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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 "common.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
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