
/*  W3 Copyright statement 
Copyright 1995 by: Massachusetts Institute of Technology (MIT), INRIA</H2>

This W3C software is being provided by the copyright holders under the
following license. By obtaining, using and/or copying this software,
you agree that you have read, understood, and will comply with the
following terms and conditions: 

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee or royalty is hereby
granted, provided that the full text of this NOTICE appears on
<EM>ALL</EM> copies of the software and documentation or portions
thereof, including modifications, that you make. 

<B>THIS SOFTWARE IS PROVIDED "AS IS," AND COPYRIGHT HOLDERS MAKE NO
REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  BY WAY OF EXAMPLE,
BUT NOT LIMITATION, COPYRIGHT HOLDERS MAKE NO REPRESENTATIONS OR
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR
THAT THE USE OF THE SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY
THIRD PARTY PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.
COPYRIGHT HOLDERS WILL BEAR NO LIABILITY FOR ANY USE OF THIS SOFTWARE
OR DOCUMENTATION.

The name and trademarks of copyright holders may NOT be used
in advertising or publicity pertaining to the software without
specific, written prior permission.  Title to copyright in this
software and any associated documentation will at all times remain
with copyright holders. 
*/
/*                                                   W3C Reference Library libwww Chunk Class
                                     THE CHUNK CLASS
                                             
 */
/*
**      (c) COPYRIGHT MIT 1995.
**      Please first read the full copyright statement in the file COPYRIGH.
*/
/*

   The Chunk Class  defines a way to automatically handle dynamic strings and other data
   types. You create a chunk with an initial size and it will then automatically grow to
   accomodate added data to the chunk. It is a general utility module. It is garanteed
   that the array is '\0' terminated at all times (and hence is a valid C type string).
   The method HTChunkTerminate can be used to explicitly add a terminating '\0'and then to
   include this character in the chunk size. If left out, the terminating character is
   _not_ considered part of the chunk.
   
   _Note_: The names without a "_" (made as a #define's) are only provided for backwards
   compatibility and should not be used.
   
   This module is implemented by HTChunk.c, and it is a part of the W3C Reference Library.
   
 */
#ifndef HTCHUNK_H
#define HTCHUNK_H

/*

THE CHUNK CLASS

   This structure should not be referenced outside this module! We only keep it here to
   maintain high performance. _Don't _use it directly!
   
 */
typedef struct {
        PRInt32     size;           /* In bytes                     */
        PRInt32     growby;         /* Allocation unit in bytes     */
        PRInt32     allocated;      /* Current size of *data        */
        char *  data;           /* Pointer to malloced area or 0 */
} HTChunk;
/*

CREATE NEW CHUNK

   Create a new chunk and specify the number of bytes to allocate at a time when the chunk
   is later extended. Arbitrary but normally a trade-off time vs. memory
   
 */
#define HTChunkCreate(growby) HTChunk_new(growby)
extern HTChunk * HTChunk_new (PRInt32 growby);
/*

FREE A CHUNK

   Free a chunk created by HTChunkCreatefrom memory
   
 */
#define HTChunkFree(ch) HTChunk_delete(ch)
extern void HTChunk_delete (HTChunk * ch);
/*

CLEAR A CHUNK

   Keep the chunk in memory but clear all data kept inside. This can be used if you know
   that you can reuse the allocated memory instead of allocating new memory.
   
 */
#define HTChunkClear(ch) HTChunk_clear(ch)
extern void HTChunk_clear (HTChunk * ch);
/*

ENSURE A CHUNK HAS A CERTAIN AMOUNT OF FREE SPACE

   Make sure that a chunk has a certain size. If this is not the case then the chunk is
   expanded. Nothing is done if the current size if bigger than the size requested.
   
 */
#define HTChunkEnsure(ch, s) HTChunk_ensure(ch, s)
extern void HTChunk_ensure (HTChunk * ch, PRInt32 s);
/*

APPEND A CHARACTER TO A CHUNK

   Add the character and increment the size of the chunk by one character
   
 */
#define HTChunkPutc(ch, c) HTChunk_putc(ch, c)
extern void HTChunk_putc (HTChunk * ch, char c);
/*

APPEND A STRING TO A CHUNK

   Add the string and increment the size of the chunk by the length of the string (without
   the trailing zero)
   
 */
#define HTChunkPuts(ch, str) HTChunk_puts(ch, str)
extern void HTChunk_puts (HTChunk * ch, const char *str);
/*

APPEND A BLOCK TO A CHUNK

   Add the block and increment the size of the chunk by the len
   
 */
extern void HTChunk_putb (HTChunk * ch, const char *block, PRInt32 len);

/*

ZERO TERMINATE A CHUNK

   As a chunk often is a dynamic string, it needs to be terminated by a zero in order to
   be used in C. However, _by default_ any chunk is _always_ zero terminated, so the only
   purpose of this function is to increment the size counter with one corresponding to the
   zero.
   
 */
#define HTChunkTerminate(ch)    HTChunk_terminate(ch)
#define HTChunk_terminate(ch)   HTChunk_putc((ch), '\0')
/*

RETURN POINTER TO DATA

   This define converts a chunk to a normal char pointer so that it can be parsed to any
   ANSI C string function.
   
 */
#define HTChunkData(me)         ((me) ? (me)->data : NULL)
#define HTChunk_data(me)         ((me) ? (me)->data : NULL)
/*

CSTRING CONVERSIONS

   A Chunk may be build from an allocated string. The chunk assumes control of the passes
   string, elminating the need for additional allocations and string copies.
   Once a string is built, the chunk may be destroyed and the string kept around.
   
 */
extern HTChunk * HTChunk_fromCString    (char * str, PRInt32 grow);
extern char * HTChunk_toCString         (HTChunk * ch);
/*

RETURN CURRENT SIZE

   Returns the current size of the chunk
   
 */
#define HTChunkSize(me)         ((me) ? (me)->size : -1)
#define HTChunk_size(me)         ((me) ? (me)->size : -1)
/*

 */
#endif
/*

   
   ___________________________________
   
                           @(#) $Id: htchunk.h,v 1.2 1999/05/07 05:26:11 neeti%netscape.com Exp $
                                                                                          
    */
