--- a/ucx/buffer.h Fri Aug 16 12:41:30 2013 +0200
+++ b/ucx/buffer.h Sat Aug 17 12:04:04 2013 +0200
@@ -26,6 +26,23 @@
* 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
@@ -37,94 +54,210 @@
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
- * if length is zero, the whole remaining buffer shall be extracted
- * the position of the new buffer is set to zero
+/**
+ * Creates a new buffer and fills it with extracted content from another buffer.
+ *
+ * <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.
+ *
+ * The new position is relative to the <code>whence</code> argument.
*
- * SEEK_SET marks the start of the buffer
- * SEEK_CUR marks the current position
- * SEEK_END marks the first 0-byte in the buffer
- *
- * ucx_buffer_seek returns 0 on success and -1 if the new position is beyond the
- * bounds of the allocated buffer. In that case the position of the buffer
- * remains unchanged.
+ * SEEK_SET marks the start of the buffer.
+ * SEEK_CUR marks the current position.
+ * SEEK_END marks the first 0-byte in the buffer.
+ *
+ * @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>.
+ *
+ * @param buffer the buffer to be cleared
+ */
+#define ucx_buffer_clear(buffer) memset(buffer->space, 0, buffer->size); \
+ buffer->size = 0; buffer->pos = 0;
-/*
- * returns non-zero, if the current buffer position has exceeded the last
- * available byte of the underlying buffer
- *
+/**
+ * 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);
-
-
-/*
- * copies all bytes from s1 to s2
- * uses the read function r to read from s1 und writes the data using the
- * write function w to s2
- * returns the number of bytes copied
+/**
+ * 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,
+ * the buffer capacity is extended by ucx_buffer_extend(). If the feature is
+ * disabled or buffer extension fails, <code>EOF</code> is returned.
+ *
+ * On successful write the position of the buffer is increased.
+ *
+ * @param buffer the buffer to write to
+ * @param c the character to write as <code>int</code> value
+ * @return the byte that has bean written as <code>int</code> value or
+ * <code>EOF</code> when the end of the stream is reached and automatic
+ * extension is not enabled or not possible
*/
-size_t ucx_buffer_generic_copy(void *s1, void *s2, read_func r, write_func w,
- size_t bufsize);
+int ucx_buffer_putc(UcxBuffer *buffer, int c);
-size_t ucx_buffer_generic_ncopy(void *s1, void *s2, read_func r, write_func w,
- size_t bufsize, size_t n);
-
-#define UCX_DEFAULT_BUFFER_SIZE 0x1000
+/**
+ * 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 as <code>int</code> value or <code>EOF</code>, if the
+ * end of the buffer is reached
+ */
+int ucx_buffer_getc(UcxBuffer *buffer);
-#define ucx_buffer_copy(s1,s2,r,w) \
- ucx_buffer_generic_copy(s1, s2, (read_func)r, (write_func)w, \
- UCX_DEFAULT_BUFFER_SIZE)
-
-#define ucx_buffer_ncopy(s1,s2,r,w, n) \
- ucx_buffer_generic_ncopy(s1, s2, (read_func)r, (write_func)w, \
- UCX_DEFAULT_BUFFER_SIZE, n)
+/**
+ * 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
}