1.1 --- a/src/ucx/buffer.h Mon Dec 30 09:54:10 2019 +0100
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,339 +0,0 @@
1.4 -/*
1.5 - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
1.6 - *
1.7 - * Copyright 2017 Mike Becker, Olaf Wintermann All rights reserved.
1.8 - *
1.9 - * Redistribution and use in source and binary forms, with or without
1.10 - * modification, are permitted provided that the following conditions are met:
1.11 - *
1.12 - * 1. Redistributions of source code must retain the above copyright
1.13 - * notice, this list of conditions and the following disclaimer.
1.14 - *
1.15 - * 2. Redistributions in binary form must reproduce the above copyright
1.16 - * notice, this list of conditions and the following disclaimer in the
1.17 - * documentation and/or other materials provided with the distribution.
1.18 - *
1.19 - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
1.20 - * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.21 - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1.22 - * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
1.23 - * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.24 - * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.25 - * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
1.26 - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
1.27 - * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.28 - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1.29 - * POSSIBILITY OF SUCH DAMAGE.
1.30 - */
1.31 -
1.32 -/**
1.33 - * @file buffer.h
1.34 - *
1.35 - * Advanced buffer implementation.
1.36 - *
1.37 - * Instances of UcxBuffer can be used to read from or to write to like one
1.38 - * would do with a stream. This allows the use of ucx_stream_copy() to copy
1.39 - * contents from one buffer to another.
1.40 - *
1.41 - * Some features for convenient use of the buffer
1.42 - * can be enabled. See the documentation of the macro constants for more
1.43 - * information.
1.44 - *
1.45 - * @author Mike Becker
1.46 - * @author Olaf Wintermann
1.47 - */
1.48 -
1.49 -#ifndef UCX_BUFFER_H
1.50 -#define UCX_BUFFER_H
1.51 -
1.52 -#include "ucx.h"
1.53 -#include <sys/types.h>
1.54 -#include <stdio.h>
1.55 -
1.56 -#ifdef __cplusplus
1.57 -extern "C" {
1.58 -#endif
1.59 -
1.60 -/**
1.61 - * No buffer features enabled (all flags cleared).
1.62 - */
1.63 -#define UCX_BUFFER_DEFAULT 0x00
1.64 -
1.65 -/**
1.66 - * If this flag is enabled, the buffer will automatically free its contents.
1.67 - */
1.68 -#define UCX_BUFFER_AUTOFREE 0x01
1.69 -
1.70 -/**
1.71 - * If this flag is enabled, the buffer will automatically extends its capacity.
1.72 - */
1.73 -#define UCX_BUFFER_AUTOEXTEND 0x02
1.74 -
1.75 -/** UCX Buffer. */
1.76 -typedef struct {
1.77 - /** A pointer to the buffer contents. */
1.78 - char *space;
1.79 - /** Current position of the buffer. */
1.80 - size_t pos;
1.81 - /** Current capacity (i.e. maximum size) of the buffer. */
1.82 - size_t capacity;
1.83 - /** Current size of the buffer content. */
1.84 - size_t size;
1.85 - /**
1.86 - * Flag register for buffer features.
1.87 - * @see #UCX_BUFFER_DEFAULT
1.88 - * @see #UCX_BUFFER_AUTOFREE
1.89 - * @see #UCX_BUFFER_AUTOEXTEND
1.90 - */
1.91 - int flags;
1.92 -} UcxBuffer;
1.93 -
1.94 -/**
1.95 - * Creates a new buffer.
1.96 - *
1.97 - * <b>Note:</b> you may provide <code>NULL</code> as argument for
1.98 - * <code>space</code>. Then this function will allocate the space and enforce
1.99 - * the #UCX_BUFFER_AUTOFREE flag.
1.100 - *
1.101 - * @param space pointer to the memory area, or <code>NULL</code> to allocate
1.102 - * new memory
1.103 - * @param capacity the capacity of the buffer
1.104 - * @param flags buffer features (see UcxBuffer.flags)
1.105 - * @return the new buffer
1.106 - */
1.107 -UcxBuffer *ucx_buffer_new(void *space, size_t capacity, int flags);
1.108 -
1.109 -/**
1.110 - * Destroys a buffer.
1.111 - *
1.112 - * If the #UCX_BUFFER_AUTOFREE feature is enabled, the contents of the buffer
1.113 - * are also freed.
1.114 - *
1.115 - * @param buffer the buffer to destroy
1.116 - */
1.117 -void ucx_buffer_free(UcxBuffer* buffer);
1.118 -
1.119 -/**
1.120 - * Creates a new buffer and fills it with extracted content from another buffer.
1.121 - *
1.122 - * <b>Note:</b> the #UCX_BUFFER_AUTOFREE feature is enforced for the new buffer.
