Merge branch 'eb/hash-transition'

Work to support a repository that work with both SHA-1 and SHA-256 hash algorithms has started. * eb/hash-transition: (30 commits) t1016-compatObjectFormat: add tests to verify the conversion between objects t1006: test oid compatibility with cat-file t1006: rename sha1 to oid test-lib: compute the compatibility hash so tests may use it builtin/ls-tree: let the oid determine the output algorithm object-file: handle compat objects in check_object_signature tree-walk: init_tree_desc take an oid to get the hash algorithm builtin/cat-file: let the oid determine the output algorithm rev-parse: add an --output-object-format parameter repository: implement extensions.compatObjectFormat object-file: update object_info_extended to reencode objects object-file-convert: convert commits that embed signed tags object-file-convert: convert commit objects when writing object-file-convert: don't leak when converting tag objects object-file-convert: convert tag objects when writing object-file-convert: add a function to convert trees between algorithms object: factor out parse_mode out of fast-import and tree-walk into in object.h cache: add a function to read an OID of a specific algorithm tag: sign both hashes commit: export add_header_signature to support handling signatures on tags ...
2024-03-28 14:13:50 -07:00
parent c75fd8d815 7673ecd2dc
commit 1002f28a52
62 changed files with 1880 additions and 385 deletions
--- a/object-file.c
+++ b/object-file.c
@@ -35,6 +35,8 @@
 #include "setup.h"
 #include "submodule.h"
 #include "fsck.h"
+#include "loose.h"
+#include "object-file-convert.h"

 /* The maximum size for an object header. */
 #define MAX_HEADER_LEN 32
@@ -1084,9 +1086,11 @@ int check_object_signature(struct repository *r, const struct object_id *oid,
 			   void *buf, unsigned long size,
 			   enum object_type type)
 {
+	const struct git_hash_algo *algo =
+		oid->algo ? &hash_algos[oid->algo] : r->hash_algo;
 	struct object_id real_oid;

-	hash_object_file(r->hash_algo, buf, size, type, &real_oid);
+	hash_object_file(algo, buf, size, type, &real_oid);

 	return !oideq(oid, &real_oid) ? -1 : 0;
 }
@@ -1652,10 +1656,101 @@ static int do_oid_object_info_extended(struct repository *r,
 	return 0;
 }

+static int oid_object_info_convert(struct repository *r,
+				   const struct object_id *input_oid,
+				   struct object_info *input_oi, unsigned flags)
+{
+	const struct git_hash_algo *input_algo = &hash_algos[input_oid->algo];
+	int do_die = flags & OBJECT_INFO_DIE_IF_CORRUPT;
+	struct strbuf type_name = STRBUF_INIT;
+	struct object_id oid, delta_base_oid;
+	struct object_info new_oi, *oi;
+	unsigned long size;
+	void *content;
+	int ret;
+
+	if (repo_oid_to_algop(r, input_oid, the_hash_algo, &oid)) {
+		if (do_die)
+			die(_("missing mapping of %s to %s"),
+			    oid_to_hex(input_oid), the_hash_algo->name);
+		return -1;
+	}
+
+	/* Is new_oi needed? */
+	oi = input_oi;
+	if (input_oi && (input_oi->delta_base_oid || input_oi->sizep ||
+			 input_oi->contentp)) {
+		new_oi = *input_oi;
+		/* Does delta_base_oid need to be converted? */
+		if (input_oi->delta_base_oid)
+			new_oi.delta_base_oid = &delta_base_oid;
+		/* Will the attributes differ when converted? */
+		if (input_oi->sizep || input_oi->contentp) {
+			new_oi.contentp = &content;
+			new_oi.sizep = &size;
+			new_oi.type_name = &type_name;
+		}
+		oi = &new_oi;
+	}
+
+	ret = oid_object_info_extended(r, &oid, oi, flags);
+	if (ret)
+		return -1;
+	if (oi == input_oi)
+		return ret;
+
+	if (new_oi.contentp) {
+		struct strbuf outbuf = STRBUF_INIT;
+		enum object_type type;
+
+		type = type_from_string_gently(type_name.buf, type_name.len,
+					       !do_die);
+		if (type == -1)
+			return -1;
+		if (type != OBJ_BLOB) {
+			ret = convert_object_file(&outbuf,
+						  the_hash_algo, input_algo,
+						  content, size, type, !do_die);
+			if (ret == -1)
+				return -1;
+			free(content);
+			size = outbuf.len;
+			content = strbuf_detach(&outbuf, NULL);
+		}
+		if (input_oi->sizep)
+			*input_oi->sizep = size;
+		if (input_oi->contentp)
+			*input_oi->contentp = content;
+		else
+			free(content);
+		if (input_oi->type_name)
+			*input_oi->type_name = type_name;
+		else
+			strbuf_release(&type_name);
+	}
+	if (new_oi.delta_base_oid == &delta_base_oid) {
+		if (repo_oid_to_algop(r, &delta_base_oid, input_algo,
+				 input_oi->delta_base_oid)) {
+			if (do_die)
+				die(_("missing mapping of %s to %s"),
+				    oid_to_hex(&delta_base_oid),
+				    input_algo->name);
+			return -1;
+		}
+	}
+	input_oi->whence = new_oi.whence;
+	input_oi->u = new_oi.u;
+	return ret;
+}
+
 int oid_object_info_extended(struct repository *r, const struct object_id *oid,
 			     struct object_info *oi, unsigned flags)
 {
 	int ret;
+
+	if (oid->algo && (hash_algo_by_ptr(r->hash_algo) != oid->algo))
+		return oid_object_info_convert(r, oid, oi, flags);
+
 	obj_read_lock();
 	ret = do_oid_object_info_extended(r, oid, oi, flags);
 	obj_read_unlock();
@@ -1944,9 +2039,12 @@ static int start_loose_object_common(struct strbuf *tmp_file,
 				     const char *filename, unsigned flags,
 				     git_zstream *stream,
 				     unsigned char *buf, size_t buflen,
-				     git_hash_ctx *c,
+				     git_hash_ctx *c, git_hash_ctx *compat_c,
 				     char *hdr, int hdrlen)
 {
+	struct repository *repo = the_repository;
+	const struct git_hash_algo *algo = repo->hash_algo;
+	const struct git_hash_algo *compat = repo->compat_hash_algo;
 	int fd;

