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* np/verify-pack: add storage size output to 'git verify-pack -v' fix unimplemented packed_object_info_detail() features make verify_one_pack() a bit less wrong wrt packed_git structure factorize revindex code out of builtin-pack-objects.c Conflicts: Makefilemaint
Junio C Hamano
17 years ago
9 changed files with 185 additions and 163 deletions
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#include "cache.h" |
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#include "pack-revindex.h" |
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/* |
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* Pack index for existing packs give us easy access to the offsets into |
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* corresponding pack file where each object's data starts, but the entries |
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* do not store the size of the compressed representation (uncompressed |
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* size is easily available by examining the pack entry header). It is |
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* also rather expensive to find the sha1 for an object given its offset. |
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* |
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* We build a hashtable of existing packs (pack_revindex), and keep reverse |
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* index here -- pack index file is sorted by object name mapping to offset; |
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* this pack_revindex[].revindex array is a list of offset/index_nr pairs |
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* ordered by offset, so if you know the offset of an object, next offset |
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* is where its packed representation ends and the index_nr can be used to |
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* get the object sha1 from the main index. |
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*/ |
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struct pack_revindex { |
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struct packed_git *p; |
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struct revindex_entry *revindex; |
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}; |
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static struct pack_revindex *pack_revindex; |
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static int pack_revindex_hashsz; |
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static int pack_revindex_ix(struct packed_git *p) |
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{ |
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unsigned long ui = (unsigned long)p; |
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int i; |
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ui = ui ^ (ui >> 16); /* defeat structure alignment */ |
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i = (int)(ui % pack_revindex_hashsz); |
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while (pack_revindex[i].p) { |
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if (pack_revindex[i].p == p) |
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return i; |
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if (++i == pack_revindex_hashsz) |
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i = 0; |
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} |
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return -1 - i; |
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} |
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void init_pack_revindex(void) |
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{ |
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int num; |
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struct packed_git *p; |
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for (num = 0, p = packed_git; p; p = p->next) |
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num++; |
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if (!num) |
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return; |
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pack_revindex_hashsz = num * 11; |
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pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz); |
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for (p = packed_git; p; p = p->next) { |
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num = pack_revindex_ix(p); |
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num = - 1 - num; |
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pack_revindex[num].p = p; |
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} |
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/* revindex elements are lazily initialized */ |
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} |
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static int cmp_offset(const void *a_, const void *b_) |
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{ |
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const struct revindex_entry *a = a_; |
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const struct revindex_entry *b = b_; |
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return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0; |
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} |
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/* |
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* Ordered list of offsets of objects in the pack. |
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*/ |
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static void create_pack_revindex(struct pack_revindex *rix) |
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{ |
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struct packed_git *p = rix->p; |
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int num_ent = p->num_objects; |
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int i; |
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const char *index = p->index_data; |
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rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1)); |
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index += 4 * 256; |
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if (p->index_version > 1) { |
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const uint32_t *off_32 = |
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(uint32_t *)(index + 8 + p->num_objects * (20 + 4)); |
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const uint32_t *off_64 = off_32 + p->num_objects; |
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for (i = 0; i < num_ent; i++) { |
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uint32_t off = ntohl(*off_32++); |
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if (!(off & 0x80000000)) { |
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rix->revindex[i].offset = off; |
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} else { |
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rix->revindex[i].offset = |
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((uint64_t)ntohl(*off_64++)) << 32; |
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rix->revindex[i].offset |= |
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ntohl(*off_64++); |
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} |
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rix->revindex[i].nr = i; |
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} |
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} else { |
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for (i = 0; i < num_ent; i++) { |
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uint32_t hl = *((uint32_t *)(index + 24 * i)); |
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rix->revindex[i].offset = ntohl(hl); |
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rix->revindex[i].nr = i; |
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} |
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} |
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/* This knows the pack format -- the 20-byte trailer |
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* follows immediately after the last object data. |
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*/ |
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rix->revindex[num_ent].offset = p->pack_size - 20; |
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rix->revindex[num_ent].nr = -1; |
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qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset); |
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} |
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struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs) |
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{ |
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int num; |
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int lo, hi; |
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struct pack_revindex *rix; |
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struct revindex_entry *revindex; |
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num = pack_revindex_ix(p); |
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if (num < 0) |
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die("internal error: pack revindex uninitialized"); |
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rix = &pack_revindex[num]; |
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if (!rix->revindex) |
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create_pack_revindex(rix); |
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revindex = rix->revindex; |
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lo = 0; |
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hi = p->num_objects + 1; |
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do { |
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int mi = (lo + hi) / 2; |
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if (revindex[mi].offset == ofs) { |
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return revindex + mi; |
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} else if (ofs < revindex[mi].offset) |
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hi = mi; |
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else |
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lo = mi + 1; |
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} while (lo < hi); |
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die("internal error: pack revindex corrupt"); |
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} |
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@ -0,0 +1,12 @@ |
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#ifndef PACK_REVINDEX_H |
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#define PACK_REVINDEX_H |
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struct revindex_entry { |
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off_t offset; |
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unsigned int nr; |
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}; |
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void init_pack_revindex(void); |
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struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs); |
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#endif |
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