596 | 596 | |
|
597 | 597 | .. Note:: |
|
598 | 598 | |
|
599 | 599 | When the clients detect a dead kernel thanks to inactivity on the heartbeat |
|
600 | 600 | socket, they simply send a forceful process termination signal, since a dead |
|
601 | 601 | process is unlikely to respond in any useful way to messages. |
|
602 | 602 | |
|
603 | 603 | |
|
604 | 604 | Messages on the PUB/SUB socket |
|
605 | 605 | ============================== |
|
606 | 606 | |
|
607 | 607 | Streams (stdout, stderr, etc) |
|
608 | 608 | ------------------------------ |
|
609 | 609 | |
|
610 | 610 | Message type: ``stream``:: |
|
611 | 611 | |
|
612 | 612 | content = { |
|
613 | 613 | # The name of the stream is one of 'stdin', 'stdout', 'stderr' |
|
614 | 614 | 'name' : str, |
|
615 | 615 | |
|
616 | 616 | # The data is an arbitrary string to be written to that stream |
|
617 | 617 | 'data' : str, |
|
618 | 618 | } |
|
619 | 619 | |
|
620 | 620 | When a kernel receives a raw_input call, it should also broadcast it on the pub |
|
621 | 621 | socket with the names 'stdin' and 'stdin_reply'. This will allow other clients |
|
622 | 622 | to monitor/display kernel interactions and possibly replay them to their user |
|
623 | 623 | or otherwise expose them. |
|
624 | 624 | |
|
625 | 625 | Python inputs |
|
626 | 626 | ------------- |
|
627 | 627 | |
|
628 | 628 | These messages are the re-broadcast of the ``execute_request``. |
|
629 | 629 | |
|
630 | 630 | Message type: ``pyin``:: |
|
631 | 631 | |
|
632 | 632 | content = { |
|
633 | 633 | # Source code to be executed, one or more lines |
|
634 | 634 | 'code' : str |
|
635 | 635 | } |
|
636 | 636 | |
|
637 | 637 | Python outputs |
|
638 | 638 | -------------- |
|
639 | 639 | |
|
640 | 640 | When Python produces output from code that has been compiled in with the |
|
641 | 641 | 'single' flag to :func:`compile`, any expression that produces a value (such as |
|
642 | 642 | ``1+1``) is passed to ``sys.displayhook``, which is a callable that can do with |
|
643 | 643 | this value whatever it wants. The default behavior of ``sys.displayhook`` in |
|
644 | 644 | the Python interactive prompt is to print to ``sys.stdout`` the :func:`repr` of |
|
645 | 645 | the value as long as it is not ``None`` (which isn't printed at all). In our |
|
646 | 646 | case, the kernel instantiates as ``sys.displayhook`` an object which has |
|
647 | 647 | similar behavior, but which instead of printing to stdout, broadcasts these |
|
648 | 648 | values as ``pyout`` messages for clients to display appropriately. |
|
649 | 649 | |
|
650 | 650 | Message type: ``pyout``:: |
|
651 | 651 | |
|
652 | 652 | content = { |
|
653 | 653 | # The data is typically the repr() of the object. |
|
654 | 654 | 'data' : str, |
|
655 | 655 | |
|
656 | 656 | # The counter for this execution is also provided so that clients can |
|
657 | 657 | # display it, since IPython automatically creates variables called _N (for |
|
658 | 658 | # prompt N). |
|
659 | 659 | 'execution_count' : int, |
|
660 | 660 | } |
|
661 | 661 | |
|
662 | 662 | Python errors |
|
663 | 663 | ------------- |
|
664 | 664 | |
|
665 | 665 | When an error occurs during code execution |
|
666 | 666 | |
|
667 | 667 | Message type: ``pyerr``:: |
|
668 | 668 | |
|
669 | 669 | content = { |
|
670 | 670 | # Similar content to the execute_reply messages for the 'error' case, |
|
671 | 671 | # except the 'status' field is omitted. |
|
672 | 672 | } |
|
673 | 673 | |
|
674 | Kernel status | |
|
675 | ------------- | |
|
676 | ||
|
677 | This message type is used by frontends to monitor the status of the kernel. | |
|
678 | ||
|
679 | Message type: ``status``:: | |
|
680 | ||
|
681 | content = { | |
|
682 | # When the kernel starts to execute code, it will enter the 'busy' | |
|
683 | # state and when it finishes, it will enter the 'idle' state. | |
|
684 | execution_state : ('busy', 'idle') | |
|
685 | } | |
|
686 | ||
|
674 | 687 | Kernel crashes |
|
675 | 688 | -------------- |
|
676 | 689 | |
|
677 | 690 | When the kernel has an unexpected exception, caught by the last-resort |
|
678 | 691 | sys.excepthook, we should broadcast the crash handler's output before exiting. |
|
679 | 692 | This will allow clients to notice that a kernel died, inform the user and |
|
680 | 693 | propose further actions. |
|
681 | 694 | |
|
682 | 695 | Message type: ``crash``:: |
|
683 | 696 | |
|
684 | 697 | content = { |
|
685 | 698 | # Similarly to the 'error' case for execute_reply messages, this will |
|
686 | 699 | # contain exc_name, exc_type and traceback fields. |
|
687 | 700 | |
|
688 | 701 | # An additional field with supplementary information such as where to |
