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authorNicolas Pitre <nico@cam.org>2006-09-21 04:07:39 (GMT)
committerJunio C Hamano <junkio@cox.net>2006-09-27 07:12:00 (GMT)
commit209c554ab45701fb78de77fdcec803fef2c8fd39 (patch)
tree1e9684843379083b9fb7df827539d3e71132539d /builtin-unpack-objects.c
parenteb32d236df0c16b936b04f0c5402addb61cdb311 (diff)
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teach git-unpack-objects about deltas with offset to base
For delta resolution to be possible, a list of sha1/offset tuple must be constructed in memory in order to load the appropriate base object. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
Diffstat (limited to 'builtin-unpack-objects.c')
-rw-r--r--builtin-unpack-objects.c138
1 files changed, 106 insertions, 32 deletions
diff --git a/builtin-unpack-objects.c b/builtin-unpack-objects.c
index c6c6368..e70a711 100644
--- a/builtin-unpack-objects.c
+++ b/builtin-unpack-objects.c
@@ -15,7 +15,7 @@ static const char unpack_usage[] = "git-unpack-objects [-n] [-q] [-r] < pack-fil
/* We always read in 4kB chunks. */
static unsigned char buffer[4096];
-static unsigned long offset, len;
+static unsigned long offset, len, consumed_bytes;
static SHA_CTX ctx;
/*
@@ -51,6 +51,7 @@ static void use(int bytes)
die("used more bytes than were available");
len -= bytes;
offset += bytes;
+ consumed_bytes += bytes;
}
static void *get_data(unsigned long size)
@@ -89,35 +90,49 @@ static void *get_data(unsigned long size)
struct delta_info {
unsigned char base_sha1[20];
+ unsigned long base_offset;
unsigned long size;
void *delta;
+ unsigned nr;
struct delta_info *next;
};
static struct delta_info *delta_list;
-static void add_delta_to_list(unsigned char *base_sha1, void *delta, unsigned long size)
+static void add_delta_to_list(unsigned nr, unsigned const char *base_sha1,
+ unsigned long base_offset,
+ void *delta, unsigned long size)
{
struct delta_info *info = xmalloc(sizeof(*info));
hashcpy(info->base_sha1, base_sha1);
+ info->base_offset = base_offset;
info->size = size;
info->delta = delta;
+ info->nr = nr;
info->next = delta_list;
delta_list = info;
}
-static void added_object(unsigned char *sha1, const char *type, void *data, unsigned long size);
+struct obj_info {
+ unsigned long offset;
+ unsigned char sha1[20];
+};
+
+static struct obj_info *obj_list;
-static void write_object(void *buf, unsigned long size, const char *type)
+static void added_object(unsigned nr, const char *type, void *data,
+ unsigned long size);
+
+static void write_object(unsigned nr, void *buf, unsigned long size,
+ const char *type)
{
- unsigned char sha1[20];
- if (write_sha1_file(buf, size, type, sha1) < 0)
+ if (write_sha1_file(buf, size, type, obj_list[nr].sha1) < 0)
die("failed to write object");
- added_object(sha1, type, buf, size);
+ added_object(nr, type, buf, size);
}
-static void resolve_delta(const char *type,
+static void resolve_delta(unsigned nr, const char *type,
void *base, unsigned long base_size,
void *delta, unsigned long delta_size)
{
@@ -130,20 +145,23 @@ static void resolve_delta(const char *type,
if (!result)
die("failed to apply delta");
free(delta);
- write_object(result, result_size, type);
+ write_object(nr, result, result_size, type);
free(result);
}
-static void added_object(unsigned char *sha1, const char *type, void *data, unsigned long size)
+static void added_object(unsigned nr, const char *type, void *data,
+ unsigned long size)
{
struct delta_info **p = &delta_list;
struct delta_info *info;
while ((info = *p) != NULL) {
- if (!hashcmp(info->base_sha1, sha1)) {
+ if (!hashcmp(info->base_sha1, obj_list[nr].sha1) ||
+ info->base_offset == obj_list[nr].offset) {
*p = info->next;
p = &delta_list;
- resolve_delta(type, data, size, info->delta, info->size);
+ resolve_delta(info->nr, type, data, size,
+ info->delta, info->size);
free(info);
continue;
}
@@ -151,7 +169,8 @@ static void added_object(unsigned char *sha1, const char *type, void *data, unsi
}
}
-static void unpack_non_delta_entry(enum object_type kind, unsigned long size)
+static void unpack_non_delta_entry(enum object_type kind, unsigned long size,
+ unsigned nr)
{
void *buf = get_data(size);
const char *type;
