diff options
| -rw-r--r-- | Documentation/technical/pack-format.txt | 19 | ||||
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | builtin/repack.c | 1 | ||||
| -rw-r--r-- | object-store.h | 10 | ||||
| -rw-r--r-- | pack-mtimes.c | 129 | ||||
| -rw-r--r-- | pack-mtimes.h | 26 | ||||
| -rw-r--r-- | packfile.c | 19 |
7 files changed, 202 insertions, 3 deletions
diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt index 6d3efb7d16..b520aa9c45 100644 --- a/Documentation/technical/pack-format.txt +++ b/Documentation/technical/pack-format.txt @@ -294,6 +294,25 @@ Pack file entry: <+ All 4-byte numbers are in network order. +== pack-*.mtimes files have the format: + +All 4-byte numbers are in network byte order. + + - A 4-byte magic number '0x4d544d45' ('MTME'). + + - A 4-byte version identifier (= 1). + + - A 4-byte hash function identifier (= 1 for SHA-1, 2 for SHA-256). + + - A table of 4-byte unsigned integers. The ith value is the + modification time (mtime) of the ith object in the corresponding + pack by lexicographic (index) order. The mtimes count standard + epoch seconds. + + - A trailer, containing a checksum of the corresponding packfile, + and a checksum of all of the above (each having length according + to the specified hash function). + == multi-pack-index (MIDX) files have the following format: The multi-pack-index files refer to multiple pack-files and loose objects. @@ -993,6 +993,7 @@ LIB_OBJS += oidtree.o LIB_OBJS += pack-bitmap-write.o LIB_OBJS += pack-bitmap.o LIB_OBJS += pack-check.o +LIB_OBJS += pack-mtimes.o LIB_OBJS += pack-objects.o LIB_OBJS += pack-revindex.o LIB_OBJS += pack-write.o diff --git a/builtin/repack.c b/builtin/repack.c index d1a563d5b6..e7a3920c6d 100644 --- a/builtin/repack.c +++ b/builtin/repack.c @@ -217,6 +217,7 @@ static struct { } exts[] = { {".pack"}, {".rev", 1}, + {".mtimes", 1}, {".bitmap", 1}, {".promisor", 1}, {".idx"}, diff --git a/object-store.h b/object-store.h index bd2322ed8c..3c98028ce6 100644 --- a/object-store.h +++ b/object-store.h @@ -115,12 +115,20 @@ struct packed_git { freshened:1, do_not_close:1, pack_promisor:1, - multi_pack_index:1; + multi_pack_index:1, + is_cruft:1; unsigned char hash[GIT_MAX_RAWSZ]; struct revindex_entry *revindex; const uint32_t *revindex_data; const uint32_t *revindex_map; size_t revindex_size; + /* + * mtimes_map points at the beginning of the memory mapped region of + * this pack's corresponding .mtimes file, and mtimes_size is the size + * of that .mtimes file + */ + const uint32_t *mtimes_map; + size_t mtimes_size; /* something like ".git/objects/pack/xxxxx.pack" */ char pack_name[FLEX_ARRAY]; /* more */ }; diff --git a/pack-mtimes.c b/pack-mtimes.c new file mode 100644 index 0000000000..0e0aafdcb0 --- /dev/null +++ b/pack-mtimes.c @@ -0,0 +1,129 @@ +#include "git-compat-util.h" +#include "pack-mtimes.h" +#include "object-store.h" +#include "packfile.h" + +static char *pack_mtimes_filename(struct packed_git *p) +{ + size_t len; + if (!strip_suffix(p->pack_name, ".pack", &len)) + BUG("pack_name does not end in .pack"); + return xstrfmt("%.*s.mtimes", (int)len, p->pack_name); +} + +#define MTIMES_HEADER_SIZE (12) + +struct mtimes_header { + uint32_t signature; + uint32_t version; + uint32_t hash_id; +}; + +static int load_pack_mtimes_file(char *mtimes_file, + uint32_t num_objects, + const uint32_t **data_p, size_t *len_p) +{ + int fd, ret = 0; + struct stat st; + uint32_t *data = NULL; + size_t mtimes_size, expected_size; + struct mtimes_header header; + + fd = git_open(mtimes_file); + + if (fd < 0) { + ret = -1; + goto cleanup; + } + if (fstat(fd, &st)) { + ret = error_errno(_("failed to read %s"), mtimes_file); + goto cleanup; + } + + mtimes_size = xsize_t(st.st_size); + + if (mtimes_size < MTIMES_HEADER_SIZE) { + ret = error(_("mtimes file %s is too small"), mtimes_file); + goto cleanup; + } + + data = xmmap(NULL, mtimes_size, PROT_READ, MAP_PRIVATE, fd, 0); + + header.signature = ntohl(data[0]); + header.version = ntohl(data[1]); + header.hash_id = ntohl(data[2]); + + if (header.signature != MTIMES_SIGNATURE) { + ret = error(_("mtimes file %s has unknown signature"), mtimes_file); + goto cleanup; + } + + if (header.version != 1) { + ret = error(_("mtimes file %s has unsupported version %"PRIu32), + mtimes_file, header.version); + goto cleanup; + } + + if (!