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diff --git a/src/util/pool.h b/src/util/pool.h
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+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+#ifndef INCLUDE_pool_h__
+#define INCLUDE_pool_h__
+
+#include "git2_util.h"
+
+#include "vector.h"
+
+typedef struct git_pool_page git_pool_page;
+
+#ifndef GIT_DEBUG_POOL
+/**
+ * Chunked allocator.
+ *
+ * A `git_pool` can be used when you want to cheaply allocate
+ * multiple items of the same type and are willing to free them
+ * all together with a single call.  The two most common cases
+ * are a set of fixed size items (such as lots of OIDs) or a
+ * bunch of strings.
+ *
+ * Internally, a `git_pool` allocates pages of memory and then
+ * deals out blocks from the trailing unused portion of each page.
+ * The pages guarantee that the number of actual allocations done
+ * will be much smaller than the number of items needed.
+ *
+ * For examples of how to set up a `git_pool` see `git_pool_init`.
+ */
+typedef struct {
+	git_pool_page *pages; /* allocated pages */
+	size_t item_size;  /* size of single alloc unit in bytes */
+	size_t page_size;  /* size of page in bytes */
+} git_pool;
+
+#define GIT_POOL_INIT { NULL, 0, 0 }
+
+#else
+
+/**
+ * Debug chunked allocator.
+ *
+ * Acts just like `git_pool` but instead of actually pooling allocations it
+ * passes them through to `git__malloc`. This makes it possible to easily debug
+ * systems that use `git_pool` using valgrind.
+ *
+ * In order to track allocations during the lifetime of the pool we use a
+ * `git_vector`. When the pool is deallocated everything in the vector is
+ * freed.
+ *
+ * `API is exactly the same as the standard `git_pool` with one exception.
+ * Since we aren't allocating pages to hand out in chunks we can't easily
+ * implement `git_pool__open_pages`.
+ */
+typedef struct {
+	git_vector allocations;
+	size_t item_size;
+	size_t page_size;
+} git_pool;
+
+#define GIT_POOL_INIT { GIT_VECTOR_INIT, 0, 0 }
+
+#endif
+
+/**
+ * Initialize a pool.
+ *
+ * To allocation strings, use like this:
+ *
+ *     git_pool_init(&string_pool, 1);
+ *     my_string = git_pool_strdup(&string_pool, your_string);
+ *
+ * To allocate items of fixed size, use like this:
+ *
+ *     git_pool_init(&pool, sizeof(item));
+ *     my_item = git_pool_malloc(&pool, 1);
+ *
+ * Of course, you can use this in other ways, but those are the
+ * two most common patterns.
+ */
+extern int git_pool_init(git_pool *pool, size_t item_size);
+
+/**
+ * Free all items in pool
+ */
+extern void git_pool_clear(git_pool *pool);
+
+/**
+ * Swap two pools with one another
+ */
+extern void git_pool_swap(git_pool *a, git_pool *b);
+
+/**
+ * Allocate space for one or more items from a pool.
+ */
+extern void *git_pool_malloc(git_pool *pool, size_t items);
+extern void *git_pool_mallocz(git_pool *pool, size_t items);
+
+/**
+ * Allocate space and duplicate string data into it.
+ *
+ * This is allowed only for pools with item_size == sizeof(char)
+ */
+extern char *git_pool_strndup(git_pool *pool, const char *str, size_t n);
+
+/**
+ * Allocate space and duplicate a string into it.
+ *
+ * This is allowed only for pools with item_size == sizeof(char)
+ */
+extern char *git_pool_strdup(git_pool *pool, const char *str);
+
+/**
+ * Allocate space and duplicate a string into it, NULL is no error.
+ *
+ * This is allowed only for pools with item_size == sizeof(char)
+ */
+extern char *git_pool_strdup_safe(git_pool *pool, const char *str);
+
+/**
+ * Allocate space for the concatenation of two strings.
+ *
+ * This is allowed only for pools with item_size == sizeof(char)
+ */
+extern char *git_pool_strcat(git_pool *pool, const char *a, const char *b);
+
+/*
+ * Misc utilities
+ */
+#ifndef GIT_DEBUG_POOL
+extern uint32_t git_pool__open_pages(git_pool *pool);
+#endif
+extern bool git_pool__ptr_in_pool(git_pool *pool, void *ptr);
+
+/**
+ * This function is being called by our global setup routines to
+ * initialize the system pool size.
+ *
+ * @return 0 on success, <0 on failure
+ */
+extern int git_pool_global_init(void);
+
+#endif