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Diffstat (limited to 'contrib/ucw/mempool.h')
-rw-r--r-- | contrib/ucw/mempool.h | 565 |
1 files changed, 565 insertions, 0 deletions
diff --git a/contrib/ucw/mempool.h b/contrib/ucw/mempool.h new file mode 100644 index 0000000..8cb1d57 --- /dev/null +++ b/contrib/ucw/mempool.h @@ -0,0 +1,565 @@ +/* + * UCW Library -- Memory Pools + * + * (c) 1997--2015 Martin Mares <mj@ucw.cz> + * (c) 2007 Pavel Charvat <pchar@ucw.cz> + * + * This software may be freely distributed and used according to the terms + * of the GNU Lesser General Public License. + */ + +#ifndef _UCW_POOLS_H +#define _UCW_POOLS_H + +#include <ucw/alloc.h> +#include <ucw/config.h> +#include <ucw/lib.h> +#include <string.h> + +#ifdef CONFIG_UCW_CLEAN_ABI +#define mp_alloc ucw_mp_alloc +#define mp_alloc_internal ucw_mp_alloc_internal +#define mp_alloc_noalign ucw_mp_alloc_noalign +#define mp_alloc_zero ucw_mp_alloc_zero +#define mp_delete ucw_mp_delete +#define mp_flush ucw_mp_flush +#define mp_grow_internal ucw_mp_grow_internal +#define mp_init ucw_mp_init +#define mp_memdup ucw_mp_memdup +#define mp_multicat ucw_mp_multicat +#define mp_new ucw_mp_new +#define mp_open ucw_mp_open +#define mp_pop ucw_mp_pop +#define mp_printf ucw_mp_printf +#define mp_printf_append ucw_mp_printf_append +#define mp_push ucw_mp_push +#define mp_realloc ucw_mp_realloc +#define mp_realloc_zero ucw_mp_realloc_zero +#define mp_restore ucw_mp_restore +#define mp_shrink ucw_mp_shrink +#define mp_spread_internal ucw_mp_spread_internal +#define mp_start ucw_mp_start +#define mp_start_internal ucw_mp_start_internal +#define mp_start_noalign ucw_mp_start_noalign +#define mp_stats ucw_mp_stats +#define mp_str_from_mem ucw_mp_str_from_mem +#define mp_strdup ucw_mp_strdup +#define mp_strjoin ucw_mp_strjoin +#define mp_total_size ucw_mp_total_size +#define mp_vprintf ucw_mp_vprintf +#define mp_vprintf_append ucw_mp_vprintf_append +#endif + +/*** + * [[defs]] + * Definitions + * ----------- + ***/ + +/** + * Memory pool state (see @mp_push(), ...). + * You should use this one as an opaque handle only, the insides are internal. + **/ +struct mempool_state { + size_t free[2]; + void *last[2]; + struct mempool_state *next; +}; + +/** + * Memory pool. + * You should use this one as an opaque handle only, the insides are internal. + **/ +struct mempool { + struct ucw_allocator allocator; // This must be the first element + struct mempool_state state; + void *unused, *last_big; + size_t chunk_size, threshold; + uint idx; + u64 total_size; +}; + +struct mempool_stats { /** Mempool statistics. See @mp_stats(). **/ + u64 total_size; /* Real allocated size in bytes */ + u64 used_size; /* Estimated size allocated from mempool to application */ + uint chain_count[3]; /* Number of allocated chunks in small/big/unused chains */ + u64 chain_size[3]; /* Size of allocated chunks in small/big/unused chains */ +}; + +/*** + * [[basic]] + * Basic manipulation + * ------------------ + ***/ + +/** + * Initialize a given mempool structure. + * @chunk_size must be in the interval `[1, SIZE_MAX / 2]`. + * It will allocate memory by this large chunks and take + * memory to satisfy requests from them. + * + * Memory pools can be treated as <<trans:respools,resources>>, see <<trans:res_mempool()>>. + **/ +void mp_init(struct mempool *pool, size_t chunk_size); + +/** + * Allocate and initialize a new memory pool. + * See @mp_init() for @chunk_size limitations. + * + * The new mempool structure is allocated on the new mempool. + * + * Memory pools can be treated as <<trans:respools,resources>>, see <<trans:res_mempool()>>. + **/ +struct mempool *mp_new(size_t chunk_size); + +/** + * Cleanup mempool initialized by mp_init or mp_new. + * Frees all the memory allocated by this mempool and, + * if created by @mp_new(), the @pool itself. + **/ +void mp_delete(struct mempool *pool); + +/** + * Frees all data on a memory pool, but leaves it working. + * It can keep some of the chunks allocated to serve + * further allocation requests. Leaves the @pool alive, + * even if it was created with @mp_new(). + **/ +void mp_flush(struct mempool *pool); + +/** + * Compute some statistics for debug purposes. + * See the definition of the <<struct_mempool_stats,mempool_stats structure>>. + * This function scans the chunk list, so it can be slow. If you are interested + * in total memory consumption only, mp_total_size() is faster. + **/ +void mp_stats(struct mempool *pool, struct mempool_stats *stats); + +/** + * Return