[PATCH v3 6/6] chunked-object: fallback checkout codepaths

From

Junio C Hamano <gitster@pobox.com>

Date

Dec 2, 2011, 00:40 UTC

Message-ID

<1322786449-25753-7-git-send-email-gitster@pobox.com>

In-Reply-To

<1322786449-25753-1-git-send-email-gitster@pobox.com>

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sha1_file.c      |   54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 t/t1050-large.sh |   14 +++++++++++++-
 2 files changed, 67 insertions(+), 1 deletions(-)

diff --git a/sha1_file.c b/sha1_file.c
index 14902cc..7355716 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1607,6 +1607,11 @@ static int packed_object_info(struct packed_git *p, off_t obj_offset,
 		if (sizep)
 			*sizep = size;
 		break;
+	case OBJ_CHUNKED_BLOB:
+		if (sizep)
+			*sizep = size;
+		type = OBJ_DEKNUHC(type);
+		break;
 	default:
 		error("unknown object type %i at offset %"PRIuMAX" in %s",
 		      type, (uintmax_t)obj_offset, p->pack_name);
@@ -1648,6 +1653,51 @@ static void *unpack_compressed_entry(struct packed_git *p,
 	return buffer;
 }
 
+static void *unpack_chunked_entry(struct packed_git *p,
+				  struct pack_window **w_curs,
+				  off_t curpos,
+				  unsigned long size)
+{
+	/*
+	 * *NOTE* *NOTE* *NOTE*
+	 *
+	 * In the longer term, we should aim to exercise this codepath
+	 * less and less often, as it defeats the whole purpose of
+	 * chuncked object encoding!
+	 */
+	unsigned char *buffer;
+	const unsigned char *in, *ptr;
+	unsigned long avail, ofs;
+	int chunk_cnt;
+
+	buffer = xmallocz(size);
+	in = use_pack(p, w_curs, curpos, &avail);
+	ptr = in;
+	chunk_cnt = decode_in_pack_varint(&ptr);
+	curpos += ptr - in;
+	ofs = 0;
+	while (chunk_cnt--) {
+		unsigned long csize;
+		unsigned char *data;
+		enum object_type type;
+
+		in = use_pack(p, w_curs, curpos, &avail);
+		data = read_sha1_file(in, &type, &csize);
+		if (!data)
+			die("malformed chunked object contents ('%s' does not exist)",
+			    sha1_to_hex(in));
+		if (type != OBJ_BLOB)
+			die("malformed chunked object contents (not a blob)");
+		if (size < ofs + csize)
+			die("malformed chunked object contents (sizes do not add up)");
+		memcpy(buffer + ofs, data, csize);
+		ofs += csize;
+		curpos += 20;
+		free(data);
+	}
+	return buffer;
+}
+
 #define MAX_DELTA_CACHE (256)
 
 static size_t delta_base_cached;
@@ -1883,6 +1933,10 @@ void *unpack_entry(struct packed_git *p, off_t obj_offset,
 	case OBJ_TAG:
 		data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
 		break;
+	case OBJ_CHUNKED_BLOB:
+		data = unpack_chunked_entry(p, &w_curs, curpos, *sizep);
+		*type = OBJ_DEKNUHC(*type);
+		break;
 	default:
 		data = NULL;
 		error("unknown object type %i at offset %"PRIuMAX" in %s",
diff --git a/t/t1050-large.sh b/t/t1050-large.sh
index d6cb66d..eea45d1 100755
--- a/t/t1050-large.sh
+++ b/t/t1050-large.sh
@@ -124,8 +124,20 @@ test_expect_success 'split limit' '
 		# switch to a better chunking heuristics.
 		echo cruft >head &&
 		cat split >>head &&
-		git add head
+		git add head &&
 
+		echo blob >expect &&
+		git cat-file -t :split >actual &&
+		test_cmp expect actual &&
+
+		git cat-file -p :split >actual &&
+		# You probably do not want to use test_cmp here...
+		cmp split actual &&
+
+		mv split expect &&
+		git checkout split &&
+		# You probably do not want to use test_cmp here...
+		cmp expect split
 	)
 '
 

-- 
1.7.8.rc4.177.g4d64