pack: move open_pack_index(), parse_pack_index()

alloc_packed_git() in packfile.c is duplicated from sha1_file.c. In a
subsequent commit, alloc_packed_git() will be removed from sha1_file.c.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/count-objects.c

@@ -10,6 +10,7 @@
 #include "builtin.h"
 #include "parse-options.h"
 #include "quote.h"
+#include "packfile.h"
 
 static unsigned long garbage;
 static off_t size_garbage;

builtin/fsck.c

@@ -15,6 +15,7 @@
 #include "progress.h"
 #include "streaming.h"
 #include "decorate.h"
+#include "packfile.h"
 
 #define REACHABLE 0x0001
 #define SEEN      0x0002

builtin/pack-objects.c

@@ -25,6 +25,7 @@
 #include "sha1-array.h"
 #include "argv-array.h"
 #include "mru.h"
+#include "packfile.h"
 
 static const char *pack_usage[] = {
 	N_("git pack-objects --stdout [<options>...] [< <ref-list> | < <object-list>]"),

cache.h

@@ -1605,8 +1605,6 @@ struct pack_entry {
 	struct packed_git *p;
 };
 
-extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);
-
 /* A hook to report invalid files in pack directory */
 #define PACKDIR_FILE_PACK 1
 #define PACKDIR_FILE_IDX 2
@@ -1641,12 +1639,6 @@ extern int odb_mkstemp(struct strbuf *template, const char *pattern);
  */
 extern int odb_pack_keep(const char *name);
 
-/*
- * mmap the index file for the specified packfile (if it is not
- * already mmapped).  Return 0 on success.
- */
-extern int open_pack_index(struct packed_git *);
-
 /*
  * munmap the index file for the specified packfile (if it is
  * currently mmapped).

pack-bitmap.c

@@ -9,6 +9,7 @@
 #include "pack-bitmap.h"
 #include "pack-revindex.h"
 #include "pack-objects.h"
+#include "packfile.h"
 
 /*
  * An entry on the bitmap index, representing the bitmap for a given

pack-check.c

@@ -2,6 +2,7 @@
 #include "pack.h"
 #include "pack-revindex.h"
 #include "progress.h"
+#include "packfile.h"
 
 struct idx_entry {
 	off_t                offset;

packfile.c

@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "mru.h"
+#include "pack.h"
 
