diff options
Diffstat (limited to 'Documentation/config/pack.txt')
| -rw-r--r-- | Documentation/config/pack.txt | 59 |
1 files changed, 47 insertions, 12 deletions
diff --git a/Documentation/config/pack.txt b/Documentation/config/pack.txt index ad7f73a..da52737 100644 --- a/Documentation/config/pack.txt +++ b/Documentation/config/pack.txt @@ -28,11 +28,16 @@ all existing objects. You can force recompression by passing the -F option to linkgit:git-repack[1]. pack.allowPackReuse:: - When true, and when reachability bitmaps are enabled, - pack-objects will try to send parts of the bitmapped packfile - verbatim. This can reduce memory and CPU usage to serve fetches, - but might result in sending a slightly larger pack. Defaults to - true. + When true or "single", and when reachability bitmaps are + enabled, pack-objects will try to send parts of the bitmapped + packfile verbatim. When "multi", and when a multi-pack + reachability bitmap is available, pack-objects will try to send + parts of all packs in the MIDX. ++ +If only a single pack bitmap is available, and `pack.allowPackReuse` +is set to "multi", reuse parts of just the bitmapped packfile. This +can reduce memory and CPU usage to serve fetches, but might result in +sending a slightly larger pack. Defaults to true. pack.island:: An extended regular expression configuring a set of delta @@ -74,7 +79,7 @@ pack.threads:: 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 + Specifying 0 will cause Git to auto-detect the number of CPUs and set the number of threads accordingly. pack.indexVersion:: @@ -83,11 +88,11 @@ pack.indexVersion:: the new pack index with capabilities for packs larger than 4 GB as well as proper protection against the repacking of corrupted packs. Version 2 is the default. Note that version 2 is enforced - and this config option ignored whenever the corresponding pack is + and this config option is ignored whenever the corresponding pack is larger than 2 GB. + If you have an old Git that does not understand the version 2 `*.idx` file, -cloning or fetching over a non native protocol (e.g. "http") +cloning or fetching over a non-native protocol (e.g. "http") that will copy both `*.pack` file and corresponding `*.idx` file from the other side may give you a repository that cannot be accessed with your older version of Git. If the `*.pack` file is smaller than 2 GB, however, @@ -102,8 +107,8 @@ pack.packSizeLimit:: in the creation of multiple packfiles. + Note that this option is rarely useful, and may result in a larger total -on-disk size (because Git will not store deltas between packs), as well -as worse runtime performance (object lookup within multiple packs is +on-disk size (because Git will not store deltas between packs) and +worse runtime performance (object lookup within multiple packs is slower than a single pack, and optimizations like reachability bitmaps cannot cope with multiple packs). + @@ -123,6 +128,23 @@ pack.useBitmaps:: true. You should not generally need to turn this off unless you are debugging pack bitmaps. +pack.useBitmapBoundaryTraversal:: + When true, Git will use an experimental algorithm for computing + reachability queries with bitmaps. Instead of building up + complete bitmaps for all of the negated tips and then OR-ing + them together, consider negated tips with existing bitmaps as + additive (i.e. OR-ing them into the result if they exist, + ignoring them otherwise), and build up a bitmap at the boundary + instead. ++ +When using this algorithm, Git may include too many objects as a result +of not opening up trees belonging to certain UNINTERESTING commits. This +inexactness matches the non-bitmap traversal algorithm. ++ +In many cases, this can provide a speed-up over the exact algorithm, +particularly when there is poor bitmap coverage of the negated side of +the query. + pack.useSparse:: When true, git will default to using the '--sparse' option in 'git pack-objects' when the '--revs' option is present. This @@ -164,9 +186,22 @@ When writing a multi-pack reachability bitmap, no new namehashes are computed; instead, any namehashes stored in an existing bitmap are permuted into their appropriate location when writing a new bitmap. +pack.writeBitmapLookupTable:: + When true, Git will include a "lookup table" section in the + bitmap index (if one is written). This table is used to defer + loading individual bitmaps as late as possible. This can be + beneficial in repositories that have relatively large bitmap + indexes. Defaults to false. + +pack.readReverseIndex:: + When true, git will read any .rev file(s) that may be available + (see: linkgit:gitformat-pack[5]). When false, the reverse index + will be generated from scratch and stored in memory. Defaults to + true. + pack.writeReverseIndex:: When true, git will write a corresponding .rev file (see: - link:../technical/pack-format.html[Documentation/technical/pack-format.txt]) + linkgit:gitformat-pack[5]) for each new packfile that it writes in all places except for linkgit:git-fast-import[1] and in the bulk checkin mechanism. - Defaults to false. + Defaults to true. |