consolidate two copies of new style object header parsing code.

diff --git a/read-cache.c b/read-cache.c
index be81ac2d2b9a68bfcc1b02b339ced49f44517efe..20c9d494ac94380c9074997e9cb3c69ff1c04a3f 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -18,16 +18,16 @@
 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
 #define CACHE_EXT_TREE 0x54524545      /* "TREE" */
 
-struct cache_entry **active_cache = NULL;
+struct cache_entry **active_cache;
 static time_t index_file_timestamp;
-unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
+unsigned int active_nr, active_alloc, active_cache_changed;
 
-struct cache_tree *active_cache_tree = NULL;
+struct cache_tree *active_cache_tree;
 
-int cache_errno = 0;
+int cache_errno;
 
-static void *cache_mmap = NULL;
-static size_t cache_mmap_size = 0;
+static void *cache_mmap;
+static size_t cache_mmap_size;
 
 /*
  * This only updates the "non-critical" parts of the directory
@@ -60,7 +60,7 @@ static int ce_compare_data(struct cache_entry *ce, struct stat *st)
        if (fd >= 0) {
                unsigned char sha1[20];
                if (!index_fd(sha1, fd, st, 0, NULL))
-                       match = memcmp(sha1, ce->sha1, 20);
+                       match = hashcmp(sha1, ce->sha1);
                /* index_fd() closed the file descriptor already */
        }
        return match;
@@ -744,7 +744,7 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
        SHA1_Init(&c);
        SHA1_Update(&c, hdr, size - 20);
        SHA1_Final(sha1, &c);
-       if (memcmp(sha1, (char *) hdr + size - 20, 20))
+       if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
                return error("bad index file sha1 signature");
        return 0;
 }
@@ -842,6 +842,23 @@ int read_cache_from(const char *path)
        die("index file corrupt");
 }
 
+int discard_cache()
+{
+       int ret;
+
+       active_nr = active_cache_changed = 0;
+       index_file_timestamp = 0;
+       cache_tree_free(&active_cache_tree);
+       if (cache_mmap == NULL)
+               return 0;
+       ret = munmap(cache_mmap, cache_mmap_size);
+       cache_mmap = NULL;
+       cache_mmap_size = 0;
+
+       /* no need to throw away allocated active_cache */
+       return ret;
+}
+
 #define WRITE_BUFFER_SIZE 8192
 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
 static unsigned long write_buffer_len;