[PATCH 9/9] read-cache.c: write index v4 format
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
builtin/update-index.c | 2 ++
cache.h | 4 ++++
config.c | 11 ++++++++++
environment.c | 1 +
read-cache.c | 56 ++++++++++++++++++++++++++++++++++++++++--------
5 files changed, 65 insertions(+), 9 deletions(-)
diff --git a/builtin/update-index.c b/builtin/update-index.c
index a6a23fa..b663f45 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -791,6 +791,8 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
"(for porcelains) forget saved unresolved conflicts",
PARSE_OPT_NOARG | PARSE_OPT_NONEG,
resolve_undo_clear_callback},
+ OPT_INTEGER(0, "index-format", &preferred_index_format,
+ "write index in this format"),
OPT_END()
};
diff --git a/cache.h b/cache.h
index 65a7aba..bdec32c 100644
--- a/cache.h
+++ b/cache.h
@@ -105,6 +105,9 @@ struct cache_header {
unsigned int hdr_entries;
};
+#define SUPPORTED_INDEX_FORMAT_LB 2
+#define SUPPORTED_INDEX_FORMAT_UB 4
+
/*
* The "cache_time" is just the low 32 bits of the
* time. It doesn't matter if it overflows - we only
@@ -537,6 +540,7 @@ extern int has_symlinks;
extern int minimum_abbrev, default_abbrev;
extern int ignore_case;
extern int assume_unchanged;
+extern int preferred_index_format;
extern int prefer_symlink_refs;
extern int log_all_ref_updates;
extern int warn_ambiguous_refs;
diff --git a/config.c b/config.c
index 68d3294..0244a85 100644
--- a/config.c
+++ b/config.c
@@ -564,6 +564,17 @@ static int git_default_core_config(const char *var, const char *value)
return 0;
}
+ if (!strcmp(var, "core.indexformat")) {
+ int val = git_config_int(var, value);
+ if (val < SUPPORTED_INDEX_FORMAT_LB ||
+ SUPPORTED_INDEX_FORMAT_UB < val)
+ return error("%s not in supported range: %d..%d",
+ var, SUPPORTED_INDEX_FORMAT_LB,
+ SUPPORTED_INDEX_FORMAT_UB);
+ preferred_index_format = val;
+ return 0;
+ }
+
if (!strcmp(var, "core.quotepath")) {
quote_path_fully = git_config_bool(var, value);
return 0;
diff --git a/environment.c b/environment.c
index c93b8f4..4ecf8e6 100644
--- a/environment.c
+++ b/environment.c
@@ -20,6 +20,7 @@ int has_symlinks = 1;
int minimum_abbrev = 4, default_abbrev = 7;
int ignore_case;
int assume_unchanged;
+int preferred_index_format;
int prefer_symlink_refs;
int is_bare_repository_cfg = -1; /* unspecified */
int log_all_ref_updates = -1; /* unspecified */
diff --git a/read-cache.c b/read-cache.c
index 1c173f7..fdac89a 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1676,15 +1676,45 @@ static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
}
}
-static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce)
+static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
+ struct strbuf *previous_name)
{
- int size = ondisk_ce_size(ce);
- struct ondisk_cache_entry *ondisk = xcalloc(1, size);
+ int size;
+ struct ondisk_cache_entry *ondisk;
char *name;
int result;
- name = copy_cache_entry_to_ondisk(ondisk, ce);
- memcpy(name, ce->name, ce_namelen(ce));
+ if (!previous_name) {
+ size = ondisk_ce_size(ce);
+ ondisk = xcalloc(1, size);
+ name = copy_cache_entry_to_ondisk(ondisk, ce);
+ memcpy(name, ce->name, ce_namelen(ce));
+ } else {
+ int common, to_remove, prefix_size;
+ unsigned char to_remove_vi[16];
+ for (common = 0;
+ (ce->name[common] &&
+ common < previous_name->len &&
+ ce->name[common] == previous_name->buf[common]);
+ common++)
+ ; /* still matching */
+ to_remove = previous_name->len - common;
+ prefix_size = encode_varint(to_remove, to_remove_vi);
+
+ if (ce->ce_flags & CE_EXTENDED)
+ size = offsetof(struct ondisk_cache_entry_extended, name);
+ else
+ size = offsetof(struct ondisk_cache_entry, name);
+ size += prefix_size + (ce_namelen(ce) - common + 1);
+
+ ondisk = xcalloc(1, size);
+ name = copy_cache_entry_to_ondisk(ondisk, ce);
+ memcpy(name, to_remove_vi, prefix_size);
+ memcpy(name + prefix_size, ce->name + common, ce_namelen(ce) - common);
+
+ strbuf_splice(previous_name, common, to_remove,
+ ce->name + common, ce_namelen(ce) - common);
+ }
result = ce_write(c, fd, ondisk, size);
free(ondisk);
@@ -1720,10 +1750,11 @@ int write_index(struct index_state *istate, int newfd)
{
git_SHA_CTX c;
struct cache_header hdr;
- int i, err, removed, extended;
+ int i, err, removed, extended, hdr_version;
struct cache_entry **cache = istate->cache;
int entries = istate->cache_nr;
struct stat st;
+ struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
for (i = removed = extended = 0; i < entries; i++) {
if (cache[i]->ce_flags & CE_REMOVE)
@@ -1737,24 +1768,31 @@ int write_index(struct index_state *istate, int newfd)
}
}
+ if (preferred_index_format)
+ hdr_version = preferred_index_format;
+ else
+ hdr_version = extended ? 3 : 2;
+
+
hdr.hdr_signature = htonl(CACHE_SIGNATURE);
- /* for extended format, increase version so older git won't try to read it */
- hdr.hdr_version = htonl(extended ? 3 : 2);
+ hdr.hdr_version = htonl(hdr_version);
hdr.hdr_entries = htonl(entries - removed);
git_SHA1_Init(&c);
if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
return -1;
+ previous_name = (hdr_version == 4) ? &previous_name_buf : NULL;
for (i = 0; i < entries; i++) {
struct cache_entry *ce = cache[i];
if (ce->ce_flags & CE_REMOVE)
continue;
if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
ce_smudge_racily_clean_entry(ce);
- if (ce_write_entry(&c, newfd, ce) < 0)
+ if (ce_write_entry(&c, newfd, ce, previous_name) < 0)
return -1;
}
+ strbuf_release(&previous_name_buf);
/* Write extension data here */
if (istate->cache_tree) {
--
1.7.10.rc4.54.g1d5dd3
Junio C Hamano <gitster@pobox.com>