pdoc.c

smallbasic for linux

/*
*	Palm DOC files 
*
*	Nicholas Christopoulos
*/

/*
*	This source code is based on ZDOC project.
*
*	>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
*	ZDOC Document Reader by Zurk Technology Inc. Ver.5.0.1b4 1998-99
*	http://www.geocities.com/Area51/7689/zdoc.html
*	This program is distributed under the terms of the GPL v.2.0 or later.
*	<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
*/

#include "sys.h"
#include "pdoc.h"

#define	IDREAD	0x52454164	// 'REAd'
#define	IDTEXT	0x54455874	// 'TEXt'

#define	MAXDOC		128
#define	MAXBM		128

#define	MAXTEXTSIZE	4096
#define BUFSIZE 	8192

#define DISP_BITS 		11
#define COUNT_BITS 		3
#define	ZMAXTEXTSIZE	4096

int		pdoc_uncompress(byte *dest, byte *source, int len)	SEC(PDOC);

/*
*	opens a PDOC file
*	returns 0 on success
*			-1 file not found
*			-2 cannot open file
*			-3 out of memory
*			-4 generic read error
*/
int		pdoc_open(const char *filename, pdoc_t *doc)
{
	LocalID		LID;
	word		maxrec;
	MemHandle	rec_h;
	MemPtr		rec_p;

	memcpy(&doc->info, 0, sizeof(pdoc_info_t));

	pdoc->page.raw = MemPtrNew(MAXTEXTSIZE+1);
	if	( pdoc->page.raw )	{
		pdoc->page.cook = MemPtrNew(BUFSIZE+1);
		if	( pdoc->page.cook )	{
			pdoc->page_no = 0;
			pdoc->info.count = 0;

			LID = DmFindDatabase(0, (char *) filename);
			if	( LID )	{
				doc->db_ref = DmOpenDatabase(0, LID, dmModeReadOnly);
				if	( doc->db_ref )	{
					maxrec  = DmNumRecords(doc->db_ref);
					rec_h = DmQueryRecord(doc->db_ref, 0);
					if	( rec_h )	{
						rec_p = MemHandleLock(rec_h);
						MemMove(&doc->info, rec_p, sizeof(pdoc_info_t));
						MemPtrUnlock(rec_p);

						DmReleaseRecord(doc->db_ref, 0, 0);

						if ( maxrec <= doc->info.page_count )	
							doc->info.page_count = maxrec -1;

						doc->page_count = doc->info.page_count;

						doc->text = NULL;
						doc->length = 0;
						doc->page_no = 0xFFFF;	// there is nothing
						}
					else	{
						DmCloseDatabase(0, LID);
						MemPtrFree(pdoc->page.raw);
						MemPtrFree(pdoc->page.cook);
						return -4;
						}
					}
				else	{
					MemPtrFree(pdoc->page.raw);
					MemPtrFree(pdoc->page.cook);
					return -2;
					}
				}
			else	{
				MemPtrFree(pdoc->page.raw);
				MemPtrFree(pdoc->page.cook);
				return -1;
				}
			}
		else	{
			MemPtrFree(pdoc->page.raw);
			return -3;
			}
		}
	else
		return -3;

	return 0;
}

/*
*	close PDOC file
*/
void	pdoc_close(pdoc_t *doc)
{
	DmCloseDatabase(0, LID);
	MemPtrFree(pdoc->page.raw);
	MemPtrFree(pdoc->page.cook);

	memcpy(&doc->info, 0, sizeof(pdoc_info_t));
	doc->text = NULL;
	doc->length = 0;
	doc->page_no = 0xFFFF;	// there is nothing
}

/*
*	uncompress a DOC text
*	returns the new length
*/
int		pdoc_uncompress(byte *dest, byte *source, int len)
{
	int		i, di, n;
	int		dest_len;
	word	c;

	for ( i = dest_len = 0; i < len; ) {
		c = source[i++];

		if ( c > 0 && c < 9 )	{
			while ( c -- ) 
				dest[dest_len ++] = source[i ++];
			}
		else if ( c < 0x80 )
			dest[dest_len ++] = c;
		else if ( c >= 0xc0 ) {
			dest[dest_len ++] = ' ';
			dest[dest_len ++] = c ^ 0x80; 
			} 
		else {
			c  = (c << 8) + source[i++];
			di = (c & 0x3fff) >> COUNT_BITS;
			n  = (c & ((1 << COUNT_BITS)-1)) + 3;
			while ( n -- ) {
				dest[dest_len] = dest[dest_len - di];
				dest_len ++; 
				}
			}
		}


	if ( dest_len > ZMAXTEXTSIZE )
		dest_len = ZMAXTEXTSIZE; 

	return dest_len;
}

/*
*	Read standard DOC record (4096KB compressed or not)
*/
void	pdoc_loadpage(pdoc_t *doc, int index)
{
	MemPtr		rec_p = NULL;
	MemHandle	rec_h = NULL;
	int			len, ulen;

	if ( doc->info.page_count < index )
		doc->length = 0;

	doc->page_no = index;

	rec_h = DmQueryRecord(doc->db_ref, index);
	rec_p = MemHandleLock(rec_h);

	len = MemPtrSize(rec_p);
	if ( len > MAXTEXTSIZE )
		len = MAXTEXTSIZE;

	ulen = doc->page.raw_len = len;

	if ( doc->info.version != 2 )		// 1 = uncompressed
		MemMove(doc->page.cook, rec_p, len);
	else	{							// 2 = compressed
		MemMove(doc->page.raw, rec_p, len);
		ulen = pdoc_uncompress(doc->page.cook, doc->page.raw, len);
		}

	doc->page.cook[ulen] = '\0';

	MemHandleUnlock(rec_h);
	DmReleaseRecord(doc->db_ref, doc->page_no, 0);

	doc->page.org_len = ulen;
	doc->length = ulen;
	doc->text = doc->page.cook;
}