 char *odb_pack_name(struct strbuf *buf,
 		    const unsigned char *sha1,
@@ -59,3 +60,151 @@ void pack_report(void)
 		pack_open_windows, peak_pack_open_windows,
 		sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
 }
+
+/*
+ * Open and mmap the index file at path, perform a couple of
+ * consistency checks, then record its information to p.  Return 0 on
+ * success.
+ */
+static int check_packed_git_idx(const char *path, struct packed_git *p)
+{
+	void *idx_map;
+	struct pack_idx_header *hdr;
+	size_t idx_size;
+	uint32_t version, nr, i, *index;
+	int fd = git_open(path);
+	struct stat st;
+
+	if (fd < 0)
+		return -1;
+	if (fstat(fd, &st)) {
+		close(fd);
+		return -1;
+	}
+	idx_size = xsize_t(st.st_size);
+	if (idx_size < 4 * 256 + 20 + 20) {
+		close(fd);
+		return error("index file %s is too small", path);
+	}
+	idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+
+	hdr = idx_map;
+	if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
+		version = ntohl(hdr->idx_version);
+		if (version < 2 || version > 2) {
+			munmap(idx_map, idx_size);
+			return error("index file %s is version %"PRIu32
+				     " and is not supported by this binary"
+				     " (try upgrading GIT to a newer version)",
+				     path, version);
+		}
+	} else
+		version = 1;
+
+	nr = 0;
+	index = idx_map;
+	if (version > 1)
+		index += 2;  /* skip index header */
+	for (i = 0; i < 256; i++) {
+		uint32_t n = ntohl(index[i]);
+		if (n < nr) {
+			munmap(idx_map, idx_size);
+			return error("non-monotonic index %s", path);
+		}
+		nr = n;
+	}
+
+	if (version == 1) {
+		/*
+		 * Total size:
+		 *  - 256 index entries 4 bytes each
+		 *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
+		 *  - 20-byte SHA1 of the packfile
+		 *  - 20-byte SHA1 file checksum
+		 */
+		if (idx_size != 4*256 + nr * 24 + 20 + 20) {
+			munmap(idx_map, idx_size);
+			return error("wrong index v1 file size in %s", path);
+		}
+	} else if (version == 2) {
+		/*
+		 * Minimum size:
+		 *  - 8 bytes of header
+		 *  - 256 index entries 4 bytes each
+		 *  - 20-byte sha1 entry * nr
+		 *  - 4-byte crc entry * nr
+		 *  - 4-byte offset entry * nr
+		 *  - 20-byte SHA1 of the packfile
+		 *  - 20-byte SHA1 file checksum
+		 * And after the 4-byte offset table might be a
+		 * variable sized table containing 8-byte entries
+		 * for offsets larger than 2^31.
+		 */
+		unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
+		unsigned long max_size = min_size;
+		if (nr)
+			max_size += (nr - 1)*8;
+		if (idx_size < min_size || idx_size > max_size) {
+			munmap(idx_map, idx_size);
+			return error("wrong index v2 file size in %s", path);
+		}
+		if (idx_size != min_size &&
+		    /*
+		     * make sure we can deal with large pack offsets.
+		     * 31-bit signed offset won't be enough, neither
+		     * 32-bit unsigned one will be.
+		     */
+		    (sizeof(off_t) <= 4)) {
+			munmap(idx_map, idx_size);
+			return error("pack too large for current definition of off_t in %s", path);
+		}
+	}
+
+	p->index_version = version;
+	p->index_data = idx_map;
+	p->index_size = idx_size;
+	p->num_objects = nr;
+	return 0;
+}
+
+int open_pack_index(struct packed_git *p)
+{
+	char *idx_name;
+	size_t len;
+	int ret;
+
+	if (p->index_data)
+		return 0;
+
+	if (!strip_suffix(p->pack_name, ".pack", &len))
+		die("BUG: pack_name does not end in .pack");
+	idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
+	ret = check_packed_git_idx(idx_name, p);
+	free(idx_name);
+	return ret;
+}
+
+static struct packed_git *alloc_packed_git(int extra)
+{
+	struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
+	memset(p, 0, sizeof(*p));
+	p->pack_fd = -1;
+	return p;
+}
+
+struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
+{
+	const char *path = sha1_pack_name(sha1);
+	size_t alloc = st_add(strlen(path), 1);
+	struct packed_git *p = alloc_packed_git(alloc);
+
+	memcpy(p->pack_name, path, alloc); /* includes NUL */
+	hashcpy(p->sha1, sha1);
+	if (check_packed_git_idx(idx_path, p)) {
+		free(p);
+		return NULL;
+	}
+
+	return p;
+}

packfile.h

@@ -33,6 +33,14 @@ extern unsigned int pack_max_fds;
 extern size_t peak_pack_mapped;
 extern size_t pack_mapped;
 
+extern struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path);
+
 extern void pack_report(void);
 
+/*
+ * mmap the index file for the specified packfile (if it is not
+ * already mmapped).  Return 0 on success.
+ */
+extern int open_pack_index(struct packed_git *);
+
 #endif

sha1_file.c

@@ -681,130 +681,6 @@ static int has_loose_object(const unsigned char *sha1)
 	return check_and_freshen(sha1, 0);
 }
 
