git/mem-pool.h
René Scharfe 8d25663d70 mem-pool: add mem_pool_strfmt()
Add a function for building a string, printf style, using a memory pool.
It uses the free space in the current block in the first attempt.  If
that suffices then the result can already be used without copying or
reformatting.

For strings that are significantly shorter on average than the block
size (ca. 1 MiB by default) this is the case most of the time, leading
to a better perfomance than a solution that doesn't access mem-pool
internals.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-26 09:35:40 -08:00

69 lines
1.7 KiB
C

#ifndef MEM_POOL_H
#define MEM_POOL_H
struct mp_block {
struct mp_block *next_block;
char *next_free;
char *end;
uintmax_t space[FLEX_ARRAY]; /* more */
};
struct mem_pool {
struct mp_block *mp_block;
/*
* The amount of available memory to grow the pool by.
* This size does not include the overhead for the mp_block.
*/
size_t block_alloc;
/* The total amount of memory allocated by the pool. */
size_t pool_alloc;
};
/*
* Initialize mem_pool with specified initial size.
*/
void mem_pool_init(struct mem_pool *pool, size_t initial_size);
/*
* Discard all the memory the memory pool is responsible for.
*/
void mem_pool_discard(struct mem_pool *pool, int invalidate_memory);
/*
* Alloc memory from the mem_pool.
*/
void *mem_pool_alloc(struct mem_pool *pool, size_t len);
/*
* Allocate and zero memory from the memory pool.
*/
void *mem_pool_calloc(struct mem_pool *pool, size_t count, size_t size);
/*
* Allocate memory from the memory pool and copy str into it.
*/
char *mem_pool_strdup(struct mem_pool *pool, const char *str);
char *mem_pool_strndup(struct mem_pool *pool, const char *str, size_t len);
/*
* Allocate memory from the memory pool and format a string into it.
*/
char *mem_pool_strfmt(struct mem_pool *pool, const char *fmt, ...);
/*
* 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 *pool, void *mem);
#endif