CACHE MANAGER FOR GATEWAY HTTPD

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

/*
** AUTHORS:
**	AL	Ari Luotonen	luotonen@dxcern.cern.ch
**
*/

#ifndef HTCACHE_H
#define HTCACHE_H

#define CACHE_INFO	".cache_info"
#define INDEX_FILE	".cache_dirindex"
#define WELCOME_FILE	".cache_welcome"
#define TMP_SUFFIX	".cache_tmp"
#define LOCK_SUFFIX	".cache_lock"
#define INFO_LINE_LEN	256

#include "HTUtils.h"
#include "HTStream.h"

typedef enum _HTCacheTask {
    CACHE_NO = 0,
    CACHE_FOUND,
    CACHE_IF_MODIFIED,
    CACHE_CREATE
} HTCacheTask;

/*
**	Look up a cache filename for url
**
** On entry:
**	url	for which we need the cache.
**	cfn	must point to valid char* storage.
**
** On exit:
**	returns CACHE_NO	if cache file doesn't exist nor should
**				it be created.
**
**		CACHE_FOUND	if cache file exists, and *cfn the name of
**				the file from which document can be read.
**
**		CACHE_IF_MODIFIED if cache file exists but may be out of date.
**				Caller should do a conditional GET with
**				If-Modified-Since header, *if_ms is the date.
**				*cfn is the cache file name and *cf is an
**				open lockfile to which document should be
**				written if it has expired.  After that
**				one of functions cache_not_modified(),
**				cache_created() or cache_cancel() should
**				be called.
**
**		CACHE_CREATE	if cache file didn't exist but should be
**				created.  *cfn is the cache file name and
**				*cf is an open lock file to write the document
**				to.  After this either cache_created() or
**				cache_cancel() should be called.
*/
PUBLIC HTCacheTask cache_lookup PARAMS((char *		url,
					char **		cfn,
					FILE **		cf,
					time_t *	if_ms,
					time_t *	expires));

PUBLIC HTStream * HTProxyCache PARAMS((HTStream *	output_stream,
				       FILE *		cf,
				       char *		cfn,
				       char *		url,
				       time_t		if_ms));

PUBLIC void gc NOPARAMS;

PUBLIC int HTExitStatusToKilos PARAMS((int status));
PUBLIC int HTBytesToExitStatus PARAMS((long bytes));

PUBLIC void HTLoadCacheToStream PARAMS((FILE *		fp,
					HTStream *	sink,
					time_t		expires));

PUBLIC FILE * HTCacheInfo_open PARAMS((char * dirname,
				       char * mode));

PUBLIC FILE * HTCacheInfo_openFor PARAMS((char * filename,
					  char * mode));

PUBLIC void HTCacheInfo_remove PARAMS((char * dirname));

PUBLIC BOOL HTCacheInfo_next PARAMS((FILE *	fp,
				     char **	filename_p,
				     time_t *	load_delay,
				     time_t *	last_checked,
				     time_t *	expires,
				     time_t *	max_unused,
				     time_t *	last_modified));

PUBLIC BOOL HTCacheInfo_for PARAMS((char *	filename,
				    time_t *	load_delay,
				    time_t *	last_checked,
				    time_t *	expires,
				    time_t *	max_unused,
				    time_t *	last_modified));

PUBLIC void HTCacheInfo_writeEntry PARAMS((FILE *	fp,
					   char *	filename,
					   time_t	load_delay,
					   time_t	last_checked,
					   time_t	expires,
					   time_t	max_unused,
					   time_t	last_modified));

PUBLIC BOOL HTCacheInfo_writeEntryFor PARAMS((char *	filename,
					      time_t	delay,
					      time_t	last_chk,
					      time_t	exp,
					      time_t	max_unused,
					      time_t	lm));

#endif