-/*
- * Open and mmap the index file at path, perform a couple of
- * consistency checks, then record its information to p.  Return 0 on
- * success.
- */
-static int check_packed_git_idx(const char *path, struct packed_git *p)
-{
-	void *idx_map;
-	struct pack_idx_header *hdr;
-	size_t idx_size;
-	uint32_t version, nr, i, *index;
-	int fd = git_open(path);
-	struct stat st;
-
-	if (fd < 0)
-		return -1;
-	if (fstat(fd, &st)) {
-		close(fd);
-		return -1;
-	}
-	idx_size = xsize_t(st.st_size);
-	if (idx_size < 4 * 256 + 20 + 20) {
-		close(fd);
-		return error("index file %s is too small", path);
-	}
-	idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
-	close(fd);
-
-	hdr = idx_map;
-	if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
-		version = ntohl(hdr->idx_version);
-		if (version < 2 || version > 2) {
-			munmap(idx_map, idx_size);
-			return error("index file %s is version %"PRIu32
-				     " and is not supported by this binary"
-				     " (try upgrading GIT to a newer version)",
-				     path, version);
-		}
-	} else
-		version = 1;
-
-	nr = 0;
-	index = idx_map;
-	if (version > 1)
-		index += 2;  /* skip index header */
-	for (i = 0; i < 256; i++) {
-		uint32_t n = ntohl(index[i]);
-		if (n < nr) {
-			munmap(idx_map, idx_size);
-			return error("non-monotonic index %s", path);
-		}
-		nr = n;
-	}
-
-	if (version == 1) {
-		/*
-		 * Total size:
-		 *  - 256 index entries 4 bytes each
-		 *  - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
-		 *  - 20-byte SHA1 of the packfile
-		 *  - 20-byte SHA1 file checksum
-		 */
-		if (idx_size != 4*256 + nr * 24 + 20 + 20) {
-			munmap(idx_map, idx_size);
-			return error("wrong index v1 file size in %s", path);
-		}
-	} else if (version == 2) {
-		/*
-		 * Minimum size:
-		 *  - 8 bytes of header
-		 *  - 256 index entries 4 bytes each
-		 *  - 20-byte sha1 entry * nr
-		 *  - 4-byte crc entry * nr
-		 *  - 4-byte offset entry * nr
-		 *  - 20-byte SHA1 of the packfile
-		 *  - 20-byte SHA1 file checksum
-		 * And after the 4-byte offset table might be a
-		 * variable sized table containing 8-byte entries
-		 * for offsets larger than 2^31.
-		 */
-		unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
-		unsigned long max_size = min_size;
-		if (nr)
-			max_size += (nr - 1)*8;
-		if (idx_size < min_size || idx_size > max_size) {
-			munmap(idx_map, idx_size);
-			return error("wrong index v2 file size in %s", path);
-		}
-		if (idx_size != min_size &&
-		    /*
-		     * make sure we can deal with large pack offsets.
-		     * 31-bit signed offset won't be enough, neither
-		     * 32-bit unsigned one will be.
-		     */
-		    (sizeof(off_t) <= 4)) {
-			munmap(idx_map, idx_size);
-			return error("pack too large for current definition of off_t in %s", path);
-		}
-	}
-
-	p->index_version = version;
-	p->index_data = idx_map;
-	p->index_size = idx_size;
-	p->num_objects = nr;
-	return 0;
-}
-
-int open_pack_index(struct packed_git *p)
-{
-	char *idx_name;
-	size_t len;
-	int ret;
-
-	if (p->index_data)
-		return 0;
-
-	if (!strip_suffix(p->pack_name, ".pack", &len))
-		die("BUG: pack_name does not end in .pack");
-	idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
-	ret = check_packed_git_idx(idx_name, p);
-	free(idx_name);
-	return ret;
-}
-
 static void scan_windows(struct packed_git *p,
 	struct packed_git **lru_p,
 	struct pack_window **lru_w,
@@ -1302,22 +1178,6 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 	return p;
 }
 
-struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
-{
-	const char *path = sha1_pack_name(sha1);
-	size_t alloc = st_add(strlen(path), 1);
-	struct packed_git *p = alloc_packed_git(alloc);
-
-	memcpy(p->pack_name, path, alloc); /* includes NUL */
-	hashcpy(p->sha1, sha1);
-	if (check_packed_git_idx(idx_path, p)) {
-		free(p);
-		return NULL;
-	}
-
-	return p;
-}
-
 void install_packed_git(struct packed_git *pack)
 {
 	if (pack->pack_fd != -1)

sha1_name.c

@@ -9,6 +9,7 @@
 #include "remote.h"
 #include "dir.h"
 #include "sha1-array.h"
+#include "packfile.h"
 
 static int get_oid_oneline(const char *, struct object_id *, struct commit_list *);