[PATCH 4/6] Inflate an object from a pack file
Support delta objects too.
Signed-off-by: Hervé Cauwelier <herve@itaapy.com>
---
src/odb.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 68 insertions(+), 1 deletions(-)
diff --git a/src/odb.c b/src/odb.c
index 349747b..c71948b 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -28,6 +28,7 @@
#include "git/zlib.h"
#include "fileops.h"
#include "hash.h"
+#include "delta-apply.h"
#include "odb.h"
#define GIT_PACK_NAME_MAX (5 + 40 + 1)
@@ -232,7 +233,7 @@ static int is_zlib_compressed_data(unsigned char *data)
unsigned int w;
w = ((unsigned int)(data[0]) << 8) + data[1];
- return data[0] == 0x78 && !(w %31);
+ return data[0] == 0x78 && !(w % 31);
}
static size_t get_binary_object_header(obj_hdr *hdr, gitfo_buf *obj)
@@ -1192,6 +1193,72 @@ int git_odb__read_loose(git_obj *out, git_odb *db, const git_oid *id)
return GIT_SUCCESS;
}
+static int inflate_pack_obj(git_obj *out, git_pack *p, off_t offset)
+{
+ obj_hdr hdr;
+ gitfo_buf buf;
+ size_t used;
+ void *data;
+ git_obj base;
+
+ /* Cast the map to a gitfo_buf */
+ buf.data = (unsigned char *)p->pack_map.data + offset;
+ buf.len = p->pack_map.len - offset;
+
+ /*
+ * Read the object header, which is an (uncompressed)
+ * binary encoding of the object type and size.
+ */
+ if (!(used = get_binary_object_header(&hdr, &buf)))
+ return GIT_ERROR;
+
+ /*
+ * Read the object data as a zlib compressed data
+ */
+ buf.data += used;
+ buf.len -= used;
+ assert(is_zlib_compressed_data(buf.data));
+
+ if (!(data = git__malloc(hdr.size + 1)))
+ return GIT_ERROR;
+ if (inflate_buffer(buf.data, buf.len, data, hdr.size))
+ goto inflate_fail;
+
+ switch (hdr.type) {
+ case GIT_OBJ_COMMIT:
+ case GIT_OBJ_TREE:
+ case GIT_OBJ_BLOB:
+ case GIT_OBJ_TAG:
+ out->data = data;
+ out->len = hdr.size;
+ out->type = hdr.type;
+ return GIT_SUCCESS;
+ case GIT_OBJ_OFS_DELTA:
+ offset -= hdr.base_offset;
+ if (inflate_pack_obj(&base, p, offset))
+ goto inflate_fail;
+ if (git__delta_apply(out, base.data, base.len, data, hdr.size))
+ goto inflate_fail;
+ out->type = base.type;
+ return GIT_SUCCESS;
+ case GIT_OBJ_REF_DELTA:
+ if (p->idx_search(&offset, p, &hdr.base_name))
+ goto inflate_fail;
+ if (inflate_pack_obj(&base, p, offset))
+ goto inflate_fail;
+ if (git__delta_apply(out, base.data, base.len, data, hdr.size))
+ goto inflate_fail;
+ out->type = base.type;
+ return GIT_SUCCESS;
+ default:
+ goto inflate_fail;
+ }
+
+inflate_fail:
+ free(data);
+ return GIT_ERROR;
+}
+
static int read_packed(git_obj *out, git_pack *p, const git_oid *id)
{
off_t pos;
--
1.6.5