diff options
Diffstat (limited to 'pack-revindex.c')
-rw-r--r-- | pack-revindex.c | 116 |
1 files changed, 33 insertions, 83 deletions
diff --git a/pack-revindex.c b/pack-revindex.c index 5c8376e978..1b7ebd8d7e 100644 --- a/pack-revindex.c +++ b/pack-revindex.c @@ -8,52 +8,13 @@ * size is easily available by examining the pack entry header). It is * also rather expensive to find the sha1 for an object given its offset. * - * We build a hashtable of existing packs (pack_revindex), and keep reverse - * index here -- pack index file is sorted by object name mapping to offset; - * this pack_revindex[].revindex array is a list of offset/index_nr pairs + * The pack index file is sorted by object name mapping to offset; + * this revindex array is a list of offset/index_nr pairs * ordered by offset, so if you know the offset of an object, next offset * is where its packed representation ends and the index_nr can be used to * get the object sha1 from the main index. */ -static struct pack_revindex *pack_revindex; -static int pack_revindex_hashsz; - -static int pack_revindex_ix(struct packed_git *p) -{ - unsigned long ui = (unsigned long)p; - int i; - - ui = ui ^ (ui >> 16); /* defeat structure alignment */ - i = (int)(ui % pack_revindex_hashsz); - while (pack_revindex[i].p) { - if (pack_revindex[i].p == p) - return i; - if (++i == pack_revindex_hashsz) - i = 0; - } - return -1 - i; -} - -static void init_pack_revindex(void) -{ - int num; - struct packed_git *p; - - for (num = 0, p = packed_git; p; p = p->next) - num++; - if (!num) - return; - pack_revindex_hashsz = num * 11; - pack_revindex = xcalloc(pack_revindex_hashsz, sizeof(*pack_revindex)); - for (p = packed_git; p; p = p->next) { - num = pack_revindex_ix(p); - num = - 1 - num; - pack_revindex[num].p = p; - } - /* revindex elements are lazily initialized */ -} - /* * This is a least-significant-digit radix sort. * @@ -83,10 +44,14 @@ static void sort_revindex(struct revindex_entry *entries, unsigned n, off_t max) * keep track of them with alias pointers, always sorting from "from" * to "to". */ - struct revindex_entry *tmp = xmalloc(n * sizeof(*tmp)); - struct revindex_entry *from = entries, *to = tmp; + struct revindex_entry *tmp, *from, *to; int bits; - unsigned *pos = xmalloc(BUCKETS * sizeof(*pos)); + unsigned *pos; + + ALLOC_ARRAY(pos, BUCKETS); + ALLOC_ARRAY(tmp, n); + from = entries; + to = tmp; /* * If (max >> bits) is zero, then we know that the radix digit we are @@ -94,7 +59,6 @@ static void sort_revindex(struct revindex_entry *entries, unsigned n, off_t max) * be a no-op, as everybody lands in the same zero-th bucket. */ for (bits = 0; max >> bits; bits += DIGIT_SIZE) { - struct revindex_entry *swap; unsigned i; memset(pos, 0, BUCKETS * sizeof(*pos)); @@ -132,9 +96,7 @@ static void sort_revindex(struct revindex_entry *entries, unsigned n, off_t max) * Now "to" contains the most sorted list, so we swap "from" and * "to" for the next iteration. */ - swap = from; - from = to; - to = swap; + SWAP(from, to); } /* @@ -142,7 +104,7 @@ static void sort_revindex(struct revindex_entry *entries, unsigned n, off_t max) * we have to move it back from the temporary storage. */ if (from != entries) - memcpy(entries, tmp, n * sizeof(*entries)); + COPY_ARRAY(entries, tmp, n); free(tmp); free(pos); @@ -154,14 +116,13 @@ static void sort_revindex(struct revindex_entry *entries, unsigned n, off_t max) /* * Ordered list of offsets of objects in the pack. */ -static void create_pack_revindex(struct pack_revindex *rix) +static void create_pack_revindex(struct packed_git *p) { - struct packed_git *p = rix->p; unsigned num_ent = p->num_objects; unsigned i; const char *index = p->index_data; - rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1)); + ALLOC_ARRAY(p->revindex, num_ent + 1); index += 4 * 256; if (p->index_version > 1) { @@ -171,55 +132,42 @@ static void create_pack_revindex(struct pack_revindex *rix) for (i = 0; i < num_ent; i++) { uint32_t off = ntohl(*off_32++); if (!(off & 0x80000000)) { - rix->revindex[i].offset = off; + p->revindex[i].offset = off; } else { - rix->revindex[i].offset = + p->revindex[i].offset = ((uint64_t)ntohl(*off_64++)) << 32; - rix->revindex[i].offset |= + p->revindex[i].offset |= ntohl(*off_64++); } - rix->revindex[i].nr = i; + p->revindex[i].nr = i; } } else { for (i = 0; i < num_ent; i++) { uint32_t hl = *((uint32_t *)(index + 24 * i)); - rix->revindex[i].offset = ntohl(hl); - rix->revindex[i].nr = i; + p->revindex[i].offset = ntohl(hl); + p->revindex[i].nr = i; } } /* This knows the pack format -- the 20-byte trailer * follows immediately after the last object data. */ - rix->revindex[num_ent].offset = p->pack_size - 20; - rix->revindex[num_ent].nr = -1; - sort_revindex(rix->revindex, num_ent, p->pack_size); + p->revindex[num_ent].offset = p->pack_size - 20; + p->revindex[num_ent].nr = -1; + sort_revindex(p->revindex, num_ent, p->pack_size); } -struct pack_revindex *revindex_for_pack(struct packed_git *p) +void load_pack_revindex(struct packed_git *p) { - int num; - struct pack_revindex *rix; - - if (!pack_revindex_hashsz) - init_pack_revindex(); - - num = pack_revindex_ix(p); - if (num < 0) - die("internal error: pack revindex fubar"); - - rix = &pack_revindex[num]; - if (!rix->revindex) - create_pack_revindex(rix); - - return rix; + if (!p->revindex) + create_pack_revindex(p); } -int find_revindex_position(struct pack_revindex *pridx, off_t ofs) +int find_revindex_position(struct packed_git *p, off_t ofs) { int lo = 0; - int hi = pridx->p->num_objects + 1; - struct revindex_entry *revindex = pridx->revindex; + int hi = p->num_objects + 1; + struct revindex_entry *revindex = p->revindex; do { unsigned mi = lo + (hi - lo) / 2; @@ -237,11 +185,13 @@ int find_revindex_position(struct pack_revindex *pridx, off_t ofs) struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs) { - struct pack_revindex *pridx = revindex_for_pack(p); - int pos = find_revindex_position(pridx, ofs); + int pos; + + load_pack_revindex(p); + pos = find_revindex_position(p, ofs); if (pos < 0) return NULL; - return pridx->revindex + pos; + return p->revindex + pos; } |