@@ -164,30 +183,80 @@ static void unpack_non_delta_entry(enum object_type kind, unsigned long size)
default: die("bad type %d", kind);
}
if (!dry_run && buf)
- write_object(buf, size, type);
+ write_object(nr, buf, size, type);
free(buf);
}
-static void unpack_delta_entry(unsigned long delta_size)
+static void unpack_delta_entry(enum object_type kind, unsigned long delta_size,
+ unsigned nr)
{
void *delta_data, *base;
unsigned long base_size;
char type[20];
unsigned char base_sha1[20];
- hashcpy(base_sha1, fill(20));
- use(20);
+ if (kind == OBJ_REF_DELTA) {
+ hashcpy(base_sha1, fill(20));
+ use(20);
+ delta_data = get_data(delta_size);
+ if (dry_run || !delta_data) {
+ free(delta_data);
+ return;
+ }
+ if (!has_sha1_file(base_sha1)) {
+ hashcpy(obj_list[nr].sha1, null_sha1);
+ add_delta_to_list(nr, base_sha1, 0, delta_data, delta_size);
+ return;
+ }
+ } else {
+ unsigned base_found = 0;
+ unsigned char *pack, c;
+ unsigned long base_offset;
+ unsigned lo, mid, hi;
- delta_data = get_data(delta_size);
- if (dry_run || !delta_data) {
- free(delta_data);
- return;
- }
+ pack = fill(1);
+ c = *pack;
+ use(1);
+ base_offset = c & 127;
+ while (c & 128) {
+ base_offset += 1;
+ if (!base_offset || base_offset & ~(~0UL >> 7))
+ die("offset value overflow for delta base object");
+ pack = fill(1);
+ c = *pack;
+ use(1);
+ base_offset = (base_offset << 7) + (c & 127);
+ }
+ base_offset = obj_list[nr].offset - base_offset;
- if (!has_sha1_file(base_sha1)) {
- add_delta_to_list(base_sha1, delta_data, delta_size);
- return;
+ delta_data = get_data(delta_size);
+ if (dry_run || !delta_data) {
+ free(delta_data);
+ return;
+ }
+ lo = 0;
+ hi = nr;
+ while (lo < hi) {
+ mid = (lo + hi)/2;
+ if (base_offset < obj_list[mid].offset) {
+ hi = mid;
+ } else if (base_offset > obj_list[mid].offset) {
+ lo = mid + 1;
+ } else {
+ hashcpy(base_sha1, obj_list[mid].sha1);
+ base_found = !is_null_sha1(base_sha1);
+ break;
+ }
+ }
+ if (!base_found) {
+ /* The delta base object is itself a delta that
+ has not been resolved yet. */
+ hashcpy(obj_list[nr].sha1, null_sha1);
+ add_delta_to_list(nr, null_sha1, base_offset, delta_data, delta_size);
+ return;
+ }
}
+
base = read_sha1_file(base_sha1, type, &base_size);
if (!base) {
error("failed to read delta-pack base object %s",
@@ -197,7 +266,7 @@ static void unpack_delta_entry(unsigned long delta_size)
has_errors = 1;
return;
}
- resolve_delta(type, base, base_size, delta_data, delta_size);
+ resolve_delta(nr, type, base, base_size, delta_data, delta_size);
free(base);
}
@@ -208,6 +277,8 @@ static void unpack_one(unsigned nr, unsigned total)
unsigned long size;
enum object_type type;
+ obj_list[nr].offset = consumed_bytes;
+
pack = fill(1);
c = *pack;
use(1);
@@ -216,7 +287,7 @@ static void unpack_one(unsigned nr, unsigned total)
shift = 4;
while (c & 0x80) {
pack = fill(1);
- c = *pack++;
+ c = *pack;
use(1);
size += (c & 0x7f) << shift;
shift += 7;
@@ -225,13 +296,14 @@ static void unpack_one(unsigned nr, unsigned total)
static unsigned long last_sec;
static unsigned last_percent;
struct timeval now;
- unsigned percentage = (nr * 100) / total;
+ unsigned percentage = ((nr+1) * 100) / total;
gettimeofday(&now, NULL);
if (percentage != last_percent || now.tv_sec != last_sec) {
last_sec = now.tv_sec;
last_percent = percentage;
- fprintf(stderr, "%4u%% (%u/%u) done\r", percentage, nr, total);
+ fprintf(stderr, "%4u%% (%u/%u) done\r",
+ percentage, (nr+1), total);
}
}
switch (type) {
@@ -239,10 +311,11 @@ static void unpack_one(unsigned nr, unsigned total)
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
- unpack_non_delta_entry(type, size);
+ unpack_non_delta_entry(type, size, nr);
return;
case OBJ_REF_DELTA:
- unpack_delta_entry(size);
+ case OBJ_OFS_DELTA:
+ unpack_delta_entry(type, size, nr);
return;
default:
error("bad object type %d", type);
@@ -265,9 +338,10 @@ static void unpack_all(void)
die("unknown pack file version %d", ntohl(hdr->hdr_version));
fprintf(stderr, "Unpacking %d objects\n", nr_objects);
+ obj_list = xmalloc(nr_objects * sizeof(*obj_list));
use(sizeof(struct pack_header));
for (i = 0; i < nr_objects; i++)
- unpack_one(i+1, nr_objects);
+ unpack_one(i, nr_objects);
if (delta_list)
die("unresolved deltas left after unpacking");
}