htcache.c

Open VXI. This is a open source.

		HTChunk_clear(me->buffer);
		continue;
	    }
	} else if (*b == CR) {
	    me->EOLstate = EOL_FCR;
	} else if (*b == LF) {
	    me->EOLstate = EOL_FLF;			       /* Line found */
	} else
	    HTChunk_putc(me->buffer, *b);
	l--; b++;
    }
    return HT_OK;
}

PRIVATE int HTCacheIndex_put_character (HTStream * me, char c)
{
    return HTCacheIndex_put_block(me, &c, 1);
}

PRIVATE int HTCacheIndex_put_string (HTStream * me, const char * s)
{
    return HTCacheIndex_put_block(me, s, (int) strlen(s));
}

PRIVATE int HTCacheIndex_flush (HTStream * me)
{
    if (me) {
	char * flush = HTChunk_data(me->buffer);
	if (flush) HTCacheIndex_parseLine(flush);
	HTChunk_clear(me->buffer);
    }
    return HT_OK;
}

PRIVATE int HTCacheIndex_free (HTStream * me)
{
    if (me) {
	int status = HTCacheIndex_flush(me);
	HTTRACE(APP_TRACE, "Cache Index. FREEING....\n");
	HTChunk_delete(me->buffer);
	HT_FREE(me);
	return status;
    }
    return HT_ERROR;
}

PRIVATE int HTCacheIndex_abort (HTStream * me, HTList * e)
{
    if (me) {
	int status = HT_ERROR;
	HTTRACE(APP_TRACE, "Cache Index. ABORTING...\n");
	HTChunk_delete(me->buffer);
	HT_FREE(me);
	return status;
    }
    return HT_ERROR;
}

/*	Structured Object Class
**	-----------------------
*/
PRIVATE const HTStreamClass HTCacheIndexClass =
{		
    "CacheIndexParser",
    HTCacheIndex_flush,
    HTCacheIndex_free,
    HTCacheIndex_abort,
    HTCacheIndex_put_character,
    HTCacheIndex_put_string,
    HTCacheIndex_put_block
};

PRIVATE HTStream * HTCacheIndexReader (HTRequest *	request)
{
    HTStream * me;
    if ((me = (HTStream *) HT_CALLOC(1, sizeof(HTStream))) == NULL)
	HT_OUTOFMEM("HTCacheIndexs");
    me->isa = &HTCacheIndexClass;
    me->request = request;
    me->buffer = HTChunk_new(512);
    me->EOLstate = EOL_BEGIN;
    return me;
}

/*
**	Read the saved set of cached entries from disk. we only allow the index
**	ro be read when there is no entries in memory. That way we can ensure
**	consistancy.
*/
PUBLIC BOOL HTCacheIndex_read (const char * cache_root)
{
    BOOL status = NO;
    if (cache_root && CacheTable == NULL) {
	BOOL wasInteractive;
	char * file = cache_index_name(cache_root);
	char * index = HTLocalToWWW(file, "cache:");
	HTAnchor * anchor = HTAnchor_findAddress(index);	
	HTRequest * request = HTRequest_new();
	HTRequest_setPreemptive(request, YES);
	HTRequest_setOutputFormat(request, WWW_SOURCE);

	/* Make sure we don't use any filters */
	HTRequest_addBefore(request, NULL, NULL, NULL, 0, YES);
	HTRequest_addAfter(request, NULL, NULL, NULL, HT_ALL, 0, YES);

	/* Set the output */    
	HTRequest_setOutputStream(request, HTCacheIndexReader(request));
	HTRequest_setAnchor(request, anchor);
	HTAnchor_setFormat((HTParentAnchor *) anchor, HTAtom_for("www/cache-index"));
	wasInteractive = HTAlert_interactive();
	HTAlert_setInteractive(NO);
	status = HTLoad(request, NO);
	HTAlert_setInteractive(wasInteractive);
	HTRequest_delete(request);
	HT_FREE(file);
	HT_FREE(index);
    }
    return status;
}

