modules/kvs: Refactor cache_entry_get_treeobj()

Return const json_t * from function, as we do not want users
to modify any json object stored in the cache.

src/modules/kvs/cache.c

@@ -186,7 +186,7 @@ int cache_entry_set_raw (struct cache_entry *hp, void *data, int len)
     return -1;
 }
 
-json_t *cache_entry_get_treeobj (struct cache_entry *hp)
+const json_t *cache_entry_get_treeobj (struct cache_entry *hp)
 {
     if (!hp || !hp->valid || !hp->data)
         return NULL;

src/modules/kvs/cache.h

@@ -82,7 +82,7 @@ int cache_entry_force_clear_dirty (struct cache_entry *hp);
 int cache_entry_get_raw (struct cache_entry *hp, void **data, int *len);
 int cache_entry_set_raw (struct cache_entry *hp, void *data, int len);
 
-json_t *cache_entry_get_treeobj (struct cache_entry *hp);
+const json_t *cache_entry_get_treeobj (struct cache_entry *hp);
 int cache_entry_set_treeobj (struct cache_entry *hp, json_t *o);
 
 /* Arrange for message handler represented by 'wait' to be restarted

src/modules/kvs/commit.c

@@ -559,6 +559,7 @@ static int commit_link_dirent (commit_t *c, int current_epoch,
         } else if (treeobj_is_dirref (dir_entry)) {
             struct cache_entry *hp;
             const char *ref;
+            const json_t *subdirtmp;
             int refcount;
 
             if ((refcount = treeobj_get_count (dir_entry)) < 0) {
@@ -584,13 +585,13 @@ static int commit_link_dirent (commit_t *c, int current_epoch,
                 goto success; /* stall */
             }
 
-            if (!(subdir = cache_entry_get_treeobj (hp))) {
+            if (!(subdirtmp = cache_entry_get_treeobj (hp))) {
                 saved_errno = ENOTRECOVERABLE;
                 goto done;
             }
 
             /* do not corrupt store by modifying orig. */
-            if (!(subdir = treeobj_copy (subdir))) {
+            if (!(subdir = treeobj_deep_copy (subdirtmp))) {
                 saved_errno = errno;
                 goto done;
             }
@@ -699,7 +700,7 @@ commit_process_t commit_process (commit_t *c,
             /* Make a copy of the root directory.
              */
             struct cache_entry *hp;
-            json_t *rootdir;
+            const json_t *rootdir;
 
             /* Caller didn't call commit_iter_missing_refs() */
             if (zlist_first (c->missing_refs_list))
@@ -725,7 +726,7 @@ commit_process_t commit_process (commit_t *c,
                 return COMMIT_PROCESS_ERROR;
             }
 
-            if (!(c->rootcpy = treeobj_copy (rootdir))) {
+            if (!(c->rootcpy = treeobj_deep_copy (rootdir))) {
                 c->errnum = errno;
                 return COMMIT_PROCESS_ERROR;
             }

src/modules/kvs/kvs.c

@@ -1421,7 +1421,7 @@ static void setroot_event_cb (flux_t *h, flux_msg_handler_t *w,
 
 static int setroot_event_send (kvs_ctx_t *ctx, json_t *names)
 {
-    json_t *root = NULL;
+    const json_t *root = NULL;
     json_t *nullobj = NULL;
     flux_msg_t *msg = NULL;
     int saved_errno, rc = -1;

src/modules/kvs/lookup.c

@@ -53,7 +53,7 @@
 typedef struct {
     int depth;
     char *path_copy;            /* for internal parsing, do not use */
-    json_t *dirent;
+    const json_t *dirent;
     zlist_t *pathcomps;
 } walk_level_t;
 
@@ -82,7 +82,7 @@ struct lookup {
     /* if valref_missing_refs is true, iterate on refs, else
      * return missing_ref string.
      */
-    json_t *valref_missing_refs;
+    const json_t *valref_missing_refs;
     const char *missing_ref;
 
     int errnum;                 /* errnum if error */
@@ -91,7 +91,7 @@ struct lookup {
     /* API internal */
     json_t *root_dirent;
     zlist_t *levels;
-    json_t *wdirent;       /* result after walk() */
+    const json_t *wdirent;       /* result after walk() */
     enum {
         LOOKUP_STATE_INIT,
         LOOKUP_STATE_CHECK_ROOT,
@@ -219,7 +219,7 @@ static walk_level_t *walk_levels_push (lookup_t *lh,
  */
 static bool walk (lookup_t *lh)
 {
-    json_t *dir;
+    const json_t *dir;
     walk_level_t *wl = NULL;
     char *pathcomp;
 
@@ -299,7 +299,7 @@ static bool walk (lookup_t *lh)
 
         /* Get directory reference of path component from directory */
 
-        if (!(wl->dirent = treeobj_get_entry (dir, pathcomp))) {
+        if (!(wl->dirent = treeobj_peek_entry (dir, pathcomp))) {
             /* if entry does not exist, not necessarily ENOENT error,
              * let caller decide.  If error not ENOENT, return to
              * caller. */
@@ -311,16 +311,13 @@ static bool walk (lookup_t *lh)
         /* Resolve dirent if it is a link */
 
         if (treeobj_is_symlink (wl->dirent)) {
-            json_t *link;
             const char *linkstr;
 
