/*
* UCW Library -- Memory Pools
*
- * (c) 1997--2005 Martin Mares <mj@ucw.cz>
+ * (c) 1997--2014 Martin Mares <mj@ucw.cz>
* (c) 2007 Pavel Charvat <pchar@ucw.cz>
*
* This software may be freely distributed and used according to the terms
#ifndef _UCW_POOLS_H
#define _UCW_POOLS_H
-/* Memory pool state (see mp_push(), ...) */
+#include <ucw/alloc.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_append_printf ucw_mp_append_printf
+#define mp_append_vprintf ucw_mp_append_vprintf
+#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_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
+#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 {
- uns free[2];
+ size_t free[2];
void *last[2];
struct mempool_state *next;
};
-/* Memory pool */
+/**
+ * Memory pool.
+ * You should use this one as an opaque handle only, the insides are internal.
+ **/
struct mempool {
+ struct ucw_allocator allocator;
struct mempool_state state;
void *unused, *last_big;
- uns chunk_size, threshold, idx;
+ size_t chunk_size, threshold;
+ uint idx;
+ u64 total_size;
};
-/* Statistics (see mp_stats()) */
-struct mempool_stats {
+struct mempool_stats { /** Mempool statistics. See @mp_stats(). **/
u64 total_size; /* Real allocated size in bytes */
- uns chain_count[3]; /* Number of allocated chunks in small/big/unused chains */
- uns chain_size[3]; /* Size of allocated chunks in small/big/unused chains */
+ 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 */
};
-/* Initialize a given mempool structure. Chunk size must be in the interval [1, UINT_MAX / 2] */
-void mp_init(struct mempool *pool, uns chunk_size);
-
-/* Allocate and initialize a new memory pool. See mp_init for chunk size limitations. */
-struct mempool *mp_new(uns chunk_size);
+/***
+ * [[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);
-/* Cleanup mempool initialized by mp_init or mp_new */
+/**
+ * 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);
-/* Free all data on a memory pool (saves some empty chunks for later allocations) */
+/**
+ * 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 mempool_stats structure. */
+/**
+ * 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);
-/*** Allocation routines ***/
+/***
+ * [[alloc]]
+ * Allocation routines
+ * -------------------
+ ***/
/* For internal use only, do not call directly */
-void *mp_alloc_internal(struct mempool *pool, uns size) LIKE_MALLOC;
+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,
+/**
+ * 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
+ * `CPU_STRUCT_ALIGN` bytes and this condition remains true also
* after future reallocations.
- */
-void *mp_alloc(struct mempool *pool, uns size);
-
-/* The same as mp_alloc, but the result may not be aligned */
-void *mp_alloc_noalign(struct mempool *pool, uns size);
-
-/* The same as mp_alloc, but fills the newly allocated data with zeroes */
-void *mp_alloc_zero(struct mempool *pool, uns size);
-
-/* Inlined version of mp_alloc() */
-static inline void *
-mp_alloc_fast(struct mempool *pool, uns size)
+ **/
+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)
{
- uns avail = pool->state.free[0] & ~(CPU_STRUCT_ALIGN - 1);
+ size_t avail = pool->state.free[0] & ~(size_t)(CPU_STRUCT_ALIGN - 1);
if (size <= avail)
{
pool->state.free[0] = avail - size;
- return pool->state.last[0] - avail;
+ 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, uns 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 = pool->state.last[0] - pool->state.free[0];
+ void *ptr = (byte *)pool->state.last[0] - pool->state.free[0];
pool->state.free[0] -= size;
return ptr;
}
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;
+}
-/*** Usage as a growing buffer ***/
+/***
+ * [[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, uns size) LIKE_MALLOC;
-void *mp_grow_internal(struct mempool *pool, uns size);
-void *mp_spread_internal(struct mempool *pool, void *p, uns size);
+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 uns
-mp_idx(struct mempool *pool, void *ptr)
+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,
+/**
+ * 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
+ * `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().
+ * 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, uns size);
-void *mp_start_noalign(struct mempool *pool, uns size);
+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, uns size)
+/**
+ * Inlined version of @mp_start().
