Dynamic Array Class

/*
**	(c) COPYRIGHT MIT 1995.
**	Please first read the full copyright statement in the file COPYRIGH.
*/

This module implements a flexible array. It is a general utility module. A chunk is a structure which may be extended. These routines create and append data to chunks, automatically reallocating them as necessary. It is garanteed that the array is '\0' terminated at all times, so the terminating function, HTChunkTerminate is only necessary to adjust the size in the chunk structure (the '\0' counts as a character when counting the size of the chunk.

This module is implemented by HTChunk.c, and it is a part of the W3C Reference Library.

#ifndef HTCHUNK_H
#define HTCHUNK_H

Private Data Structure

This structure should not be referenced outside this module

typedef struct {
	int	size;		/* In bytes			*/
	int	growby;		/* Allocation unit in bytes	*/
	int	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

extern HTChunk * HTChunkCreate (int growby);

Free a chunk

Free a chunk created by HTChunkCreatefrom memory

extern void HTChunkFree (HTChunk * ch);

Clear a chunk

Keep the chunk in memory but clear all data kept inside.

extern void HTChunkClear (HTChunk * ch);

Ensure a chunk has a certain space in

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.

extern void HTChunkEnsure (HTChunk * ch, int s);

Append a character to a chunk

Add the character and increment the size of the chunk by one character

extern void HTChunkPutc (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)

extern void HTChunkPuts (HTChunk * ch, CONST char *str);

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.

extern void HTChunkTerminate (HTChunk * ch);

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)

Return Current Size

Returns the current size of the chunk

#define HTChunkSize(me)		((me) ? (me)->size : -1)

#endif

End of Declaration