ucx: src/ucx/buffer.h@2f5dea574a75 (annotated)

src/ucx/buffer.h@2f5dea574a75 (annotated)

src/ucx/buffer.h

Sat, 28 Oct 2017 15:43:51 +0200

author: Mike Becker <universe@uap-core.de>
date: Sat, 28 Oct 2017 15:43:51 +0200
changeset 259: 2f5dea574a75
parent 251: fae240d633fc
child 289: a5eabd407774
permissions: -rw-r--r--

modules documentation

 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
  * Copyright 2017 Mike Becker, Olaf Wintermann All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *   1. Redistributions of source code must retain the above copyright
  *      notice, this list of conditions and the following disclaimer.
  *
  *   2. Redistributions in binary form must reproduce the above copyright
  *      notice, this list of conditions and the following disclaimer in the
  *      documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * 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>
 #include <stdio.h>
 #ifdef	__cplusplus
 extern "C" {
 #endif
 /**
  * No buffer features enabled (all flags cleared).
  */
 #define UCX_BUFFER_DEFAULT      0x00
 /**
  * If this flag is enabled, the buffer will automatically free its contents.
  */
 #define UCX_BUFFER_AUTOFREE     0x01
 /**
  * If this flag is enabled, the buffer will automatically extends its capacity.
  */
 #define UCX_BUFFER_AUTOEXTEND   0x02
 /** 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;
 /**
  * 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 capacity the capacity of the buffer
  * @param flags buffer features (see UcxBuffer.flags)
  * @return the new buffer
  */
 UcxBuffer *ucx_buffer_new(void *space, size_t capacity, 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);
 /**
  * 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 (must not be zero)
  * @param flags feature mask for the new buffer
  * @return a new buffer containing the extraction
  */
 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, (src)->capacity, flags)
 /**
  * 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 end of the buffer.
  *
  * With an offset of zero, this function sets the buffer position to zero
  * (SEEK_SET), the buffer size (SEEK_END) or leaves the buffer position
  * unchanged (SEEK_CUR).
  *
  * @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);
 /**
  * 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;
 /**
  * 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);
 /**
  * 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 number of <i>additional</i>
  * bytes the buffer shall hold. It is <b>NOT</b> the total number of bytes the
  * buffer shall hold.
  *
  * @param buffer the buffer to extend
  * @param additional_bytes the number 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 a UcxBuffer.
  *
  * The position of the buffer is increased by the number of bytes written.
  *
  * @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 a 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 number of elements read
  */
 size_t ucx_buffer_read(void *ptr, size_t size, size_t nitems,
         UcxBuffer *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 #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
  */
 int ucx_buffer_putc(UcxBuffer *buffer, int c);
 /**
  * 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);
 /**
  * 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
 #endif	/* UCX_BUFFER_H */

Mercurial > hg > ucx / annotate

src/ucx/buffer.h@2f5dea574a75 (annotated)

src/ucx/buffer.h