/*

 * $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