 	fd = create_tmpfile(tmp_file, filename);
@@ -1966,14 +2064,18 @@ static int start_loose_object_common(struct strbuf *tmp_file,
 	git_deflate_init(stream, zlib_compression_level);
 	stream->next_out = buf;
 	stream->avail_out = buflen;
-	the_hash_algo->init_fn(c);
+	algo->init_fn(c);
+	if (compat && compat_c)
+		compat->init_fn(compat_c);

 	/*  Start to feed header to zlib stream */
 	stream->next_in = (unsigned char *)hdr;
 	stream->avail_in = hdrlen;
 	while (git_deflate(stream, 0) == Z_OK)
 		; /* nothing */
-	the_hash_algo->update_fn(c, hdr, hdrlen);
+	algo->update_fn(c, hdr, hdrlen);
+	if (compat && compat_c)
+		compat->update_fn(compat_c, hdr, hdrlen);

 	return fd;
 }
@@ -1982,16 +2084,21 @@ static int start_loose_object_common(struct strbuf *tmp_file,
 * Common steps for the inner git_deflate() loop for writing loose
 * objects. Returns what git_deflate() returns.
 */
-static int write_loose_object_common(git_hash_ctx *c,
+static int write_loose_object_common(git_hash_ctx *c, git_hash_ctx *compat_c,
 				     git_zstream *stream, const int flush,
 				     unsigned char *in0, const int fd,
 				     unsigned char *compressed,
 				     const size_t compressed_len)
 {
+	struct repository *repo = the_repository;
+	const struct git_hash_algo *algo = repo->hash_algo;
+	const struct git_hash_algo *compat = repo->compat_hash_algo;
 	int ret;

 	ret = git_deflate(stream, flush ? Z_FINISH : 0);
-	the_hash_algo->update_fn(c, in0, stream->next_in - in0);
+	algo->update_fn(c, in0, stream->next_in - in0);
+	if (compat && compat_c)
+		compat->update_fn(compat_c, in0, stream->next_in - in0);
 	if (write_in_full(fd, compressed, stream->next_out - compressed) < 0)
 		die_errno(_("unable to write loose object file"));
 	stream->next_out = compressed;
@@ -2006,15 +2113,21 @@ static int write_loose_object_common(git_hash_ctx *c,
 * - End the compression of zlib stream.
 * - Get the calculated oid to "oid".
 */
-static int end_loose_object_common(git_hash_ctx *c, git_zstream *stream,
-				   struct object_id *oid)
+static int end_loose_object_common(git_hash_ctx *c, git_hash_ctx *compat_c,
+				   git_zstream *stream, struct object_id *oid,
+				   struct object_id *compat_oid)
 {
+	struct repository *repo = the_repository;
+	const struct git_hash_algo *algo = repo->hash_algo;
+	const struct git_hash_algo *compat = repo->compat_hash_algo;
 	int ret;

