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@@ -1,397 +1,433 b'' | |||
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1 | 1 | # obsolete.py - obsolete markers handling |
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2 | 2 | # |
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3 | 3 | # Copyright 2012 Pierre-Yves David <pierre-yves.david@ens-lyon.org> |
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4 | 4 | # Logilab SA <contact@logilab.fr> |
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5 | 5 | # |
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6 | 6 | # This software may be used and distributed according to the terms of the |
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7 | 7 | # GNU General Public License version 2 or any later version. |
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8 | 8 | |
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9 | 9 | """Obsolete markers handling |
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10 | 10 | |
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11 | 11 | An obsolete marker maps an old changeset to a list of new |
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12 | 12 | changesets. If the list of new changesets is empty, the old changeset |
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13 | 13 | is said to be "killed". Otherwise, the old changeset is being |
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14 | 14 | "replaced" by the new changesets. |
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15 | 15 | |
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16 | 16 | Obsolete markers can be used to record and distribute changeset graph |
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17 | 17 | transformations performed by history rewriting operations, and help |
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18 | 18 | building new tools to reconciliate conflicting rewriting actions. To |
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19 | 19 | facilitate conflicts resolution, markers include various annotations |
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20 | 20 | besides old and news changeset identifiers, such as creation date or |
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21 | 21 | author name. |
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22 | 22 | |
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23 | 23 | |
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24 | 24 | Format |
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25 | 25 | ------ |
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26 | 26 | |
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27 | 27 | Markers are stored in an append-only file stored in |
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28 | 28 | '.hg/store/obsstore'. |
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29 | 29 | |
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30 | 30 | The file starts with a version header: |
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31 | 31 | |
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32 | 32 | - 1 unsigned byte: version number, starting at zero. |
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33 | 33 | |
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34 | 34 | |
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35 | 35 | The header is followed by the markers. Each marker is made of: |
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36 | 36 | |
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37 | 37 | - 1 unsigned byte: number of new changesets "R", could be zero. |
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38 | 38 | |
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39 | 39 | - 1 unsigned 32-bits integer: metadata size "M" in bytes. |
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40 | 40 | |
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41 | 41 | - 1 byte: a bit field. It is reserved for flags used in obsolete |
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42 | 42 | markers common operations, to avoid repeated decoding of metadata |
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43 | 43 | entries. |
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44 | 44 | |
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45 | 45 | - 20 bytes: obsoleted changeset identifier. |
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46 | 46 | |
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47 | 47 | - N*20 bytes: new changesets identifiers. |
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48 | 48 | |
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49 | 49 | - M bytes: metadata as a sequence of nul-terminated strings. Each |
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50 | 50 | string contains a key and a value, separated by a color ':', without |
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51 | 51 | additional encoding. Keys cannot contain '\0' or ':' and values |
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52 | 52 | cannot contain '\0'. |
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53 | 53 | """ |
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54 | 54 | import struct |
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55 | 55 | import util, base85 |
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56 | 56 | from i18n import _ |
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57 | 57 | |
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58 | 58 | _pack = struct.pack |
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59 | 59 | _unpack = struct.unpack |
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60 | 60 | |
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61 | 61 | _SEEK_END = 2 # os.SEEK_END was introduced in Python 2.5 |
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62 | 62 | |
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63 | 63 | # the obsolete feature is not mature enough to be enabled by default. |
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64 | 64 | # you have to rely on third party extension extension to enable this. |
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65 | 65 | _enabled = False |
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66 | 66 | |
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67 | 67 | # data used for parsing and writing |
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68 | 68 | _fmversion = 0 |
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69 | 69 | _fmfixed = '>BIB20s' |
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70 | 70 | _fmnode = '20s' |
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71 | 71 | _fmfsize = struct.calcsize(_fmfixed) |
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72 | 72 | _fnodesize = struct.calcsize(_fmnode) |
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73 | 73 | |
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74 | 74 | def _readmarkers(data): |
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75 | 75 | """Read and enumerate markers from raw data""" |
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76 | 76 | off = 0 |
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77 | 77 | diskversion = _unpack('>B', data[off:off + 1])[0] |
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78 | 78 | off += 1 |
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79 | 79 | if diskversion != _fmversion: |
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80 | 80 | raise util.Abort(_('parsing obsolete marker: unknown version %r') |
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81 | 81 | % diskversion) |
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82 | 82 | |
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83 | 83 | # Loop on markers |
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84 | 84 | l = len(data) |
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85 | 85 | while off + _fmfsize <= l: |
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86 | 86 | # read fixed part |
