--- a/ucx/cx/buffer.h Sun Aug 31 14:39:13 2025 +0200
+++ b/ucx/cx/buffer.h Sat Nov 08 23:06:11 2025 +0100
@@ -62,7 +62,7 @@
* If this flag is enabled, the buffer will automatically free its contents when destroyed.
*
* Do NOT set this flag together with #CX_BUFFER_COPY_ON_WRITE. It will be automatically
- * set when the copy-on-write operations is performed.
+ * set when the copy-on-write operation is performed.
*/
#define CX_BUFFER_FREE_CONTENTS 0x01
@@ -74,7 +74,7 @@
/**
* If this flag is enabled, the buffer will allocate new memory when written to.
*
- * The current contents of the buffer will be copied to the new memory and the flag
+ * The current contents of the buffer will be copied to the new memory, and the flag
* will be cleared while the #CX_BUFFER_FREE_CONTENTS flag will be set automatically.
*/
#define CX_BUFFER_COPY_ON_WRITE 0x04
@@ -127,7 +127,7 @@
size_t blkmax;
/**
- * The target for write function.
+ * The target for the write function.
*/
void *target;
@@ -202,7 +202,7 @@
* you will need to cast the pointer, and you should set the
* #CX_BUFFER_COPY_ON_WRITE flag.
*
- * You need to set the size manually after initialization, if
+ * You need to set the size manually after initialization if
* you provide @p space which already contains data.
*
* When you specify stack memory as @p space and decide to use
@@ -210,7 +210,7 @@
* #CX_BUFFER_COPY_ON_EXTEND flag, instead of the
* #CX_BUFFER_AUTO_EXTEND flag.
*
- * @note You may provide @c NULL as argument for @p space.
+ * @note You may provide @c NULL as the argument for @p space.
* Then this function will allocate the space and enforce
* the #CX_BUFFER_FREE_CONTENTS flag. In that case, specifying
* copy-on-write should be avoided, because the allocated
@@ -222,19 +222,13 @@
* @param capacity the capacity of the buffer
* @param allocator the allocator this buffer shall use for automatic
* memory management
- * (if @c NULL, a default stdlib allocator will be used)
+ * (if @c NULL, the cxDefaultAllocator will be used)
* @param flags buffer features (see cx_buffer_s.flags)
* @return zero on success, non-zero if a required allocation failed
*/
cx_attr_nonnull_arg(1)
-cx_attr_export
-int cxBufferInit(
- CxBuffer *buffer,
- void *space,
- size_t capacity,
- const CxAllocator *allocator,
- int flags
-);
+CX_EXPORT int cxBufferInit(CxBuffer *buffer, void *space, size_t capacity,
+ const CxAllocator *allocator, int flags);
/**
* Configures the buffer for flushing.
@@ -251,11 +245,7 @@
* @see cxBufferWrite()
*/
cx_attr_nonnull
-cx_attr_export
-int cxBufferEnableFlushing(
- CxBuffer *buffer,
- CxBufferFlushConfig config
-);
+CX_EXPORT int cxBufferEnableFlushing(CxBuffer *buffer, CxBufferFlushConfig config);
/**
* Destroys the buffer contents.
@@ -267,8 +257,7 @@
* @see cxBufferInit()
*/
cx_attr_nonnull
-cx_attr_export
-void cxBufferDestroy(CxBuffer *buffer);
+CX_EXPORT void cxBufferDestroy(CxBuffer *buffer);
/**
* Deallocates the buffer.
@@ -276,14 +265,10 @@
* If the #CX_BUFFER_FREE_CONTENTS feature is enabled, this function also destroys
* the contents. If you @em only want to destroy the contents, use cxBufferDestroy().
*
- * @remark As with all free() functions, this accepts @c NULL arguments in which
- * case it does nothing.
- *
* @param buffer the buffer to deallocate
* @see cxBufferCreate()
*/
-cx_attr_export
-void cxBufferFree(CxBuffer *buffer);
+CX_EXPORT void cxBufferFree(CxBuffer *buffer);
/**
* Allocates and initializes a fresh buffer.
@@ -296,7 +281,7 @@
* #CX_BUFFER_COPY_ON_EXTEND flag, instead of the
* #CX_BUFFER_AUTO_EXTEND flag.
*
- * @note You may provide @c NULL as argument for @p space.
+ * @note You may provide @c NULL as the argument for @p space.
* Then this function will allocate the space and enforce
* the #CX_BUFFER_FREE_CONTENTS flag.
