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printbuf.c
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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 
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 }
#define json_max(a, b)
Definition: bits.h:20
int bpos
Definition: printbuf.h:25
int size
Definition: printbuf.h:26
struct printbuf * printbuf_new(void)
Definition: printbuf.c:34
void printbuf_free(struct printbuf *p)
Definition: printbuf.c:186
static int vasprintf(char **buf, const char *fmt, va_list ap)
Definition: printbuf.c:119
int printbuf_memset(struct printbuf *pb, int offset, int charvalue, int len)
Definition: printbuf.c:91
char * buf
Definition: printbuf.h:24
#define MC_DEBUG(x,...)
Definition: debug.h:63
int printbuf_memappend(struct printbuf *p, const char *buf, int size)
Definition: printbuf.c:79
int sprintbuf(struct printbuf *p, const char *msg,...)
Definition: printbuf.c:152
void printbuf_reset(struct printbuf *p)
Definition: printbuf.c:180
static int printbuf_extend(struct printbuf *p, int min_size)
Definition: printbuf.c:58