Blob and tag objects have no particular changes except for their object
header.
Delta objects are also copied as is, except for their delta base reference
which is converted to the new way as used elsewhere in pack v4 encoding
i.e. an index into the SHA1 table or a literal SHA1 prefixed by 0 if not
found in the table (see encode_sha1ref). This is true for both REF_DELTA
as well as OFS_DELTA.
Object payload is validated against the recorded CRC32 in the source
pack index file when possible before being copied.
Signed-off-by: Nicolas Pitre <nico@xxxxxxxxxxx>
---
packv4-create.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)
diff --git a/packv4-create.c b/packv4-create.c
index 6098062..b0e344f 100644
--- a/packv4-create.c
+++ b/packv4-create.c
@@ -12,6 +12,7 @@
#include "object.h"
#include "tree-walk.h"
#include "pack.h"
+#include "pack-revindex.h"
#include "varint.h"
@@ -662,6 +663,65 @@ static int write_object_header(struct sha1file *f, enum object_type type, unsign
return len;
}
+static unsigned long copy_object_data(struct sha1file *f, struct packed_git *p,
+ off_t offset)
+{
+ struct pack_window *w_curs = NULL;
+ struct revindex_entry *revidx;
+ enum object_type type;
+ unsigned long avail, size, datalen, written;
+ int hdrlen, reflen, idx_nr;
+ unsigned char *src, buf[24];
+
+ revidx = find_pack_revindex(p, offset);
+ idx_nr = revidx->nr;
+ datalen = revidx[1].offset - offset;
+
+ src = use_pack(p, &w_curs, offset, &avail);
+ hdrlen = unpack_object_header_buffer(src, avail, &type, &size);
+
+ written = write_object_header(f, type, size);
+
+ if (type == OBJ_OFS_DELTA) {
+ const unsigned char *cp = src + hdrlen;
+ off_t base_offset = decode_varint(&cp);
+ hdrlen = cp - src;
+ base_offset = offset - base_offset;
+ if (base_offset <= 0 || base_offset >= offset)
+ die("delta offset out of bound");
+ revidx = find_pack_revindex(p, base_offset);
+ reflen = encode_sha1ref(nth_packed_object_sha1(p, revidx->nr), buf);
+ sha1write(f, buf, reflen);
+ written += reflen;
+ } else if (type == OBJ_REF_DELTA) {
+ reflen = encode_sha1ref(src + hdrlen, buf);
+ hdrlen += 20;
+ sha1write(f, buf, reflen);
+ written += reflen;
+ }
+
+ if (p->index_version > 1 &&
+ check_pack_crc(p, &w_curs, offset, datalen, idx_nr))
+ die("bad CRC for object at offset %"PRIuMAX" in %s",
+ (uintmax_t)offset, p->pack_name);
+
+ offset += hdrlen;
+ datalen -= hdrlen;
+
+ while (datalen) {
+ src = use_pack(p, &w_curs, offset, &avail);
+ if (avail > datalen)
+ avail = datalen;
+ sha1write(f, src, avail);
+ written += avail;
+ offset += avail;
+ datalen -= avail;
+ }
+ unuse_pack(&w_curs);
+
+ return written;
+}
+
static struct packed_git *open_pack(const char *path)
{
char arg[PATH_MAX];
--
1.8.4.38.g317e65b
--
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