[PATCH 7/8] cache-tree.c: dump "TREE" extension as json

[Nguyễn Thái Ngọc Duy]

Signed-off-by: Nguyễn Thái Ngọc Duy <pclo...@gmail.com>
---
 cache-tree.c | 41 ++++++++++++++++++++++++++++++++++++-----
 cache-tree.h |  5 ++++-
 read-cache.c |  2 +-
 3 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/cache-tree.c b/cache-tree.c
index b13bfaf71e..fc44016fe8 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -3,6 +3,7 @@
 #include "tree.h"
 #include "tree-walk.h"
 #include "cache-tree.h"
+#include "json-writer.h"
 #include "object-store.h"
 #include "replace-object.h"
 
@@ -492,7 +493,8 @@ void cache_tree_write(struct strbuf *sb, struct cache_tree 
*root)
        write_one(sb, root, "", 0);
 }
 
-static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
+static struct cache_tree *read_one(const char **buffer, unsigned long *size_p,
+                                  struct json_writer *jw)
 {
        const char *buf = *buffer;
        unsigned long size = *size_p;
@@ -546,6 +548,15 @@ static struct cache_tree *read_one(const char **buffer, 
unsigned long *size_p)
                        *buffer, subtree_nr);
 #endif
 
+       if (jw) {
+               if (it->entry_count >= 0) {
+                       jw_object_string(jw, "oid", oid_to_hex(&it->oid));
+                       jw_object_intmax(jw, "entry_count", it->entry_count);
+               } else {
+                       jw_object_null(jw, "oid");
+               }
+               jw_object_inline_begin_array(jw, "subdirs");
+       }
        /*
         * Just a heuristic -- we do not add directories that often but
         * we do not want to have to extend it immediately when we do,
@@ -559,12 +570,18 @@ static struct cache_tree *read_one(const char **buffer, 
unsigned long *size_p)
                struct cache_tree_sub *subtree;
                const char *name = buf;
 
-               sub = read_one(&buf, &size);
+               if (jw) {
+                       jw_array_inline_begin_object(jw);
+                       jw_object_string(jw, "name", name);
+               }
+               sub = read_one(&buf, &size, jw);
+               jw_end_gently(jw);
                if (!sub)
                        goto free_return;
                subtree = cache_tree_sub(it, name);
                subtree->cache_tree = sub;
        }
+       jw_end_gently(jw);
        if (subtree_nr != it->subtree_nr)
                die("cache-tree: internal error");
        *buffer = buf;
@@ -576,11 +593,25 @@ static struct cache_tree *read_one(const char **buffer, 
unsigned long *size_p)
        return NULL;
 }
 
-struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
+struct cache_tree *cache_tree_read(const char *buffer, unsigned long size,
+                                  struct json_writer *jw)
 {
+       struct cache_tree *ret;
+
+       if (jw) {
+               jw_object_inline_begin_object(jw, "cache-tree");
+               jw_object_intmax(jw, "ext-size", size);
+               jw_object_inline_begin_object(jw, "root");
+       }
        if (buffer[0])
-               return NULL; /* not the whole tree */
-       return read_one(&buffer, &size);
+               ret = NULL; /* not the whole tree */
+       else
+               ret = read_one(&buffer, &size, jw);
+       if (jw) {
+               jw_end(jw);     /* root */
+               jw_end(jw);     /* cache-tree */
+       }
+       return ret;
 }
 
 static struct cache_tree *cache_tree_find(struct cache_tree *it, const char 
*path)
diff --git a/cache-tree.h b/cache-tree.h
index 757bbc48bc..fc3c73284b 100644
--- a/cache-tree.h
+++ b/cache-tree.h
@@ -6,6 +6,8 @@
 #include "tree-walk.h"
 
 struct cache_tree;
+struct json_writer;
+
 struct cache_tree_sub {
        struct cache_tree *cache_tree;
        int count;              /* internally used by update_one() */
@@ -28,7 +30,8 @@ void cache_tree_invalidate_path(struct index_state *, const 
char *);
 struct cache_tree_sub *cache_tree_sub(struct cache_tree *, const char *);
 
 void cache_tree_write(struct strbuf *, struct cache_tree *root);
-struct cache_tree *cache_tree_read(const char *buffer, unsigned long size);
+struct cache_tree *cache_tree_read(const char *buffer, unsigned long size,
+                                  struct json_writer *jw);
 
 int cache_tree_fully_valid(struct cache_tree *);
 int cache_tree_update(struct index_state *, int);
diff --git a/read-cache.c b/read-cache.c
index 200834e77e..289705b816 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1698,7 +1698,7 @@ static int read_index_extension(struct index_state 
*istate,
 {
        switch (CACHE_EXT(ext)) {
        case CACHE_EXT_TREE:
-               istate->cache_tree = cache_tree_read(data, sz);
+               istate->cache_tree = cache_tree_read(data, sz, istate->jw);
                break;
        case CACHE_EXT_RESOLVE_UNDO:
                istate->resolve_undo = resolve_undo_read(data, sz, istate->jw);
-- 
2.22.0.rc0.322.g2b0371e29a