Introduce close_pack_index to permit replacement

By closing the pack index, a caller can later overwrite the index
with an updated index file, possibly after converting from v1 to
the v2 format.  Because p->index_data is NULL after close, on the
next access the index will be opened again and the other members
will be updated with new data.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/cache.h b/cache.h
index 6e54993256befed7b77fc54559ff196d01292ef2..0eba039dbfe581d057212efe6a21702fa736a980 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -911,6 +911,7 @@ extern struct packed_git *find_sha1_pack(const unsigned char *sha1,
 
 extern void pack_report(void);
 extern int open_pack_index(struct packed_git *);
+extern void close_pack_index(struct packed_git *);
 extern unsigned char *use_pack(struct packed_git *, struct pack_window **, off_t, unsigned int *);
 extern void close_pack_windows(struct packed_git *);
 extern void unuse_pack(struct pack_window **);

diff --git a/sha1_file.c b/sha1_file.c
index c23cc5e6e19a2d8c9a92161b0a5d62a5ef8e920b..4e82654d7c1636f22854f50219ee97bc4027c144 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -606,6 +606,14 @@ void unuse_pack(struct pack_window **w_cursor)
        }
 }
 
+void close_pack_index(struct packed_git *p)
+{
+       if (p->index_data) {
+               munmap((void *)p->index_data, p->index_size);
+               p->index_data = NULL;
+       }
+}
+
 /*
  * This is used by git-repack in case a newly created pack happens to
  * contain the same set of objects as an existing one.  In that case
@@ -627,8 +635,7 @@ void free_pack_by_name(const char *pack_name)
                        close_pack_windows(p);
                        if (p->pack_fd != -1)
                                close(p->pack_fd);
-                       if (p->index_data)
-                               munmap((void *)p->index_data, p->index_size);
+                       close_pack_index(p);
                        free(p->bad_object_sha1);
                        *pp = p->next;
                        free(p);