1.123 - *
1.124 - * @param src the source buffer
1.125 - * @param start the start position of extraction
1.126 - * @param length the count of bytes to extract (must not be zero)
1.127 - * @param flags feature mask for the new buffer
1.128 - * @return a new buffer containing the extraction
1.129 - */
1.130 -UcxBuffer* ucx_buffer_extract(UcxBuffer *src,
1.131 - size_t start, size_t length, int flags);
1.132 -
1.133 -/**
1.134 - * A shorthand macro for the full extraction of the buffer.
1.135 - *
1.136 - * @param src the source buffer
1.137 - * @param flags feature mask for the new buffer
1.138 - * @return a new buffer with the extracted content
1.139 - */
1.140 -#define ucx_buffer_clone(src,flags) \
1.141 - ucx_buffer_extract(src, 0, (src)->capacity, flags)
1.142 -
1.143 -
1.144 -/**
1.145 - * Shifts the contents of the buffer by the given offset.
1.146 - *
1.147 - * If the offset is positive, the contents are shifted to the right.
1.148 - * If auto extension is enabled, the buffer grows, if necessary.
1.149 - * In case the auto extension fails, this function returns a non-zero value and
1.150 - * no contents are changed.
1.151 - * If auto extension is disabled, the contents that do not fit into the buffer
1.152 - * are discarded.
1.153 - *
1.154 - * If the offset is negative, the contents are shifted to the left where the
1.155 - * first <code>shift</code> bytes are discarded.
1.156 - * The new size of the buffer is the old size minus
1.157 - * the absolute shift value.
1.158 - * If this value is larger than the buffer size, the buffer is emptied (but
1.159 - * not cleared, see the security note below).
1.160 - *
1.161 - * The buffer position gets shifted alongside with the content but is kept
1.162 - * within the boundaries of the buffer.
1.163 - *
1.164 - * <b>Security note:</b> the shifting operation does <em>not</em> erase the
1.165 - * previously occupied memory cells. You can easily do that manually, e.g. by
1.166 - * calling <code>memset(buffer->space, 0, shift)</code> for a right shift or
1.167 - * <code>memset(buffer->size, 0, buffer->capacity-buffer->size)</code>
1.168 - * for a left shift.
1.169 - *
1.170 - * @param buffer the buffer
1.171 - * @param shift the shift offset (negative means left shift)
1.172 - * @return 0 on success, non-zero if a required auto-extension fails
1.173 - */
1.174 -int ucx_buffer_shift(UcxBuffer* buffer, off_t shift);
1.175 -
1.176 -/**
1.177 - * Shifts the buffer to the right.
1.178 - * See ucx_buffer_shift() for details.
1.179 - *
1.180 - * @param buffer the buffer
1.181 - * @param shift the shift offset
1.182 - * @return 0 on success, non-zero if a required auto-extension fails
1.183 - * @see ucx_buffer_shift()
1.184 - */
1.185 -int ucx_buffer_shift_right(UcxBuffer* buffer, size_t shift);
1.186 -
1.187 -/**
1.188 - * Shifts the buffer to the left.
1.189 - *
1.190 - * See ucx_buffer_shift() for details. Note, however, that this method expects
1.191 - * a positive shift offset.
1.192 - *
1.193 - * Since a left shift cannot fail due to memory allocation problems, this
1.194 - * function always returns zero.
1.195 - *
1.196 - * @param buffer the buffer
1.197 - * @param shift the shift offset
1.198 - * @return always zero
1.199 - * @see ucx_buffer_shift()
1.200 - */
1.201 -int ucx_buffer_shift_left(UcxBuffer* buffer, size_t shift);
1.202 -
1.203 -
1.204 -/**
1.205 - * Moves the position of the buffer.
1.206 - *
1.207 - * The new position is relative to the <code>whence</code> argument.
1.208 - *
1.209 - * SEEK_SET marks the start of the buffer.
1.210 - * SEEK_CUR marks the current position.
1.211 - * SEEK_END marks the end of the buffer.
1.212 - *
1.213 - * With an offset of zero, this function sets the buffer position to zero
1.214 - * (SEEK_SET), the buffer size (SEEK_END) or leaves the buffer position
1.215 - * unchanged (SEEK_CUR).
1.216 - *
1.217 - * @param buffer
1.218 - * @param offset position offset relative to <code>whence</code>
1.219 - * @param whence one of SEEK_SET, SEEK_CUR or SEEK_END
1.220 - * @return 0 on success, non-zero if the position is invalid
1.221 - *
1.222 - */
1.223 -int ucx_buffer_seek(UcxBuffer *buffer, off_t offset, int whence);
1.224 -
1.225 -/**
1.226 - * Clears the buffer by resetting the position and deleting the data.
1.227 - *
1.228 - * The data is deleted by a zeroing it with call to <code>memset()</code>.