*
@@ -305,20 +290,13 @@
* @param capacity the capacity of the buffer
* @param allocator the allocator to use for allocating the structure and the automatic
* memory management within the buffer
- * (if @c NULL, a default stdlib allocator will be used)
+ * (if @c NULL, the cxDefaultAllocator will be used)
* @param flags buffer features (see cx_buffer_s.flags)
* @return a pointer to the buffer on success, @c NULL if a required allocation failed
*/
-cx_attr_malloc
-cx_attr_dealloc(cxBufferFree, 1)
-cx_attr_nodiscard
-cx_attr_export
-CxBuffer *cxBufferCreate(
- void *space,
- size_t capacity,
- const CxAllocator *allocator,
- int flags
-);
+cx_attr_malloc cx_attr_dealloc(cxBufferFree, 1) cx_attr_nodiscard
+CX_EXPORT CxBuffer *cxBufferCreate(void *space, size_t capacity,
+ const CxAllocator *allocator, int flags);
/**
* Shifts the contents of the buffer by the given offset.
@@ -327,8 +305,8 @@
* If auto extension is enabled, the buffer grows, if necessary.
* In case the auto extension fails, this function returns a non-zero value and
* no contents are changed.
- * If auto extension is disabled, the contents that do not fit into the buffer
- * are discarded.
+ * When the auto extension is disabled, the contents that do not fit into the
+ * buffer are discarded.
*
* If the offset is negative, the contents are shifted to the left where the
* first @p shift bytes are discarded.
@@ -336,15 +314,15 @@
* If this value is larger than the buffer size, the buffer is emptied (but
* not cleared, see the security note below).
*
- * The buffer position gets shifted alongside with the content but is kept
+ * The buffer position gets shifted alongside the content but is kept
* within the boundaries of the buffer.
*
* @note For situations where @c off_t is not large enough, there are specialized cxBufferShiftLeft() and
- * cxBufferShiftRight() functions using a @c size_t as parameter type.
+ * cxBufferShiftRight() functions using a @c size_t as the parameter type.
*
* @attention
* Security Note: The shifting operation does @em not erase the previously occupied memory cells.
- * But you can easily do that manually, e.g. by calling
+ * But you can do that manually by calling
* <code>memset(buffer->bytes, 0, shift)</code> for a right shift or
* <code>memset(buffer->bytes + buffer->size, 0, buffer->capacity - buffer->size)</code>
* for a left shift.
@@ -357,11 +335,7 @@
* @see cxBufferShiftRight()
*/
cx_attr_nonnull
-cx_attr_export
-int cxBufferShift(
- CxBuffer *buffer,
- off_t shift
-);
+CX_EXPORT int cxBufferShift(CxBuffer *buffer, off_t shift);
/**
* Shifts the buffer to the right.
@@ -374,11 +348,7 @@
* @see cxBufferShift()
*/
cx_attr_nonnull
-cx_attr_export
-int cxBufferShiftRight(
- CxBuffer *buffer,
- size_t shift
-);
+CX_EXPORT int cxBufferShiftRight(CxBuffer *buffer, size_t shift);
/**
* Shifts the buffer to the left.
@@ -391,11 +361,7 @@
* @see cxBufferShift()
*/
cx_attr_nonnull
-cx_attr_export
-int cxBufferShiftLeft(
- CxBuffer *buffer,
- size_t shift
-);
+CX_EXPORT int cxBufferShiftLeft(CxBuffer *buffer, size_t shift);
/**
@@ -419,12 +385,7 @@
*
*/
cx_attr_nonnull
-cx_attr_export
-int cxBufferSeek(
- CxBuffer *buffer,
- off_t offset,
- int whence
-);
+CX_EXPORT int cxBufferSeek(CxBuffer *buffer, off_t offset, int whence);
/**
* Clears the buffer by resetting the position and deleting the data.
@@ -439,8 +400,7 @@
* @see cxBufferReset()
*/
cx_attr_nonnull
-cx_attr_export
-void cxBufferClear(CxBuffer *buffer);
+CX_EXPORT void cxBufferClear(CxBuffer *buffer);
/**
* Resets the buffer by resetting the position and size to zero.
@@ -452,8 +412,7 @@
* @see cxBufferClear()
*/
cx_attr_nonnull
-cx_attr_export
-void cxBufferReset(CxBuffer *buffer);
+CX_EXPORT void cxBufferReset(CxBuffer *buffer);
/**
* Tests, if the buffer position has exceeded the buffer size.