 	ret = git_deflate_end_gently(stream);
 	if (ret != Z_OK)
 		return ret;
-	the_hash_algo->final_oid_fn(oid, c);
+	algo->final_oid_fn(oid, c);
+	if (compat && compat_c)
+		compat->final_oid_fn(compat_oid, compat_c);

 	return Z_OK;
 }
@@ -2038,7 +2151,7 @@ static int write_loose_object(const struct object_id *oid, char *hdr,

 	fd = start_loose_object_common(&tmp_file, filename.buf, flags,
 				       &stream, compressed, sizeof(compressed),
-				       &c, hdr, hdrlen);
+				       &c, NULL, hdr, hdrlen);
 	if (fd < 0)
 		return -1;

@@ -2048,14 +2161,14 @@ static int write_loose_object(const struct object_id *oid, char *hdr,
 	do {
 		unsigned char *in0 = stream.next_in;

-		ret = write_loose_object_common(&c, &stream, 1, in0, fd,
+		ret = write_loose_object_common(&c, NULL, &stream, 1, in0, fd,
 						compressed, sizeof(compressed));
 	} while (ret == Z_OK);

 	if (ret != Z_STREAM_END)
 		die(_("unable to deflate new object %s (%d)"), oid_to_hex(oid),
 		    ret);
-	ret = end_loose_object_common(&c, &stream, &parano_oid);
+	ret = end_loose_object_common(&c, NULL, &stream, &parano_oid, NULL);
 	if (ret != Z_OK)
 		die(_("deflateEnd on object %s failed (%d)"), oid_to_hex(oid),
 		    ret);
@@ -2100,10 +2213,12 @@ static int freshen_packed_object(const struct object_id *oid)
 int stream_loose_object(struct input_stream *in_stream, size_t len,
 			struct object_id *oid)
 {
+	const struct git_hash_algo *compat = the_repository->compat_hash_algo;
+	struct object_id compat_oid;
 	int fd, ret, err = 0, flush = 0;
 	unsigned char compressed[4096];
 	git_zstream stream;
-	git_hash_ctx c;
+	git_hash_ctx c, compat_c;
 	struct strbuf tmp_file = STRBUF_INIT;
 	struct strbuf filename = STRBUF_INIT;
 	int dirlen;
@@ -2127,7 +2242,7 @@ int stream_loose_object(struct input_stream *in_stream, size_t len,
 	 */
 	fd = start_loose_object_common(&tmp_file, filename.buf, 0,
 				       &stream, compressed, sizeof(compressed),
-				       &c, hdr, hdrlen);
+				       &c, &compat_c, hdr, hdrlen);
 	if (fd < 0) {
 		err = -1;
 		goto cleanup;
@@ -2145,7 +2260,7 @@ int stream_loose_object(struct input_stream *in_stream, size_t len,
 			if (in_stream->is_finished)
 				flush = 1;
 		}
-		ret = write_loose_object_common(&c, &stream, flush, in0, fd,
+		ret = write_loose_object_common(&c, &compat_c, &stream, flush, in0, fd,
 						compressed, sizeof(compressed));
 		/*
 		 * Unlike write_loose_object(), we do not have the entire
@@ -2168,7 +2283,7 @@ int stream_loose_object(struct input_stream *in_stream, size_t len,
 	 */
 	if (ret != Z_STREAM_END)
 		die(_("unable to stream deflate new object (%d)"), ret);
-	ret = end_loose_object_common(&c, &stream, oid);
+	ret = end_loose_object_common(&c, &compat_c, &stream, oid, &compat_oid);
 	if (ret != Z_OK)
 		die(_("deflateEnd on stream object failed (%d)"), ret);
 	close_loose_object(fd, tmp_file.buf);
@@ -2195,6 +2310,8 @@ int stream_loose_object(struct input_stream *in_stream, size_t len,
 	}

 	err = finalize_object_file(tmp_file.buf, filename.buf);
+	if (!err && compat)
+		err = repo_add_loose_object_map(the_repository, oid, &compat_oid);
 cleanup:
 	strbuf_release(&tmp_file);
 	strbuf_release(&filename);
@@ -2203,19 +2320,42 @@ cleanup:

 int write_object_file_flags(const void *buf, unsigned long len,
 			    enum object_type type, struct object_id *oid,
-			    unsigned flags)
+			    struct object_id *compat_oid_in, unsigned flags)
 {
+	struct repository *repo = the_repository;
+	const struct git_hash_algo *algo = repo->hash_algo;
+	const struct git_hash_algo *compat = repo->compat_hash_algo;
+	struct object_id compat_oid;
 	char hdr[MAX_HEADER_LEN];
 	int hdrlen = sizeof(hdr);