how many bytes were allocated by the pool, including unused parts + * of chunks. This function runs in constant time. + **/ +u64 mp_total_size(struct mempool *pool); + +/** + * Release unused chunks of memory reserved for further allocation + * requests, but stop if mp_total_size() would drop below @min_total_size. + **/ +void mp_shrink(struct mempool *pool, u64 min_total_size); + +/*** + * [[alloc]] + * Allocation routines + * ------------------- + ***/ + +/* For internal use only, do not call directly */ +void *mp_alloc_internal(struct mempool *pool, size_t size) LIKE_MALLOC; + +/** + * The function allocates new @size bytes on a given memory pool. + * If the @size is zero, the resulting pointer is undefined, + * but it may be safely reallocated or used as the parameter + * to other functions below. + * + * The resulting pointer is always aligned to a multiple of + * `CPU_STRUCT_ALIGN` bytes and this condition remains true also + * after future reallocations. + **/ +void *mp_alloc(struct mempool *pool, size_t size); + +/** + * The same as @mp_alloc(), but the result may be unaligned. + **/ +void *mp_alloc_noalign(struct mempool *pool, size_t size); + +/** + * The same as @mp_alloc(), but fills the newly allocated memory with zeroes. + **/ +void *mp_alloc_zero(struct mempool *pool, size_t size); + +/** + * Inlined version of @mp_alloc(). + **/ +static inline void *mp_alloc_fast(struct mempool *pool, size_t size) +{ + size_t avail = pool->state.free[0] & ~(size_t)(CPU_STRUCT_ALIGN - 1); + if (size <= avail) + { + pool->state.free[0] = avail - size; + return (byte *)pool->state.last[0] - avail; + } + else + return mp_alloc_internal(pool, size); +} + +/** + * Inlined version of @mp_alloc_noalign(). + **/ +static inline void *mp_alloc_fast_noalign(struct mempool *pool, size_t size) +{ + if (size <= pool->state.free[0]) + { + void *ptr = (byte *)pool->state.last[0] - pool->state.free[0]; + pool->state.free[0] -= size; + return ptr; + } + else + return mp_alloc_internal(pool, size); +} + +/** + * Return a generic allocator representing the given mempool. + **/ +static inline struct ucw_allocator *mp_get_allocator(struct mempool *mp) +{ + return &mp->allocator; +} + +/*** + * [[gbuf]] + * Growing buffers + * --------------- + * + * You do not need to know, how a buffer will need to be large, + * you can grow it incrementally to needed size. You can grow only + * one buffer at a time on a given mempool. + * + * Similar functionality is provided by <<growbuf:,growing buffes>> module. + ***/ + +/* For internal use only, do not call directly */ +void *mp_start_internal(struct mempool *pool, size_t size) LIKE_MALLOC; +void *mp_grow_internal(struct mempool *pool, size_t size); +void *mp_spread_internal(struct mempool *pool, void *p, size_t size); + +static inline uint mp_idx(struct mempool *pool, void *ptr) +{ + return ptr == pool->last_big; +} + +/** + * Open a new growing buffer (at least @size bytes long). + * If the @size is zero, the resulting pointer is undefined, + * but it may be safely reallocated or used as the parameter + * to other functions below. + * + * The resulting pointer is always aligned to a multiple of + * `CPU_STRUCT_ALIGN` bytes and this condition remains true also + * after future reallocations. There is an unaligned version as well. + * + * Keep in mind that you can't make any other pool allocations + * before you "close" the growing buffer with @mp_end(). + */ +void *mp_start(struct mempool *pool, size_t size); +void *mp_start_noalign(struct mempool *pool, size_t size); + +/** + * Inlined version of @mp_start(). + **/ +static inline void *mp_start_fast(struct mempool *pool, size_t size) +{ + size_t avail = pool->state.free[0] & ~(size_t)(CPU_STRUCT_ALIGN - 1); + if (size <= avail) + { + pool->idx = 0; + pool->state.free[0] = avail; + return (byte *)pool->state.last[0] - avail; + } + else + return mp_start_internal(pool, size); +} + +/** + * Inlined version of @mp_start_noalign(). + **/ +static inline void *mp_start_fast_noalign(struct mempool *pool, size_t size) +{ + if (size <= pool->state.free[0]) + { + pool->idx = 0; + return (byte *)pool->state.last[0] - pool->state.free[0]; + } + else + return mp_start_internal(pool, size); +} + +/** + * Return start pointer of the growing buffer allocated by latest @mp_start() or a similar function. + **/ +static inline void *mp_ptr(struct mempool *pool) +{ + return (byte *)pool->state.last[pool->idx] - pool->state.free[pool->idx]; +} + +/** + * Return the number of bytes available