@@ -463,10 +422,8 @@
* byte of the buffer's contents
* @retval false otherwise
*/
-cx_attr_nonnull
-cx_attr_nodiscard
-cx_attr_export
-bool cxBufferEof(const CxBuffer *buffer);
+cx_attr_nonnull cx_attr_nodiscard
+CX_EXPORT bool cxBufferEof(const CxBuffer *buffer);
/**
@@ -474,23 +431,42 @@
*
* If the current capacity is not sufficient, the buffer will be extended.
*
+ * The new capacity will be a power of two until the system's page size is reached.
+ * Then, the new capacity will be a multiple of the page size.
+ *
* @param buffer the buffer
* @param capacity the minimum required capacity for this buffer
* @retval zero the capacity was already sufficient or successfully increased
* @retval non-zero on allocation failure
+ * @see cxBufferShrink()
*/
cx_attr_nonnull
-cx_attr_export
-int cxBufferMinimumCapacity(
- CxBuffer *buffer,
- size_t capacity
-);
+CX_EXPORT int cxBufferMinimumCapacity(CxBuffer *buffer, size_t capacity);
+
+/**
+ * Shrinks the capacity of the buffer to fit its current size.
+ *
+ * If @p reserve is larger than zero, the buffer is shrunk to its size plus
+ * the number of reserved bytes.
+ *
+ * If the current capacity is not larger than the size plus the reserved bytes,
+ * nothing happens.
+ *
+ * If the #CX_BUFFER_COPY_ON_WRITE or #CX_BUFFER_COPY_ON_EXTEND flag is set,
+ * this function does nothing.
+ *
+ * @param buffer the buffer
+ * @param reserve the number of bytes that shall remain reserved
+ * @see cxBufferMinimumCapacity()
+ */
+cx_attr_nonnull
+CX_EXPORT void cxBufferShrink(CxBuffer *buffer, size_t reserve);
/**
* Writes data to a CxBuffer.
*
* If automatic flushing is not enabled, the data is simply written into the
- * buffer at the current position and the position of the buffer is increased
+ * buffer at the current position, and the position of the buffer is increased
* by the number of bytes written.
*
* If flushing is enabled and the buffer needs to flush, the data is flushed to
@@ -499,7 +475,7 @@
* data in this buffer is shifted to the beginning of this buffer so that the
* newly available space can be used to append as much data as possible.
*
- * This function only stops writing more elements, when the flush target and this
+ * This function only stops writing more elements when the flush target and this
* buffer are both incapable of taking more data or all data has been written.
*
* If, after flushing, the number of items that shall be written still exceeds
@@ -507,14 +483,14 @@
* to the flush target, if possible.
*
* The number returned by this function is the number of elements from
- * @c ptr that could be written to either the flush target or the buffer
- * (so it does not include the number of items that had been already in the buffer
- * in were flushed during the process).
+ * @c ptr that could be written to either the flush target or the buffer.
+ * That means it does @em not include the number of items that were already in
+ * the buffer and were also flushed during the process.
*
* @attention
* When @p size is larger than one and the contents of the buffer are not aligned
* with @p size, flushing stops after all complete items have been flushed, leaving
- * the mis-aligned part in the buffer.
+ * the misaligned part in the buffer.
* Afterward, this function only writes as many items as possible to the buffer.
*
* @note The signature is compatible with the fwrite() family of functions.
@@ -528,13 +504,8 @@
* @see cxBufferRead()
*/
cx_attr_nonnull
-cx_attr_export
-size_t cxBufferWrite(
- const void *ptr,
- size_t size,
- size_t nitems,
- CxBuffer *buffer
-);
+CX_EXPORT size_t cxBufferWrite(const void *ptr, size_t size,
+ size_t nitems, CxBuffer *buffer);
/**
* Appends data to a CxBuffer.
@@ -556,13 +527,8 @@
* @see cxBufferRead()
*/
cx_attr_nonnull
-cx_attr_export
-size_t cxBufferAppend(
- const void *ptr,
- size_t size,
- size_t nitems,
- CxBuffer *buffer
-);
+CX_EXPORT size_t cxBufferAppend(const void *ptr, size_t size,
+ size_t nitems, CxBuffer *buffer);
/**
* Performs a single flush-run on the specified buffer.
@@ -587,19 +553,19 @@
* at position 200. The flush configuration is
* @c blkmax=4 and @c blksize=64 .
* Assume that the entire flush operation is successful.