+ **/
+static inline void *mp_start_fast(struct mempool *pool, size_t size)
{
- uns avail = pool->state.free[0] & ~(CPU_STRUCT_ALIGN - 1);
+ 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 pool->state.last[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, uns 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 pool->state.last[0] - pool->state.free[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 mp_start() or a similar function */
-static inline void *
-mp_ptr(struct mempool *pool)
+/**
+ * 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 pool->state.last[pool->idx] - pool->state.free[pool->idx];
+ return (byte *)pool->state.last[pool->idx] - pool->state.free[pool->idx];
}
-/* Return the number of bytes available for extending the growing buffer */
-static inline uns
-mp_avail(struct mempool *pool)
+/**
+ * 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
+/**
+ * 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, uns size)
+ * 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(pool, mp_avail(pool) + 1) */
-static inline void *
-mp_expand(struct mempool *pool)
+/**
+ * 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, uns size)
+/**
+ * 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)
{
- return (((uns)(pool->state.last[pool->idx] - p) >= size) ? p : mp_spread_internal(pool, p, size));
+ 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;
}
-/* 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)
+/**
+ * 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] = pool->state.last[pool->idx] - end;
+ pool->state.free[pool->idx] = (byte *)pool->state.last[pool->idx] - (byte *)end;
return p;
}
-/* Return size in bytes of the last allocated memory block (with mp_alloc*() or mp_end()). */
-static inline uns
-mp_size(struct mempool *pool, void *ptr)
+/**
+ * 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)
{
- uns idx = mp_idx(pool, ptr);
- return pool->state.last[idx] - ptr - pool->state.free[idx];
+ end = mp_append_char(pool, end, 0);
+ return mp_end(pool, end);
}
-/* 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. */
-uns mp_open(struct mempool *pool, void *ptr);
+/**
+ * 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];
+}
-/* Inlined version of mp_open() */
-static inline uns
-mp_open_fast(struct mempool *pool, void *ptr)
+/**
+ * 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);
- uns size = pool->state.last[pool->idx] - ptr - pool->state.free[pool->idx];
+ 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, uns size);
-
-/* The same as mp_realloc(), but fills the additional bytes (if any) with zeroes */
-void *mp_realloc_zero(struct mempool *pool, void *ptr, uns size);
-
-/* Inlined version of mp_realloc() */
-static inline void *
-mp_realloc_fast(struct mempool *pool, void *ptr, uns 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, ptr + size);
+ mp_end(pool, (byte *)ptr + size);
return ptr;
}
-
-/*** Usage as a stack ***/
-
-/* 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)
+/***
+ * [[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. */
+/**
+ * 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
+/**
+ * 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. */
+ * You can't reallocate the last memory block from the saved state.
+ **/
void mp_restore(struct mempool *pool, struct mempool_state *state);
-/* 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. */
+/**
+ * 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);
-/*** mempool-str.c ***/
+/***
+ * [[string]]
+ * String operations
+ * -----------------
+ ***/
-char *mp_strdup(struct mempool *, const char *) LIKE_MALLOC;
-void *mp_memdup(struct mempool *, const void *, uns) LIKE_MALLOC;
+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;
-static inline char * LIKE_MALLOC
-mp_strcat(struct mempool *mp, const char *x, const char *y)
+/**
+ * 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);
}
-char *mp_strjoin(struct mempool *p, char **a, uns n, uns sep) LIKE_MALLOC;
-
-
-/*** mempool-fmt.c ***/
-
+/**
+ * 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;
-char *mp_printf_append(struct mempool *mp, char *ptr, const char *fmt, ...) FORMAT_CHECK(printf,3,4);
-char *mp_vprintf_append(struct mempool *mp, char *ptr, const char *fmt, va_list args);
+/**
+ * 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).
+ *
+ * Alternatively, this function may be called mp_printf_append() for compatibility with
+ * previous releases of LibUCW.
+ **/
+char *mp_append_printf(struct mempool *mp, char *ptr, const char *fmt, ...) FORMAT_CHECK(printf,3,4);
+#define mp_printf_append mp_append_printf
+/**
+ * Like @mp_append_printf(), but uses `va_list` for parameters.
+ *
+ * Alternatively, this function may be called mp_vprintf_append() for compatibility with
+ * previous releases of LibUCW.
+ **/
+char *mp_append_vprintf(struct mempool *mp, char *ptr, const char *fmt, va_list args);
+#define mp_vprintf_append mp_append_vprintf
#endif