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87 | 87 | cur = data[off:off + _fmfsize] |
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88 | 88 | off += _fmfsize |
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89 | 89 | nbsuc, mdsize, flags, pre = _unpack(_fmfixed, cur) |
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90 | 90 | # read replacement |
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91 | 91 | sucs = () |
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92 | 92 | if nbsuc: |
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93 | 93 | s = (_fnodesize * nbsuc) |
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94 | 94 | cur = data[off:off + s] |
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95 | 95 | sucs = _unpack(_fmnode * nbsuc, cur) |
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96 | 96 | off += s |
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97 | 97 | # read metadata |
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98 | 98 | # (metadata will be decoded on demand) |
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99 | 99 | metadata = data[off:off + mdsize] |
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100 | 100 | if len(metadata) != mdsize: |
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101 | 101 | raise util.Abort(_('parsing obsolete marker: metadata is too ' |
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102 | 102 | 'short, %d bytes expected, got %d') |
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103 | 103 | % (mdsize, len(metadata))) |
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104 | 104 | off += mdsize |
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105 | 105 | yield (pre, sucs, flags, metadata) |
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106 | 106 | |
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107 | 107 | def encodemeta(meta): |
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108 | 108 | """Return encoded metadata string to string mapping. |
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109 | 109 | |
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110 | 110 | Assume no ':' in key and no '\0' in both key and value.""" |
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111 | 111 | for key, value in meta.iteritems(): |
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112 | 112 | if ':' in key or '\0' in key: |
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113 | 113 | raise ValueError("':' and '\0' are forbidden in metadata key'") |
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114 | 114 | if '\0' in value: |
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115 | 115 | raise ValueError("':' are forbidden in metadata value'") |
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116 | 116 | return '\0'.join(['%s:%s' % (k, meta[k]) for k in sorted(meta)]) |
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117 | 117 | |
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118 | 118 | def decodemeta(data): |
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119 | 119 | """Return string to string dictionary from encoded version.""" |
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120 | 120 | d = {} |
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121 | 121 | for l in data.split('\0'): |
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122 | 122 | if l: |
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123 | 123 | key, value = l.split(':') |
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124 | 124 | d[key] = value |
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125 | 125 | return d |
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126 | 126 | |
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127 | 127 | class marker(object): |
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128 | 128 | """Wrap obsolete marker raw data""" |
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129 | 129 | |
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130 | 130 | def __init__(self, repo, data): |
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131 | 131 | # the repo argument will be used to create changectx in later version |
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132 | 132 | self._repo = repo |
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133 | 133 | self._data = data |
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134 | 134 | self._decodedmeta = None |
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135 | 135 | |
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136 | 136 | def precnode(self): |
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137 | 137 | """Precursor changeset node identifier""" |
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138 | 138 | return self._data[0] |
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139 | 139 | |
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140 | 140 | def succnodes(self): |
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141 | 141 | """List of successor changesets node identifiers""" |
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142 | 142 | return self._data[1] |
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143 | 143 | |
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144 | 144 | def metadata(self): |
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145 | 145 | """Decoded metadata dictionary""" |
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146 | 146 | if self._decodedmeta is None: |
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147 | 147 | self._decodedmeta = decodemeta(self._data[3]) |
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148 | 148 | return self._decodedmeta |
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149 | 149 | |
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150 | 150 | def date(self): |
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151 | 151 | """Creation date as (unixtime, offset)""" |
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152 | 152 | parts = self.metadata()['date'].split(' ') |
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153 | 153 | return (float(parts[0]), int(parts[1])) |
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154 | 154 | |
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155 | 155 | class obsstore(object): |
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156 | 156 | """Store obsolete markers |
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157 | 157 | |
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158 | 158 | Markers can be accessed with two mappings: |
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159 | 159 | - precursors: old -> set(new) |
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160 | 160 | - successors: new -> set(old) |
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161 | 161 | """ |
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162 | 162 | |
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163 | 163 | def __init__(self, sopener): |
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164 | 164 | # caches for various obsolescence related cache |
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165 | 165 | self.caches = {} |
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166 | 166 | self._all = [] |
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167 | 167 | # new markers to serialize |
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168 | 168 | self.precursors = {} |
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169 | 169 | self.successors = {} |
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170 | 170 | self.sopener = sopener |
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171 | 171 | data = sopener.tryread('obsstore') |
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172 | 172 | if data: |
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173 | 173 | self._load(_readmarkers(data)) |
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174 | 174 | |
