dav: comparison ucx/cx/buffer.h

-:b60487c3ec36
+:af685cc9d623
 /**
 * 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
 /**
 * If this flag is enabled, the buffer will automatically extend its capacity.
 #define CX_BUFFER_AUTO_EXTEND 0x02
 /**
 * 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
 /**
 * flush target accepts no more data.
 */
 size_t blkmax;
 /**
-* The target for write function.
+* The target for the write function.
 */
 void *target;
 /**
 * The write-function used for flushing.
 *
 * You may also provide a read-only @p space, in which case
 * 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
 * the auto-extension feature, you @em must use the
 * #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
 * space will be leaking after the copy-on-write operation.
 *
 * @param space pointer to the memory area, or @c NULL to allocate
 * new memory
 * @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
+CX_EXPORT int cxBufferInit(CxBuffer *buffer, void *space, size_t capacity,
-int cxBufferInit(
+const CxAllocator *allocator, int flags);
-CxBuffer *buffer,
-void *space,
-size_t capacity,
-const CxAllocator *allocator,
-int flags
-);
 /**
 * Configures the buffer for flushing.
 *
 * Flushing can happen automatically when data is written
 * @retval non-zero failure
 * @see cxBufferFlush()
 * @see cxBufferWrite()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT int cxBufferEnableFlushing(CxBuffer *buffer, CxBufferFlushConfig config);
-int cxBufferEnableFlushing(
-CxBuffer *buffer,
-CxBufferFlushConfig config
-);
 /**
 * Destroys the buffer contents.
 *
 * Has no effect if the #CX_BUFFER_FREE_CONTENTS feature is not enabled.
 *
 * @param buffer the buffer which contents shall be destroyed
 * @see cxBufferInit()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT void cxBufferDestroy(CxBuffer *buffer);
-void cxBufferDestroy(CxBuffer *buffer);
 /**
 * Deallocates the buffer.
 *
 * 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
+CX_EXPORT void cxBufferFree(CxBuffer *buffer);
-void cxBufferFree(CxBuffer *buffer);
 /**
 * Allocates and initializes a fresh buffer.
 *
 * You may also provide a read-only @p space, in which case
 * When you specify stack memory as @p space and decide to use
 * the auto-extension feature, you @em must use the
 * #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.
 *
 * @param space pointer to the memory area, or @c NULL to allocate
 * new memory
 * @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_malloc cx_attr_dealloc(cxBufferFree, 1) cx_attr_nodiscard
-cx_attr_dealloc(cxBufferFree, 1)
+CX_EXPORT CxBuffer *cxBufferCreate(void *space, size_t capacity,
-cx_attr_nodiscard
+const CxAllocator *allocator, int flags);
-cx_attr_export
-CxBuffer *cxBufferCreate(
-void *space,
-size_t capacity,
-const CxAllocator *allocator,
-int flags
-);
 /**
 * Shifts the contents of the buffer by the given offset.
 *
 * If the offset is positive, the contents are shifted to the right.
 * 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
+* When the auto extension is disabled, the contents that do not fit into the
-* are discarded.
+* buffer are discarded.
 *
 * If the offset is negative, the contents are shifted to the left where the
 * first @p shift bytes are discarded.
 * The new size of the buffer is the old size minus the absolute shift value.
 * 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.
 *
 * @param buffer the buffer
 * @retval non-zero if a required auto-extension or copy-on-write fails
 * @see cxBufferShiftLeft()
 * @see cxBufferShiftRight()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT int cxBufferShift(CxBuffer *buffer, off_t shift);
-int cxBufferShift(
-CxBuffer *buffer,
-off_t shift
-);
 /**
 * Shifts the buffer to the right.
 * See cxBufferShift() for details.
 *
 * @retval zero success
 * @retval non-zero if a required auto-extension or copy-on-write fails
 * @see cxBufferShift()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT int cxBufferShiftRight(CxBuffer *buffer, size_t shift);
-int cxBufferShiftRight(
-CxBuffer *buffer,
-size_t shift
-);
 /**
 * Shifts the buffer to the left.
 * See cxBufferShift() for details.
 *
 * @retval zero success
 * @retval non-zero if the buffer uses copy-on-write and the allocation fails
 * @see cxBufferShift()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT int cxBufferShiftLeft(CxBuffer *buffer, size_t shift);
-int cxBufferShiftLeft(
-CxBuffer *buffer,
-size_t shift
-);
 /**
 * Moves the position of the buffer.
 *
 * @retval zero success
 * @retval non-zero if the position is invalid
 *
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT int cxBufferSeek(CxBuffer *buffer, off_t offset, int whence);
-int cxBufferSeek(
-CxBuffer *buffer,
-off_t offset,
-int whence
-);
 /**
 * Clears the buffer by resetting the position and deleting the data.
 *
 * The data is deleted by zeroing it with a call to memset().
 *
 * @param buffer the buffer to be cleared
 * @see cxBufferReset()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT void cxBufferClear(CxBuffer *buffer);
-void cxBufferClear(CxBuffer *buffer);
 /**
 * Resets the buffer by resetting the position and size to zero.
