Subject: [PATCH v2 02/10] read-cache.c: dump common extension info in json

From: Nguyễn Thái Ngọc Duy <[email-masked]>
Date: Mon, 24 Jun 2019 20:02:18 +0700

Signed-off-by: Nguyễn Thái Ngọc Duy <[email-masked]>
---
 read-cache.c | 49 +++++++++++++++++++++++++++++++++++--------------
 1 file changed, 35 insertions(+), 14 deletions(-)

diff --git a/read-cache.c b/read-cache.c
index db5147d088..4accd8bb08 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1694,8 +1694,26 @@ static int verify_hdr(const struct cache_header *hdr, unsigned long size)
 }
 
 static int read_index_extension(struct index_state *istate,
-				const char *ext, const char *data, unsigned long sz)
+				const char *map,
+				unsigned long *offset)
 {
+	int ret = 0;
+	const char *ext = map + *offset;
+	uint32_t sz = get_be32(ext + 4);
+	const char *data = ext + 8;
+
+	if (istate->jw) {
+		char buf[5];
+
+		memcpy(buf, ext, 4);
+		buf[4] = '\0';
+		jw_object_inline_begin_object(istate->jw, buf);
+
+		jw_object_intmax(istate->jw, "file_offset", *offset);
+		jw_object_intmax(istate->jw, "ext_size", sz);
+	}
+	*offset += sz + 8;
+
 	switch (CACHE_EXT(ext)) {
 	case CACHE_EXT_TREE:
 		istate->cache_tree = cache_tree_read(data, sz);
@@ -1704,8 +1722,7 @@ static int read_index_extension(struct index_state *istate,
 		istate->resolve_undo = resolve_undo_read(data, sz);
 		break;
 	case CACHE_EXT_LINK:
-		if (read_link_extension(istate, data, sz))
-			return -1;
+		ret = read_link_extension(istate, data, sz);
 		break;
 	case CACHE_EXT_UNTRACKED:
 		istate->untracked = read_untracked_extension(data, sz);
@@ -1719,12 +1736,14 @@ static int read_index_extension(struct index_state *istate,
 		break;
 	default:
 		if (*ext < 'A' || 'Z' < *ext)
-			return error(_("index uses %.4s extension, which we do not understand"),
+			ret = error(_("index uses %.4s extension, which we do not understand"),
 				     ext);
-		fprintf_ln(stderr, _("ignoring %.4s extension"), ext);
+		else
+			  fprintf_ln(stderr, _("ignoring %.4s extension"), ext);
 		break;
 	}
-	return 0;
+	jw_end_gently(istate->jw);
+	return ret;
 }
 
 static struct cache_entry *create_from_disk(struct mem_pool *ce_mem_pool,
@@ -1930,25 +1949,27 @@ static void *load_index_extensions(void *_data)
 {
 	struct load_index_extensions *p = _data;
 	unsigned long src_offset = p->src_offset;
+	int dump_json = 0;
 
 	while (src_offset <= p->mmap_size - the_hash_algo->rawsz - 8) {
-		/* After an array of active_nr index entries,
+		if (p->istate->jw && !dump_json) {
+			jw_object_inline_begin_object(p->istate->jw, "extensions");
+			dump_json = 1;
+		}
+		/*
+		 * 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.
 		 */
-		uint32_t extsize = get_be32(p->mmap + src_offset + 4);
-		if (read_index_extension(p->istate,
-					 p->mmap + src_offset,
-					 p->mmap + src_offset + 8,
-					 extsize) < 0) {
+		if (read_index_extension(p->istate, p->mmap, &src_offset) < 0) {
 			munmap((void *)p->mmap, p->mmap_size);
 			die(_("index file corrupt"));
 		}
-		src_offset += 8;
-		src_offset += extsize;
 	}
+	if (dump_json)
+		jw_end(p->istate->jw);
 
 	return NULL;
 }
-- 
2.22.0.rc0.322.g2b0371e29a