dav: comparison ucx/buffer.h

-:5dbef9e07376
+:11dffb40cd91
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
+/**
+* @file buffer.h
+*
+* Advanced buffer implementation.
+*
+* Instances of UcxBuffer can be used to read from or to write to like one
+* would do with a stream. This allows the use of ucx_stream_copy() to copy
+* contents from one buffer to another.
+*
+* Some features for convenient use of the buffer
+* can be enabled. See the documentation of the macro constants for more
+* information.
+*
+* @author Mike Becker
+* @author Olaf Wintermann
+*/
 #ifndef UCX_BUFFER_H
 #define	UCX_BUFFER_H
 #include "ucx.h"
 #include <sys/types.h>
 #ifdef	__cplusplus
 extern "C" {
 #endif
-/* no autoextend or autofree behaviour */
+/**
+* No buffer features enabled (all flags cleared).
+*/
 #define UCX_BUFFER_DEFAULT      0x00
-/* the buffer shall free the occupied memory space */
+/**
+* If this flag is enabled, the buffer will automatically free its contents.
+*/
 #define UCX_BUFFER_AUTOFREE     0x01
-/* the buffer may automatically double its size on write operations */
+/**
+* If this flag is enabled, the buffer will automatically extends its capacity.
+*/
 #define UCX_BUFFER_AUTOEXTEND   0x02
-/* the user shall not modify values, but may get the latest pointer */
+/** UCX Buffer. */
 typedef struct {
+/** A pointer to the buffer contents. */
 char *space;
+/** Current position of the buffer. */
 size_t pos;
+/** Current capacity (i.e. maximum size) of the buffer. */
 size_t capacity;
+/** Current size of the buffer content. */
 size_t size;
+/**
+* Flag register for buffer features.
+* @see #UCX_BUFFER_DEFAULT
+* @see #UCX_BUFFER_AUTOFREE
+* @see #UCX_BUFFER_AUTOEXTEND
+*/
 int flags;
 } UcxBuffer;
-/* if space is NULL, new space is allocated and the autofree flag is enforced */
+/**
+* Creates a new buffer.
+*
+* <b>Note:</b> you may provide <code>NULL</code> as argument for
+* <code>space</code>. Then this function will allocate the space and enforce
+* the #UCX_BUFFER_AUTOFREE flag.
+*
+* @param space pointer to the memory area, or <code>NULL</code> to allocate
+* new memory
+* @param size the size of the buffer
+* @param flags buffer features (see UcxBuffer.flags)
+* @return the new buffer
+*/
 UcxBuffer *ucx_buffer_new(void *space, size_t size, int flags);
+/**
+* Destroys a buffer.
+*
+* If the #UCX_BUFFER_AUTOFREE feature is enabled, the contents of the buffer
+* are also freed.
+*
+* @param buffer the buffer to destroy
+*/
 void ucx_buffer_free(UcxBuffer* buffer);
-/*
+/**
-* the autofree flag is enforced for the new buffer
+* Creates a new buffer and fills it with extracted content from another buffer.
-* if length is zero, the whole remaining buffer shall be extracted
+*
-* the position of the new buffer is set to zero
+* <b>Note:</b> the #UCX_BUFFER_AUTOFREE feature is enforced for the new buffer.
+*
+* @param src the source buffer
+* @param start the start position of extraction
+* @param length the count of bytes to extract or 0 if all of the remaining
+* bytes shall be extracted
+* @param flags feature mask for the new buffer
+* @return
 */
 UcxBuffer* ucx_buffer_extract(UcxBuffer *src,
 size_t start, size_t length, int flags);
+/**
+* A shorthand macro for the full extraction of the buffer.
+*
+* @param src the source buffer
+* @param flags feature mask for the new buffer
+* @return a new buffer with the extracted content
+*/
 #define ucx_buffer_clone(src,flags) \
 ucx_buffer_extract(src, 0, 0, flags)
-/*
+/**
-* Moves the position of the buffer to a new position relative to whence.
+* Moves the position of the buffer.
 *
-* SEEK_SET marks the start of the buffer
+* The new position is relative to the <code>whence</code> argument.
-* SEEK_CUR marks the current position
+*
-* SEEK_END marks the first 0-byte in the buffer
+* SEEK_SET marks the start of the buffer.
-*
+* SEEK_CUR marks the current position.
-* ucx_buffer_seek returns 0 on success and -1 if the new position is beyond the
+* SEEK_END marks the first 0-byte in the buffer.
-* bounds of the allocated buffer. In that case the position of the buffer
+*
-* remains unchanged.
+* @param buffer
+* @param offset position offset relative to <code>whence</code>
+* @param whence one of SEEK_SET, SEEK_CUR or SEEK_END
+* @return 0 on success, non-zero if the position is invalid
 *
 */
 int ucx_buffer_seek(UcxBuffer *buffer, off_t offset, int whence);
-#define ucx_buffer_clear(buffer)    memset(buffer->space, 0, buffer->size); \