 *
 * The data in the buffer is not deleted. If you need a safe
 *
 * @param buffer the buffer to be cleared
 * @see cxBufferClear()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT void cxBufferReset(CxBuffer *buffer);
-void cxBufferReset(CxBuffer *buffer);
 /**
 * Tests, if the buffer position has exceeded the buffer size.
 *
 * @param buffer the buffer to test
 * @retval true if the current buffer position has exceeded the last
 * byte of the buffer's contents
 * @retval false otherwise
 */
-cx_attr_nonnull
+cx_attr_nonnull cx_attr_nodiscard
-cx_attr_nodiscard
+CX_EXPORT bool cxBufferEof(const CxBuffer *buffer);
-cx_attr_export
-bool cxBufferEof(const CxBuffer *buffer);
 /**
 * Ensures that the buffer has a minimum capacity.
 *
 * 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
+cx_attr_nonnull
-int cxBufferMinimumCapacity(
+CX_EXPORT int cxBufferMinimumCapacity(CxBuffer *buffer, size_t capacity);
-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
 * the target until the target signals that it cannot take more data by
 * returning zero via the respective write function. In that case, the remaining
 * 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
 * the capacity or flush threshold, this function tries to write all items directly
 * 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
+* @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
+* That means it does @em not include the number of items that were already in
-* in were flushed during the process).
+* 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.
 *
 * @param ptr a pointer to the memory area containing the bytes to be written
 * @return the total count of elements written
 * @see cxBufferAppend()
 * @see cxBufferRead()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT size_t cxBufferWrite(const void *ptr, size_t size,
-size_t cxBufferWrite(
+size_t nitems, CxBuffer *buffer);
-const void *ptr,
-size_t size,
-size_t nitems,
-CxBuffer *buffer
-);
 /**
 * Appends data to a CxBuffer.
 *
 * The data is always appended to current data within the buffer,
 * @return the total count of elements written
 * @see cxBufferWrite()
 * @see cxBufferRead()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT size_t cxBufferAppend(const void *ptr, size_t size,
-size_t cxBufferAppend(
+size_t nitems, CxBuffer *buffer);
-const void *ptr,
-size_t size,
-size_t nitems,
-CxBuffer *buffer
-);
 /**
 * Performs a single flush-run on the specified buffer.
 *
 * Does nothing when the position in the buffer is zero.
 * @par Example 1
 * Assume you have a buffer with size 340 and you are
 * 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.
 *
 * @remark Just returns zero when flushing was not enabled with
 * cxBufferEnableFlushing().
 *
 * @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
+* buffer because it makes little sense to put
-* readonly data into an UCX buffer for flushing, instead
+* readonly data into an UCX buffer for flushing instead
 * of writing it directly to the target.
 *
 * @param buffer the buffer
 * @return the number of successfully flushed bytes
 * @see cxBufferEnableFlushing()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT size_t cxBufferFlush(CxBuffer *buffer);
-size_t cxBufferFlush(CxBuffer *buffer);
 /**
 * Reads data from a CxBuffer.
 *
 * The position of the buffer is increased by the number of bytes read.
 * @return the total number of elements read
 * @see cxBufferWrite()
 * @see cxBufferAppend()
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT size_t cxBufferRead(void *ptr, size_t size,
-size_t cxBufferRead(
+size_t nitems, CxBuffer *buffer);
-void *ptr,
-size_t size,
-size_t nitems,
-CxBuffer *buffer
-);
 /**
 * Writes a character to a buffer.
 *
 * 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.
 *
 * @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
+CX_EXPORT int cxBufferPut(CxBuffer *buffer, int c);
-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
+* If successful, sets the size to the current position and advances the position by one.
-* increased.
 *
 * 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
+CX_EXPORT int cxBufferTerminate(CxBuffer *buffer);
-int cxBufferTerminate(CxBuffer *buffer);
 /**
 * Writes a string to a buffer.
 *
 * This is a convenience function for <code>cxBufferWrite(str, 1, strlen(str), buffer)</code>.
 *
 * @param buffer the buffer
 * @param str the zero-terminated string
 * @return the number of bytes written
 */
-cx_attr_nonnull
+cx_attr_nonnull cx_attr_cstr_arg(2)
-cx_attr_cstr_arg(2)
+CX_EXPORT size_t cxBufferPutString(CxBuffer *buffer, const char *str);
-cx_attr_export
-size_t cxBufferPutString(
-CxBuffer *buffer,
-const char *str
-);
 /**
 * Gets a character from a buffer.
 *
 * The current position of the buffer is increased after a successful read.
 *
 * @param buffer the buffer to read from
 * @return the character or @c EOF, if the end of the buffer is reached
 */
 cx_attr_nonnull
-cx_attr_export
+CX_EXPORT int cxBufferGet(CxBuffer *buffer);
-int cxBufferGet(CxBuffer *buffer);
 #ifdef __cplusplus
 }
 #endif

Mercurial > hg > dav / file comparison

comparison: ucx/cx/buffer.h

ucx/cx/buffer.h