ucx: src/buffer.c@a6184aff5108

     1 /*

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

     3  *

     4  * Copyright 2017 Mike Becker, 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 "ucx/buffer.h"

    31 #include <stdarg.h>

    32 #include <stdlib.h>

    33 #include <string.h>

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

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

    37     if (buffer) {

    38         buffer->flags = flags;

    39         if (!space) {

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

    41             if (!buffer->space) {

    42                 free(buffer);

    43                 return NULL;

    44             }

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

    46             buffer->flags |= UCX_BUFFER_AUTOFREE;

    47         } else {

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

    49         }

    50         buffer->capacity = capacity;

    51         buffer->size = 0;

    53         buffer->pos = 0;

    54     }

    56     return buffer;

    57 }

    59 void ucx_buffer_free(UcxBuffer *buffer) {

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

    61         free(buffer->space);

    62     }

    63     free(buffer);

    64 }

    66 UcxBuffer* ucx_buffer_extract(

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

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

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

    70     {

    71         return NULL;

    72     }

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

    75     if (dst) {

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

    77         if (!dst->space) {

    78             free(dst);

    79             return NULL;

    80         }

    81         dst->capacity = length;

    82         dst->size = length;

    83         dst->flags = flags | UCX_BUFFER_AUTOFREE;

    84         dst->pos = 0;

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

    86     }

    87     return dst;

    88 }

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

    91     size_t npos;

    92     switch (whence) {

    93     case SEEK_CUR:

    94         npos = buffer->pos;

    95         break;

    96     case SEEK_END:

    97         npos = buffer->size;

    98         break;

    99     case SEEK_SET:

   100         npos = 0;

   101         break;

   102     default:

   103         return -1;

   104     }

   106     size_t opos = npos;

   107     npos += offset;

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

   110         return -1;

   111     }

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

   114         return -1;

   115     } else {

   116         buffer->pos = npos;

   117         return 0;

   118     }

   120 }

   122 int ucx_buffer_eof(UcxBuffer *buffer) {

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

   124 }

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

   127     size_t newcap = buffer->capacity;

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

   130         return -1;

   131     }

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

   134         newcap <<= 1;

   135         if (newcap < buffer->capacity) {

   136             return -1;

   137         }

   138     }

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

   141     if (newspace) {

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

   143         buffer->space = newspace;

   144         buffer->capacity = newcap;

   145     } else {

   146         return -1;

   147     }

   149     return 0;

   150 }

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

   153         UcxBuffer *buffer) {

   154     size_t len = size * nitems;

   155     size_t required = buffer->pos + len;

   156     if (buffer->pos > required) {

   157         return 0;

   158     }

   160     if (required > buffer->capacity) {

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

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

   163                 return 0;

   164             }

   165         } else {

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

   167             if (size > 1) {

   168                 len -= len%size;

   169             }

   170         }

   171     }

   173     if (len == 0) {

   174         return len;

   175     }

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

   178     buffer->pos += len;

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

   180         buffer->size = buffer->pos;

   181     }

   183     return len / size;

   184 }

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

   187         UcxBuffer *buffer) {

   188     size_t len = size * nitems;

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

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

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

   192     }

   194     if (len <= 0) {

   195         return len;

   196     }

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

   199     buffer->pos += len;

   201     return len / size;

   202 }

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

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

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

   207             if(ucx_buffer_extend(buffer, 1)) {

   208                 return EOF;

   209             }

   210         } else {

   211             return EOF;

   212         }

   213     }

   215     c &= 0xFF;

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

   217     buffer->pos++;

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

   219         buffer->size = buffer->pos;

   220     }

   221     return c;

   222 }

   224 int ucx_buffer_getc(UcxBuffer *buffer) {

   225     if (ucx_buffer_eof(buffer)) {

   226         return EOF;

   227     } else {

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

   229         buffer->pos++;

   230         return c;

   231     }

   232 }

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

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

   236 }

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