for extending the growing buffer. + * (Before a reallocation will be needed). + **/ +static inline size_t mp_avail(struct mempool *pool) +{ + return pool->state.free[pool->idx]; +} + +/** + * Grow the buffer allocated by @mp_start() to be at least @size bytes long + * (@size may be less than @mp_avail(), even zero). Reallocated buffer may + * change its starting position. The content will be unchanged to the minimum + * of the old and new sizes; newly allocated memory will be uninitialized. + * Multiple calls to mp_grow() have amortized linear cost wrt. the maximum value of @size. */ +static inline void *mp_grow(struct mempool *pool, size_t size) +{ + return (size <= mp_avail(pool)) ? mp_ptr(pool) : mp_grow_internal(pool, size); +} + +/** + * Grow the buffer by at least one byte -- equivalent to <<mp_grow(),`mp_grow`>>`(@pool, @mp_avail(pool) + 1)`. + **/ +static inline void *mp_expand(struct mempool *pool) +{ + return mp_grow_internal(pool, mp_avail(pool) + 1); +} + +/** + * Ensure that there is at least @size bytes free after @p, + * if not, reallocate and adjust @p. + **/ +static inline void *mp_spread(struct mempool *pool, void *p, size_t size) +{ + return (((size_t)((byte *)pool->state.last[pool->idx] - (byte *)p) >= size) ? p : mp_spread_internal(pool, p, size)); +} + +/** + * Append a character to the growing buffer. Called with @p pointing after + * the last byte in the buffer, returns a pointer after the last byte + * of the new (possibly reallocated) buffer. + **/ +static inline char *mp_append_char(struct mempool *pool, char *p, uint c) +{ + p = mp_spread(pool, p, 1); + *p++ = c; + return p; +} + +/** + * Append a memory block to the growing buffer. Called with @p pointing after + * the last byte in the buffer, returns a pointer after the last byte + * of the new (possibly reallocated) buffer. + **/ +static inline void *mp_append_block(struct mempool *pool, void *p, const void *block, size_t size) +{ + char *q = mp_spread(pool, p, size); + memcpy(q, block, size); + return q + size; +} + +/** + * Append a string to the growing buffer. Called with @p pointing after + * the last byte in the buffer, returns a pointer after the last byte + * of the new (possibly reallocated) buffer. + **/ +static inline void *mp_append_string(struct mempool *pool, void *p, const char *str) +{ + return mp_append_block(pool, p, str, strlen(str)); +} + +/** + * Close the growing buffer. The @end must point just behind the data, you want to keep + * allocated (so it can be in the interval `[@mp_ptr(@pool), @mp_ptr(@pool) + @mp_avail(@pool)]`). + * Returns a pointer to the beginning of the just closed block. + **/ +static inline void *mp_end(struct mempool *pool, void *end) +{ + void *p = mp_ptr(pool); + pool->state.free[pool->idx] = (byte *)pool->state.last[pool->idx] - (byte *)end; + return p; +} + +/** + * Close the growing buffer as a string. That is, append a zero byte and call mp_end(). + **/ +static inline char *mp_end_string(struct mempool *pool, void *end) +{ + end = mp_append_char(pool, end, 0); + return mp_end(pool, end); +} + +/** + * Return size in bytes of the last allocated memory block (with @mp_alloc() or @mp_end()). + **/ +static inline size_t mp_size(struct mempool *pool, void *ptr) +{ + uint idx = mp_idx(pool, ptr); + return ((byte *)pool->state.last[idx] - (byte *)ptr) - pool->state.free[idx]; +} + +/** + * Open the last memory block (allocated with @mp_alloc() or @mp_end()) + * for growing and return its size in bytes. The contents and the start pointer + * remain unchanged. Do not forget to call @mp_end() to close it. + **/ +size_t mp_open(struct mempool *pool, void *ptr); + +/** + * Inlined version of @mp_open(). + **/ +static inline size_t mp_open_fast(struct mempool *pool, void *ptr) +{ + pool->idx = mp_idx(pool, ptr); + size_t size = ((byte *)pool->state.last[pool->idx] - (byte *)ptr) - pool->state.free[pool->idx]; + pool->state.free[pool->idx] += size; + return size; +} + +/** + * Reallocate the last memory block (allocated with @mp_alloc() or @mp_end()) + * to the new @size. Behavior is similar to @mp_grow(), but the resulting + * block is closed. + **/ +void *mp_realloc(struct mempool *pool, void *ptr, size_t size); + +/** + * The same as @mp_realloc(), but fills the additional bytes (if any) with zeroes. + **/ +void *mp_realloc_zero(struct mempool *pool, void *ptr, size_t size); + +/** + * Inlined version of @mp_realloc(). + **/ +static inline void *mp_realloc_fast(struct mempool *pool, void *ptr, size_t size) +{ + mp_open_fast(pool, ptr); + ptr = mp_grow(pool, size); + mp_end(pool, (byte *)ptr + size); + return ptr; +} + +/*** + * [[store]] + * Storing and restoring state + * --------------------------- + * + * Mempools can remember history of what was allocated and return back + * in time. + ***/ + +/** + * Save the current state of a memory pool. + * Do not call this function with an opened growing buffer. + **/ +static inline void mp_save(struct mempool *pool, struct mempool_state *state) +{ + *state = pool->state; + pool->state.next = state; +} + +/** + * Save the current state to a newly allocated mempool_state structure. + * Do not call this function with an opened growing buffer. + **/ +struct mempool_state *mp_push(struct mempool *pool); + +/** + * Restore the state saved by @mp_save() or @mp_push() and free all + * data allocated after that point (including the state structure itself). + * You can't reallocate the last memory block from the saved state. + **/ +void mp_restore(struct mempool *pool, struct mempool_state *state); + +/** + * Inlined version of @mp_restore(). + **/ +static inline void mp_restore_fast(struct mempool *pool, struct mempool_state *state) +{ + if (pool->state.last[0] != state->last[0] || pool->state.last[1] != state->last[1]) + mp_restore(pool, state); + else + { + pool->state = *state; + pool->last_big = &pool->last_big; + } +} + +/** + * Restore the state saved by the last call to @mp_push(). + * @mp_pop() and @mp_push() works as a stack so you can push more states safely. + **/ +void mp_pop(struct mempool *pool); + + +/*** + * [[string]] + * String operations + * ----------------- + ***/ + +char *mp_strdup(struct mempool *, const char *) LIKE_MALLOC; /** Makes a copy of a string on a mempool. Returns NULL for NULL string. **/ +void *mp_memdup(struct mempool *, const void *, size_t) LIKE_MALLOC; /** Makes a copy of a memory block on a mempool. **/ +/** + * Concatenates all passed strings. The last parameter must be NULL. + * This will concatenate two strings: + * + * char *message = mp_multicat(pool, "hello ", "world", NULL); + **/ +char *mp_multicat(struct mempool *, ...) LIKE_MALLOC SENTINEL_CHECK; +/** + * Concatenates two strings and stores result on @mp. + */ +static inline char *LIKE_MALLOC mp_strcat(struct mempool *mp, const char *x, const char *y) +{ + return mp_multicat(mp, x, y, NULL); +} +/** + * Join strings and place @sep between each two neighboring. + * @p is the mempool to provide memory, @a is array of strings and @n + * tells how many there is of them. + **/ +char *mp_strjoin(struct mempool *p, char **a, uint n, uint sep) LIKE_MALLOC; +/** + * Convert memory block to a string. Makes a copy of the given memory block + * in the mempool @p, adding an extra terminating zero byte at the end. + **/ +char *mp_str_from_mem(struct mempool *p, const void *mem, size_t len) LIKE_MALLOC; + + +/*** + * [[format]] + * Formatted output + * --------------- + ***/ + +/** + * printf() into a in-memory string, allocated on the memory pool. + **/ +char *mp_printf(struct mempool *mp, const char *fmt, ...) FORMAT_CHECK(printf,2,3) LIKE_MALLOC; +/** + * Like @mp_printf(), but uses `va_list` for parameters. + **/ +char *mp_vprintf(struct mempool *mp, const char *fmt, va_list args) LIKE_MALLOC; +/** + * Like @mp_printf(), but it appends the data at the end of string + * pointed to by @ptr. The string is @mp_open()ed, so you have to + * provide something that can be. + * + * Returns pointer to the beginning of the string (the pointer may have + * changed due to reallocation). + * + * In some versions of LibUCW, this function was called mp_append_printf(). However, + * this name turned out to be confusing -- unlike other appending functions, this one is + * not called on an opened growing buffer. The old name will be preserved for backward + * compatibility for the time being. + **/ +char *mp_printf_append(struct mempool *mp, char *ptr, const char *fmt, ...) FORMAT_CHECK(printf,3,4); +#define mp_append_printf mp_printf_append +/** + * Like @mp_printf_append(), but uses `va_list` for parameters. + * + * In some versions of LibUCW, this function was called mp_append_vprintf(). However, + * this name turned out to be confusing -- unlike other appending functions, this one is + * not called on an opened growing buffer. The old name will be preserved for backward + * compatibility for the time being. + **/ +char *mp_vprintf_append(struct mempool *mp, char *ptr, const char *fmt, va_list args); +#define mp_append_vprintf mp_vprintf_append + +#endif |