1 /*
2  * $Id: printbuf.h,v 1.4 2006/01/26 02:16:28 mclark Exp $
3  *
4  * Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd.
5  * Michael Clark <[email protected]>
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 #ifndef _printbuf_h_
17 #define _printbuf_h_
18 
19 #ifdef __cplusplus
20 extern "C" {
21 #endif
22 
23 struct printbuf {
24   char *buf;
25   int bpos;
26   int size;
27 };
28 
29 extern struct printbuf*
30 printbuf_new(void);
31 
32 /* As an optimization, printbuf_memappend_fast is defined as a macro
33  * that handles copying data if the buffer is large enough; otherwise
34  * it invokes printbuf_memappend_real() which performs the heavy
35  * lifting of realloc()ing the buffer and copying data.
36  * Your code should not use printbuf_memappend directly--use
37  * printbuf_memappend_fast instead.
38  */
39 extern int
40 printbuf_memappend(struct printbuf *p, const char *buf, int size);
41 
42 #define printbuf_memappend_fast(p, bufptr, bufsize)          \
43 do {                                                         \
44   if ((p->size - p->bpos) > bufsize) {                       \
45     memcpy(p->buf + p->bpos, (bufptr), bufsize);             \
46     p->bpos += bufsize;                                      \
47     p->buf[p->bpos]= '\0';                                   \
48   } else {  printbuf_memappend(p, (bufptr), bufsize); }      \
49 } while (0)
50 
51 #define printbuf_length(p) ((p)->bpos)
52 
53 /**
54  * Set len bytes of the buffer to charvalue, starting at offset offset.
55  * Similar to calling memset(x, charvalue, len);
56  *
57  * The memory allocated for the buffer is extended as necessary.
58  *
59  * If offset is -1, this starts at the end of the current data in the buffer.
60  */
61 extern int
62 printbuf_memset(struct printbuf *pb, int offset, int charvalue, int len);
63 
64 extern int
65 sprintbuf(struct printbuf *p, const char *msg, ...);
66 
67 extern void
68 printbuf_reset(struct printbuf *p);
69 
70 extern void
71 printbuf_free(struct printbuf *p);
72 
73 #ifdef __cplusplus
74 }
75 #endif
76 
77 #endif
78