+	/* Generate compat_oid */
+	if (compat) {
+		if (compat_oid_in)
+			oidcpy(&compat_oid, compat_oid_in);
+		else if (type == OBJ_BLOB)
+			hash_object_file(compat, buf, len, type, &compat_oid);
+		else {
+			struct strbuf converted = STRBUF_INIT;
+			convert_object_file(&converted, algo, compat,
+					    buf, len, type, 0);
+			hash_object_file(compat, converted.buf, converted.len,
+					 type, &compat_oid);
+			strbuf_release(&converted);
+		}
+	}
+
 	/* Normally if we have it in the pack then we do not bother writing
 	 * it out into .git/objects/??/?{38} file.
 	 */
-	write_object_file_prepare(the_hash_algo, buf, len, type, oid, hdr,
-				  &hdrlen);
+	write_object_file_prepare(algo, buf, len, type, oid, hdr, &hdrlen);
 	if (freshen_packed_object(oid) || freshen_loose_object(oid))
 		return 0;
-	return write_loose_object(oid, hdr, hdrlen, buf, len, 0, flags);
+	if (write_loose_object(oid, hdr, hdrlen, buf, len, 0, flags))
+		return -1;
+	if (compat)
+		return repo_add_loose_object_map(repo, oid, &compat_oid);
+	return 0;
 }

 int write_object_file_literally(const void *buf, unsigned long len,
@@ -2223,7 +2363,27 @@ int write_object_file_literally(const void *buf, unsigned long len,
 				unsigned flags)
 {
 	char *header;
+	struct repository *repo = the_repository;
+	const struct git_hash_algo *algo = repo->hash_algo;
+	const struct git_hash_algo *compat = repo->compat_hash_algo;
+	struct object_id compat_oid;
 	int hdrlen, status = 0;
+	int compat_type = -1;
+
+	if (compat) {
+		compat_type = type_from_string_gently(type, -1, 1);
+		if (compat_type == OBJ_BLOB)
+			hash_object_file(compat, buf, len, compat_type,
+					 &compat_oid);
+		else if (compat_type != -1) {
+			struct strbuf converted = STRBUF_INIT;
+			convert_object_file(&converted, algo, compat,
+					    buf, len, compat_type, 0);
+			hash_object_file(compat, converted.buf, converted.len,
+					 compat_type, &compat_oid);
+			strbuf_release(&converted);
+		}
+	}

 	/* type string, SP, %lu of the length plus NUL must fit this */
 	hdrlen = strlen(type) + MAX_HEADER_LEN;
@@ -2236,6 +2396,8 @@ int write_object_file_literally(const void *buf, unsigned long len,
 	if (freshen_packed_object(oid) || freshen_loose_object(oid))
 		goto cleanup;
 	status = write_loose_object(oid, header, hdrlen, buf, len, 0, 0);
+	if (compat_type != -1)
+		return repo_add_loose_object_map(repo, oid, &compat_oid);

 cleanup:
 	free(header);
@@ -2244,9 +2406,12 @@ cleanup:

 int force_object_loose(const struct object_id *oid, time_t mtime)
 {
+	struct repository *repo = the_repository;
+	const struct git_hash_algo *compat = repo->compat_hash_algo;
 	void *buf;
 	unsigned long len;
 	struct object_info oi = OBJECT_INFO_INIT;
+	struct object_id compat_oid;
 	enum object_type type;
 	char hdr[MAX_HEADER_LEN];
 	int hdrlen;
@@ -2259,8 +2424,15 @@ int force_object_loose(const struct object_id *oid, time_t mtime)
 	oi.contentp = &buf;
 	if (oid_object_info_extended(the_repository, oid, &oi, 0))
 		return error(_("cannot read object for %s"), oid_to_hex(oid));
+	if (compat) {
+		if (repo_oid_to_algop(repo, oid, compat, &compat_oid))
+			return error(_("cannot map object %s to %s"),
+				     oid_to_hex(oid), compat->name);
+	}
 	hdrlen = format_object_header(hdr, sizeof(hdr), type, len);
 	ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime, 0);
+	if (!ret && compat)
+		ret = repo_add_loose_object_map(the_repository, oid, &compat_oid);
 	free(buf);

 	return ret;