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

[Nguyễn Thái Ngọc Duy]

Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com>
---
 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