[PATCH v3 3/7] midx.c: respect 'pack.writeBitmapHashcache' when writing bitmaps
- From
Taylor Blau <me@ttaylorr.com>
- Date
- Sep 17, 2021, 21:21 UTC
- Message-ID
- <f0d8f106c22dae64eaf4b77d1ecf67ef79c4515c.1631913631.git.me@ttaylorr.com>
- In-Reply-To
- <cover.1631913631.git.me@ttaylorr.com>
In the previous commit, the bitmap writing code learned to propagate values from an existing hash-cache extension into the bitmap that it is writing.
Now that that functionality exists, let's expose it by teaching the 'git multi-pack-index' builtin to respect the `pack.writeBitmapHashCache` option so that the hash-cache may be written at all.
Two minor points worth noting here:
- The 'git multi-pack-index write' sub-command didn't previously read
any configuration (instead this is handled in the base command). A
separate handler is added here to respect this write-specific
config option. - I briefly considered adding a 'bitmap_flags' field to the static
options struct, but decided against it since it would require
plumbing through a new parameter to the write_midx_file() function. Instead, a new MIDX-specific flag is added, which is translated to
the corresponding bitmap one.Signed-off-by: Taylor Blau <me@ttaylorr.com> --- Documentation/config/pack.txt | 4 ++++ builtin/multi-pack-index.c | 21 +++++++++++++++++++++ midx.c | 6 +++++- midx.h | 1 + 4 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/Documentation/config/pack.txt b/Documentation/config/pack.txt index 763f7af7c4..ad7f73a1ea 100644 --- a/Documentation/config/pack.txt +++ b/Documentation/config/pack.txt @@ -159,6 +159,10 @@ pack.writeBitmapHashCache:: between an older, bitmapped pack and objects that have been pushed since the last gc). The downside is that it consumes 4 bytes per object of disk space. Defaults to true. ++ +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.writeReverseIndex:: When true, git will write a corresponding .rev file (see: diff --git a/builtin/multi-pack-index.c b/builtin/multi-pack-index.c index 73c0113b48..578ffea6e8 100644 --- a/builtin/multi-pack-index.c +++ b/builtin/multi-pack-index.c @@ -61,6 +61,23 @@ static struct option *add_common_options(struct option *prev) return parse_options_concat(common_opts, prev); } +static int git_multi_pack_index_write_config(const char *var, const char *value, + void *cb) +{ + if (!strcmp(var, "pack.writebitmaphashcache")) { + if (git_config_bool(var, value)) + opts.flags |= MIDX_WRITE_BITMAP_HASH_CACHE; + else + opts.flags &= ~MIDX_WRITE_BITMAP_HASH_CACHE; + } + + /* + * We should never make a fall-back call to 'git_default_config', since + * this was already called in 'cmd_multi_pack_index()'. + */ + return 0; +} + static int cmd_multi_pack_index_write(int argc, const char **argv) { struct option *options; @@ -73,6 +90,10 @@ static int cmd_multi_pack_index_write(int argc, const char **argv) OPT_END(), }; + opts.flags |= MIDX_WRITE_BITMAP_HASH_CACHE; + + git_config(git_multi_pack_index_write_config, NULL); + options = add_common_options(builtin_multi_pack_index_write_options); trace2_cmd_mode(argv[0]); diff --git a/midx.c b/midx.c index 864034a6ad..38c8600458 100644 --- a/midx.c +++ b/midx.c @@ -1008,9 +1008,13 @@ static int write_midx_bitmap(char *midx_name, unsigned char *midx_hash, struct pack_idx_entry **index; struct commit **commits = NULL; uint32_t i, commits_nr; + uint16_t options = 0; char *bitmap_name = xstrfmt("%s-%s.bitmap", midx_name, hash_to_hex(midx_hash)); int ret; + if (flags & MIDX_WRITE_BITMAP_HASH_CACHE) + options |= BITMAP_OPT_HASH_CACHE; + prepare_midx_packing_data(&pdata, ctx); commits = find_commits_for_midx_bitmap(&commits_nr, ctx); @@ -1049,7 +1053,7 @@ static int write_midx_bitmap(char *midx_name, unsigned char *midx_hash, goto cleanup; bitmap_writer_set_checksum(midx_hash); - bitmap_writer_finish(index, pdata.nr_objects, bitmap_name, 0); + bitmap_writer_finish(index, pdata.nr_objects, bitmap_name, options); cleanup: free(index); diff --git a/midx.h b/midx.h index aa3da557bb..541d9ac728 100644 --- a/midx.h +++ b/midx.h @@ -44,6 +44,7 @@ struct multi_pack_index { #define MIDX_PROGRESS (1 << 0) #define MIDX_WRITE_REV_INDEX (1 << 1) #define MIDX_WRITE_BITMAP (1 << 2) +#define MIDX_WRITE_BITMAP_HASH_CACHE (1 << 3) const unsigned char *get_midx_checksum(struct multi_pack_index *m); char *get_midx_filename(const char *object_dir);
-- 2.33.0.96.g73915697e6