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[PATCH 09/12] read-cache: abstract away uses of SHA-1

From
brian m. carlson <sandals@crustytoothpaste.net>
Date
Jan 28, 2018, 15:57 UTC
Message-ID
<20180128155722.880805-10-sandals@crustytoothpaste.net>
In-Reply-To
<20180128155722.880805-1-sandals@crustytoothpaste.net>

Convert various uses of direct calls to SHA-1 and 20- and 40-based constants to use the_hash_algo instead. Don't yet convert the on-disk data structures, which will be handled in a future commit.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
---
 read-cache.c | 54 +++++++++++++++++++++++++++---------------------------
 1 file changed, 27 insertions(+), 27 deletions(-)
diff --git a/read-cache.c b/read-cache.c
index 2eb81a66b9..4f7aac23af 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1545,8 +1545,8 @@ int verify_ce_order;
 
 static int verify_hdr(struct cache_header *hdr, unsigned long size)
 {
-	git_SHA_CTX c;
-	unsigned char sha1[20];
+	git_hash_ctx c;
+	unsigned char hash[GIT_MAX_RAWSZ];
 	int hdr_version;
 
 	if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
@@ -1558,10 +1558,10 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
 	if (!verify_index_checksum)
 		return 0;
 
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, hdr, size - 20);
-	git_SHA1_Final(sha1, &c);
-	if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, hdr, size - the_hash_algo->rawsz);
+	the_hash_algo->final_fn(hash, &c);
+	if (hashcmp(hash, (unsigned char *)hdr + size - the_hash_algo->rawsz))
 		return error("bad index file sha1 signature");
 	return 0;
 }
@@ -1791,7 +1791,7 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
 		die_errno("cannot stat the open index");
 
 	mmap_size = xsize_t(st.st_size);
-	if (mmap_size < sizeof(struct cache_header) + 20)
+	if (mmap_size < sizeof(struct cache_header) + the_hash_algo->rawsz)
 		die("index file smaller than expected");
 
 	mmap = xmmap(NULL, mmap_size, PROT_READ, MAP_PRIVATE, fd, 0);
@@ -1803,7 +1803,7 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
 	if (verify_hdr(hdr, mmap_size) < 0)
 		goto unmap;
 
-	hashcpy(istate->sha1, (const unsigned char *)hdr + mmap_size - 20);
+	hashcpy(istate->sha1, (const unsigned char *)hdr + mmap_size - the_hash_algo->rawsz);
 	istate->version = ntohl(hdr->hdr_version);
 	istate->cache_nr = ntohl(hdr->hdr_entries);
 	istate->cache_alloc = alloc_nr(istate->cache_nr);
@@ -1831,7 +1831,7 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
 	istate->timestamp.sec = st.st_mtime;
 	istate->timestamp.nsec = ST_MTIME_NSEC(st);
 
-	while (src_offset <= mmap_size - 20 - 8) {
+	while (src_offset <= mmap_size - the_hash_algo->rawsz - 8) {
 		/* After an array of active_nr index entries,
 		 * there can be arbitrary number of extended
 		 * sections, each of which is prefixed with
@@ -1957,11 +1957,11 @@ int unmerged_index(const struct index_state *istate)
 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
 static unsigned long write_buffer_len;
 
-static int ce_write_flush(git_SHA_CTX *context, int fd)
+static int ce_write_flush(git_hash_ctx *context, int fd)
 {
 	unsigned int buffered = write_buffer_len;
 	if (buffered) {
-		git_SHA1_Update(context, write_buffer, buffered);
+		the_hash_algo->update_fn(context, write_buffer, buffered);
 		if (write_in_full(fd, write_buffer, buffered) < 0)
 			return -1;
 		write_buffer_len = 0;
@@ -1969,7 +1969,7 @@ static int ce_write_flush(git_SHA_CTX *context, int fd)
 	return 0;
 }
 
-static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
+static int ce_write(git_hash_ctx *context, int fd, void *data, unsigned int len)
 {
 	while (len) {
 		unsigned int buffered = write_buffer_len;
@@ -1991,7 +1991,7 @@ static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
 	return 0;
 }
 
-static int write_index_ext_header(git_SHA_CTX *context, int fd,
+static int write_index_ext_header(git_hash_ctx *context, int fd,
 				  unsigned int ext, unsigned int sz)
 {
 	ext = htonl(ext);
@@ -2000,26 +2000,26 @@ static int write_index_ext_header(git_SHA_CTX *context, int fd,
 		(ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
 }
 
-static int ce_flush(git_SHA_CTX *context, int fd, unsigned char *sha1)
+static int ce_flush(git_hash_ctx *context, int fd, unsigned char *hash)
 {
 	unsigned int left = write_buffer_len;
 
 	if (left) {
 		write_buffer_len = 0;
-		git_SHA1_Update(context, write_buffer, left);
+		the_hash_algo->update_fn(context, write_buffer, left);
 	}
 
