* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
+#include "cache-tree.h"
+
+/* Index extensions.
+ *
+ * The first letter should be 'A'..'Z' for extensions that are not
+ * necessary for a correct operation (i.e. optimization data).
+ * When new extensions are added that _needs_ to be understood in
+ * order to correctly interpret the index file, pick character that
+ * is outside the range, to cause the reader to abort.
+ */
+
+#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;
static time_t index_file_timestamp;
unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
+struct cache_tree *active_cache_tree = NULL;
+
/*
* This only updates the "non-critical" parts of the directory
* cache, ie the parts that aren't tracked by GIT, and only used
return 0;
}
-static int verify_hdr(struct cache_header *hdr, unsigned long size, unsigned char *sha1)
+static int verify_hdr(struct cache_header *hdr, unsigned long size)
{
SHA_CTX c;
- unsigned char sha1_buf[20];
- if (!sha1)
- sha1 = sha1_buf;
+ unsigned char sha1[20];
if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
return error("bad signature");
return 0;
}
-int read_cache_1(unsigned char *cache_sha1)
+static int read_index_extension(const char *ext, void *data, unsigned long sz)
+{
+ switch (CACHE_EXT(ext)) {
+ case CACHE_EXT_TREE:
+ active_cache_tree = cache_tree_read(data, sz);
+ break;
+ default:
+ if (*ext < 'A' || 'Z' < *ext)
+ return error("index uses %.4s extension, which we do not understand",
+ ext);
+ fprintf(stderr, "ignoring %.4s extension\n", ext);
+ break;
+ }
+ return 0;
+}
+
+int read_cache(void)
{
int fd, i;
struct stat st;
die("index file mmap failed (%s)", strerror(errno));
hdr = map;
- if (verify_hdr(hdr, size, cache_sha1) < 0)
+ if (verify_hdr(hdr, size) < 0)
goto unmap;
active_nr = ntohl(hdr->hdr_entries);
active_cache[i] = ce;
}
index_file_timestamp = st.st_mtime;
+ while (offset <= size - 20 - 8) {
+ /* After an array of active_nr index entries,
+ * there can be arbitrary number of extended
+ * sections, each of which is prefixed with
+ * extension name (4-byte) and section length
+ * in 4-byte network byte order.
+ */
+ unsigned long extsize;
+ memcpy(&extsize, map + offset + 4, 4);
+ extsize = ntohl(extsize);
+ if (read_index_extension(map + offset,
+ map + offset + 8, extsize) < 0)
+ goto unmap;
+ offset += 8;
+ offset += extsize;
+ }
return active_nr;
unmap:
return 0;
}
-static int ce_flush(SHA_CTX *context, int fd, unsigned char *sha1)
+static int write_index_ext_header(SHA_CTX *context, int fd,
+ unsigned long ext, unsigned long sz)
+{
+ ext = htonl(ext);
+ sz = htonl(sz);
+ if ((ce_write(context, fd, &ext, 4) < 0) ||
+ (ce_write(context, fd, &sz, 4) < 0))
+ return -1;
+ return 0;
+}
+
+static int ce_flush(SHA_CTX *context, int fd)
{
unsigned int left = write_buffer_len;
}
/* Append the SHA1 signature at the end */
- SHA1_Final(sha1, context);
- memcpy(write_buffer + left, sha1, 20);
+ SHA1_Final(write_buffer + left, context);
left += 20;
if (write(fd, write_buffer, left) != left)
return -1;
}
}
-int write_cache_1(int newfd, struct cache_entry **cache, int entries,
- unsigned char *cache_sha1)
+int write_cache(int newfd, struct cache_entry **cache, int entries)
{
SHA_CTX c;
struct cache_header hdr;
int i, removed;
- int status;
- unsigned char sha1[20];
for (i = removed = 0; i < entries; i++)
if (!cache[i]->ce_mode)
if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
return -1;
}
- status = ce_flush(&c, newfd, sha1);
- if (cache_sha1)
- memcpy(cache_sha1, sha1, 20);
- return status;
-}
-int read_cache(void)
-{
- return read_cache_1(NULL);
-}
-
-int write_cache(int newfd, struct cache_entry **cache, int entries)
-{
- return write_cache_1(newfd, cache, entries, NULL);
+ /* Write extension data here */
+ if (active_cache_tree) {
+ unsigned long sz;
+ void *data = cache_tree_write(active_cache_tree, &sz);
+ if (data &&
+ !write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sz) &&
+ !ce_write(&c, newfd, data, sz))
+ ;
+ else {
+ free(data);
+ return -1;
+ }
+ }
+ return ce_flush(&c, newfd);
}