- * All 200 bytes on the left hand-side from the current
+ * All 200 bytes on the left-hand-side from the current
* position are written.
- * That means, the size of the buffer is now 140 and the
+ * That means the size of the buffer is now 140 and the
* position is zero.
*
* @par Example 2
* Same as Example 1, but now the @c blkmax is 1.
- * The size of the buffer is now 276 and the position is 136.
+ * The size of the buffer is now 276, and the position is 136.
*
* @par Example 3
* Same as Example 1, but now assume the flush target
* only accepts 100 bytes before returning zero.
- * That means, the flush operations manages to flush
+ * That means the flush operation manages to flush
* one complete block and one partial block, ending
* up with a buffer with size 240 and position 100.
*
@@ -609,8 +575,8 @@
* @remark When the buffer uses copy-on-write, the memory
* is copied first, before attempting any flush.
* This is, however, considered an erroneous use of the
- * buffer, because it does not make much sense to put
- * readonly data into an UCX buffer for flushing, instead
+ * buffer because it makes little sense to put
+ * readonly data into an UCX buffer for flushing instead
* of writing it directly to the target.
*
* @param buffer the buffer
@@ -618,8 +584,7 @@
* @see cxBufferEnableFlushing()
*/
cx_attr_nonnull
-cx_attr_export
-size_t cxBufferFlush(CxBuffer *buffer);
+CX_EXPORT size_t cxBufferFlush(CxBuffer *buffer);
/**
* Reads data from a CxBuffer.
@@ -637,13 +602,8 @@
* @see cxBufferAppend()
*/
cx_attr_nonnull
-cx_attr_export
-size_t cxBufferRead(
- void *ptr,
- size_t size,
- size_t nitems,
- CxBuffer *buffer
-);
+CX_EXPORT size_t cxBufferRead(void *ptr, size_t size,
+ size_t nitems, CxBuffer *buffer);
/**
* Writes a character to a buffer.
@@ -651,9 +611,9 @@
* The least significant byte of the argument is written to the buffer. If the
* end of the buffer is reached and #CX_BUFFER_AUTO_EXTEND feature is enabled,
* the buffer capacity is extended by cxBufferMinimumCapacity(). If the feature
- * is disabled or buffer extension fails, @c EOF is returned.
+ * is disabled or the buffer extension fails, @c EOF is returned.
*
- * On successful write, the position of the buffer is increased.
+ * On successful writing, the position of the buffer is increased.
*
* If you just want to write a null-terminator at the current position, you
* should use cxBufferTerminate() instead.
@@ -661,31 +621,25 @@
* @param buffer the buffer to write to
* @param c the character to write
* @return the byte that has been written or @c EOF when the end of the stream is
- * reached and automatic extension is not enabled or not possible
+ * reached, and automatic extension is not enabled or not possible
* @see cxBufferTerminate()
*/
cx_attr_nonnull
-cx_attr_export
-int cxBufferPut(
- CxBuffer *buffer,
- int c
-);
+CX_EXPORT int cxBufferPut(CxBuffer *buffer, int c);
/**
* Writes a terminating zero to a buffer at the current position.
*
- * On successful write, @em neither the position @em nor the size of the buffer is
- * increased.
+ * If successful, sets the size to the current position and advances the position by one.
*
* The purpose of this function is to have the written data ready to be used as
- * a C string.
+ * a C string with the buffer's size being the length of that string.
*
* @param buffer the buffer to write to
* @return zero, if the terminator could be written, non-zero otherwise
*/
cx_attr_nonnull
-cx_attr_export
-int cxBufferTerminate(CxBuffer *buffer);
+CX_EXPORT int cxBufferTerminate(CxBuffer *buffer);
/**
* Writes a string to a buffer.
@@ -696,13 +650,8 @@
* @param str the zero-terminated string
* @return the number of bytes written
*/
-cx_attr_nonnull
-cx_attr_cstr_arg(2)
-cx_attr_export
-size_t cxBufferPutString(
- CxBuffer *buffer,
- const char *str
-);
+cx_attr_nonnull cx_attr_cstr_arg(2)
+CX_EXPORT size_t cxBufferPutString(CxBuffer *buffer, const char *str);
/**
* Gets a character from a buffer.
@@ -713,8 +662,7 @@
* @return the character or @c EOF, if the end of the buffer is reached
*/
cx_attr_nonnull
-cx_attr_export
-int cxBufferGet(CxBuffer *buffer);
+CX_EXPORT int cxBufferGet(CxBuffer *buffer);
#ifdef __cplusplus
}