is_in_twindow.c

seed格式数据解压程序,地震分析人员必备

/*===========================================================================*/
/*                 |                                       |                 */
/*===========================================================================*/
/*
	Name:		is_in_twindow
	Purpose:	determine if a blockette overlaps a time window
	Usage:		
	Input:		
	Output:		returns +1 if this blockette's effective time
				was explicit and was in window, 0 if blockette time
				was disjoint with window.
	Externals:	
	Warnings:	
	Errors:		
	Fatals:
	Called by:	
	Calls to:	
	Algorithm:	
	Notes:		
	Problems:	
	References:	
	Language:	
	Author:		03/??/89	Mark WIederspahn
	Revisions:	mm/dd/yy  pgmr name  change

				06/21/89	mw	fix incorrect start offset for find_btime
								of 059 blockettes: was 9, should be 7.

				15may90		mw	enhancement
								allow 043-048 as abbreviation blockettes
								allow 060 as blockette for SEED v2.1 spec.

				24apr91		mw	change
								this routine is called so often, do not
								print out debug start/end unless DEBUG is
								at a high level.

				05dec91		mw	change
								blockette 041 abbreviation blockette,
								061 is legal blockette for v2.2 SEED

				18mar99		Stephane Zuzlewski
								Blockette 042 abbreviation blockette,
								062 is legal blockette for v2.3 SEED
*/

#include "output.h"

int is_in_twindow( top, btype, blen, start, end )
char	*top;				/* start of blockette */
int		btype;				/* blockette's type */
int		blen;				/* blockette's length */
struct	input_time	start;	/* start time of desired window */
struct	input_time	end;	/* end time of desired window */
{
	int	result;					/* what we decided */
	struct input_time zeros;	/* null time */
	struct input_time bstart;	/* blockette start time */
	struct input_time bend;		/* blockette end time */
	int	err;					/* oops flag */
	int	ivers;					/* seed version, sort of */


	if( Debug >= D_MAX ) fprintf( D_OUT,"[is_in_twindow] start\n" );

	memset( &zeros, 0, sizeof( struct input_time ) );

	result = FALSE;							/* do not accept this blockette */

/*
 * abbreviation blockettes are always accepted. However, what a legal
 * abbreviation blockette number is, depends on what version we write.
 *
 * for v2.0: only   30-35
 * for v2.1: v2.0 + 43-48
 * for v2.2: v2.1 + 41
 * for v2.3: v2.2 + 42
 */
	if( btype >= 30 && btype <= 35 ||
	    btype == 41                ||
	    btype == 42		       ||
		btype >= 43 && btype <= 48 )		/* an abbreviation blockette */
	{
		if( SEED_Version >= 20 )
			if( btype >= 30 && btype <=35 ) result = TRUE;
		if( SEED_Version >= 21 )
			if( btype >= 43 && btype <= 48 ) result = TRUE;
		if( SEED_Version >= 22 )
			if( btype == 41 )                result = TRUE;
		if( SEED_Version >= 23 )
			if( btype == 42 )                result = TRUE;
	}
	else if( (btype >= 50) && (btype <= 62) )	/* station/channel blockette */
	{
/*
 * find_btime gets the effective times of the blockette, using a "clever"
 * scheme which depends on the SEED format of the blockette. This is
 * similar, but not identical, for each of the interesting blockettes.
 * This is what the three mysterious constants do here:
 * count = how many ~ terminated strings occur BEFORE the start time.
 * offset = how far from the ~+1 byte does the start time begin?
 * max = how many bytes (worst case) before we give up finding a ~.
 * (max should *never* be needed...)
 */
		if( (btype == 50) ||
			(btype == 51) ||
			(btype == 52) ||
			(btype == 59) )
		{
			if( btype == 50 )
				err=find_btime( top, 1, 9, 108, &bstart, &bend );
			else if( btype == 51 )
				err=find_btime( top, 0, 7, 999, &bstart, &bend );
			else if( btype == 52 )
				err=find_btime( top, 2, 0, 156, &bstart, &bend );
			else if( btype == 59 )
				err=find_btime( top, 0, 7, 999, &bstart, &bend );
			if( err )
				(void) error_handler( ERROR,"[is_in_twindow] bad blockette" );

/*
 * if the blockette start is the same as the end time, do not include it.
 * this prevents incorrect inclusion when the blockette really ends at
 * 23:59:59.9999, but says 00:00:00.0000 of the next day.
 */
			if( cmp_longtime( bend, zeros ) == 0 )	/* if a null end time */
			{
				if( cmp_longtime( bstart, end ) <  0 ) result = TRUE;
				if( Debug >= D_MAX ) fprintf(D_OUT,
					"[is_in_twindow] B%d is, end null\n", btype );
			}
			else
			{
				if( cmp_longtime( bstart, end   ) <  0 &&
					cmp_longtime( bend,   start ) >= 0 )
				{
					result = TRUE;
					if( Debug >= D_MAX ) fprintf(D_OUT,
						"[is_in_twindow] B%d is, end explicit\n", btype );
				}

			}
		}
		else	/* btype =50,51,52,59 */
		{
/*
 *			accept any (53-58) since we can't tell the time
 *			and accept 60,61,62 depending on version we write
 */
			if( btype >= 53 && btype <= 58 )
			{
				result = TRUE;
			}
			else
			{
				if( SEED_Version >= 21 && btype == 60 ) result = TRUE;
				if( SEED_Version >= 22 && btype == 61 ) result = TRUE;
				if( SEED_Version >= 23 && btype == 62 ) result = TRUE;
			}

			if( result && Debug >= D_MAX ) fprintf(D_OUT,
				"[is_in_twindow] assume B%d is\n", btype );
		}
	}
	else
	{
		fprintf( D_OUT,"bad blockette: btype=%d blen=%d top=%.7s\n",
			btype, blen, top );
		(void) error_handler( FATAL,"[is_in_twindow] illegal blockette" );
		result = 0;
	}
	if( result == FALSE )
		if( Debug >= D_MAX )
			fprintf( D_OUT,"[is_in_twindow] B%d ain't\n", btype);

	if( Debug >= D_MAX ) fprintf( D_OUT,"[is_in_twindow] end\n" );
	return( result );
}