[PATCH v4 0/4] Don't lazy-fetch commits when parsing them

Thanks everyone for your comments. Here's a reroll.

Jonathan Tan (4):
  object-file: remove OBJECT_INFO_IGNORE_LOOSE
  object-file: refactor map_loose_object_1()
  object-file: emit corruption errors when detected
  commit: don't lazy-fetch commits

 commit.c       |  15 ++++++-
 object-file.c  | 108 ++++++++++++++++++++++++-------------------------
 object-store.h |   7 ++--
 3 files changed, 69 insertions(+), 61 deletions(-)

Range-diff against v3:
1:  be0b08cac2 = 1:  be0b08cac2 object-file: remove OBJECT_INFO_IGNORE_LOOSE
2:  7419e4ac70 ! 2:  4b2fb68743 object-file: refactor map_loose_object_1()
    @@ Commit message
          2. Simultaneously gets a path and fd given an OID
          3. Memory maps an fd
     
    -    Split this function up. Only one caller needs 1, so inline that. As for
    -    2, a future patch will also need this functionality and, in addition,
    -    the calculated path, so extract this into a separate function with an
    -    out parameter for the path.
    +    Keep 3 (renaming the function accordingly) and inline 1 and 2 into their
    +    respective callers.
     
         Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
     
    @@ object-file.c: static int quick_has_loose(struct repository *r,
      	return map;
      }
      
    -+static void *map_loose_object_1(struct repository *r,
    -+				const struct object_id *oid,
    -+				unsigned long *size,
    -+				const char **path)
    -+{
    +@@ object-file.c: void *map_loose_object(struct repository *r,
    + 		       const struct object_id *oid,
    + 		       unsigned long *size)
    + {
    +-	return map_loose_object_1(r, NULL, oid, size);
     +	const char *p;
     +	int fd = open_loose_object(r, oid, &p);
     +
     +	if (fd < 0)
     +		return NULL;
    -+	if (path)
    -+		*path = p;
     +	return map_fd(fd, p, size);
    -+}
    -+
    - void *map_loose_object(struct repository *r,
    - 		       const struct object_id *oid,
    - 		       unsigned long *size)
    - {
    --	return map_loose_object_1(r, NULL, oid, size);
    -+	return map_loose_object_1(r, oid, size, NULL);
      }
      
      enum unpack_loose_header_result unpack_loose_header(git_zstream *stream,
3:  7c9ed861e7 ! 3:  07d28db92c object-file: emit corruption errors when detected
    @@ Commit message
         which an indirect caller of do_oid_object_info_extended() will need
         such functionality.
     
    +    Helped-by: Jeff King <peff@peff.net>
         Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
     
      ## object-file.c ##
     @@ object-file.c: static int loose_object_info(struct repository *r,
    + 			     struct object_info *oi, int flags)
      {
      	int status = 0;
    ++	int fd;
      	unsigned long mapsize;
    -+	const char *path = NULL;
    ++	const char *path;
      	void *map;
      	git_zstream stream;
      	char hdr[MAX_HEADER_LEN];
    +@@ object-file.c: static int loose_object_info(struct repository *r,
    + 	 * object even exists.
    + 	 */
    + 	if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
    +-		const char *path;
    + 		struct stat st;
    + 		if (!oi->disk_sizep && (flags & OBJECT_INFO_QUICK))
    + 			return quick_has_loose(r, oid) ? 0 : -1;
     @@ object-file.c: static int loose_object_info(struct repository *r,
      		return 0;
      	}
      
     -	map = map_loose_object(r, oid, &mapsize);
    -+	map = map_loose_object_1(r, oid, &mapsize, &path);
    ++	fd = open_loose_object(r, oid, &path);
    ++	if (fd < 0) {
    ++		if (errno != ENOENT)
    ++			error_errno(_("unable to open loose object %s"), path);
    ++		return -1;
    ++	}
    ++	map = map_fd(fd, path, &mapsize);
      	if (!map)
      		return -1;
      
    @@ object-file.c: static void *read_object(struct repository *r,
      	oi.contentp = &content;
      
     -	if (oid_object_info_extended(r, oid, &oi, 0) < 0)
    -+	if (oid_object_info_extended(r, oid, &oi,
    -+				     die_if_corrupt ? OBJECT_INFO_DIE_IF_CORRUPT : 0)
    -+	    < 0)
    ++	if (oid_object_info_extended(r, oid, &oi, die_if_corrupt
    ++				     ? OBJECT_INFO_DIE_IF_CORRUPT : 0) < 0)
      		return NULL;
      	return content;
      }
4:  5924a5120b = 4:  1a0cd5b244 commit: don't lazy-fetch commits