 	/* Flush first if not enough space for SHA1 signature */
-	if (left + 20 > WRITE_BUFFER_SIZE) {
+	if (left + the_hash_algo->rawsz > WRITE_BUFFER_SIZE) {
 		if (write_in_full(fd, write_buffer, left) < 0)
 			return -1;
 		left = 0;
 	}
 
 	/* Append the SHA1 signature at the end */
-	git_SHA1_Final(write_buffer + left, context);
-	hashcpy(sha1, write_buffer + left);
-	left += 20;
+	the_hash_algo->final_fn(write_buffer + left, context);
+	hashcpy(hash, write_buffer + left);
+	left += the_hash_algo->rawsz;
 	return (write_in_full(fd, write_buffer, left) < 0) ? -1 : 0;
 }
 
@@ -2100,7 +2100,7 @@ static void copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
 	}
 }
 
-static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
+static int ce_write_entry(git_hash_ctx *c, int fd, struct cache_entry *ce,
 			  struct strbuf *previous_name, struct ondisk_cache_entry *ondisk)
 {
 	int size;
@@ -2167,7 +2167,7 @@ static int verify_index_from(const struct index_state *istate, const char *path)
 	int fd;
 	ssize_t n;
 	struct stat st;
-	unsigned char sha1[20];
+	unsigned char hash[GIT_MAX_RAWSZ];
 
 	if (!istate->initialized)
 		return 0;
@@ -2179,14 +2179,14 @@ static int verify_index_from(const struct index_state *istate, const char *path)
 	if (fstat(fd, &st))
 		goto out;
 
-	if (st.st_size < sizeof(struct cache_header) + 20)
+	if (st.st_size < sizeof(struct cache_header) + the_hash_algo->rawsz)
 		goto out;
 
-	n = pread_in_full(fd, sha1, 20, st.st_size - 20);
-	if (n != 20)
+	n = pread_in_full(fd, hash, the_hash_algo->rawsz, st.st_size - the_hash_algo->rawsz);
+	if (n != the_hash_algo->rawsz)
 		goto out;
 
-	if (hashcmp(istate->sha1, sha1))
+	if (hashcmp(istate->sha1, hash))
 		goto out;
 
 	close(fd);
@@ -2235,7 +2235,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 			  int strip_extensions)
 {
 	int newfd = tempfile->fd;
-	git_SHA_CTX c;
+	git_hash_ctx c;
 	struct cache_header hdr;
 	int i, err = 0, removed, extended, hdr_version;
 	struct cache_entry **cache = istate->cache;
@@ -2273,7 +2273,7 @@ static int do_write_index(struct index_state *istate, struct tempfile *tempfile,
 	hdr.hdr_version = htonl(hdr_version);
 	hdr.hdr_entries = htonl(entries - removed);
 
-	git_SHA1_Init(&c);
+	the_hash_algo->init_fn(&c);
 	if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
 		return -1;
Previous: Patryk ObaraNext: Eric Sunshine
Message 7 of 22 in “object_id part 11 (the_hash_algo)”
  1. 00/12 object_id part 11 (the_hash_algo)brian m. carlson, Jan 28, 2018
  2. 01/12 hash: move SHA-1 macros to hash.hbrian m. carlson, Jan 28, 2018
  3. 04/12 builtin/unpack-objects: switch uses of SHA-1 to the_hash_algobrian m. carlson, Jan 28, 2018
  4. 05/12 sha1_file: switch uses of SHA-1 to the_hash_algobrian m. carlson, Jan 28, 2018
  5. 06/12 fast-import: switch various uses of SHA-1 to the_hash_algobrian m. carlson, Jan 28, 2018
  6. Patryk ObaraJan 28, 2018
  7. 09/12 read-cache: abstract away uses of SHA-1brian m. carlson, Jan 28, 2018
  8. Eric SunshineJan 28, 2018
  9. brian m. carlsonJan 28, 2018
  10. 12/12 bulk-checkin: abstract SHA-1 usagebrian m. carlson, Jan 28, 2018
  11. 03/12 builtin/index-pack: improve hash function abstractionbrian m. carlson, Jan 28, 2018
  12. 11/12 csum-file: abstract uses of SHA-1brian m. carlson, Jan 28, 2018
  13. 10/12 csum-file: rename sha1file to hashfilebrian m. carlson, Jan 28, 2018
  14. 02/12 hash: create union for hash context allocationbrian m. carlson, Jan 28, 2018
  15. Patryk ObaraJan 28, 2018
  16. brian m. carlsonJan 28, 2018
  17. 07/12 pack-check: convert various uses of SHA-1 to abstract formsbrian m. carlson, Jan 28, 2018
  18. 08/12 pack-write: switch various SHA-1 values to abstract formsbrian m. carlson, Jan 28, 2018
  19. Patryk ObaraJan 28, 2018
  20. brian m. carlsonJan 28, 2018
  21. Patryk ObaraJan 28, 2018
  22. brian m. carlsonJan 28, 2018

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