[t:5133] fix a memory leak, clean up the ule API.

git-svn-id: file:///svn/toku/tokudb@45044 c7de825b-a66e-492c-adef-691d508d4ae1

ft/ule.c

@@ -77,9 +77,9 @@ toku_le_get_status(LE_STATUS statp) {
 //
 
 ULEHANDLE 
-toku_ule_create(void * le_p) {
+toku_ule_create(const LEAFENTRY le) {
     ULE ule_p = toku_xmalloc(sizeof(ULE_S));
-    le_unpack(ule_p, le_p);
+    le_unpack(ule_p, le);
     return (ULEHANDLE) ule_p;
 }
 
@@ -518,7 +518,7 @@ ule_cleanup(ULE ule) {
 
 // Purpose of le_unpack() is to populate our private workspace with the contents of the given le.
 void
-le_unpack(ULE ule, LEAFENTRY le) {
+le_unpack(ULE ule, const LEAFENTRY le) {
     //Read the keylen
     ule->keylen = toku_dtoh32(le->keylen);
     uint8_t  type = le->type;

ft/ule.h

@@ -23,7 +23,8 @@ extern "C" {
 typedef struct ule *ULEHANDLE;	
 typedef struct uxr *UXRHANDLE;
 
-ULEHANDLE toku_ule_create(void * le_p);
+// create a ULE by copying the contents of the given leafentry
+ULEHANDLE toku_ule_create(const LEAFENTRY le);
 
 void toku_ule_free(ULEHANDLE ule_p);
 

src/indexer.c

@@ -364,16 +364,21 @@ struct le_cursor_extra {
 // cachetable pair locks. because no txn can commit on this db, read
 // the provisional info for the newly read ule.
 static int
-le_cursor_callback(ITEMLEN UU(keylen), bytevec UU(key), ITEMLEN vallen, bytevec val, void *extra, bool lock_only) {
+le_cursor_callback(ITEMLEN UU(keylen), bytevec UU(key), ITEMLEN UU(vallen), bytevec val, void *extra, bool lock_only) {
     if (lock_only || val == NULL) {
-        ; // do nothing if only locking or val==NULL, meaning there are no more elements
+        ; // do nothing if only locking. do nothing if val==NULL, means DB_NOTFOUND
     } else {
         struct le_cursor_extra *cursor_extra = extra;
         struct ule_prov_info *prov_info = cursor_extra->prov_info;
-        // TODO(John): Do we need to actually copy this ule and save it after
-        // copying all of the provisional info? or is the info all we need?
-        void *le_buf = toku_xmemdup(val, vallen);
-        ULEHANDLE ule = toku_ule_create(le_buf);
+        // the val here is a leafentry. ule_create copies the contents of a
+        // leafentry into its own buffers, so we don't need to malloc space
+        // for this value to exist outside the callback.
+        //
+        // this cast is only necssary because the typedef is preventing us
+        // from declaring a "const LEAFENTRY" le. we're only able to say
+        // const "LEAFENTRY le".
+        const LEAFENTRY le = (const LEAFENTRY) val;
+        ULEHANDLE ule = toku_ule_create(le);
         invariant(ule);
         ule_prov_info_init(prov_info, ule);
         indexer_fill_prov_info(cursor_extra->indexer, prov_info);