Remove resize_chunk API

The last user has been dropped in the previous commit. This has
never worked meaningfully in the first place.

Author: nikic

ext/mysqlnd/mysqlnd_block_alloc.c

@@ -43,33 +43,6 @@ mysqlnd_mempool_free_chunk(MYSQLND_MEMORY_POOL * pool, void * ptr)
 /* }}} */
 
 
-/* {{{ mysqlnd_mempool_resize_chunk */
-static void *
-mysqlnd_mempool_resize_chunk(MYSQLND_MEMORY_POOL * pool, void * ptr, size_t old_size, size_t size)
-{
-	DBG_ENTER("mysqlnd_mempool_resize_chunk");
-
-#ifndef ZEND_TRACK_ARENA_ALLOC
-	/* Try to back-off and guess if this is the last block allocated */
-	if (ptr == pool->last
-	  && (ZEND_MM_ALIGNED_SIZE(size) <= ((char*)pool->arena->end - (char*)ptr))) {
-		/*
-			This was the last allocation. Lucky us, we can free
-			a bit of memory from the pool. Next time we will return from the same ptr.
-		*/
-		pool->arena->ptr = (char*)ptr + ZEND_MM_ALIGNED_SIZE(size);
-		DBG_RETURN(ptr);
-	}
-#endif
-
-	void *new_ptr = zend_arena_alloc(&pool->arena, size);
-	memcpy(new_ptr, ptr, MIN(old_size, size));
-	pool->last = ptr = new_ptr;
-	DBG_RETURN(ptr);
-}
-/* }}} */
-
-
 /* {{{ mysqlnd_mempool_get_chunk */
 static void *
 mysqlnd_mempool_get_chunk(MYSQLND_MEMORY_POOL * pool, size_t size)
@@ -100,7 +73,6 @@ mysqlnd_mempool_create(size_t arena_size)
 	ret->checkpoint = NULL;
 	ret->get_chunk = mysqlnd_mempool_get_chunk;
 	ret->free_chunk = mysqlnd_mempool_free_chunk;
-	ret->resize_chunk = mysqlnd_mempool_resize_chunk;
 	DBG_RETURN(ret);
 }
 /* }}} */

ext/mysqlnd/mysqlnd_structs.h

@@ -55,7 +55,6 @@ struct st_mysqlnd_memory_pool
 	void            *checkpoint;
 
 	void*	(*get_chunk)(MYSQLND_MEMORY_POOL * pool, size_t size);
-	void*	(*resize_chunk)(MYSQLND_MEMORY_POOL * pool, void * ptr, size_t old_size, size_t size);
 	void	(*free_chunk)(MYSQLND_MEMORY_POOL * pool, void * ptr);
 };