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175 | 175 | def __iter__(self): |
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176 | 176 | return iter(self._all) |
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177 | 177 | |
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178 | 178 | def __nonzero__(self): |
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179 | 179 | return bool(self._all) |
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180 | 180 | |
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181 | 181 | def create(self, transaction, prec, succs=(), flag=0, metadata=None): |
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182 | 182 | """obsolete: add a new obsolete marker |
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183 | 183 | |
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184 | 184 | * ensuring it is hashable |
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185 | 185 | * check mandatory metadata |
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186 | 186 | * encode metadata |
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187 | 187 | """ |
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188 | 188 | if metadata is None: |
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189 | 189 | metadata = {} |
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190 | 190 | if len(prec) != 20: |
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191 | 191 | raise ValueError(prec) |
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192 | 192 | for succ in succs: |
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193 | 193 | if len(succ) != 20: |
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194 | 194 | raise ValueError(succ) |
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195 | 195 | marker = (str(prec), tuple(succs), int(flag), encodemeta(metadata)) |
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196 | 196 | self.add(transaction, [marker]) |
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197 | 197 | |
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198 | 198 | def add(self, transaction, markers): |
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199 | 199 | """Add new markers to the store |
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200 | 200 | |
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201 | 201 | Take care of filtering duplicate. |
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202 | 202 | Return the number of new marker.""" |
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203 | 203 | if not _enabled: |
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204 | 204 | raise util.Abort('obsolete feature is not enabled on this repo') |
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205 | 205 | new = [m for m in markers if m not in self._all] |
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206 | 206 | if new: |
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207 | 207 | f = self.sopener('obsstore', 'ab') |
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208 | 208 | try: |
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209 | 209 | # Whether the file's current position is at the begin or at |
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210 | 210 | # the end after opening a file for appending is implementation |
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211 | 211 | # defined. So we must seek to the end before calling tell(), |
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212 | 212 | # or we may get a zero offset for non-zero sized files on |
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213 | 213 | # some platforms (issue3543). |
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214 | 214 | f.seek(0, _SEEK_END) |
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215 | 215 | offset = f.tell() |
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216 | 216 | transaction.add('obsstore', offset) |
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217 | 217 | # offset == 0: new file - add the version header |
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218 | 218 | for bytes in _encodemarkers(new, offset == 0): |
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219 | 219 | f.write(bytes) |
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220 | 220 | finally: |
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221 | 221 | # XXX: f.close() == filecache invalidation == obsstore rebuilt. |
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222 | 222 | # call 'filecacheentry.refresh()' here |
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223 | 223 | f.close() |
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224 | 224 | self._load(new) |
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225 | 225 | # new marker *may* have changed several set. invalidate the cache. |
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226 | 226 | self.caches.clear() |
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227 | 227 | return len(new) |
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228 | 228 | |
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229 | 229 | def mergemarkers(self, transation, data): |
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230 | 230 | markers = _readmarkers(data) |
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231 | 231 | self.add(transation, markers) |
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232 | 232 | |
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233 | 233 | def _load(self, markers): |
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234 | 234 | for mark in markers: |
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235 | 235 | self._all.append(mark) |
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236 | 236 | pre, sucs = mark[:2] |
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237 | 237 | self.precursors.setdefault(pre, set()).add(mark) |
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238 | 238 | for suc in sucs: |
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239 | 239 | self.successors.setdefault(suc, set()).add(mark) |
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240 | 240 | |
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241 | 241 | def _encodemarkers(markers, addheader=False): |
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242 | 242 | # Kept separate from flushmarkers(), it will be reused for |
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243 | 243 | # markers exchange. |
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244 | 244 | if addheader: |
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245 | 245 | yield _pack('>B', _fmversion) |
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246 | 246 | for marker in markers: |
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247 | 247 | yield _encodeonemarker(marker) |
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248 | 248 | |
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249 | 249 | |
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250 | 250 | def _encodeonemarker(marker): |
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251 | 251 | pre, sucs, flags, metadata = marker |
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252 | 252 | nbsuc = len(sucs) |
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253 | 253 | format = _fmfixed + (_fmnode * nbsuc) |
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254 | 254 | data = [nbsuc, len(metadata), flags, pre] |
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255 | 255 | data.extend(sucs) |
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256 | 256 | return _pack(format, *data) + metadata |
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257 | 257 | |
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258 | 258 | # arbitrary picked to fit into 8K limit from HTTP server |
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259 | 259 | # you have to take in account: |
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260 | 260 | # - the version header |
