ucx: ucx/buffer.c@b7d1317b138e

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  *

     4  * Copyright 2017 Olaf Wintermann. All rights reserved.

     5  *

     6  * Redistribution and use in source and binary forms, with or without

     7  * modification, are permitted provided that the following conditions are met:

     8  *

     9  *   1. Redistributions of source code must retain the above copyright

    10  *      notice, this list of conditions and the following disclaimer.

    11  *

    12  *   2. Redistributions in binary form must reproduce the above copyright

    13  *      notice, this list of conditions and the following disclaimer in the

    14  *      documentation and/or other materials provided with the distribution.

    15  *

    16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

    17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

    20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    26  * POSSIBILITY OF SUCH DAMAGE.

    27  */

    29 #include "buffer.h"

    30 #include <stdarg.h>

    31 #include <stdlib.h>

    32 #include <string.h>

    34 UcxBuffer *ucx_buffer_new(void *space, size_t capacity, int flags) {

    35     UcxBuffer *buffer = (UcxBuffer*) malloc(sizeof(UcxBuffer));

    36     if (buffer) {

    37         buffer->flags = flags;

    38         if (!space) {

    39             buffer->space = (char*)malloc(capacity);

    40             if (!buffer->space) {

    41                 free(buffer);

    42                 return NULL;

    43             }

    44             memset(buffer->space, 0, capacity);

    45             buffer->flags |= UCX_BUFFER_AUTOFREE;

    46         } else {

    47             buffer->space = (char*)space;

    48         }

    49         buffer->capacity = capacity;

    50         buffer->size = 0;

    52         buffer->pos = 0;

    53     }

    55     return buffer;

    56 }

    58 void ucx_buffer_free(UcxBuffer *buffer) {

    59     if ((buffer->flags & UCX_BUFFER_AUTOFREE) == UCX_BUFFER_AUTOFREE) {

    60         free(buffer->space);

    61     }

    62     free(buffer);

    63 }

    65 UcxBuffer* ucx_buffer_extract(

    66         UcxBuffer *src, size_t start, size_t length, int flags) {

    67     if (src->size == 0 || length == 0 ||

    68         ((size_t)-1) - start < length || start+length > src->capacity)

    69     {

    70         return NULL;

    71     }

    73     UcxBuffer *dst = (UcxBuffer*) malloc(sizeof(UcxBuffer));

    74     if (dst) {

    75         dst->space = (char*)malloc(length);

    76         if (!dst->space) {

    77             free(dst);

    78             return NULL;

    79         }

    80         dst->capacity = length;

    81         dst->size = length;

    82         dst->flags = flags | UCX_BUFFER_AUTOFREE;

    83         dst->pos = 0;

    84         memcpy(dst->space, src->space+start, length);

    85     }

    86     return dst;

    87 }

    89 int ucx_buffer_seek(UcxBuffer *buffer, off_t offset, int whence) {

    90     size_t npos;

    91     switch (whence) {

    92     case SEEK_CUR:

    93         npos = buffer->pos;

    94         break;

    95     case SEEK_END:

    96         npos = buffer->size;

    97         break;

    98     case SEEK_SET:

    99         npos = 0;

   100         break;

   101     default:

   102         return -1;

   103     }

   105     size_t opos = npos;

   106     npos += offset;

   108     if ((offset > 0 && npos < opos) || (offset < 0 && npos > opos)) {

   109         return -1;

   110     }

   112     if (npos >= buffer->size) {

   113         return -1;

   114     } else {

   115         buffer->pos = npos;

   116         return 0;

   117     }

   119 }

   121 int ucx_buffer_eof(UcxBuffer *buffer) {

   122     return buffer->pos >= buffer->size;

   123 }

   125 int ucx_buffer_extend(UcxBuffer *buffer, size_t len) {

   126     size_t newcap = buffer->capacity;

   128     if (buffer->capacity + len < buffer->capacity) {

   129         return -1;

   130     }

   132     while (buffer->capacity + len > newcap) {

   133         newcap <<= 1;

   134         if (newcap < buffer->capacity) {

   135             return -1;

   136         }

   137     }

   139     char *newspace = (char*)realloc(buffer->space, newcap);

   140     if (newspace) {

   141         memset(newspace+buffer->size, 0, newcap-buffer->size);

   142         buffer->space = newspace;

   143         buffer->capacity = newcap;

   144     } else {

   145         return -1;

   146     }

   148     return 0;

   149 }

   151 size_t ucx_buffer_write(const void *ptr, size_t size, size_t nitems,

   152         UcxBuffer *buffer) {

   153     size_t len = size * nitems;

   154     size_t required = buffer->pos + len;

   155     if (buffer->pos > required) {

   156         return 0;

   157     }

   159     if (required > buffer->capacity) {

   160         if ((buffer->flags & UCX_BUFFER_AUTOEXTEND) == UCX_BUFFER_AUTOEXTEND) {

   161             if (ucx_buffer_extend(buffer, required - buffer->capacity)) {

   162                 return 0;

   163             }

   164         } else {

   165             len = buffer->capacity - buffer->pos;

   166             if (size > 1) {

   167                 len -= len%size;

   168             }

   169         }

   170     }

   172     if (len == 0) {

   173         return len;

   174     }

   176     memcpy(buffer->space + buffer->pos, ptr, len);

   177     buffer->pos += len;

   178     if(buffer->pos > buffer->size) {

   179         buffer->size = buffer->pos;

   180     }

   182     return len / size;

   183 }

   185 size_t ucx_buffer_read(void *ptr, size_t size, size_t nitems,

   186         UcxBuffer *buffer) {

   187     size_t len = size * nitems;

   188     if (buffer->pos + len > buffer->size) {

   189         len = buffer->size - buffer->pos;

   190         if (size > 1) len -= len%size;

   191     }

   193     if (len <= 0) {

   194         return len;

   195     }

   197     memcpy(ptr, buffer->space + buffer->pos, len);

   198     buffer->pos += len;

   200     return len / size;

   201 }

   203 int ucx_buffer_putc(UcxBuffer *buffer, int c) {

   204     if(buffer->pos >= buffer->capacity) {

   205         if ((buffer->flags & UCX_BUFFER_AUTOEXTEND) == UCX_BUFFER_AUTOEXTEND) {

   206             if(ucx_buffer_extend(buffer, 1)) {

   207                 return EOF;

   208             }

   209         } else {

   210             return EOF;

   211         }

   212     }

   214     c &= 0xFF;

   215     buffer->space[buffer->pos] = (char) c;

   216     buffer->pos++;

   217     if(buffer->pos > buffer->size) {

   218         buffer->size = buffer->pos;

   219     }

   220     return c;

   221 }

   223 int ucx_buffer_getc(UcxBuffer *buffer) {

   224     if (ucx_buffer_eof(buffer)) {

   225         return EOF;

   226     } else {

   227         int c = buffer->space[buffer->pos];

   228         buffer->pos++;

   229         return c;

   230     }

   231 }

   233 size_t ucx_buffer_puts(UcxBuffer *buffer, char *str) {

   234     return ucx_buffer_write((const void*)str, 1, strlen(str), buffer);

   235 }

Mercurial > hg > ucx / file revision