-            if (!(link = treeobj_get_data (wl->dirent))) {
+            if (!(linkstr = treeobj_get_symlink (wl->dirent))) {
                 lh->errnum = errno;
                 goto error;
             }
 
-            linkstr = json_string_value (link);
-
             /* Follow link if in middle of path or if end of path,
              * flags say we can follow it
              */
@@ -779,7 +776,7 @@ static int get_multi_blobref_valref_value (lookup_t *lh, int refcount,
 
 bool lookup (lookup_t *lh)
 {
-    json_t *valtmp = NULL;
+    const json_t *valtmp = NULL;
     const char *reftmp;
     struct cache_entry *hp;
     int refcount;

src/modules/kvs/test/cache.c

@@ -190,7 +190,8 @@ void cache_entry_raw_tests (void)
 void cache_entry_treeobj_tests (void)
 {
     struct cache_entry *e;
-    json_t *otmp, *o1, *o2, *otest;
+    json_t *o1, *o2, *otest;
+    const json_t *otmp;
     char *data;
 
     /* Play with one entry.
@@ -215,7 +216,7 @@ void cache_entry_treeobj_tests (void)
         "cache_entry_set_dirty fails b/c entry non-valid");
     ok (cache_entry_get_dirty (e) == false,
         "cache entry does not set dirty, b/c no data");
-    ok ((otmp = cache_entry_get_treeobj (e)) == NULL,
+    ok (cache_entry_get_treeobj (e) == NULL,
         "cache_entry_get_treeobj returns NULL, no treeobj set");
     ok (cache_entry_set_treeobj (e, o1) == 0,
         "cache_entry_set_treeobj success");
@@ -259,7 +260,8 @@ void cache_entry_treeobj_tests (void)
     ok ((otmp = cache_entry_get_treeobj (e)) != NULL,
         "treeobj retrieved from cache entry");
     otest = treeobj_create_val ("foo", 3);
-    ok (json_equal (otmp, otest) == 1,
+    /* XXX - json_equal takes const in jansson > 2.10 */
+    ok (json_equal ((json_t *)otmp, otest) == 1,
         "expected treeobj object returned");
     json_decref (otest);
 
@@ -270,7 +272,8 @@ void cache_entry_treeobj_tests (void)
 void cache_entry_raw_and_treeobj_tests (void)
 {
     struct cache_entry *e;
-    json_t *o1, *otmp, *otest;
+    json_t *o1, *otest;
+    const json_t *otmp;
     char *data, *datatmp;
     int len;
 
@@ -283,7 +286,7 @@ void cache_entry_raw_and_treeobj_tests (void)
         "cache_entry_create works");
     ok (cache_entry_set_raw (e, data, strlen (data) + 1) == 0,
         "cache_entry_set_raw success");
-    ok ((otmp = cache_entry_get_treeobj (e)) == NULL,
+    ok (cache_entry_get_treeobj (e) == NULL,
         "cache_entry_get_treeobj returns NULL for non-treeobj raw data");
     cache_entry_destroy (e);
 
@@ -293,7 +296,7 @@ void cache_entry_raw_and_treeobj_tests (void)
         "cache_entry_create works");
     ok (cache_entry_set_raw (e, NULL, 0) == 0,
         "cache_entry_set_raw success");
-    ok ((otmp = cache_entry_get_treeobj (e)) == NULL,
+    ok (cache_entry_get_treeobj (e) == NULL,
         "cache_entry_get_treeobj returns NULL for zero length raw data");
     cache_entry_destroy (e);
 
@@ -311,7 +314,8 @@ void cache_entry_raw_and_treeobj_tests (void)
     ok ((otmp = cache_entry_get_treeobj (e)) != NULL,
         "cache_entry_get_treeobj returns non-NULL for treeobj-legal raw data");
     otest = treeobj_create_val ("foo", 3);
-    ok (json_equal (otmp, otest) == true,
+    /* XXX - json_equal takes const in jansson > 2.10 */
+    ok (json_equal ((json_t *)otmp, otest) == true,
         "treeobj returned from cache entry correct");
     json_decref (o1);
     cache_entry_destroy (e);
@@ -582,8 +586,8 @@ void cache_expiration_tests (void)
     tstat_t ts;
     int size, incomplete, dirty;
     json_t *o1;
-    json_t *otmp;
     json_t *otest;
+    const json_t *otmp;
 
     /* Put entry in cache and test lookup, expire
      */
@@ -638,7 +642,8 @@ void cache_expiration_tests (void)
     ok ((otmp = cache_entry_get_treeobj (e4)) != NULL,
         "cache_entry_get_treeobj found entry");
     otest = treeobj_create_val ("foo", 3);
-    ok (json_equal (otmp, otest) == 1,
+    /* XXX - json_equal takes const in jansson > 2.10 */
+    ok (json_equal ((json_t *)otmp, otest) == 1,
         "expected treeobj object found");
     json_decref (otest);
     ok (cache_count_entries (cache) == 2,