+/**
-buffer->size = 0; buffer->pos = 0;
+* Clears the buffer by resetting the position and deleting the data.
+*
-/*
+* The data is deleted by a zeroing it with call to <code>memset()</code>.
-* returns non-zero, if the current buffer position has exceeded the last
+*
-* available byte of the underlying buffer
+* @param buffer the buffer to be cleared
-*
+*/
+#define ucx_buffer_clear(buffer) memset(buffer->space, 0, buffer->size); \
+buffer->size = 0; buffer->pos = 0;
+/**
+* Tests, if the buffer position has exceeded the buffer capacity.
+*
+* @param buffer the buffer to test
+* @return non-zero, if the current buffer position has exceeded the last
+* available byte of the buffer.
 */
 int ucx_buffer_eof(UcxBuffer *buffer);
-int ucx_buffere_extend(UcxBuffer *buffer, size_t len);
+/**
+* Extends the capacity of the buffer.
+*
+* <b>Note:</b> The buffer capacity increased by a power of two. I.e.
+* the buffer capacity is doubled, as long as it would not hold the current
+* content plus the additional required bytes.
+*
+* <b>Attention:</b> the argument provided is the count of <i>additional</i>
+* bytes the buffer shall hold. It is <b>NOT</b> the total count of bytes the
+* buffer shall hold.
+*
+* @param buffer the buffer to extend
+* @param additional_bytes the count of additional bytes the buffer shall
+* <i>at least</i> hold
+* @return 0 on success or a non-zero value on failure
+*/
+int ucx_buffer_extend(UcxBuffer *buffer, size_t additional_bytes);
+/**
+* Writes data to an UcxBuffer.
+*
+* The position of the buffer is increased by the number of bytes read.
+*
+* @param ptr a pointer to the memory area containing the bytes to be written
+* @param size the length of one element
+* @param nitems the element count
+* @param buffer the UcxBuffer to write to
+* @return the total count of bytes written
+*/
 size_t ucx_buffer_write(const void *ptr, size_t size, size_t nitems,
 UcxBuffer *buffer);
+/**
+* Reads data from an UcxBuffer.
+*
+* The position of the buffer is increased by the number of bytes read.
+*
+* @param ptr a pointer to the memory area where to store the read data
+* @param size the length of one element
+* @param nitems the element count
+* @param buffer the UcxBuffer to read from
+* @return the total count of bytes read
+*/
 size_t ucx_buffer_read(void *ptr, size_t size, size_t nitems,
 UcxBuffer *buffer);
-int ucx_buffer_putc(UcxBuffer *b, int c);
+/**
-int ucx_buffer_getc(UcxBuffer *b);
+* 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 #UCX_BUFFER_AUTOEXTEND feature is enabled,
-* copies all bytes from s1 to s2
+* the buffer capacity is extended by ucx_buffer_extend(). If the feature is
-* uses the read function r to read from s1 und writes the data using the
+* disabled or buffer extension fails, <code>EOF</code> is returned.
-* write function w to s2
+*
-* returns the number of bytes copied
+* On successful write the position of the buffer is increased.
-*/
+*
-size_t ucx_buffer_generic_copy(void *s1, void *s2, read_func r, write_func w,
+* @param buffer the buffer to write to
-size_t bufsize);
+* @param c the character to write as <code>int</code> value
+* @return the byte that has bean written as <code>int</code> value or
-size_t ucx_buffer_generic_ncopy(void *s1, void *s2, read_func r, write_func w,
+* <code>EOF</code> when the end of the stream is reached and automatic
-size_t bufsize, size_t n);
+* extension is not enabled or not possible
+*/
-#define UCX_DEFAULT_BUFFER_SIZE 0x1000
+int ucx_buffer_putc(UcxBuffer *buffer, int c);
-#define ucx_buffer_copy(s1,s2,r,w) \
+/**
-ucx_buffer_generic_copy(s1, s2, (read_func)r, (write_func)w, \
+* Gets a character from a buffer.
-UCX_DEFAULT_BUFFER_SIZE)
+*
+* The current position of the buffer is increased after a successful read.
-#define ucx_buffer_ncopy(s1,s2,r,w, n) \
+*
-ucx_buffer_generic_ncopy(s1, s2, (read_func)r, (write_func)w, \
+* @param buffer the buffer to read from
-UCX_DEFAULT_BUFFER_SIZE, n)
+* @return the character as <code>int</code> value or <code>EOF</code>, if the
+* end of the buffer is reached
+*/
+int ucx_buffer_getc(UcxBuffer *buffer);
+/**
+* Writes a string to a buffer.
+*
+* @param buffer the buffer
+* @param str the string
+* @return the number of bytes written
+*/
+size_t ucx_buffer_puts(UcxBuffer *buffer, char *str);
 #ifdef	__cplusplus
 }
 #endif

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comparison: ucx/buffer.h

ucx/buffer.h