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@@ -1,303 +1,305 b'' | |||
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1 | 1 | /* |
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2 | 2 | dirs.c - dynamic directory diddling for dirstates |
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3 | 3 | |
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4 | 4 | Copyright 2013 Facebook |
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5 | 5 | |
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6 | 6 | This software may be used and distributed according to the terms of |
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7 | 7 | the GNU General Public License, incorporated herein by reference. |
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8 | 8 | */ |
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9 | 9 | |
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10 | 10 | #define PY_SSIZE_T_CLEAN |
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11 | 11 | #include <Python.h> |
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12 | 12 | |
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13 | 13 | #include "util.h" |
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14 | 14 | |
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15 | 15 | #ifdef IS_PY3K |
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16 | 16 | #define PYLONG_VALUE(o) ((PyLongObject *)o)->ob_digit[1] |
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17 | 17 | #else |
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18 | 18 | #define PYLONG_VALUE(o) PyInt_AS_LONG(o) |
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19 | 19 | #endif |
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20 | 20 | |
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21 | 21 | /* |
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22 | 22 | * This is a multiset of directory names, built from the files that |
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23 | 23 | * appear in a dirstate or manifest. |
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24 | 24 | * |
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25 | 25 | * A few implementation notes: |
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26 | 26 | * |
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27 | 27 | * We modify Python integers for refcounting, but those integers are |
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28 | 28 | * never visible to Python code. |
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29 | 29 | */ |
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30 | /* clang-format off */ | |
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30 | 31 | typedef struct { |
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31 | 32 | PyObject_HEAD |
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32 | 33 | PyObject *dict; |
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33 | 34 | } dirsObject; |
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35 | /* clang-format on */ | |
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34 | 36 | |
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35 | 37 | static inline Py_ssize_t _finddir(const char *path, Py_ssize_t pos) |
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36 | 38 | { |
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37 | 39 | while (pos != -1) { |
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38 | 40 | if (path[pos] == '/') |
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39 | 41 | break; |
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40 | 42 | pos -= 1; |
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41 | 43 | } |
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42 | 44 | if (pos == -1) { |
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43 | 45 | return 0; |
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44 | 46 | } |
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45 | 47 | |
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46 | 48 | return pos; |
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47 | 49 | } |
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48 | 50 | |
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49 | 51 | static int _addpath(PyObject *dirs, PyObject *path) |
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50 | 52 | { |
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51 | 53 | const char *cpath = PyBytes_AS_STRING(path); |
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52 | 54 | Py_ssize_t pos = PyBytes_GET_SIZE(path); |
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53 | 55 | PyObject *key = NULL; |
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54 | 56 | int ret = -1; |
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55 | 57 | |
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56 | 58 | /* This loop is super critical for performance. That's why we inline |
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57 | 59 | * access to Python structs instead of going through a supported API. |
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58 | 60 | * The implementation, therefore, is heavily dependent on CPython |
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59 | 61 | * implementation details. We also commit violations of the Python |
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60 | 62 | * "protocol" such as mutating immutable objects. But since we only |
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61 | 63 | * mutate objects created in this function or in other well-defined |
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62 | 64 | * locations, the references are known so these violations should go |
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63 | 65 | * unnoticed. */ |
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64 | 66 | while ((pos = _finddir(cpath, pos - 1)) != -1) { |
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65 | 67 | PyObject *val; |
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66 | 68 | |
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67 | 69 | key = PyBytes_FromStringAndSize(cpath, pos); |
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68 | 70 | if (key == NULL) |
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69 | 71 | goto bail; |
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70 | 72 | |
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71 | 73 | val = PyDict_GetItem(dirs, key); |
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72 | 74 | if (val != NULL) { |
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73 | 75 | PYLONG_VALUE(val) += 1; |
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74 | 76 | Py_CLEAR(key); |
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75 | 77 | break; |
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76 | 78 | } |
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77 | 79 | |
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78 | 80 | /* Force Python to not reuse a small shared int. */ |
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79 | 81 | #ifdef IS_PY3K |
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80 | 82 | val = PyLong_FromLong(0x1eadbeef); |
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81 | 83 | #else |
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82 | 84 | val = PyInt_FromLong(0x1eadbeef); |
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83 | 85 | #endif |
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84 | 86 | |
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85 | 87 | if (val == NULL) |
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86 | 88 | goto bail; |
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87 | 89 | |
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88 | 90 | PYLONG_VALUE(val) = 1; |
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89 | 91 | ret = PyDict_SetItem(dirs, key, val); |
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90 | 92 | Py_DECREF(val); |
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91 | 93 | if (ret == -1) |
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92 | 94 | goto bail; |
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93 | 95 | Py_CLEAR(key); |
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94 | 96 | } |
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95 | 97 | ret = 0; |
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96 | 98 | |
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97 | 99 | bail: |
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98 | 100 | Py_XDECREF(key); |
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99 | 101 | |