(header.hash_id == 1 || header.hash_id == 2)) { + ret = error(_("mtimes file %s has unsupported hash id %"PRIu32), + mtimes_file, header.hash_id); + goto cleanup; + } + + + expected_size = MTIMES_HEADER_SIZE; + expected_size = st_add(expected_size, st_mult(sizeof(uint32_t), num_objects)); + expected_size = st_add(expected_size, 2 * (header.hash_id == 1 ? GIT_SHA1_RAWSZ : GIT_SHA256_RAWSZ)); + + if (mtimes_size != expected_size) { + ret = error(_("mtimes file %s is corrupt"), mtimes_file); + goto cleanup; + } + +cleanup: + if (ret) { + if (data) + munmap(data, mtimes_size); + } else { + *len_p = mtimes_size; + *data_p = data; + } + + close(fd); + return ret; +} + +int load_pack_mtimes(struct packed_git *p) +{ + char *mtimes_name = NULL; + int ret = 0; + + if (!p->is_cruft) + return ret; /* not a cruft pack */ + if (p->mtimes_map) + return ret; /* already loaded */ + + ret = open_pack_index(p); + if (ret < 0) + goto cleanup; + + mtimes_name = pack_mtimes_filename(p); + ret = load_pack_mtimes_file(mtimes_name, + p->num_objects, + &p->mtimes_map, + &p->mtimes_size); +cleanup: + free(mtimes_name); + return ret; +} + +uint32_t nth_packed_mtime(struct packed_git *p, uint32_t pos) +{ + if (!p->mtimes_map) + BUG("pack .mtimes file not loaded for %s", p->pack_name); + if (p->num_objects <= pos) + BUG("pack .mtimes out-of-bounds (%"PRIu32" vs %"PRIu32")", + pos, p->num_objects); + + return get_be32(p->mtimes_map + pos + 3); +} diff --git a/pack-mtimes.h b/pack-mtimes.h new file mode 100644 index 0000000000..cc957b3e85 --- /dev/null +++ b/pack-mtimes.h @@ -0,0 +1,26 @@ +#ifndef PACK_MTIMES_H +#define PACK_MTIMES_H + +#include "git-compat-util.h" + +#define MTIMES_SIGNATURE 0x4d544d45 /* "MTME" */ +#define MTIMES_VERSION 1 + +struct packed_git; + +/* + * Loads the .mtimes file corresponding to "p", if any, returning zero + * on success. + */ +int load_pack_mtimes(struct packed_git *p); + +/* Returns the mtime associated with the object at position "pos" (in + * lexicographic/index order) in pack "p". + * + * Note that it is a BUG() to call this function if either (a) "p" does + * not have a corresponding .mtimes file, or (b) it does, but it hasn't + * been loaded + */ +uint32_t nth_packed_mtime(struct packed_git *p, uint32_t pos); + +#endif diff --git a/packfile.c b/packfile.c index 835b2d2716..fc0245fbab 100644 --- a/packfile.c +++ b/packfile.c @@ -334,12 +334,22 @@ static void close_pack_revindex(struct packed_git *p) p->revindex_data = NULL; } +static void close_pack_mtimes(struct packed_git *p) +{ + if (!p->mtimes_map) + return; + + munmap((void *)p->mtimes_map, p->mtimes_size); + p->mtimes_map = NULL; +} + void close_pack(struct packed_git *p) { close_pack_windows(p); close_pack_fd(p); close_pack_index(p); close_pack_revindex(p); + close_pack_mtimes(p); oidset_clear(&p->bad_objects); } @@ -363,7 +373,7 @@ void close_object_store(struct raw_object_store *o) void unlink_pack_path(const char *pack_name, int force_delete) { - static const char *exts[] = {".pack", ".idx", ".rev", ".keep", ".bitmap", ".promisor"}; + static const char *exts[] = {".pack", ".idx", ".rev", ".keep", ".bitmap", ".promisor", ".mtimes"}; int i; struct strbuf buf = STRBUF_INIT; size_t plen; @@ -718,6 +728,10 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local) if (!access(p->pack_name, F_OK)) p->pack_promisor = 1; + xsnprintf(p->pack_name + path_len, alloc - path_len, ".mtimes"); + if (!access(p->pack_name, F_OK)) + p->is_cruft = 1; + xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack"); if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) { free(p); @@ -869,7 +883,8 @@ static void prepare_pack(const char *full_name, size_t full_name_len, ends_with(file_name, ".pack") || ends_with(file_name, ".bitmap") || ends_with(file_name, ".keep") || - ends_with(file_name, ".promisor")) + ends_with(file_name, ".promisor") || + ends_with(file_name, ".mtimes")) string_list_append(data->garbage, full_name); else report_garbage(PACKDIR_FILE_GARBAGE, full_name); |