git repack: keep commits hidden by a graft
[git/git.git] / Documentation / git-pack-objects.txt
1 git-pack-objects(1)
2 ===================
3
4 NAME
5 ----
6 git-pack-objects - Create a packed archive of objects
7
8
9 SYNOPSIS
10 --------
11 [verse]
12 'git pack-objects' [-q] [--no-reuse-delta] [--delta-base-offset] [--non-empty]
13 [--local] [--incremental] [--window=N] [--depth=N] [--all-progress]
14 [--revs [--unpacked | --all]*] [--stdout | base-name]
15 [--keep-true-parents] < object-list
16
17
18 DESCRIPTION
19 -----------
20 Reads list of objects from the standard input, and writes a packed
21 archive with specified base-name, or to the standard output.
22
23 A packed archive is an efficient way to transfer set of objects
24 between two repositories, and also is an archival format which
25 is efficient to access. The packed archive format (.pack) is
26 designed to be self contained so that it can be unpacked without
27 any further information, but for fast, random access to the objects
28 in the pack, a pack index file (.idx) will be generated.
29
30 Placing both in the pack/ subdirectory of $GIT_OBJECT_DIRECTORY (or
31 any of the directories on $GIT_ALTERNATE_OBJECT_DIRECTORIES)
32 enables git to read from such an archive.
33
34 The 'git-unpack-objects' command can read the packed archive and
35 expand the objects contained in the pack into "one-file
36 one-object" format; this is typically done by the smart-pull
37 commands when a pack is created on-the-fly for efficient network
38 transport by their peers.
39
40 In a packed archive, an object is either stored as a compressed
41 whole, or as a difference from some other object. The latter is
42 often called a delta.
43
44
45 OPTIONS
46 -------
47 base-name::
48 Write into a pair of files (.pack and .idx), using
49 <base-name> to determine the name of the created file.
50 When this option is used, the two files are written in
51 <base-name>-<SHA1>.{pack,idx} files. <SHA1> is a hash
52 of the sorted object names to make the resulting filename
53 based on the pack content, and written to the standard
54 output of the command.
55
56 --stdout::
57 Write the pack contents (what would have been written to
58 .pack file) out to the standard output.
59
60 --revs::
61 Read the revision arguments from the standard input, instead of
62 individual object names. The revision arguments are processed
63 the same way as 'git-rev-list' with the `--objects` flag
64 uses its `commit` arguments to build the list of objects it
65 outputs. The objects on the resulting list are packed.
66
67 --unpacked::
68 This implies `--revs`. When processing the list of
69 revision arguments read from the standard input, limit
70 the objects packed to those that are not already packed.
71
72 --all::
73 This implies `--revs`. In addition to the list of
74 revision arguments read from the standard input, pretend
75 as if all refs under `$GIT_DIR/refs` are specified to be
76 included.
77
78 --include-tag::
79 Include unasked-for annotated tags if the object they
80 reference was included in the resulting packfile. This
81 can be useful to send new tags to native git clients.
82
83 --window=[N]::
84 --depth=[N]::
85 These two options affect how the objects contained in
86 the pack are stored using delta compression. The
87 objects are first internally sorted by type, size and
88 optionally names and compared against the other objects
89 within --window to see if using delta compression saves
90 space. --depth limits the maximum delta depth; making
91 it too deep affects the performance on the unpacker
92 side, because delta data needs to be applied that many
93 times to get to the necessary object.
94 The default value for --window is 10 and --depth is 50.
95
96 --window-memory=[N]::
97 This option provides an additional limit on top of `--window`;
98 the window size will dynamically scale down so as to not take
99 up more than N bytes in memory. This is useful in
100 repositories with a mix of large and small objects to not run
101 out of memory with a large window, but still be able to take
102 advantage of the large window for the smaller objects. The
103 size can be suffixed with "k", "m", or "g".
104 `--window-memory=0` makes memory usage unlimited, which is the
105 default.