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261 | 261 | # - the base85 encoding |
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262 | 262 | _maxpayload = 5300 |
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263 | 263 | |
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264 | 264 | def listmarkers(repo): |
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265 | 265 | """List markers over pushkey""" |
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266 | 266 | if not repo.obsstore: |
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267 | 267 | return {} |
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268 | 268 | keys = {} |
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269 | 269 | parts = [] |
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270 | 270 | currentlen = _maxpayload * 2 # ensure we create a new part |
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271 | 271 | for marker in repo.obsstore: |
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272 | 272 | nextdata = _encodeonemarker(marker) |
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273 | 273 | if (len(nextdata) + currentlen > _maxpayload): |
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274 | 274 | currentpart = [] |
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275 | 275 | currentlen = 0 |
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276 | 276 | parts.append(currentpart) |
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277 | 277 | currentpart.append(nextdata) |
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278 | 278 | currentlen += len(nextdata) |
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279 | 279 | for idx, part in enumerate(reversed(parts)): |
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280 | 280 | data = ''.join([_pack('>B', _fmversion)] + part) |
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281 | 281 | keys['dump%i' % idx] = base85.b85encode(data) |
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282 | 282 | return keys |
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283 | 283 | |
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284 | 284 | def pushmarker(repo, key, old, new): |
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285 | 285 | """Push markers over pushkey""" |
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286 | 286 | if not key.startswith('dump'): |
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287 | 287 | repo.ui.warn(_('unknown key: %r') % key) |
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288 | 288 | return 0 |
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289 | 289 | if old: |
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290 | 290 | repo.ui.warn(_('unexpected old value') % key) |
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291 | 291 | return 0 |
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292 | 292 | data = base85.b85decode(new) |
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293 | 293 | lock = repo.lock() |
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294 | 294 | try: |
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295 | 295 | tr = repo.transaction('pushkey: obsolete markers') |
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296 | 296 | try: |
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297 | 297 | repo.obsstore.mergemarkers(tr, data) |
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298 | 298 | tr.close() |
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299 | 299 | return 1 |
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300 | 300 | finally: |
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301 | 301 | tr.release() |
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302 | 302 | finally: |
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303 | 303 | lock.release() |
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304 | 304 | |
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305 | 305 | def allmarkers(repo): |
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306 | 306 | """all obsolete markers known in a repository""" |
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307 | 307 | for markerdata in repo.obsstore: |
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308 | 308 | yield marker(repo, markerdata) |
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309 | 309 | |
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310 | 310 | def precursormarkers(ctx): |
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311 | 311 | """obsolete marker making this changeset obsolete""" |
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312 | 312 | for data in ctx._repo.obsstore.precursors.get(ctx.node(), ()): |
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313 | 313 | yield marker(ctx._repo, data) |
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314 | 314 | |
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315 | 315 | def successormarkers(ctx): |
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316 | 316 | """obsolete marker marking this changeset as a successors""" |
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317 | 317 | for data in ctx._repo.obsstore.successors.get(ctx.node(), ()): |
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318 | 318 | yield marker(ctx._repo, data) |
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319 | 319 | |
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320 | 320 | def anysuccessors(obsstore, node): |
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321 | 321 | """Yield every successor of <node> |
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322 | 322 | |
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323 | 323 | This is a linear yield unsuitable to detect split changesets.""" |
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324 | 324 | remaining = set([node]) |
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325 | 325 | seen = set(remaining) |
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326 | 326 | while remaining: |
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327 | 327 | current = remaining.pop() |
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328 | 328 | yield current |
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329 | 329 | for mark in obsstore.precursors.get(current, ()): |
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330 | 330 | for suc in mark[1]: |
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331 | 331 | if suc not in seen: |
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332 | 332 | seen.add(suc) |
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333 | 333 | remaining.add(suc) |
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334 | 334 | |
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335 | 335 | # mapping of 'set-name' -> <function to computer this set> |
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336 | 336 | cachefuncs = {} |
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337 | 337 | def cachefor(name): |
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338 | 338 | """Decorator to register a function as computing the cache for a set""" |
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339 | 339 | def decorator(func): |
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340 | 340 | assert name not in cachefuncs |
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341 | 341 | cachefuncs[name] = func |
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342 | 342 | return func |
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343 | 343 | return decorator |
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344 | 344 | |
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345 | 345 | def getobscache(repo, name): |
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346 | 346 | """Return the set of revision that belong to the <name> set |
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347 | 347 | |
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348 | 348 | Such access may compute the set and cache it for future use""" |