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100 | 102 | return ret; |
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101 | 103 | } |
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102 | 104 | |
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103 | 105 | static int _delpath(PyObject *dirs, PyObject *path) |
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104 | 106 | { |
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105 | 107 | char *cpath = PyBytes_AS_STRING(path); |
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106 | 108 | Py_ssize_t pos = PyBytes_GET_SIZE(path); |
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107 | 109 | PyObject *key = NULL; |
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108 | 110 | int ret = -1; |
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109 | 111 | |
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110 | 112 | while ((pos = _finddir(cpath, pos - 1)) != -1) { |
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111 | 113 | PyObject *val; |
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112 | 114 | |
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113 | 115 | key = PyBytes_FromStringAndSize(cpath, pos); |
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114 | 116 | |
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115 | 117 | if (key == NULL) |
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116 | 118 | goto bail; |
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117 | 119 | |
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118 | 120 | val = PyDict_GetItem(dirs, key); |
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119 | 121 | if (val == NULL) { |
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120 | 122 | PyErr_SetString(PyExc_ValueError, |
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121 | 123 | "expected a value, found none"); |
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122 | 124 | goto bail; |
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123 | 125 | } |
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124 | 126 | |
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125 | 127 | if (--PYLONG_VALUE(val) <= 0) { |
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126 | 128 | if (PyDict_DelItem(dirs, key) == -1) |
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127 | 129 | goto bail; |
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128 | 130 | } else |
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129 | 131 | break; |
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130 | 132 | Py_CLEAR(key); |
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131 | 133 | } |
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132 | 134 | ret = 0; |
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133 | 135 | |
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134 | 136 | bail: |
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135 | 137 | Py_XDECREF(key); |
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136 | 138 | |
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137 | 139 | return ret; |
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138 | 140 | } |
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139 | 141 | |
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140 | 142 | static int dirs_fromdict(PyObject *dirs, PyObject *source, char skipchar) |
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141 | 143 | { |
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142 | 144 | PyObject *key, *value; |
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143 | 145 | Py_ssize_t pos = 0; |
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144 | 146 | |
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145 | 147 | while (PyDict_Next(source, &pos, &key, &value)) { |
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146 | 148 | if (!PyBytes_Check(key)) { |
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147 | 149 | PyErr_SetString(PyExc_TypeError, "expected string key"); |
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148 | 150 | return -1; |
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149 | 151 | } |
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150 | 152 | if (skipchar) { |
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151 | 153 | if (!dirstate_tuple_check(value)) { |
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152 | 154 | PyErr_SetString(PyExc_TypeError, |
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153 | 155 | "expected a dirstate tuple"); |
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154 | 156 | return -1; |
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155 | 157 | } |
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156 | 158 | if (((dirstateTupleObject *)value)->state == skipchar) |
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157 | 159 | continue; |
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158 | 160 | } |
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159 | 161 | |
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160 | 162 | if (_addpath(dirs, key) == -1) |
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161 | 163 | return -1; |
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162 | 164 | } |
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163 | 165 | |
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164 | 166 | return 0; |
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165 | 167 | } |
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166 | 168 | |
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167 | 169 | static int dirs_fromiter(PyObject *dirs, PyObject *source) |
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168 | 170 | { |
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169 | 171 | PyObject *iter, *item = NULL; |
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170 | 172 | int ret; |
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171 | 173 | |
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172 | 174 | iter = PyObject_GetIter(source); |
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173 | 175 | if (iter == NULL) |
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174 | 176 | return -1; |
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175 | 177 | |
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176 | 178 | while ((item = PyIter_Next(iter)) != NULL) { |
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177 | 179 | if (!PyBytes_Check(item)) { |
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178 | 180 | PyErr_SetString(PyExc_TypeError, "expected string"); |
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179 | 181 | break; |
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180 | 182 | } |
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181 | 183 | |
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182 | 184 | if (_addpath(dirs, item) == -1) |
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183 | 185 | break; |
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184 | 186 | Py_CLEAR(item); |
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185 | 187 | } |
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186 | 188 | |
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187 | 189 | ret = PyErr_Occurred() ? -1 : 0; |
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188 | 190 | Py_DECREF(iter); |
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189 | 191 | Py_XDECREF(item); |
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190 | 192 | return ret; |
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191 | 193 | } |
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192 | 194 | |
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193 | 195 | /* |
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194 | 196 | * Calculate a refcounted set of directory names for the files in a |
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195 | 197 | * dirstate. |
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196 | 198 | */ |
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197 | 199 | static int dirs_init(dirsObject *self, PyObject *args) |
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198 | 200 | { |
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199 | 201 | PyObject *dirs = NULL, *source = NULL; |
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200 | 202 | char skipchar = 0; |
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201 | 203 | int ret = -1; |
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202 | 204 | |
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203 | 205 | self->dict = NULL; |
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204 | 206 | |
