sha1_file: switch uses of SHA-1 to the_hash_algo

Switch various uses of explicit calls to SHA-1 into references to
the_hash_algo for better abstraction.  Convert some calls to use struct
object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

sha1_file.c

@@ -786,16 +786,16 @@ void *xmmap(void *start, size_t length,
 int check_sha1_signature(const unsigned char *sha1, void *map,
 			 unsigned long size, const char *type)
 {
-	unsigned char real_sha1[20];
+	struct object_id real_oid;
 	enum object_type obj_type;
 	struct git_istream *st;
-	git_SHA_CTX c;
+	git_hash_ctx c;
 	char hdr[32];
 	int hdrlen;
 
 	if (map) {
-		hash_sha1_file(map, size, type, real_sha1);
-		return hashcmp(sha1, real_sha1) ? -1 : 0;
+		hash_sha1_file(map, size, type, real_oid.hash);
+		return hashcmp(sha1, real_oid.hash) ? -1 : 0;
 	}
 
 	st = open_istream(sha1, &obj_type, &size, NULL);
@@ -806,8 +806,8 @@ int check_sha1_signature(const unsigned char *sha1, void *map,
 	hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
 
 	/* Sha1.. */
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, hdr, hdrlen);
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, hdr, hdrlen);
 	for (;;) {
 		char buf[1024 * 16];
 		ssize_t readlen = read_istream(st, buf, sizeof(buf));
@@ -818,11 +818,11 @@ int check_sha1_signature(const unsigned char *sha1, void *map,
 		}
 		if (!readlen)
 			break;
-		git_SHA1_Update(&c, buf, readlen);
+		the_hash_algo->update_fn(&c, buf, readlen);
 	}
-	git_SHA1_Final(real_sha1, &c);
+	the_hash_algo->final_fn(real_oid.hash, &c);
 	close_istream(st);
-	return hashcmp(sha1, real_sha1) ? -1 : 0;
+	return hashcmp(sha1, real_oid.hash) ? -1 : 0;
 }
 
 int git_open_cloexec(const char *name, int flags)
@@ -1421,16 +1421,16 @@ static void write_sha1_file_prepare(const void *buf, unsigned long len,
                                     const char *type, unsigned char *sha1,
                                     char *hdr, int *hdrlen)
 {
-	git_SHA_CTX c;
+	git_hash_ctx c;
 
 	/* Generate the header */
 	*hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
 
 	/* Sha1.. */
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, hdr, *hdrlen);
-	git_SHA1_Update(&c, buf, len);
-	git_SHA1_Final(sha1, &c);
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, hdr, *hdrlen);
+	the_hash_algo->update_fn(&c, buf, len);
+	the_hash_algo->final_fn(sha1, &c);
 }
 
 /*
@@ -1552,8 +1552,8 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 	int fd, ret;
 	unsigned char compressed[4096];
 	git_zstream stream;
-	git_SHA_CTX c;
-	unsigned char parano_sha1[20];
+	git_hash_ctx c;
+	struct object_id parano_oid;
 	static struct strbuf tmp_file = STRBUF_INIT;
 	const char *filename = sha1_file_name(sha1);
 
@@ -1569,14 +1569,14 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 	git_deflate_init(&stream, zlib_compression_level);
 	stream.next_out = compressed;
 	stream.avail_out = sizeof(compressed);
-	git_SHA1_Init(&c);
+	the_hash_algo->init_fn(&c);
 
 	/* First header.. */
 	stream.next_in = (unsigned char *)hdr;
 	stream.avail_in = hdrlen;
 	while (git_deflate(&stream, 0) == Z_OK)
 		; /* nothing */
-	git_SHA1_Update(&c, hdr, hdrlen);
+	the_hash_algo->update_fn(&c, hdr, hdrlen);
 
 	/* Then the data itself.. */
 	stream.next_in = (void *)buf;
@@ -1584,7 +1584,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 	do {
 		unsigned char *in0 = stream.next_in;
 		ret = git_deflate(&stream, Z_FINISH);
-		git_SHA1_Update(&c, in0, stream.next_in - in0);
+		the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
 		if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
 			die("unable to write sha1 file");
 		stream.next_out = compressed;
@@ -1596,8 +1596,8 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
 	ret = git_deflate_end_gently(&stream);
 	if (ret != Z_OK)
 		die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
-	git_SHA1_Final(parano_sha1, &c);
-	if (hashcmp(sha1, parano_sha1) != 0)
+	the_hash_algo->final_fn(parano_oid.hash, &c);
+	if (hashcmp(sha1, parano_oid.hash) != 0)
 		die("confused by unstable object source data for %s", sha1_to_hex(sha1));
 
 	close_sha1_file(fd);
@@ -2091,14 +2091,14 @@ static int check_stream_sha1(git_zstream *stream,
 			     const char *path,
 			     const unsigned char *expected_sha1)
 {
-	git_SHA_CTX c;
+	git_hash_ctx c;
 	unsigned char real_sha1[GIT_MAX_RAWSZ];
 	unsigned char buf[4096];
 	unsigned long total_read;
 	int status = Z_OK;
 
-	git_SHA1_Init(&c);
-	git_SHA1_Update(&c, hdr, stream->total_out);
+	the_hash_algo->init_fn(&c);
+	the_hash_algo->update_fn(&c, hdr, stream->total_out);
 
 	/*
 	 * We already read some bytes into hdr, but the ones up to the NUL
@@ -2117,7 +2117,7 @@ static int check_stream_sha1(git_zstream *stream,
 		if (size - total_read < stream->avail_out)
 			stream->avail_out = size - total_read;
 		status = git_inflate(stream, Z_FINISH);
-		git_SHA1_Update(&c, buf, stream->next_out - buf);
+		the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
 		total_read += stream->next_out - buf;
 	}
 	git_inflate_end(stream);
@@ -2132,7 +2132,7 @@ static int check_stream_sha1(git_zstream *stream,
 		return -1;
 	}
 
-	git_SHA1_Final(real_sha1, &c);
+	the_hash_algo->final_fn(real_sha1, &c);
 	if (hashcmp(expected_sha1, real_sha1)) {
 		error("sha1 mismatch for %s (expected %s)", path,
 		      sha1_to_hex(expected_sha1));