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/*
* $Id: printbuf.h,v 1.4 2006/01/26 02:16:28 mclark Exp $
*
* Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd.
* Michael Clark <michael@metaparadigm.com>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the MIT license. See COPYING for details.
*
*
* Copyright (c) 2008-2009 Yahoo! Inc. All rights reserved.
* The copyrights to the contents of this file are licensed under the MIT License
* (http://www.opensource.org/licenses/mit-license.php)
*/
/**
* @file
* @brief Internal string buffer handing. Unless you're writing a
* json_object_to_json_string_fn implementation for use with
* json_object_set_serializer() direct use of this is not
* recommended.
*/
#ifndef _printbuf_h_
#define _printbuf_h_
#ifdef __cplusplus
extern "C" {
#endif
struct printbuf {
char *buf;
int bpos;
int size;
};
typedef struct printbuf printbuf;
extern struct printbuf*
printbuf_new(void);
/* As an optimization, printbuf_memappend_fast() is defined as a macro
* that handles copying data if the buffer is large enough; otherwise
* it invokes printbuf_memappend() which performs the heavy
* lifting of realloc()ing the buffer and copying data.
*
* Your code should not use printbuf_memappend() directly unless it
* checks the return code. Use printbuf_memappend_fast() instead.
*/
extern int
printbuf_memappend(struct printbuf *p, const char *buf, int size);
#define printbuf_memappend_fast(p, bufptr, bufsize) \
do { \
if ((p->size - p->bpos) > bufsize) { \
memcpy(p->buf + p->bpos, (bufptr), bufsize); \
p->bpos += bufsize; \
p->buf[p->bpos]= '\0'; \
} else { printbuf_memappend(p, (bufptr), bufsize); } \
} while (0)
#define printbuf_length(p) ((p)->bpos)
/**
* Results in a compile error if the argument is not a string literal.
*/
#define _printbuf_check_literal(mystr) ("" mystr)
/**
* This is an optimization wrapper around printbuf_memappend() that is useful
* for appending string literals. Since the size of string constants is known
* at compile time, using this macro can avoid a costly strlen() call. This is
* especially helpful when a constant string must be appended many times. If
* you got here because of a compilation error caused by passing something
* other than a string literal, use printbuf_memappend_fast() in conjunction
* with strlen().
*
* See also:
* printbuf_memappend_fast()
* printbuf_memappend()
* sprintbuf()
*/
#define printbuf_strappend(pb, str) \
printbuf_memappend ((pb), _printbuf_check_literal(str), sizeof(str) - 1)
/**
* Set len bytes of the buffer to charvalue, starting at offset offset.
* Similar to calling memset(x, charvalue, len);
*
* The memory allocated for the buffer is extended as necessary.
*
* If offset is -1, this starts at the end of the current data in the buffer.
*/
extern int
printbuf_memset(struct printbuf *pb, int offset, int charvalue, int len);
/**
* Formatted print to printbuf.
*
* This function is the most expensive of the available functions for appending
* string data to a printbuf and should be used only where convenience is more
* important than speed. Avoid using this function in high performance code or
* tight loops; in these scenarios, consider using snprintf() with a static
* buffer in conjunction with one of the printbuf_*append() functions.
*
* See also:
* printbuf_memappend_fast()
* printbuf_memappend()
* printbuf_strappend()
*/
extern int
sprintbuf(struct printbuf *p, const char *msg, ...);
extern void
printbuf_reset(struct printbuf *p);
extern void
printbuf_free(struct printbuf *p);
#ifdef __cplusplus
}
#endif
#endif
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