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349 | 349 | if not repo.obsstore: |
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350 | 350 | return () |
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351 | 351 | if name not in repo.obsstore.caches: |
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352 | 352 | repo.obsstore.caches[name] = cachefuncs[name](repo) |
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353 | 353 | return repo.obsstore.caches[name] |
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354 | 354 | |
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355 | 355 | # To be simple we need to invalidate obsolescence cache when: |
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356 | 356 | # |
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357 | 357 | # - new changeset is added: |
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358 | 358 | # - public phase is changed |
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359 | 359 | # - obsolescence marker are added |
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360 | 360 | # - strip is used a repo |
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361 | 361 | def clearobscaches(repo): |
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362 | 362 | """Remove all obsolescence related cache from a repo |
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363 | 363 | |
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364 | 364 | This remove all cache in obsstore is the obsstore already exist on the |
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365 | 365 | repo. |
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366 | 366 | |
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367 | 367 | (We could be smarter here given the exact event that trigger the cache |
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368 | 368 | clearing)""" |
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369 | 369 | # only clear cache is there is obsstore data in this repo |
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370 | 370 | if 'obsstore' in repo._filecache: |
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371 | 371 | repo.obsstore.caches.clear() |
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372 | 372 | |
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373 | 373 | @cachefor('obsolete') |
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374 | 374 | def _computeobsoleteset(repo): |
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375 | 375 | """the set of obsolete revisions""" |
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376 | 376 | obs = set() |
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377 | 377 | nm = repo.changelog.nodemap |
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378 | 378 | for prec in repo.obsstore.precursors: |
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379 | 379 | rev = nm.get(prec) |
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380 | 380 | if rev is not None: |
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381 | 381 | obs.add(rev) |
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382 | 382 | return set(repo.revs('%ld - public()', obs)) |
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383 | 383 | |
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384 | 384 | @cachefor('unstable') |
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385 | 385 | def _computeunstableset(repo): |
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386 | 386 | """the set of non obsolete revisions with obsolete parents""" |
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387 | 387 | return set(repo.revs('(obsolete()::) - obsolete()')) |
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388 | 388 | |
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389 | 389 | @cachefor('suspended') |
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390 | 390 | def _computesuspendedset(repo): |
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391 | 391 | """the set of obsolete parents with non obsolete descendants""" |
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392 | 392 | return set(repo.revs('obsolete() and obsolete()::unstable()')) |
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393 | 393 | |
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394 | 394 | @cachefor('extinct') |
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395 | 395 | def _computeextinctset(repo): |
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396 | 396 | """the set of obsolete parents without non obsolete descendants""" |
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397 | 397 | return set(repo.revs('obsolete() - obsolete()::unstable()')) |
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398 | ||
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399 | def createmarkers(repo, relations, flag=0, metadata=None): | |
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400 | """Add obsolete markers between changesets in a repo | |
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401 | ||
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402 | <relations> must be an iterable of (<old>, (<new>, ...)) tuple. | |
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403 | `old` and `news` are changectx. | |
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404 | ||
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405 | Trying to obsolete a public changeset will raise an exception. | |
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406 | ||
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407 | Current user and date are used except if specified otherwise in the | |
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408 | metadata attribute. | |
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409 | ||
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410 | This function operates within a transaction of its own, but does | |
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411 | not take any lock on the repo. | |
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412 | """ | |
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413 | # prepare metadata | |
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414 | if metadata is None: | |
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415 | metadata = {} | |
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416 | if 'date' not in metadata: | |
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417 | metadata['date'] = '%i %i' % util.makedate() | |
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418 | if 'user' not in metadata: | |
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419 | metadata['user'] = repo.ui.username() | |
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420 | tr = repo.transaction('add-obsolescence-marker') | |
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421 | try: | |
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422 | for prec, sucs in relations: | |
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423 | if not prec.mutable(): | |
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424 | raise util.Abort("cannot obsolete immutable changeset: %s" | |
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425 | % prec) | |
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426 | nprec = prec.node() | |
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427 | nsucs = tuple(s.node() for s in sucs) | |
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428 | if nprec in nsucs: | |
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429 | raise util.Abort("changeset %s cannot obsolete itself" % prec) | |
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430 | repo.obsstore.create(tr, nprec, nsucs, flag, metadata) | |
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431 | tr.close() | |
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432 | finally: | |
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433 | tr.release() |
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