[PATCH v3 5/7] mem-pool: fill out functionality

[Jameson Miller <jamill@microsoft.com>]

Add functions for:

    - combining two memory pools

    - determining if a memory address is within the range managed by a
      memory pool

These functions will be used by future commits.

Signed-off-by: Jameson Miller <jamill@microsoft.com>
---
 mem-pool.c | 40 ++++++++++++++++++++++++++++++++++++++++
 mem-pool.h | 13 +++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/mem-pool.c b/mem-pool.c
index 01595bcca5..cc7d3a7ab1 100644
--- a/mem-pool.c
+++ b/mem-pool.c
@@ -108,3 +108,43 @@ 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)
+{
+	/* 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.
+		 */
+		dst->mp_block_tail->next_block = src->mp_block;
+		dst->mp_block_tail = src->mp_block_tail;
+	} else if (src->mp_block) {
+		/*
+		 * src has blocks, dst is empty
+		 * use pointers from src to set up dst.
+		 */
+		dst->mp_block = src->mp_block;
+		dst->mp_block_tail = src->mp_block_tail;
+	} else {
+		// src is empty, nothing to do.
+	}
+
+	dst->pool_alloc += src->pool_alloc;
+	src->pool_alloc = 0;
+	src->mp_block = NULL;
+	src->mp_block_tail = NULL;
+}
diff --git a/mem-pool.h b/mem-pool.h
index 5d3e6a367a..5c892d3bdb 100644
--- a/mem-pool.h
+++ b/mem-pool.h
@@ -41,4 +41,17 @@ void *mem_pool_alloc(struct mem_pool *pool, size_t len);
  */
 void *mem_pool_calloc(struct mem_pool *pool, size_t count, size_t size);
 
+/*
+ * Move the memory associated with the 'src' pool to the 'dst' pool. The 'src'
+ * pool will be empty and not contain any memory. It still needs to be free'd
+ * with a call to `mem_pool_discard`.
+ */
+void mem_pool_combine(struct mem_pool *dst, struct mem_pool *src);
+
+/*
+ * Check if a memory pointed at by 'mem' is part of the range of
+ * memory managed by the specified mem_pool.
+ */
+int mem_pool_contains(struct mem_pool *mem_pool, void *mem);
+
 #endif
-- 
2.14.3