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diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt new file mode 100644 index 0000000000..8c354bd470 --- /dev/null +++ b/Documentation/git-pack-objects.txt @@ -0,0 +1,212 @@ +git-pack-objects(1) +=================== + +NAME +---- +git-pack-objects - Create a packed archive of objects + + +SYNOPSIS +-------- +[verse] +'git pack-objects' [-q] [--no-reuse-delta] [--delta-base-offset] [--non-empty] + [--local] [--incremental] [--window=N] [--depth=N] [--all-progress] + [--revs [--unpacked | --all]*] [--stdout | base-name] < object-list + + +DESCRIPTION +----------- +Reads list of objects from the standard input, and writes a packed +archive with specified base-name, or to the standard output. + +A packed archive is an efficient way to transfer set of objects +between two repositories, and also is an archival format which +is efficient to access. The packed archive format (.pack) is +designed to be self contained so that it can be unpacked without +any further information, but for fast, random access to the objects +in the pack, a pack index file (.idx) will be generated. + +Placing both in the pack/ subdirectory of $GIT_OBJECT_DIRECTORY (or +any of the directories on $GIT_ALTERNATE_OBJECT_DIRECTORIES) +enables git to read from such an archive. + +The 'git-unpack-objects' command can read the packed archive and +expand the objects contained in the pack into "one-file +one-object" format; this is typically done by the smart-pull +commands when a pack is created on-the-fly for efficient network +transport by their peers. + +In a packed archive, an object is either stored as a compressed +whole, or as a difference from some other object. The latter is +often called a delta. + + +OPTIONS +------- +base-name:: + Write into a pair of files (.pack and .idx), using + <base-name> to determine the name of the created file. + When this option is used, the two files are written in + <base-name>-<SHA1>.{pack,idx} files. <SHA1> is a hash + of the sorted object names to make the resulting filename + based on the pack content, and written to the standard + output of the command. + +--stdout:: + Write the pack contents (what would have been written to + .pack file) out to the standard output. + +--revs:: + Read the revision arguments from the standard input, instead of + individual object names. The revision arguments are processed + the same way as 'git-rev-list' with the `--objects` flag + uses its `commit` arguments to build the list of objects it + outputs. The objects on the resulting list are packed. + +--unpacked:: + This implies `--revs`. When processing the list of + revision arguments read from the standard input, limit + the objects packed to those that are not already packed. + +--all:: + This implies `--revs`. In addition to the list of + revision arguments read from the standard input, pretend + as if all refs under `$GIT_DIR/refs` are specified to be + included. + +--include-tag:: + Include unasked-for annotated tags if the object they + reference was included in the resulting packfile. This + can be useful to send new tags to native git clients. + +--window=[N]:: +--depth=[N]:: + These two options affect how the objects contained in + the pack are stored using delta compression. The + objects are first internally sorted by type, size and + optionally names and compared against the other objects + within --window to see if using delta compression saves + space. --depth limits the maximum delta depth; making + it too deep affects the performance on the unpacker + side, because delta data needs to be applied that many + times to get to the necessary object. + The default value for --window is 10 and --depth is 50. + +--window-memory=[N]:: + This option provides an additional limit on top of `--window`; + the window size will dynamically scale down so as to not take + up more than N bytes in memory. This is useful in + repositories with a mix of large and small objects to not run + out of memory with a large window, but still be able to take + advantage of the large window for the smaller objects. The + size can be suffixed with "k", "m", or "g". + `--window-memory=0` makes memory usage unlimited, which is the + default. + +--max-pack-size=<n>:: + Maximum size of each output packfile, expressed in MiB. + If specified, multiple packfiles may be created. + The default is unlimited, unless the config variable + `pack.packSizeLimit` is set. + +--incremental:: + This flag causes an object already in a pack ignored + even if it appears in the standard input. + +--local:: + This flag is similar to `--incremental`; instead of + ignoring all packed objects, it only ignores objects + that are packed and not in the local object store + (i.e. borrowed from an alternate). + +--non-empty:: + Only create a packed archive if it would contain at + least one object. + +--progress:: + Progress status is reported on the standard error stream + by default when it is attached to a terminal, unless -q + is specified. This flag forces progress status even if + the standard error stream is not directed to a terminal. + +--all-progress:: + When --stdout is specified then progress report is + displayed during the object count and deltification phases + but inhibited during the write-out phase. The reason is + that in some cases the output stream is directly linked + to another command which may wish to display progress + status of its own as it processes incoming pack data. + This flag is like --progress except that it forces progress + report for the write-out phase as well even if --stdout is + used. + +-q:: + This flag makes the command not to report its progress + on the standard error stream. + +--no-reuse-delta:: + When creating a packed archive in a repository that + has existing packs, the command reuses existing deltas. + This sometimes results in a slightly suboptimal pack. + This flag tells the command not to reuse existing deltas + but compute them from scratch. + +--no-reuse-object:: + This flag tells the command not to reuse existing object data at all, + including non deltified object, forcing recompression of everything. + This implies --no-reuse-delta. Useful only in the obscure case where + wholesale enforcement of a different compression level on the + packed data is desired. + +--compression=[N]:: + Specifies compression level for newly-compressed data in the + generated pack. If not specified, pack compression level is + determined first by pack.compression, then by core.compression, + and defaults to -1, the zlib default, if neither is set. + Add --no-reuse-object if you want to force a uniform compression + level on all data no matter the source. + +--delta-base-offset:: + A packed archive can express base object of a delta as + either 20-byte object name or as an offset in the + stream, but older version of git does not understand the + latter. By default, 'git-pack-objects' only uses the + former format for better compatibility. This option + allows the command to use the latter format for + compactness. Depending on the average delta chain + length, this option typically shrinks the resulting + packfile by 3-5 per-cent. + +--threads=<n>:: + Specifies the number of threads to spawn when searching for best + delta matches. This requires that pack-objects be compiled with + pthreads otherwise this option is ignored with a warning. + This is meant to reduce packing time on multiprocessor machines. + The required amount of memory for the delta search window is + however multiplied by the number of threads. + Specifying 0 will cause git to auto-detect the number of CPU's + and set the number of threads accordingly. + +--index-version=<version>[,<offset>]:: + This is intended to be used by the test suite only. It allows + to force the version for the generated pack index, and to force + 64-bit index entries on objects located above the given offset. + + +Author +------ +Written by Linus Torvalds <torvalds@osdl.org> + +Documentation +------------- +Documentation by Junio C Hamano + +SEE ALSO +-------- +linkgit:git-rev-list[1] +linkgit:git-repack[1] +linkgit:git-prune-packed[1] + +GIT +--- +Part of the linkgit:git[1] suite |