[PATCH 05/15] pack-objects: use bitfield for object_entry::depth
- From
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
- Date
- Apr 14, 2018, 15:35 UTC
- Message-ID
- <20180414153513.9902-6-pclouds@gmail.com>
- In-Reply-To
- <20180414153513.9902-1-pclouds@gmail.com>
Because of struct packing from now on we can only handle max depth 4095 (or even lower when new booleans are added in this struct). This should be ok since long delta chain will cause significant slow down anyway.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> --- Documentation/config.txt | 1 + Documentation/git-pack-objects.txt | 4 +++- Documentation/git-repack.txt | 4 +++- builtin/pack-objects.c | 6 ++++++ pack-objects.h | 5 ++--- 5 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/Documentation/config.txt b/Documentation/config.txt index 2659153cb3..d97f10722c 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -2422,6 +2422,7 @@ pack.window:: pack.depth:: The maximum delta depth used by linkgit:git-pack-objects[1] when no maximum depth is given on the command line. Defaults to 50. + Maximum value is 4095. pack.windowMemory:: The maximum size of memory that is consumed by each thread diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt index 81bc490ac5..3503c9e3e6 100644 --- a/Documentation/git-pack-objects.txt +++ b/Documentation/git-pack-objects.txt @@ -96,7 +96,9 @@ base-name:: 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. ++ +The default value for --window is 10 and --depth is 50. The maximum +depth is 4095. --window-memory=<n>:: This option provides an additional limit on top of `--window`; diff --git a/Documentation/git-repack.txt b/Documentation/git-repack.txt index ae750e9e11..25c83c4927 100644 --- a/Documentation/git-repack.txt +++ b/Documentation/git-repack.txt @@ -90,7 +90,9 @@ other objects in that pack they already have locally. 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. ++ +The default value for --window is 10 and --depth is 50. The maximum +depth is 4095. --threads=<n>:: This option is passed through to `git pack-objects`. diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c index cc3c31747e..b231e80f17 100644 --- a/builtin/pack-objects.c +++ b/builtin/pack-objects.c @@ -3068,6 +3068,12 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix) if (pack_to_stdout != !base_name || argc) usage_with_options(pack_usage, pack_objects_options); + if (depth >= (1 << OE_DEPTH_BITS)) { + warning(_("delta chain depth %d is too deep, forcing %d"), + depth, (1 << OE_DEPTH_BITS) - 1); + depth = (1 << OE_DEPTH_BITS) - 1; + } + argv_array_push(&rp, "pack-objects"); if (thin) { use_internal_rev_list = 1; diff --git a/pack-objects.h b/pack-objects.h index 080ef62d31..cdce1648de 100644 --- a/pack-objects.h +++ b/pack-objects.h @@ -2,6 +2,7 @@ #define PACK_OBJECTS_H #define OE_DFS_STATE_BITS 2 +#define OE_DEPTH_BITS 12 /* * State flags for depth-first search used for analyzing delta cycles. @@ -89,9 +90,7 @@ struct object_entry { unsigned tagged:1; /* near the very tip of refs */ unsigned filled:1; /* assigned write-order */ unsigned dfs_state:OE_DFS_STATE_BITS; - - int depth; - + unsigned depth:OE_DEPTH_BITS; }; struct packing_data {
-- 2.17.0.367.g5dd2e386c3