client/deps/tinycbor/open_memstream.c

   1 /****************************************************************************
   2 **
   3 ** Copyright (C) 2015 Intel Corporation
   4 **
   5 ** Permission is hereby granted, free of charge, to any person obtaining a copy
   6 ** of this software and associated documentation files (the "Software"), to deal
   7 ** in the Software without restriction, including without limitation the rights
   8 ** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9 ** copies of the Software, and to permit persons to whom the Software is
  10 ** furnished to do so, subject to the following conditions:
  11 **
  12 ** The above copyright notice and this permission notice shall be included in
  13 ** all copies or substantial portions of the Software.
  14 **
  15 ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 ** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 ** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18 ** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19 ** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 ** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21 ** THE SOFTWARE.
  22 **
  23 ****************************************************************************/
  24
  25 #define _BSD_SOURCE 1
  26 #define _DEFAULT_SOURCE 1
  27 #define _GNU_SOURCE 1
  28
  29 #include <sys/types.h>
  30 #include <errno.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34
  35 #if defined(__unix__) || defined(__APPLE__)
  36 #  include <unistd.h>
  37 #endif
  38
  39 #if defined(__APPLE__) || defined(__ANDROID__) || defined(ANDROID)
  40 typedef int RetType;
  41 typedef int LenType;
  42 #elif __GLIBC__
  43 typedef ssize_t RetType;
  44 typedef size_t LenType;
  45 #else
  46 #  error "Cannot implement open_memstream!"
  47 #endif
  48
  49 #include "compilersupport_p.h"
  50
  51 struct Buffer {
  52     char **ptr;
  53     size_t *len;
  54     size_t alloc;
  55 };
  56
  57 static RetType write_to_buffer(void *cookie, const char *data, LenType len) {
  58     struct Buffer *b = (struct Buffer *)cookie;
  59     char *ptr = *b->ptr;
  60     size_t newsize;
  61
  62     errno = EFBIG;
  63     if (unlikely(add_check_overflow(*b->len, len, &newsize)))
  64         return -1;
  65
  66     if (newsize >= b->alloc) { // NB! one extra byte is needed to avoid buffer overflow at close_buffer
  67         // make room
  68         size_t newalloc = newsize + newsize / 2 + 1;    // give 50% more room
  69
  70         char *tmp = realloc(ptr, newalloc);
  71         if (tmp == NULL) {
  72             free(ptr);
  73             return -1;
  74         } else {
  75             ptr = tmp;
  76         }
  77
  78         b->alloc = newalloc;
  79         *b->ptr = ptr;
  80     }
  81
  82     memcpy(ptr + *b->len, data, len);
  83     *b->len = newsize;
  84     return len;
  85 }
  86
  87 static int close_buffer(void *cookie) {
  88     struct Buffer *b = (struct Buffer *)cookie;
  89     if (*b->ptr)
  90         (*b->ptr)[*b->len] = '\0';
  91     free(b);
  92     return 0;
  93 }
  94
  95 FILE *open_memstream(char **bufptr, size_t *lenptr) {
  96     struct Buffer *b = (struct Buffer *)calloc(sizeof(struct Buffer), sizeof(uint8_t));
  97     if (b == NULL)
  98         return NULL;
  99     b->alloc = 0;
 100     b->len = lenptr;
 101     b->ptr = bufptr;
 102     *bufptr = NULL;
 103     *lenptr = 0;
 104
 105 #if defined(__APPLE__) || defined(__ANDROID__) || defined(ANDROID)
 106     return funopen(b, NULL, write_to_buffer, NULL, close_buffer);
 107 #elif __GLIBC__
 108     static const cookie_io_functions_t vtable = {
 109         NULL,
 110         write_to_buffer,
 111         NULL,
 112         close_buffer
 113     };
 114     return fopencookie(b, "w", vtable);
 115 #endif
 116 }
 117