Merge branch 'maint'

[git.git] / pack.h

diff --git a/pack.h b/pack.h
index 694e0c56f0b67c1ae9b7a94a243aca7b8859e50c..b31b37608d7f1901c74a20552770c306e633670c 100644 (file)
--- a/pack.h
+++ b/pack.h
@@ -1,20 +1,7 @@
 #ifndef PACK_H
 #define PACK_H
 
-/*
- * The packed object type is stored in 3 bits.
- * The type value 0 is a reserved prefix if ever there is more than 7
- * object types, or any future format extensions.
- */
-enum object_type {
-       OBJ_EXT = 0,
-       OBJ_COMMIT = 1,
-       OBJ_TREE = 2,
-       OBJ_BLOB = 3,
-       OBJ_TAG = 4,
-       /* 5/6 for future expansion */
-       OBJ_DELTA = 7,
-};
+#include "object.h"
 
 /*
  * Packed object header
@@ -23,13 +10,59 @@ enum object_type {
 #define PACK_VERSION 2
 #define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
 struct pack_header {
-       unsigned int hdr_signature;
-       unsigned int hdr_version;
-       unsigned int hdr_entries;
+       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" */
+
+/* These may be overridden by command-line parameters */
+extern uint32_t pack_idx_default_version;
+extern uint32_t pack_idx_off32_limit;
+
+/*
+ * Packed object index header
+ */
+struct pack_idx_header {
+       uint32_t idx_signature;
+       uint32_t idx_version;
+};
+
+/*
+ * Common part of object structure used for write_idx_file
+ */
+struct pack_idx_entry {
+       unsigned char sha1[20];
+       uint32_t crc32;
+       off_t offset;
+};
+
+extern char *write_idx_file(char *index_name, struct pack_idx_entry **objects, int nr_objects, unsigned char *sha1);
+
 extern int verify_pack(struct packed_git *, int);
-extern int check_reuse_pack_delta(struct packed_git *, unsigned long,
-                                 unsigned char *, unsigned long *,
-                                 enum object_type *);
+extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t);
+extern char *index_pack_lockfile(int fd);
+
+#define PH_ERROR_EOF           (-1)
+#define PH_ERROR_PACK_SIGNATURE        (-2)
+#define PH_ERROR_PROTOCOL      (-3)
+extern int read_pack_header(int fd, struct pack_header *);
 #endif