Merge branch 'jk/pack-revindex'

In-core storage of the reverse index for .pack files (which lets
you go from a pack offset to an object name) has been streamlined.

* jk/pack-revindex:
pack-revindex: store entries directly in packed_git
pack-revindex: drop hash table

diff --git a/cache.h b/cache.h
index c63fcc113a6e511a53f0170a07bd5dbbf12cc120..bf00ce55f8094e36d414722035a1201789fe79ac 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -9,6 +9,7 @@
 #include "convert.h"
 #include "trace.h"
 #include "string-list.h"
+#include "pack-revindex.h"
 
 #include SHA1_HEADER
 #ifndef platform_SHA_CTX
@@ -1299,6 +1300,7 @@ extern struct packed_git {
                 freshened:1,
                 do_not_close:1;
        unsigned char sha1[20];
+       struct revindex_entry *revindex;
        /* something like ".git/objects/pack/xxxxx.pack" */
        char pack_name[FLEX_ARRAY]; /* more */
 } *packed_git;

diff --git a/pack-bitmap.c b/pack-bitmap.c
index cb9c62280389cfdb3bcaf483ac4edf2f0a00969f..dd8dc16e676fb3e928560002c0cb7e1f36910e1a 100644 (file)
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -33,9 +33,6 @@ static struct bitmap_index {
        /* Packfile to which this bitmap index belongs to */
        struct packed_git *pack;
 
-       /* reverse index for the packfile */
-       struct pack_revindex *reverse_index;
-
        /*
         * Mark the first `reuse_objects` in the packfile as reused:
         * they will be sent as-is without using them for repacking
@@ -308,7 +305,7 @@ static int load_pack_bitmap(void)
 
        bitmap_git.bitmaps = kh_init_sha1();
        bitmap_git.ext_index.positions = kh_init_sha1_pos();
-       bitmap_git.reverse_index = revindex_for_pack(bitmap_git.pack);
+       load_pack_revindex(bitmap_git.pack);
 
        if (!(bitmap_git.commits = read_bitmap_1(&bitmap_git)) ||
                !(bitmap_git.trees = read_bitmap_1(&bitmap_git)) ||
@@ -380,7 +377,7 @@ static inline int bitmap_position_packfile(const unsigned char *sha1)
        if (!offset)
                return -1;
 
-       return find_revindex_position(bitmap_git.reverse_index, offset);
+       return find_revindex_position(bitmap_git.pack, offset);
 }
 
 static int bitmap_position(const unsigned char *sha1)
@@ -630,7 +627,7 @@ static void show_objects_for_type(
                        if (pos + offset < bitmap_git.reuse_objects)
                                continue;
 
-                       entry = &bitmap_git.reverse_index->revindex[pos + offset];
+                       entry = &bitmap_git.pack->revindex[pos + offset];
                        sha1 = nth_packed_object_sha1(bitmap_git.pack, entry->nr);
 
                        if (bitmap_git.hashes)
@@ -804,7 +801,7 @@ int reuse_partial_packfile_from_bitmap(struct packed_git **packfile,
                return -1;
 
        bitmap_git.reuse_objects = *entries = reuse_objects;
-       *up_to = bitmap_git.reverse_index->revindex[reuse_objects].offset;
+       *up_to = bitmap_git.pack->revindex[reuse_objects].offset;
        *packfile = bitmap_git.pack;
 
        return 0;
@@ -1038,7 +1035,7 @@ int rebuild_existing_bitmaps(struct packing_data *mapping,
                struct revindex_entry *entry;
                struct object_entry *oe;
 
-               entry = &bitmap_git.reverse_index->revindex[i];
+               entry = &bitmap_git.pack->revindex[i];
                sha1 = nth_packed_object_sha1(bitmap_git.pack, entry->nr);
                oe = packlist_find(mapping, sha1, NULL);
 

diff --git a/pack-revindex.c b/pack-revindex.c
index e542ea7703a740916f8d2cac9176674782d37f61..155a8a3d69bf7d1c4c72aaa36ad483dae33ca9b5 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.
  *
@@ -154,14 +115,13 @@ 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));
+       p->revindex = xmalloc(sizeof(*p->revindex) * (num_ent + 1));
        index += 4 * 256;
 
        if (p->index_version > 1) {
@@ -171,55 +131,42 @@ 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 +184,13 @@ 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;
 }

diff --git a/pack-revindex.h b/pack-revindex.h
index d737f989659da7f58d7df153de9a2ac30b162108..e262f3efe84962e774c1784129de4c17de3936c8 100644 (file)
--- a/pack-revindex.h
+++ b/pack-revindex.h
@@ -1,18 +1,15 @@
 #ifndef PACK_REVINDEX_H
 #define PACK_REVINDEX_H
 
+struct packed_git;
+
 struct revindex_entry {
        off_t offset;
        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);
+void load_pack_revindex(struct packed_git *p);
+int find_revindex_position(struct packed_git *p, off_t ofs);
 
 struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs);