Show changes to 3 files +72 −4
builtin/pack-objects.c, csum-file.c, csum-file.h
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 4dae5b1..417c830 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -75,6 +75,9 @@ static unsigned long cache_max_small_delta_size = 1000;
static unsigned long window_memory_limit = 0;
+static struct object_id skip_hash;
+static int skip_opt = -1;
+
/*
* stats
*/
@@ -781,6 +784,11 @@ static void write_pack_file(void)
else
f = create_tmp_packfile(&pack_tmp_name);
+ if (skip_opt > 0) {
+ f->skip = skip_opt;
+ hashcpy(f->skip_hash, skip_hash.hash);
+ }
+
offset = write_pack_header(f, nr_remaining);
if (reuse_packfile) {
@@ -2597,6 +2605,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
struct argv_array rp = ARGV_ARRAY_INIT;
int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
int rev_list_index = 0;
+ const char *skip_hash_hex = NULL;
struct option pack_objects_options[] = {
OPT_SET_INT('q', "quiet", &progress,
N_("do not show progress meter"), 0),
@@ -2669,6 +2678,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
N_("use a bitmap index if available to speed up counting objects")),
OPT_BOOL(0, "write-bitmap-index", &write_bitmap_index,
N_("write a bitmap index together with the pack index")),
+ OPT_STRING(0, "skip-hash", &skip_hash_hex, "hash",
+ N_("hash of the skipped part of the pack")),
+ OPT_INTEGER(0, "skip", &skip_opt,
+ N_("do not produce the first <n> bytes of the pack")),
OPT_END(),
};
@@ -2689,6 +2702,14 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
}
if (pack_to_stdout != !base_name || argc)
usage_with_options(pack_usage, pack_objects_options);
+ if (skip_opt >= 0) {
+ if (skip_opt > 0) {
+ if (!skip_hash_hex)
+ die(_("--skip-hash is required if --skip is non-zero"));
+ if (get_oid_hex(skip_hash_hex, &skip_hash))
+ die(_("%s is not SHA-1"), skip_hash_hex);
+ }
+ }
argv_array_push(&rp, "pack-objects");
if (thin) {
diff --git a/csum-file.c b/csum-file.c
index a172199..284847f 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -11,8 +11,27 @@
#include "progress.h"
#include "csum-file.h"
+static void check_skip_hash(struct sha1file *f, off_t old_total)
+{
+ if (old_total < f->skip && f->total > f->skip)
+ die("BUG: flush() must stop at skip boundary");
+
+ if (f->total == f->skip) {
+ git_SHA_CTX ctx;
+ unsigned char hash[20];
+
+ ctx = f->ctx;
+ git_SHA1_Final(hash, &ctx);
+ if (hashcmp(hash, f->skip_hash))
+ die("skip hash does not match, expected %s got %s",
+ sha1_to_hex(f->skip_hash), sha1_to_hex(hash));
+ }
+}
+
static void flush(struct sha1file *f, const void *buf, unsigned int count)
{
+ off_t old_total = f->total;
+
if (0 <= f->check_fd && count) {
unsigned char check_buffer[8192];
ssize_t ret = read_in_full(f->check_fd, check_buffer, count);
@@ -26,7 +45,11 @@ static void flush(struct sha1file *f, const void *buf, unsigned int count)
}
for (;;) {
- int ret = xwrite(f->fd, buf, count);
+ int ret;
+ if (f->total + count <= f->skip)
+ ret = count;
+ else
+ ret = xwrite(f->fd, buf, count);
if (ret > 0) {
f->total += ret;
display_throughput(f->tp, f->total);
@@ -34,6 +57,8 @@ static void flush(struct sha1file *f, const void *buf, unsigned int count)
count -= ret;
if (count)
continue;
+ if (f->skip > 0)
+ check_skip_hash(f, old_total);
return;
}
if (!ret)
@@ -45,12 +70,25 @@ static void flush(struct sha1file *f, const void *buf, unsigned int count)
void sha1flush(struct sha1file *f)
{
unsigned offset = f->offset;
+ const unsigned char *buffer = f->buffer;
+
+ if (!offset)
+ return;
+
+ if (f->total < f->skip && f->skip < f->total + offset) {
+ unsigned size = f->skip - f->total;
+ git_SHA1_Update(&f->ctx, buffer, size);
+ flush(f, buffer, size);
+ buffer += size;
+ offset -= size;
+ }
if (offset) {
- git_SHA1_Update(&f->ctx, f->buffer, offset);
- flush(f, f->buffer, offset);
- f->offset = 0;
+ git_SHA1_Update(&f->ctx, buffer, offset);
+ flush(f, buffer, offset);
}
+
+ f->offset = 0;
}
int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
@@ -62,6 +100,8 @@ int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
if (result)
hashcpy(result, f->buffer);
if (flags & (CSUM_CLOSE | CSUM_FSYNC)) {
+ if (f->skip > f->total)
+ die(_("can't skip in the middle of, or beyond the trailing SHA-1"));
/* write checksum and close fd */
flush(f, f->buffer, 20);
if (flags & CSUM_FSYNC)
@@ -94,6 +134,9 @@ void sha1write(struct sha1file *f, const void *buf, unsigned int count)
unsigned nr = count > left ? left : count;
const void *data;
+ if (f->total < f->skip && f->skip - f->total < nr)
+ nr = f->skip - f->total;
+
if (f->do_crc)
f->crc32 = crc32(f->crc32, buf, nr);
@@ -149,6 +192,7 @@ struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp
f->tp = tp;
f->name = name;
f->do_crc = 0;
+ f->skip = 0;
git_SHA1_Init(&f->ctx);
return f;
}
diff --git a/csum-file.h b/csum-file.h
index 7530927..5a9475f 100644
--- a/csum-file.h
+++ b/csum-file.h
@@ -15,6 +15,9 @@ struct sha1file {
int do_crc;
uint32_t crc32;
unsigned char buffer[8192];
+
+ off_t skip;
+ unsigned char skip_hash[20];
};
/* Checkpoint */
Nguyễn Thái Ngọc Duy