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205 | 207 | if (!PyArg_ParseTuple(args, "|Oc:__init__", &source, &skipchar)) |
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206 | 208 | return -1; |
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207 | 209 | |
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208 | 210 | dirs = PyDict_New(); |
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209 | 211 | |
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210 | 212 | if (dirs == NULL) |
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211 | 213 | return -1; |
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212 | 214 | |
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213 | 215 | if (source == NULL) |
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214 | 216 | ret = 0; |
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215 | 217 | else if (PyDict_Check(source)) |
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216 | 218 | ret = dirs_fromdict(dirs, source, skipchar); |
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217 | 219 | else if (skipchar) |
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218 | 220 | PyErr_SetString(PyExc_ValueError, |
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219 | 221 | "skip character is only supported " |
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220 | 222 | "with a dict source"); |
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221 | 223 | else |
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222 | 224 | ret = dirs_fromiter(dirs, source); |
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223 | 225 | |
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224 | 226 | if (ret == -1) |
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225 | 227 | Py_XDECREF(dirs); |
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226 | 228 | else |
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227 | 229 | self->dict = dirs; |
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228 | 230 | |
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229 | 231 | return ret; |
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230 | 232 | } |
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231 | 233 | |
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232 | 234 | PyObject *dirs_addpath(dirsObject *self, PyObject *args) |
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233 | 235 | { |
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234 | 236 | PyObject *path; |
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235 | 237 | |
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236 | 238 | if (!PyArg_ParseTuple(args, "O!:addpath", &PyBytes_Type, &path)) |
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237 | 239 | return NULL; |
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238 | 240 | |
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239 | 241 | if (_addpath(self->dict, path) == -1) |
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240 | 242 | return NULL; |
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241 | 243 | |
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242 | 244 | Py_RETURN_NONE; |
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243 | 245 | } |
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244 | 246 | |
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245 | 247 | static PyObject *dirs_delpath(dirsObject *self, PyObject *args) |
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246 | 248 | { |
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247 | 249 | PyObject *path; |
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248 | 250 | |
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249 | 251 | if (!PyArg_ParseTuple(args, "O!:delpath", &PyBytes_Type, &path)) |
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250 | 252 | return NULL; |
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251 | 253 | |
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252 | 254 | if (_delpath(self->dict, path) == -1) |
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253 | 255 | return NULL; |
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254 | 256 | |
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255 | 257 | Py_RETURN_NONE; |
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256 | 258 | } |
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257 | 259 | |
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258 | 260 | static int dirs_contains(dirsObject *self, PyObject *value) |
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259 | 261 | { |
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260 | 262 | return PyBytes_Check(value) ? PyDict_Contains(self->dict, value) : 0; |
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261 | 263 | } |
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262 | 264 | |
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263 | 265 | static void dirs_dealloc(dirsObject *self) |
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264 | 266 | { |
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265 | 267 | Py_XDECREF(self->dict); |
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266 | 268 | PyObject_Del(self); |
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267 | 269 | } |
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268 | 270 | |
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269 | 271 | static PyObject *dirs_iter(dirsObject *self) |
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270 | 272 | { |
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271 | 273 | return PyObject_GetIter(self->dict); |
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272 | 274 | } |
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273 | 275 | |
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274 | 276 | static PySequenceMethods dirs_sequence_methods; |
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275 | 277 | |
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276 | 278 | static PyMethodDef dirs_methods[] = { |
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277 | 279 | {"addpath", (PyCFunction)dirs_addpath, METH_VARARGS, "add a path"}, |
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278 | 280 | {"delpath", (PyCFunction)dirs_delpath, METH_VARARGS, "remove a path"}, |
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279 | 281 | {NULL} /* Sentinel */ |
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280 | 282 | }; |
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281 | 283 | |
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282 | 284 | static PyTypeObject dirsType = { PyVarObject_HEAD_INIT(NULL, 0) }; |
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283 | 285 | |
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284 | 286 | void dirs_module_init(PyObject *mod) |
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285 | 287 | { |
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286 | 288 | dirs_sequence_methods.sq_contains = (objobjproc)dirs_contains; |
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287 | 289 | dirsType.tp_name = "parsers.dirs"; |
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288 | 290 | dirsType.tp_new = PyType_GenericNew; |
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289 | 291 | dirsType.tp_basicsize = sizeof(dirsObject); |
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290 | 292 | dirsType.tp_dealloc = (destructor)dirs_dealloc; |
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291 | 293 | dirsType.tp_as_sequence = &dirs_sequence_methods; |
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292 | 294 | dirsType.tp_flags = Py_TPFLAGS_DEFAULT; |
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293 | 295 | dirsType.tp_doc = "dirs"; |
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294 | 296 | dirsType.tp_iter = (getiterfunc)dirs_iter; |
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295 | 297 | dirsType.tp_methods = dirs_methods; |
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296 | 298 | dirsType.tp_init = (initproc)dirs_init; |
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297 | 299 | |
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298 | 300 | if (PyType_Ready(&dirsType) < 0) |
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299 | 301 | return; |
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300 | 302 | Py_INCREF(&dirsType); |
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301 | 303 | |
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302 | 304 | PyModule_AddObject(mod, "dirs", (PyObject *)&dirsType); |
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303 | 305 | } |
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