1 files changed, 114 insertions, 0 deletions
diff --git a/src/pack.h b/src/pack.h
new file mode 100644
index 000000000..a7112a6aa
--- /dev/null
+++ b/src/pack.h
@@ -0,0 +1,114 @@
+/*
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2,
+ * as published by the Free Software Foundation.
+ *
+ * In addition to the permissions in the GNU General Public License,
+ * the authors give you unlimited permission to link the compiled
+ * version of this file into combinations with other programs,
+ * and to distribute those combinations without any restriction
+ * coming from the use of this file.  (The General Public License
+ * restrictions do apply in other respects; for example, they cover
+ * modification of the file, and distribution when not linked into
+ * a combined executable.)
+ *
+ * This file is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDE_pack_h__
+#define INCLUDE_pack_h__
+
+#include "git2/oid.h"
+
+#include "common.h"
+#include "map.h"
+#include "mwindow.h"
+#include "odb.h"
+
+#define PACK_SIGNATURE 0x5041434b	/* "PACK" */
+#define PACK_VERSION 2
+#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
+struct git_pack_header {
+	uint32_t hdr_signature;
+	uint32_t hdr_version;
+	uint32_t hdr_entries;
+};
+
+/*
+ * The first four bytes of index formats later than version 1 should
+ * start with this signature, as all older git binaries would find this
+ * value illegal and abort reading the file.
+ *
+ * This is the case because the number of objects in a packfile
+ * cannot exceed 1,431,660,000 as every object would need at least
+ * 3 bytes of data and the overall packfile cannot exceed 4 GiB with
+ * version 1 of the index file due to the offsets limited to 32 bits.
+ * Clearly the signature exceeds this maximum.
+ *
+ * Very old git binaries will also compare the first 4 bytes to the
+ * next 4 bytes in the index and abort with a "non-monotonic index"
+ * error if the second 4 byte word is smaller than the first 4
+ * byte word.  This would be true in the proposed future index
+ * format as idx_signature would be greater than idx_version.
+ */
+
+#define PACK_IDX_SIGNATURE 0xff744f63	/* "\377tOc" */
+
+struct git_pack_idx_header {
+	uint32_t idx_signature;
+	uint32_t idx_version;
+};
+
+struct git_pack_file {
+	git_mwindow_file mwf;
+	git_map index_map;
+
+	uint32_t num_objects;
+	uint32_t num_bad_objects;
+	git_oid *bad_object_sha1; /* array of git_oid */
+
+	int index_version;
+	git_time_t mtime;
+	unsigned pack_local:1, pack_keep:1;
+	git_oid sha1;
+
+	/* something like ".git/objects/pack/xxxxx.pack" */
+	char pack_name[GIT_FLEX_ARRAY]; /* more */
+};
+
+struct git_pack_entry {
+	off_t offset;
+	git_oid sha1;
+	struct git_pack_file *p;
+};
+
+int git_packfile_unpack_header(
+		size_t *size_p,
+		git_otype *type_p,
+		git_mwindow_file *mwf,
+		git_mwindow **w_curs,
+		off_t *curpos);
+
+int git_packfile_unpack(git_rawobj *obj, struct git_pack_file *p, off_t *obj_offset);
+
+off_t get_delta_base(struct git_pack_file *p, git_mwindow **w_curs,
+		off_t *curpos, git_otype type,
+		off_t delta_obj_offset);
+
+void packfile_free(struct git_pack_file *p);
+int git_packfile_check(struct git_pack_file **pack_out, const char *path);
+int git_pack_entry_find(
+		struct git_pack_entry *e,
+		struct git_pack_file *p,
+		const git_oid *short_oid,
+		unsigned int len);
+
+#endif