git-svn: allow --version to work anywhere

[thirdparty/git.git] / pack-revindex.c

diff --git a/pack-revindex.c b/pack-revindex.c
index f6a3613bebe4ae8d398ab3b0ada22ba81b1339ee..96d51c3467b9ef864f62962aa3567247338d2c3a 100644 (file)
--- 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)(intptr_t)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.
  *
@@ -158,14 +119,13 @@ 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;
 
-       ALLOC_ARRAY(rix->revindex, num_ent + 1);
+       ALLOC_ARRAY(p->revindex, num_ent + 1);
        index += 4 * 256;
 
        if (p->index_version > 1) {
@@ -175,55 +135,42 @@ 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;
@@ -241,11 +188,13 @@ 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;
 }