|
689 | 702 | # send the crash message |
|
690 | 703 | 'info' : str, |
|
691 | 704 | } |
|
692 | 705 | |
|
693 | 706 | |
|
694 | 707 | Future ideas |
|
695 | 708 | ------------ |
|
696 | 709 | |
|
697 | 710 | Other potential message types, currently unimplemented, listed below as ideas. |
|
698 | 711 | |
|
699 | 712 | Message type: ``file``:: |
|
700 | 713 | |
|
701 | 714 | content = { |
|
702 | 715 | 'path' : 'cool.jpg', |
|
703 | 716 | 'mimetype' : str, |
|
704 | 717 | 'data' : str, |
|
705 | 718 | } |
|
706 | 719 | |
|
707 | 720 | |
|
708 | 721 | Messages on the REQ/REP socket |
|
709 | 722 | ============================== |
|
710 | 723 | |
|
711 | 724 | This is a socket that goes in the opposite direction: from the kernel to a |
|
712 | 725 | *single* frontend, and its purpose is to allow ``raw_input`` and similar |
|
713 | 726 | operations that read from ``sys.stdin`` on the kernel to be fulfilled by the |
|
714 | 727 | client. For now we will keep these messages as simple as possible, since they |
|
715 | 728 | basically only mean to convey the ``raw_input(prompt)`` call. |
|
716 | 729 | |
|
717 | 730 | Message type: ``input_request``:: |
|
718 | 731 | |
|
719 | 732 | content = { 'prompt' : str } |
|
720 | 733 | |
|
721 | 734 | Message type: ``input_reply``:: |
|
722 | 735 | |
|
723 | 736 | content = { 'value' : str } |
|
724 | 737 | |
|
725 | 738 | .. Note:: |
|
726 | 739 | |
|
727 | 740 | We do not explicitly try to forward the raw ``sys.stdin`` object, because in |
|
728 | 741 | practice the kernel should behave like an interactive program. When a |
|
729 | 742 | program is opened on the console, the keyboard effectively takes over the |
|
730 | 743 | ``stdin`` file descriptor, and it can't be used for raw reading anymore. |
|
731 | 744 | Since the IPython kernel effectively behaves like a console program (albeit |
|
732 | 745 | one whose "keyboard" is actually living in a separate process and |
|
733 | 746 | transported over the zmq connection), raw ``stdin`` isn't expected to be |
|
734 | 747 | available. |
|
735 | 748 | |
|
736 | 749 | |
|
737 | 750 | Heartbeat for kernels |
|
738 | 751 | ===================== |
|
739 | 752 | |
|
740 | 753 | Initially we had considered using messages like those above over ZMQ for a |
|
741 | 754 | kernel 'heartbeat' (a way to detect quickly and reliably whether a kernel is |
|
742 | 755 | alive at all, even if it may be busy executing user code). But this has the |
|
743 | 756 | problem that if the kernel is locked inside extension code, it wouldn't execute |
|
744 | 757 | the python heartbeat code. But it turns out that we can implement a basic |
|
745 | 758 | heartbeat with pure ZMQ, without using any Python messaging at all. |
|
746 | 759 | |
|
747 | 760 | The monitor sends out a single zmq message (right now, it is a str of the |
|
748 | 761 | monitor's lifetime in seconds), and gets the same message right back, prefixed |
|
749 | 762 | with the zmq identity of the XREQ socket in the heartbeat process. This can be |
|
750 | 763 | a uuid, or even a full message, but there doesn't seem to be a need for packing |
|
751 | 764 | up a message when the sender and receiver are the exact same Python object. |
|
752 | 765 | |
|
753 | 766 | The model is this:: |
|
754 | 767 | |
|
755 | 768 | monitor.send(str(self.lifetime)) # '1.2345678910' |
|
756 | 769 | |
|
757 | 770 | and the monitor receives some number of messages of the form:: |
|
758 | 771 | |
|
759 | 772 | ['uuid-abcd-dead-beef', '1.2345678910'] |
|
760 | 773 | |
|
761 | 774 | where the first part is the zmq.IDENTITY of the heart's XREQ on the engine, and |
|
762 | 775 | the rest is the message sent by the monitor. No Python code ever has any |
|
763 | 776 | access to the message between the monitor's send, and the monitor's recv. |
|
764 | 777 | |
|
765 | 778 | |
|
766 | 779 | ToDo |
|
767 | 780 | ==== |
|
768 | 781 | |
|
769 | 782 | Missing things include: |
|
770 | 783 | |
|
771 | 784 | * Important: finish thinking through the payload concept and API. |
|
772 | 785 | |
|
773 | 786 | * Important: ensure that we have a good solution for magics like %edit. It's |
|
774 | 787 | likely that with the payload concept we can build a full solution, but not |
|
775 | 788 | 100% clear yet. |
|
776 | 789 | |
|
777 | 790 | * Finishing the details of the heartbeat protocol. |
|
778 | 791 | |
|
779 | 792 | * Signal handling: specify what kind of information kernel should broadcast (or |
|
780 | 793 | not) when it receives signals. |
|
781 | 794 | |
|
782 | 795 | .. include:: ../links.rst |
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