(svn r1763) -Add: pool.c / pool.h: generalized routines for dynamic arrays (MemoryPools)

pool.c

@@ -0,0 +1,79 @@
+#include "stdafx.h"
+#include "ttd.h"
+#include "pool.h"
+
+/**
+ * Clean a pool in a safe way (does free all blocks)
+ */
+void CleanPool(MemoryPool *pool)
+{
+	uint i;
+
+	DEBUG(misc, 4)("[Pool] (%s) Cleaing pool..", pool->name);
+
+	/* Free all blocks */
+	for (i = 0; i < pool->current_blocks; i++)
+		free(pool->blocks[i]);
+
+	/* Free the block itself */
+	free(pool->blocks);
+
+	/* Clear up some critical data */
+	pool->total_items = 0;
+	pool->current_blocks = 0;
+	pool->blocks = NULL;
+}
+
+/**
+ * This function tries to increase the size of array by adding
+ *  1 block too it
+ *
+ * @return Returns false if the pool could not be increased
+ */
+bool AddBlockToPool(MemoryPool *pool)
+{
+	/* Is the pool at his max? */
+	if (pool->max_blocks == pool->current_blocks)
+		return false;
+
+	pool->total_items = (pool->current_blocks + 1) * (1 << pool->block_size_bits);
+
+	DEBUG(misc, 4)("[Pool] (%s) Increasing size of pool to %d items (%d bytes)", pool->name, pool->total_items, pool->total_items * pool->item_size);
+
+	/* Increase the poolsize */
+	pool->blocks = realloc(pool->blocks, sizeof(pool->blocks[0]) * (pool->current_blocks + 1));
+	if (pool->blocks == NULL)
+		error("Pool: (%s) could not allocate memory for blocks", pool->name);
+
+	/* Allocate memory to the new block item */
+	pool->blocks[pool->current_blocks] = malloc(pool->item_size * (1 << pool->block_size_bits));
+	if (pool->blocks[pool->current_blocks] == NULL)
+		error("Pool: (%s) could not allocate memory for blocks", pool->name);
+
+	/* Clean the content of the new block */
+	memset(pool->blocks[pool->current_blocks], 0, pool->item_size * (1 << pool->block_size_bits));
+
+	/* Call a custom function if defined (e.g. to fill indexes) */
+	if (pool->new_block_proc != NULL)
+		pool->new_block_proc(pool->current_blocks * (1 << pool->block_size_bits));
+
+	/* We have a new block */
+	pool->current_blocks++;
+
+	return true;
+}
+
+/**
+ * Adds blocks to the pool if needed (and possible) till index fits inside the pool
+ *
+ * @return Returns false if adding failed
+ */
+bool AddBlockIfNeeded(MemoryPool *pool, uint index)
+{
+	while (index >= pool->total_items) {
+		if (!AddBlockToPool(pool))
+			return false;
+	}
+
+	return true;
+}