[PATCH 25/38] pack v4: initial pack index v3 support on the read side
A bit crud but good enough for now.
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
---
cache.h | 1 +
pack-check.c | 4 +++-
pack-revindex.c | 7 ++++---
sha1_file.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++------
4 files changed, 58 insertions(+), 10 deletions(-)
diff --git a/cache.h b/cache.h
index 4231dfa..c939b60 100644
--- a/cache.h
+++ b/cache.h
@@ -1021,6 +1021,7 @@ extern struct packed_git {
off_t pack_size;
const void *index_data;
size_t index_size;
+ const unsigned char *sha1_table;
uint32_t num_objects;
uint32_t num_bad_objects;
unsigned char *bad_object_sha1;
diff --git a/pack-check.c b/pack-check.c
index 63a595c..8200f24 100644
--- a/pack-check.c
+++ b/pack-check.c
@@ -25,6 +25,7 @@ int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
{
const uint32_t *index_crc;
uint32_t data_crc = crc32(0, NULL, 0);
+ unsigned sha1_table;
do {
unsigned long avail;
@@ -36,8 +37,9 @@ int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
len -= avail;
} while (len);
+ sha1_table = p->index_version < 3 ? (p->num_objects * (20/4)) : 0;
index_crc = p->index_data;
- index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
+ index_crc += 2 + 256 + sha1_table + nr;
return data_crc != ntohl(*index_crc);
}
diff --git a/pack-revindex.c b/pack-revindex.c
index b4d2b35..739a568 100644
--- a/pack-revindex.c
+++ b/pack-revindex.c
@@ -170,9 +170,10 @@ static void create_pack_revindex(struct pack_revindex *rix)
index += 4 * 256;
if (p->index_version > 1) {
- const uint32_t *off_32 =
- (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
- const uint32_t *off_64 = off_32 + p->num_objects;
+ const uint32_t *off_32, *off_64;
+ unsigned sha1 = p->index_version < 3 ? 20 : 0;
+ off_32 = (uint32_t *)(index + 8 + p->num_objects * (sha1 + 4));
+ off_64 = off_32 + p->num_objects;
for (i = 0; i < num_ent; i++) {
uint32_t off = ntohl(*off_32++);
if (!(off & 0x80000000)) {
diff --git a/sha1_file.c b/sha1_file.c
index c2020d0..5c63781 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -504,7 +504,7 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
hdr = idx_map;
if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
version = ntohl(hdr->idx_version);
- if (version < 2 || version > 2) {
+ if (version < 2 || version > 3) {
munmap(idx_map, idx_size);
return error("index file %s is version %"PRIu32
" and is not supported by this binary"
@@ -539,12 +539,13 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
munmap(idx_map, idx_size);
return error("wrong index v1 file size in %s", path);
}
- } else if (version == 2) {
+ } else if (version == 2 || version == 3) {
+ unsigned long min_size, max_size;
/*
* Minimum size:
* - 8 bytes of header
* - 256 index entries 4 bytes each
- * - 20-byte sha1 entry * nr
+ * - 20-byte sha1 entry * nr (version 2 only)
* - 4-byte crc entry * nr
* - 4-byte offset entry * nr
* - 20-byte SHA1 of the packfile
@@ -553,8 +554,10 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
* variable sized table containing 8-byte entries
* for offsets larger than 2^31.
*/
- unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
- unsigned long max_size = min_size;
+ min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
+ if (version != 2)
+ min_size -= nr*20;
+ max_size = min_size;
if (nr)
max_size += (nr - 1)*8;
if (idx_size < min_size || idx_size > max_size) {
@@ -573,6 +576,36 @@ static int check_packed_git_idx(const char *path, struct packed_git *p)
}
}
+ if (version >= 3) {
+ /* the SHA1 table is located in the main pack file */
+ void *pack_map;
+ struct pack_header *pack_hdr;
+
+ fd = git_open_noatime(p->pack_name);
+ if (fd < 0) {
+ munmap(idx_map, idx_size);
+ return error("unable to open %s", p->pack_name);
+ }
+ if (fstat(fd, &st) != 0 || xsize_t(st.st_size) < 12 + nr*20) {
+ close(fd);
+ munmap(idx_map, idx_size);
+ return error("size of %s is wrong", p->pack_name);
+ }
+ pack_map = xmmap(NULL, 12 + nr*20, PROT_READ, MAP_PRIVATE, fd, 0);
+ close(fd);
+ pack_hdr = pack_map;
+ if (pack_hdr->hdr_signature != htonl(PACK_SIGNATURE) ||
+ pack_hdr->hdr_version != htonl(4) ||
+ pack_hdr->hdr_entries != htonl(nr)) {
+ munmap(idx_map, idx_size);
+ munmap(pack_map, 12 + nr*20);
+ return error("packfile for %s doesn't match expectations", path);
+ }
+ p->sha1_table = pack_map;
+ p->sha1_table += 12;
+ } else
+ p->sha1_table = NULL;
+
p->index_version = version;
p->index_data = idx_map;
p->index_size = idx_size;
@@ -697,6 +730,10 @@ void close_pack_index(struct packed_git *p)
munmap((void *)p->index_data, p->index_size);
p->index_data = NULL;
}
+ if (p->sha1_table) {
+ munmap((void *)(p->sha1_table - 12), 12 + p->num_objects * 20);
+ p->sha1_table = NULL;
+ }
}
/*
@@ -2226,9 +2263,12 @@ const unsigned char *nth_packed_object_sha1(struct packed_git *p,
index += 4 * 256;
if (p->index_version == 1) {
return index + 24 * n + 4;
- } else {
+ } else if (p->index_version == 2) {
index += 8;
return index + 20 * n;
+ } else {
+ index = p->sha1_table;
+ return index + 20 * n;
}
}
@@ -2241,6 +2281,8 @@ off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
} else {
uint32_t off;
index += 8 + p->num_objects * (20 + 4);
+ if (p->index_version != 2)
+ index -= p->num_objects * 20;
off = ntohl(*((uint32_t *)(index + 4 * n)));
if (!(off & 0x80000000))
return off;
@@ -2281,6 +2323,8 @@ off_t find_pack_entry_one(const unsigned char *sha1,
stride = 24;
index += 4;
}
+ if (p->index_version > 2)
+ index = p->sha1_table;
if (debug_lookup)
printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
--
1.8.4.38.g317e65b
Nicolas Pitre <nico@fluxnic.net>