allow delta data reuse even if base object is a preferred base
[git/git.git] / Documentation / git-pack-objects.txt
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1git-pack-objects(1)
2===================
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3
4NAME
5----
7bd7f280 6git-pack-objects - Create a packed archive of objects
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7
8
9SYNOPSIS
10--------
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11[verse]
12'git-pack-objects' [-q] [--no-reuse-delta] [--non-empty]
13 [--local] [--incremental] [--window=N] [--depth=N]
4321134c 14 [--revs [--unpacked | --all]*] [--stdout | base-name] < object-list
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15
16
17DESCRIPTION
18-----------
19Reads list of objects from the standard input, and writes a packed
20archive with specified base-name, or to the standard output.
21
22A packed archive is an efficient way to transfer set of objects
23between two repositories, and also is an archival format which
24is efficient to access. The packed archive format (.pack) is
25designed to be unpackable without having anything else, but for
26random access, accompanied with the pack index file (.idx).
27
28'git-unpack-objects' command can read the packed archive and
29expand the objects contained in the pack into "one-file
30one-object" format; this is typically done by the smart-pull
31commands when a pack is created on-the-fly for efficient network
32transport by their peers.
33
2c6e4771 34Placing both in the pack/ subdirectory of $GIT_OBJECT_DIRECTORY (or
5f40520f 35any of the directories on $GIT_ALTERNATE_OBJECT_DIRECTORIES)
72e9340c 36enables git to read from such an archive.
5f40520f 37
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38In a packed archive, an object is either stored as a compressed
39whole, or as a difference from some other object. The latter is
40often called a delta.
41
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42
43OPTIONS
44-------
45base-name::
46 Write into a pair of files (.pack and .idx), using
47 <base-name> to determine the name of the created file.
48 When this option is used, the two files are written in
49 <base-name>-<SHA1>.{pack,idx} files. <SHA1> is a hash
50 of object names (currently in random order so it does
51 not have any useful meaning) to make the resulting
52 filename reasonably unique, and written to the standard
53 output of the command.
54
55--stdout::
89438677 56 Write the pack contents (what would have been written to
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57 .pack file) out to the standard output.
58
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59--revs::
60 Read the revision arguments from the standard input, instead of
61 individual object names. The revision arguments are processed
62 the same way as gitlink:git-rev-list[1] with `--objects` flag
63 uses its `commit` arguments to build the list of objects it
64 outputs. The objects on the resulting list are packed.
65
66--unpacked::
67 This implies `--revs`. When processing the list of
68 revision arguments read from the standard input, limit
69 the objects packed to those that are not already packed.
70
71--all::
72 This implies `--revs`. In addition to the list of
73 revision arguments read from the standard input, pretend
74 as if all refs under `$GIT_DIR/refs` are specifed to be
75 included.
76
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77--window and --depth::
78 These two options affects how the objects contained in
79 the pack are stored using delta compression. The
80 objects are first internally sorted by type, size and
81 optionally names and compared against the other objects
82 within --window to see if using delta compression saves
83 space. --depth limits the maximum delta depth; making
84 it too deep affects the performance on the unpacker
85 side, because delta data needs to be applied that many
86 times to get to the necessary object.
87
88--incremental::
89 This flag causes an object already in a pack ignored
90 even if it appears in the standard input.
91
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92--local::
93 This flag is similar to `--incremental`; instead of
94 ignoring all packed objects, it only ignores objects
95 that are packed and not in the local object store
96 (i.e. borrowed from an alternate).
5f40520f 97
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98--non-empty::
99 Only create a packed archive if it would contain at
100 least one object.
101
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102-q::
103 This flag makes the command not to report its progress
104 on the standard error stream.
105
106--no-reuse-delta::
107 When creating a packed archive in a repository that
108 has existing packs, the command reuses existing deltas.
109 This sometimes results in a slightly suboptimal pack.
110 This flag tells the command not to reuse existing deltas
111 but compute them from scratch.
112
113
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114Author
115------
116Written by Linus Torvalds <torvalds@osdl.org>
117
118Documentation
119-------------
120Documentation by Junio C Hamano
121
46444f51 122See Also
e31bb3bb 123--------
4321134c 124gitlink:git-rev-list[1]
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125gitlink:git-repack[1]
126gitlink:git-prune-packed[1]
e31bb3bb 127
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128GIT
129---
a7154e91 130Part of the gitlink:git[7] suite
5f40520f 131