Permalink
Browse files

factorize revindex code out of builtin-pack-objects.c

No functional change. This is needed to fix verify-pack in a later patch.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
  • Loading branch information...
1 parent 6d21667 commit 3449f8c4cb93a0ec445db22ee7549d0b051446d6 Nicolas Pitre committed with gitster Feb 28, 2008
Showing with 167 additions and 152 deletions.
  1. +3 −2 Makefile
  2. +10 −150 builtin-pack-objects.c
  3. +142 −0 pack-revindex.c
  4. +12 −0 pack-revindex.h
View
@@ -304,7 +304,8 @@ LIB_H = \
run-command.h strbuf.h tag.h tree.h git-compat-util.h revision.h \
tree-walk.h log-tree.h dir.h path-list.h unpack-trees.h builtin.h \
utf8.h reflog-walk.h patch-ids.h attr.h decorate.h progress.h \
- mailmap.h remote.h parse-options.h transport.h diffcore.h hash.h
+ mailmap.h remote.h parse-options.h transport.h diffcore.h hash.h \
+ pack-revindex.h
DIFF_OBJS = \
diff.o diff-lib.o diffcore-break.o diffcore-order.o \
@@ -328,7 +329,7 @@ LIB_OBJS = \
color.o wt-status.o archive-zip.o archive-tar.o shallow.o utf8.o \
convert.o attr.o decorate.o progress.o mailmap.o symlinks.o remote.o \
transport.o bundle.o walker.o parse-options.o ws.o archive.o branch.o \
- alias.o
+ alias.o pack-revindex.o
BUILTIN_OBJS = \
builtin-add.o \
View
@@ -8,6 +8,7 @@
#include "tree.h"
#include "delta.h"
#include "pack.h"
+#include "pack-revindex.h"
#include "csum-file.h"
#include "tree-walk.h"
#include "diff.h"
@@ -93,157 +94,11 @@ static int *object_ix;
static int object_ix_hashsz;
/*
- * Pack index for existing packs give us easy access to the offsets into
- * corresponding pack file where each object's data starts, but the entries
- * do not store the size of the compressed representation (uncompressed
- * 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
- * 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.
- */
-struct revindex_entry {
- off_t offset;
- unsigned int nr;
-};
-struct pack_revindex {
- struct packed_git *p;
- struct revindex_entry *revindex;
-};
-static struct pack_revindex *pack_revindex;
-static int pack_revindex_hashsz;
-
-/*
* stats
*/
static uint32_t written, written_delta;
static uint32_t reused, reused_delta;
-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 prepare_pack_ix(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(sizeof(*pack_revindex), pack_revindex_hashsz);
- 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 */
-}
-
-static int cmp_offset(const void *a_, const void *b_)
-{
- const struct revindex_entry *a = a_;
- const struct revindex_entry *b = b_;
- return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
-}
-
-/*
- * Ordered list of offsets of objects in the pack.
- */
-static void prepare_pack_revindex(struct pack_revindex *rix)
-{
- struct packed_git *p = rix->p;
- int num_ent = p->num_objects;
- int i;
- const char *index = p->index_data;
-
- rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
- index += 4 * 256;
-
- if (p->index_version > 1) {
- const uint32_t *off_32 =
- (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
- const uint32_t *off_64 = off_32 + p->num_objects;
- for (i = 0; i < num_ent; i++) {
- uint32_t off = ntohl(*off_32++);
- if (!(off & 0x80000000)) {
- rix->revindex[i].offset = off;
- } else {
- rix->revindex[i].offset =
- ((uint64_t)ntohl(*off_64++)) << 32;
- rix->revindex[i].offset |=
- ntohl(*off_64++);
- }
- rix->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;
- }
- }
-
- /* 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;
- qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
-}
-
-static struct revindex_entry * find_packed_object(struct packed_git *p,
- off_t ofs)
-{
- int num;
- int lo, hi;
- struct pack_revindex *rix;
- struct revindex_entry *revindex;
- num = pack_revindex_ix(p);
- if (num < 0)
- die("internal error: pack revindex uninitialized");
- rix = &pack_revindex[num];
- if (!rix->revindex)
- prepare_pack_revindex(rix);
- revindex = rix->revindex;
- lo = 0;
- hi = p->num_objects + 1;
- do {
- int mi = (lo + hi) / 2;
- if (revindex[mi].offset == ofs) {
- return revindex + mi;
- }
- else if (ofs < revindex[mi].offset)
- hi = mi;
- else
- lo = mi + 1;
- } while (lo < hi);
- die("internal error: pack revindex corrupt");
-}
-
