1 files changed, 102 insertions, 12 deletions

diff --git a/mem-pool.c b/mem-pool.c
index 389d7af..a2841a4 100644
--- a/mem-pool.c
+++ b/mem-pool.c
@@ -5,40 +5,88 @@
 #include "cache.h"
 #include "mem-pool.h"
 
-static struct mp_block *mem_pool_alloc_block(struct mem_pool *mem_pool, size_t block_alloc)
+#define BLOCK_GROWTH_SIZE 1024*1024 - sizeof(struct mp_block);
+
+/*
+ * Allocate a new mp_block and insert it after the block specified in
+ * `insert_after`. If `insert_after` is NULL, then insert block at the
+ * head of the linked list.
+ */
+static struct mp_block *mem_pool_alloc_block(struct mem_pool *mem_pool, size_t block_alloc, struct mp_block *insert_after)
 {
 	struct mp_block *p;
 
 	mem_pool->pool_alloc += sizeof(struct mp_block) + block_alloc;
 	p = xmalloc(st_add(sizeof(struct mp_block), block_alloc));
-	p->next_block = mem_pool->mp_block;
+
 	p->next_free = (char *)p->space;
 	p->end = p->next_free + block_alloc;
-	mem_pool->mp_block = p;
+
+	if (insert_after) {
+		p->next_block = insert_after->next_block;
+		insert_after->next_block = p;
+	} else {
+		p->next_block = mem_pool->mp_block;
+		mem_pool->mp_block = p;
+	}
 
 	return p;
 }
 
+void mem_pool_init(struct mem_pool **mem_pool, size_t initial_size)
+{
+	struct mem_pool *pool;
+
+	if (*mem_pool)
+		return;
+
+	pool = xcalloc(1, sizeof(*pool));
+
+	pool->block_alloc = BLOCK_GROWTH_SIZE;
+
+	if (initial_size > 0)
+		mem_pool_alloc_block(pool, initial_size, NULL);
+
+	*mem_pool = pool;
+}
+
+void mem_pool_discard(struct mem_pool *mem_pool, int invalidate_memory)
+{
+	struct mp_block *block, *block_to_free;
+
+	block = mem_pool->mp_block;
+	while (block)
+	{
+		block_to_free = block;
+		block = block->next_block;
+
+		if (invalidate_memory)
+			memset(block_to_free->space, 0xDD, ((char *)block_to_free->end) - ((char *)block_to_free->space));
+
+		free(block_to_free);
+	}
+
+	free(mem_pool);
+}
+
 void *mem_pool_alloc(struct mem_pool *mem_pool, size_t len)
 {
-	struct mp_block *p;
+	struct mp_block *p = NULL;
 	void *r;
 
 	/* round up to a 'uintmax_t' alignment */
 	if (len & (sizeof(uintmax_t) - 1))
 		len += sizeof(uintmax_t) - (len & (sizeof(uintmax_t) - 1));
 
-	for (p = mem_pool->mp_block; p; p = p->next_block)
-		if (p->end - p->next_free >= len)
-			break;
+	if (mem_pool->mp_block &&
+	    mem_pool->mp_block->end - mem_pool->mp_block->next_free >= len)
+		p = mem_pool->mp_block;
 
 	if (!p) {
-		if (len >= (mem_pool->block_alloc / 2)) {
-			mem_pool->pool_alloc += len;
-			return xmalloc(len);
-		}
+		if (len >= (mem_pool->block_alloc / 2))
+			return mem_pool_alloc_block(mem_pool, len, mem_pool->mp_block);
 
-		p = mem_pool_alloc_block(mem_pool, mem_pool->block_alloc);
+		p = mem_pool_alloc_block(mem_pool, mem_pool->block_alloc, NULL);
 	}
 
 	r = p->next_free;
@@ -53,3 +101,45 @@ void *mem_pool_calloc(struct mem_pool *mem_pool, size_t count, size_t size)
 	memset(r, 0, len);
 	return r;
 }
+
+int mem_pool_contains(struct mem_pool *mem_pool, void *mem)
+{
+	struct mp_block *p;
+
+	/* Check if memory is allocated in a block */
+	for (p = mem_pool->mp_block; p; p = p->next_block)
+		if ((mem >= ((void *)p->space)) &&
+		    (mem < ((void *)p->end)))
+			return 1;
+
+	return 0;
+}
+
+void mem_pool_combine(struct mem_pool *dst, struct mem_pool *src)
+{
+	struct mp_block *p;
+
+	/* Append the blocks from src to dst */
+	if (dst->mp_block && src->mp_block) {
+		/*
+		 * src and dst have blocks, append
+		 * blocks from src to dst.
+		 */
+		p = dst->mp_block;
+		while (p->next_block)
+			p = p->next_block;
+
+		p->next_block = src->mp_block;
+	} else if (src->mp_block) {
+		/*
+		 * src has blocks, dst is empty.
+		 */
+		dst->mp_block = src->mp_block;
+	} else {
+		/* src is empty, nothing to do. */
+	}
+
+	dst->pool_alloc += src->pool_alloc;
+	src->pool_alloc = 0;
+	src->mp_block = NULL;
+}