1 Repositories contain a file (``.hg/requires``) containing a list of |
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2 features/capabilities that are *required* for clients to interface |
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3 with the repository. This file has been present in Mercurial since |
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4 version 0.9.2 (released December 2006). |
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5 |
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6 One of the first things clients do when opening a repository is read |
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7 ``.hg/requires`` and verify that all listed requirements are supported, |
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8 aborting if not. Requirements are therefore a strong mechanism to |
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9 prevent incompatible clients from reading from unknown repository |
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10 formats or even corrupting them by writing to them. |
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11 |
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12 Extensions may add requirements. When they do this, clients not running |
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13 an extension will be unable to read from repositories. |
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14 |
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15 The following sections describe the requirements defined by the |
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16 Mercurial core distribution. |
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17 |
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18 revlogv1 |
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19 ======== |
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20 |
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21 When present, revlogs are version 1 (RevlogNG). RevlogNG was introduced |
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22 in 2006. The ``revlogv1`` requirement has been enabled by default |
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23 since the ``requires`` file was introduced in Mercurial 0.9.2. |
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24 |
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25 If this requirement is not present, version 0 revlogs are assumed. |
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26 |
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27 store |
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28 ===== |
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29 |
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30 The *store* repository layout should be used. |
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31 |
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32 This requirement has been enabled by default since the ``requires`` file |
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33 was introduced in Mercurial 0.9.2. |
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34 |
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35 fncache |
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36 ======= |
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37 |
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38 The *fncache* repository layout should be used. |
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39 |
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40 The *fncache* layout hash encodes filenames with long paths and |
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41 encodes reserved filenames. |
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42 |
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43 This requirement is enabled by default when the *store* requirement is |
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44 enabled (which is the default behavior). It was introduced in Mercurial |
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45 1.1 (released December 2008). |
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46 |
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47 shared |
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48 ====== |
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49 |
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50 Denotes that the store for a repository is shared from another location |
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51 (defined by the ``.hg/sharedpath`` file). |
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52 |
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53 This requirement is set when a repository is created via :hg:`share`. |
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54 |
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55 The requirement was added in Mercurial 1.3 (released July 2009). |
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56 |
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57 relshared |
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58 ========= |
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59 |
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60 Derivative of ``shared``; the location of the store is relative to the |
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61 store of this repository. |
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62 |
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63 This requirement is set when a repository is created via :hg:`share` |
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64 using the ``--relative`` option. |
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65 |
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66 The requirement was added in Mercurial 4.2 (released May 2017). |
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67 |
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68 dotencode |
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69 ========= |
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70 |
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71 The *dotencode* repository layout should be used. |
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72 |
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73 The *dotencode* layout encodes the first period or space in filenames |
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74 to prevent issues on OS X and Windows. |
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75 |
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76 This requirement is enabled by default when the *store* requirement |
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77 is enabled (which is the default behavior). It was introduced in |
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78 Mercurial 1.7 (released November 2010). |
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79 |
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80 parentdelta |
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81 =========== |
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82 |
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83 Denotes a revlog delta encoding format that was experimental and |
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84 replaced by *generaldelta*. It should not be seen in the wild because |
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85 it was never enabled by default. |
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86 |
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87 This requirement was added in Mercurial 1.7 and removed in Mercurial |
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88 1.9. |
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89 |
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90 generaldelta |
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91 ============ |
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92 |
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93 Revlogs should be created with the *generaldelta* flag enabled. The |
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94 generaldelta flag will cause deltas to be encoded against a parent |
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95 revision instead of the previous revision in the revlog. |
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96 |
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97 Support for this requirement was added in Mercurial 1.9 (released |
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98 July 2011). The requirement was disabled on new repositories by |
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99 default until Mercurial 3.7 (released February 2016). |
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100 |
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101 manifestv2 |
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102 ========== |
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103 |
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104 Denotes that version 2 of manifests are being used. |
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105 |
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106 Support for this requirement was added in Mercurial 3.4 (released |
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107 May 2015). The new format failed to meet expectations and support |
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108 for the format and requirement were removed in Mercurial 4.6 |
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109 (released May 2018) since the feature never graduated frome experiment |
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110 status. |
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111 |
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112 treemanifest |
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113 ============ |
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114 |
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115 Denotes that tree manifests are being used. Tree manifests are |
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116 one manifest per directory (as opposed to a single flat manifest). |
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117 |
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118 Support for this requirement was added in Mercurial 3.4 (released |
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119 August 2015). The requirement is currently experimental and is |
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120 disabled by default. |
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121 |
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122 exp-sparse |
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123 ========== |
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124 |
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125 The working directory is sparse (only contains a subset of files). |
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126 |
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127 Support for this requirement was added in Mercurial 4.3 (released |
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128 August 2017). This requirement and feature are experimental and may |
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129 disappear in a future Mercurial release. The requirement will only |
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130 be present on repositories that have opted in to a sparse working |
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131 directory. |
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132 |
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133 bookmarksinstore |
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134 ================== |
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135 |
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136 Bookmarks are stored in ``.hg/store/`` instead of directly in ``.hg/`` |
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137 where they used to be stored. The active bookmark is still stored |
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138 directly in ``.hg/``. This makes them always shared by ``hg share``, |
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139 whether or not ``-B`` was passed. |
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140 |
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141 Support for this requirement was added in Mercurial 5.1 (released |
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142 August 2019). The requirement will only be present on repositories |
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143 that have opted in to this format (by having |
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144 ``format.bookmarks-in-store=true`` set when they were created). |
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