-static const unsigned char *find_packed_object_name(struct packed_git *p,
- off_t ofs)
-{
- struct revindex_entry *entry = find_packed_object(p, ofs);
- return nth_packed_object_sha1(p, entry->nr);
-}
static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
{
@@ -510,7 +365,7 @@ static unsigned long write_object(struct sha1file *f,
}
hdrlen = encode_header(obj_type, entry->size, header);
offset = entry->in_pack_offset;
- revidx = find_packed_object(p, offset);
+ revidx = find_pack_revindex(p, offset);
datalen = revidx[1].offset - offset;
if (!pack_to_stdout && p->index_version > 1 &&
check_pack_crc(p, &w_curs, offset, datalen, revidx->nr))
@@ -1162,8 +1017,11 @@ static void check_object(struct object_entry *entry)
die("delta base offset out of bound for %s",
sha1_to_hex(entry->idx.sha1));
ofs = entry->in_pack_offset - ofs;
- if (!no_reuse_delta && !entry->preferred_base)
- base_ref = find_packed_object_name(p, ofs);
+ if (!no_reuse_delta && !entry->preferred_base) {
+ struct revindex_entry *revidx;
+ revidx = find_pack_revindex(p, ofs);
+ base_ref = nth_packed_object_sha1(p, revidx->nr);
+ }
entry->in_pack_header_size = used + used_0;
break;
}
@@ -1240,9 +1098,11 @@ static void get_object_details(void)
sorted_by_offset[i] = objects + i;
qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
- prepare_pack_ix();
+ init_pack_revindex();
+
for (i = 0; i < nr_objects; i++)
check_object(sorted_by_offset[i]);
+
free(sorted_by_offset);
}
View
@@ -0,0 +1,142 @@
+#include "cache.h"
+#include "pack-revindex.h"
+
+/*
+ * Pack index for existing packs give us easy access to the offsets into
+ * corresponding pack file where each object's data starts, but the entries
+ * do not store the size of the compressed representation (uncompressed
+ * 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
+ * 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.
+ */
+
+struct pack_revindex {
+ struct packed_git *p;
+ struct revindex_entry *revindex;
+};
+
+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;
+}
+
+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(sizeof(*pack_revindex), pack_revindex_hashsz);
+ 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 */
+}
+
+static int cmp_offset(const void *a_, const void *b_)
+{
+ const struct revindex_entry *a = a_;
+ const struct revindex_entry *b = b_;
+ return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
+}
+
+/*
+ * Ordered list of offsets of objects in the pack.
+ */
+static void create_pack_revindex(struct pack_revindex *rix)
+{
+ struct packed_git *p = rix->p;
+ int num_ent = p->num_objects;
+ int i;
+ const char *index = p->index_data;
+
+ rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
+ index += 4 * 256;
+
+ if (p->index_version > 1) {
+ const uint32_t *off_32 =
+ (uint32_t *)(index + 8 + p->num_objects * (20 + 4));
+ const uint32_t *off_64 = off_32 + p->num_objects;
+ for (i = 0; i < num_ent; i++) {
+ uint32_t off = ntohl(*off_32++);
+ if (!(off & 0x80000000)) {
+ rix->revindex[i].offset = off;
+ } else {
+ rix->revindex[i].offset =
+ ((uint64_t)ntohl(*off_64++)) << 32;
+ rix->revindex[i].offset |=
+ ntohl(*off_64++);
+ }
+ rix->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;
+ }
+ }
+
+ /* 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;
+ qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
+}
+
+struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs)
+{
+ int num;
+ int lo, hi;
+ struct pack_revindex *rix;
+ struct revindex_entry *revindex;
+
+ num = pack_revindex_ix(p);
+ if (num < 0)
+ die("internal error: pack revindex uninitialized");
+
+ rix = &pack_revindex[num];
+ if (!rix->revindex)
+ create_pack_revindex(rix);
+ revindex = rix->revindex;
+
+ lo = 0;
+ hi = p->num_objects + 1;
+ do {
+ int mi = (lo + hi) / 2;
+ if (revindex[mi].offset == ofs) {
+ return revindex + mi;
+ } else if (ofs < revindex[mi].offset)
+ hi = mi;
+ else
+ lo = mi + 1;
+ } while (lo < hi);
+ die("internal error: pack revindex corrupt");
+}
View
@@ -0,0 +1,12 @@
+#ifndef PACK_REVINDEX_H
+#define PACK_REVINDEX_H
+
+struct revindex_entry {
+ off_t offset;
+ unsigned int nr;
+};
+
+void init_pack_revindex(void);
+struct revindex_entry *find_pack_revindex(struct packed_git *p, off_t ofs);
+
+#endif

0 comments on commit 3449f8c

Please sign in to comment.