1.229 - *
1.230 - * @param buffer the buffer to be cleared
1.231 - */
1.232 -#define ucx_buffer_clear(buffer) memset((buffer)->space, 0, (buffer)->size); \
1.233 - (buffer)->size = 0; (buffer)->pos = 0;
1.234 -
1.235 -/**
1.236 - * Tests, if the buffer position has exceeded the buffer capacity.
1.237 - *
1.238 - * @param buffer the buffer to test
1.239 - * @return non-zero, if the current buffer position has exceeded the last
1.240 - * available byte of the buffer.
1.241 - */
1.242 -int ucx_buffer_eof(UcxBuffer *buffer);
1.243 -
1.244 -
1.245 -/**
1.246 - * Extends the capacity of the buffer.
1.247 - *
1.248 - * <b>Note:</b> The buffer capacity increased by a power of two. I.e.
1.249 - * the buffer capacity is doubled, as long as it would not hold the current
1.250 - * content plus the additional required bytes.
1.251 - *
1.252 - * <b>Attention:</b> the argument provided is the number of <i>additional</i>
1.253 - * bytes the buffer shall hold. It is <b>NOT</b> the total number of bytes the
1.254 - * buffer shall hold.
1.255 - *
1.256 - * @param buffer the buffer to extend
1.257 - * @param additional_bytes the number of additional bytes the buffer shall
1.258 - * <i>at least</i> hold
1.259 - * @return 0 on success or a non-zero value on failure
1.260 - */
1.261 -int ucx_buffer_extend(UcxBuffer *buffer, size_t additional_bytes);
1.262 -
1.263 -/**
1.264 - * Writes data to a UcxBuffer.
1.265 - *
1.266 - * The position of the buffer is increased by the number of bytes written.
1.267 - *
1.268 - * @param ptr a pointer to the memory area containing the bytes to be written
1.269 - * @param size the length of one element
1.270 - * @param nitems the element count
1.271 - * @param buffer the UcxBuffer to write to
1.272 - * @return the total count of bytes written
1.273 - */
1.274 -size_t ucx_buffer_write(const void *ptr, size_t size, size_t nitems,
1.275 - UcxBuffer *buffer);
1.276 -
1.277 -/**
1.278 - * Reads data from a UcxBuffer.
1.279 - *
1.280 - * The position of the buffer is increased by the number of bytes read.
1.281 - *
1.282 - * @param ptr a pointer to the memory area where to store the read data
1.283 - * @param size the length of one element
1.284 - * @param nitems the element count
1.285 - * @param buffer the UcxBuffer to read from
1.286 - * @return the total number of elements read
1.287 - */
1.288 -size_t ucx_buffer_read(void *ptr, size_t size, size_t nitems,
1.289 - UcxBuffer *buffer);
1.290 -
1.291 -/**
1.292 - * Writes a character to a buffer.
1.293 - *
1.294 - * The least significant byte of the argument is written to the buffer. If the
1.295 - * end of the buffer is reached and #UCX_BUFFER_AUTOEXTEND feature is enabled,
1.296 - * the buffer capacity is extended by ucx_buffer_extend(). If the feature is
1.297 - * disabled or buffer extension fails, <code>EOF</code> is returned.
1.298 - *
1.299 - * On successful write the position of the buffer is increased.
1.300 - *
1.301 - * @param buffer the buffer to write to
1.302 - * @param c the character to write as <code>int</code> value
1.303 - * @return the byte that has bean written as <code>int</code> value or
1.304 - * <code>EOF</code> when the end of the stream is reached and automatic
1.305 - * extension is not enabled or not possible
1.306 - */
1.307 -int ucx_buffer_putc(UcxBuffer *buffer, int c);
1.308 -
1.309 -/**
1.310 - * Gets a character from a buffer.
1.311 - *
1.312 - * The current position of the buffer is increased after a successful read.
1.313 - *
1.314 - * @param buffer the buffer to read from
1.315 - * @return the character as <code>int</code> value or <code>EOF</code>, if the
1.316 - * end of the buffer is reached
1.317 - */
1.318 -int ucx_buffer_getc(UcxBuffer *buffer);
1.319 -
1.320 -/**
1.321 - * Writes a string to a buffer.
1.322 - *
1.323 - * @param buffer the buffer
1.324 - * @param str the string
1.325 - * @return the number of bytes written
1.326 - */
1.327 -size_t ucx_buffer_puts(UcxBuffer *buffer, const char *str);
1.328 -
1.329 -/**
1.330 - * Returns the complete buffer content as sstr_t.
1.331 - * @param buffer the buffer
1.332 - * @return the result of <code>sstrn()</code> with the buffer space and size
1.333 - * as arguments
1.334 - */
1.335 -#define ucx_buffer_to_sstr(buffer) sstrn((buffer)->space, (buffer)->size)
1.336 -
1.337 -#ifdef __cplusplus
1.338 -}
1.339 -#endif
1.340 -
1.341 -#endif /* UCX_BUFFER_H */
1.342 -