106
107 --max-pack-size=<n>::
108 Maximum size of each output packfile, expressed in MiB.
109 If specified, multiple packfiles may be created.
110 The default is unlimited, unless the config variable
111 `pack.packSizeLimit` is set.
112
113 --honor-pack-keep::
114 This flag causes an object already in a local pack that
115 has a .keep file to be ignored, even if it appears in the
116 standard input.
117
118 --incremental::
119 This flag causes an object already in a pack ignored
120 even if it appears in the standard input.
121
122 --local::
123 This flag is similar to `--incremental`; instead of
124 ignoring all packed objects, it only ignores objects
125 that are packed and/or not in the local object store
126 (i.e. borrowed from an alternate).
127
128 --non-empty::
129 Only create a packed archive if it would contain at
130 least one object.
131
132 --progress::
133 Progress status is reported on the standard error stream
134 by default when it is attached to a terminal, unless -q
135 is specified. This flag forces progress status even if
136 the standard error stream is not directed to a terminal.
137
138 --all-progress::
139 When --stdout is specified then progress report is
140 displayed during the object count and deltification phases
141 but inhibited during the write-out phase. The reason is
142 that in some cases the output stream is directly linked
143 to another command which may wish to display progress
144 status of its own as it processes incoming pack data.
145 This flag is like --progress except that it forces progress
146 report for the write-out phase as well even if --stdout is
147 used.
148
149 -q::
150 This flag makes the command not to report its progress
151 on the standard error stream.
152
153 --no-reuse-delta::
154 When creating a packed archive in a repository that
155 has existing packs, the command reuses existing deltas.
156 This sometimes results in a slightly suboptimal pack.
157 This flag tells the command not to reuse existing deltas
158 but compute them from scratch.
159
160 --no-reuse-object::
161 This flag tells the command not to reuse existing object data at all,
162 including non deltified object, forcing recompression of everything.
163 This implies --no-reuse-delta. Useful only in the obscure case where
164 wholesale enforcement of a different compression level on the
165 packed data is desired.
166
167 --compression=[N]::
168 Specifies compression level for newly-compressed data in the
169 generated pack. If not specified, pack compression level is
170 determined first by pack.compression, then by core.compression,
171 and defaults to -1, the zlib default, if neither is set.
172 Add --no-reuse-object if you want to force a uniform compression
173 level on all data no matter the source.
174
175 --delta-base-offset::
176 A packed archive can express base object of a delta as
177 either 20-byte object name or as an offset in the
178 stream, but older version of git does not understand the
179 latter. By default, 'git-pack-objects' only uses the
180 former format for better compatibility. This option
181 allows the command to use the latter format for
182 compactness. Depending on the average delta chain
183 length, this option typically shrinks the resulting
184 packfile by 3-5 per-cent.
185
186 --threads=<n>::
187 Specifies the number of threads to spawn when searching for best
188 delta matches. This requires that pack-objects be compiled with
189 pthreads otherwise this option is ignored with a warning.
190 This is meant to reduce packing time on multiprocessor machines.
191 The required amount of memory for the delta search window is
192 however multiplied by the number of threads.
193 Specifying 0 will cause git to auto-detect the number of CPU's
194 and set the number of threads accordingly.
195
196 --index-version=<version>[,<offset>]::
197 This is intended to be used by the test suite only. It allows
198 to force the version for the generated pack index, and to force
199 64-bit index entries on objects located above the given offset.
200
201 --keep-true-parents::
202 With this option, parents that are hidden by grafts are packed
203 nevertheless.
204
205
206 Author
207 ------
208 Written by Linus Torvalds <torvalds@osdl.org>
209
210 Documentation
211 -------------
212 Documentation by Junio C Hamano
213
214 SEE ALSO
215 --------
216 linkgit:git-rev-list[1]
217 linkgit:git-repack[1]
218 linkgit:git-prune-packed[1]
219
220 GIT
221 ---
222 Part of the linkgit:git[1] suite