revindex: export new APIs

Allow users to efficiently lookup consecutive entries that are expected
to be found on the same revindex by exporting `find_revindex_position`:
this function takes a pointer to revindex itself, instead of looking up
the proper revindex for a given packfile on each call.

Signed-off-by: Vicent Marti <tanoku@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/pack-revindex.c b/pack-revindex.c
index b4d2b35bb37120f97ec000524d12a85d91949119..0bb13b1ba62ed4bc091c9a2a22266839dba05d7d 100644 (file)
--- a/pack-revindex.c
+++ b/pack-revindex.c
@@ -16,11 +16,6 @@
  * get the object sha1 from the main index.
  */
 
-struct pack_revindex {
-       struct packed_git *p;
-       struct revindex_entry *revindex;
-};
-
 static struct pack_revindex *pack_revindex;
 static int pack_revindex_hashsz;
 
@@ -201,15 +196,14 @@ static void create_pack_revindex(struct pack_revindex *rix)
        sort_revindex(rix->revindex, num_ent, p->pack_size);
 }
 
-struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs)
+struct pack_revindex *revindex_for_pack(struct packed_git *p)
 {
        int num;
-       unsigned lo, hi;
        struct pack_revindex *rix;
-       struct revindex_entry *revindex;
 
        if (!pack_revindex_hashsz)
                init_pack_revindex();
+
        num = pack_revindex_ix(p);
        if (num < 0)
                die("internal error: pack revindex fubar");
@@ -217,21 +211,39 @@ struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs)
        rix = &pack_revindex[num];
        if (!rix->revindex)
                create_pack_revindex(rix);
-       revindex = rix->revindex;
 
-       lo = 0;
-       hi = p->num_objects + 1;
+       return rix;
+}
+
+int find_revindex_position(struct pack_revindex *pridx, off_t ofs)
+{
+       int lo = 0;
+       int hi = pridx->p->num_objects + 1;
+       struct revindex_entry *revindex = pridx->revindex;
+
        do {
                unsigned mi = lo + (hi - lo) / 2;
                if (revindex[mi].offset == ofs) {
-                       return revindex + mi;
+                       return mi;
                } else if (ofs < revindex[mi].offset)
                        hi = mi;
                else
                        lo = mi + 1;
        } while (lo < hi);
+
        error("bad offset for revindex");
-       return NULL;
+       return -1;
+}
+
+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);
+
+       if (pos < 0)
+               return NULL;
+
+       return pridx->revindex + pos;
 }
 
 void discard_revindex(void)

diff --git a/pack-revindex.h b/pack-revindex.h
index 8d5027ad917224f689e786e9a0b4e9a387e59dfe..866ca9c57137b0c4143157bc97f4aa21aac87887 100644 (file)
--- a/pack-revindex.h
+++ b/pack-revindex.h
@@ -6,6 +6,14 @@ struct revindex_entry {
        unsigned int nr;
 };
 
+struct pack_revindex {
+       struct packed_git *p;
+       struct revindex_entry *revindex;
+};
+
+struct pack_revindex *revindex_for_pack(struct packed_git *p);
+int find_revindex_position(struct pack_revindex *pridx, off_t ofs);
+
 struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs);
 void discard_revindex(void);