release/src/router/libjson-c/printbuf.c

   1 /*
   2  * $Id: printbuf.c,v 1.5 2006/01/26 02:16:28 mclark Exp $
   3  *
   4  * Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd.
   5  * Michael Clark <michael@metaparadigm.com>
   6  *
   7  * This library is free software; you can redistribute it and/or modify
   8  * it under the terms of the MIT license. See COPYING for details.
   9  *
  10  *
  11  * Copyright (c) 2008-2009 Yahoo! Inc.  All rights reserved.
  12  * The copyrights to the contents of this file are licensed under the MIT License
  13  * (http://www.opensource.org/licenses/mit-license.php)
  14  */
  15
  16 #include "config.h"
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21
  22 #ifdef HAVE_STDARG_H
  23 # include <stdarg.h>
  24 #else /* !HAVE_STDARG_H */
  25 # error Not enough var arg support!
  26 #endif /* HAVE_STDARG_H */
  27
  28 #include "bits.h"
  29 #include "debug.h"
  30 #include "printbuf.h"
  31
  32 static int printbuf_extend(struct printbuf *p, int min_size);
  33
  34 struct printbuf* printbuf_new(void)
  35 {
  36   struct printbuf *p;
  37
  38   p = (struct printbuf*)calloc(1, sizeof(struct printbuf));
  39   if(!p) return NULL;
  40   p->size = 32;
  41   p->bpos = 0;
  42   if(!(p->buf = (char*)malloc(p->size))) {
  43     free(p);
  44     return NULL;
  45   }
  46   return p;
  47 }
  48
  49
  50 /**
  51  * Extend the buffer p so it has a size of at least min_size.
  52  *
  53  * If the current size is large enough, nothing is changed.
  54  *
  55  * Note: this does not check the available space!  The caller
  56  *  is responsible for performing those calculations.
  57  */
  58 static int printbuf_extend(struct printbuf *p, int min_size)
  59 {
  60         char *t;
  61         int new_size;
  62
  63         if (p->size >= min_size)
  64                 return 0;
  65
  66         new_size = json_max(p->size * 2, min_size + 8);
  67 #ifdef PRINTBUF_DEBUG
  68         MC_DEBUG("printbuf_memappend: realloc "
  69           "bpos=%d min_size=%d old_size=%d new_size=%d\n",
  70           p->bpos, min_size, p->size, new_size);
  71 #endif /* PRINTBUF_DEBUG */
  72         if(!(t = (char*)realloc(p->buf, new_size)))
  73                 return -1;
  74         p->size = new_size;
  75         p->buf = t;
  76         return 0;
  77 }
  78
  79 int printbuf_memappend(struct printbuf *p, const char *buf, int size)
  80 {
  81   if (p->size <= p->bpos + size + 1) {
  82     if (printbuf_extend(p, p->bpos + size + 1) < 0)
  83       return -1;
  84   }
  85   memcpy(p->buf + p->bpos, buf, size);
  86   p->bpos += size;
  87   p->buf[p->bpos]= '\0';
  88   return size;
  89 }
  90
  91 int printbuf_memset(struct printbuf *pb, int offset, int charvalue, int len)
  92 {
  93         int size_needed;
  94
  95         if (offset == -1)
  96                 offset = pb->bpos;
  97         size_needed = offset + len;
  98         if (pb->size < size_needed)
  99         {
 100                 if (printbuf_extend(pb, size_needed) < 0)
 101                         return -1;
 102         }
 103
 104         memset(pb->buf + offset, charvalue, len);
 105         if (pb->bpos < size_needed)
 106                 pb->bpos = size_needed;
 107
 108         return 0;
 109 }
 110
 111 #if !defined(HAVE_VSNPRINTF) && defined(_MSC_VER)
 112 # define vsnprintf _vsnprintf
 113 #elif !defined(HAVE_VSNPRINTF) /* !HAVE_VSNPRINTF */
 114 # error Need vsnprintf!
 115 #endif /* !HAVE_VSNPRINTF && defined(WIN32) */
 116
 117 #if !defined(HAVE_VASPRINTF)
 118 /* CAW: compliant version of vasprintf */
 119 static int vasprintf(char **buf, const char *fmt, va_list ap)
 120 {
 121 #ifndef WIN32
 122         static char _T_emptybuffer = '\0';
 123 #endif /* !defined(WIN32) */
 124         int chars;
 125         char *b;
 126
 127         if(!buf) { return -1; }
 128
 129 #ifdef WIN32
 130         chars = _vscprintf(fmt, ap)+1;
 131 #else /* !defined(WIN32) */
 132         /* CAW: RAWR! We have to hope to god here that vsnprintf doesn't overwrite
 133            our buffer like on some 64bit sun systems.... but hey, its time to move on */
 134         chars = vsnprintf(&_T_emptybuffer, 0, fmt, ap)+1;
 135         if(chars < 0) { chars *= -1; } /* CAW: old glibc versions have this problem */
 136 #endif /* defined(WIN32) */
 137
 138         b = (char*)malloc(sizeof(char)*chars);
 139         if(!b) { return -1; }
 140
 141         if((chars = vsprintf(b, fmt, ap)) < 0)
 142         {
 143                 free(b);
 144         } else {
 145                 *buf = b;
 146         }
 147
 148         return chars;
 149 }
 150 #endif /* !HAVE_VASPRINTF */
 151
 152 int sprintbuf(struct printbuf *p, const char *msg, ...)
 153 {
 154   va_list ap;
 155   char *t;
 156   int size;
 157   char buf[128];
 158
 159   /* user stack buffer first */
 160   va_start(ap, msg);
 161   size = vsnprintf(buf, 128, msg, ap);
 162   va_end(ap);
 163   /* if string is greater than stack buffer, then use dynamic string
 164      with vasprintf.  Note: some implementation of vsnprintf return -1
 165      if output is truncated whereas some return the number of bytes that
 166      would have been written - this code handles both cases. */
 167   if(size == -1 || size > 127) {
 168     va_start(ap, msg);
 169     if((size = vasprintf(&t, msg, ap)) < 0) { va_end(ap); return -1; }
 170     va_end(ap);
 171     printbuf_memappend(p, t, size);
 172     free(t);
 173     return size;
 174   } else {
 175     printbuf_memappend(p, buf, size);
 176     return size;
 177   }
 178 }
 179
 180 void printbuf_reset(struct printbuf *p)
 181 {
 182   p->buf[0] = '\0';
 183   p->bpos = 0;
 184 }
 185
 186 void printbuf_free(struct printbuf *p)
 187 {
 188   if(p) {
 189     free(p->buf);
 190     free(p);
 191   }
 192 }