/* ------------------------------------------------------------------------- */
/*  			      CACHE PARAMETERS				     */
/* ------------------------------------------------------------------------- */

PRIVATE BOOL create_cache_root (const char * cache_root)
{
    struct stat stat_info;
    char * loc = NULL;
    char * cur = NULL;
    BOOL create = NO;
    if (!cache_root) return NO;
    StrAllocCopy(loc, cache_root);			 /* Get our own copy */
#ifdef WWW_MSWINDOWS
    cur = *(loc+1) == ':' ? loc+3 : loc+1;
#else
    cur = loc+1;
#endif
    while ((cur = strchr(cur, DIR_SEPARATOR_CHAR))) {
	*cur = '\0';
	if (create || HT_STAT(loc, &stat_info) == -1) {
	    create = YES;		   /* To avoid doing stat()s in vain */
	    HTTRACE(CACHE_TRACE, "Cache....... Creating dir `%s\'\n" _ loc);
	    if (MKDIR(loc, 0777) < 0) {
		HTTRACE(CACHE_TRACE, "Cache....... can't create\n");
		HT_FREE(loc);
		return NO;
	    }
	} else {
	    HTTRACE(CACHE_TRACE, "Cache....... dir `%s\' already exists\n" _ loc);
	}
	*cur++ = DIR_SEPARATOR_CHAR;
    }
    HT_FREE(loc);
    return YES;
}

/*
**	If `cache_root' is NULL then the current value (might be a define)
**	Should we check if the cache_root is actually OK? I think not!
*/
PRIVATE BOOL HTCacheMode_setRoot (const char * cache_root)
{
    if (cache_root) {
        if ((HTCacheRoot = HTWWWToLocal(cache_root, "file:", NULL)) == NULL)
            return NO;
        if (*(HTCacheRoot+strlen(HTCacheRoot)-1) != DIR_SEPARATOR_CHAR)
	    StrAllocCat(HTCacheRoot, DIR_SEPARATOR_STR);
    } else {
	/*
	**  If no cache root has been indicated then look for a suitable
	**  location.
	*/
	char * addr = NULL;
	char * cr = (char *) getenv("WWW_CACHE");
	if (!cr) cr = (char *) getenv("TMP");
	if (!cr) cr = (char *) getenv("TEMP");
	if (!cr) cr = HT_CACHE_LOC;
	addr = HTLocalToWWW(cr, NULL);
	if (*(addr+strlen(addr)-1) != DIR_SEPARATOR_CHAR)
	    StrAllocCat(addr, DIR_SEPARATOR_STR);
	StrAllocCat(addr, HT_CACHE_ROOT);
	if (*(addr+strlen(addr)-1) != DIR_SEPARATOR_CHAR)
	    StrAllocCat(addr, DIR_SEPARATOR_STR);
        if ((HTCacheRoot = HTWWWToLocal(addr, "file:", NULL)) == NULL) {
            HT_FREE(addr);
            return NO;
        }
        HT_FREE(addr);
    }
    if (create_cache_root(HTCacheRoot) == NO) return NO;
    HTTRACE(CACHE_TRACE, "Cache Root.. Local root set to `%s\'\n" _ HTCacheRoot);
    return YES;
}

/*
**	Return the value of the cache root. The cache root can only be
**	set through the HTCacheInit() function
*/
PUBLIC char * HTCacheMode_getRoot (void)
{
    return HTLocalToWWW(HTCacheRoot, NULL);
}

/*
**	As this is a single user cache, we have to lock it when in use.
*/
PRIVATE FILE *locked_open_file = {NULL};

PRIVATE BOOL HTCache_getSingleUserLock (const char * root)
{
    if (root && !locked_open_file) {
	FILE * fp;
	char * location = NULL;
	if ((location = (char *)
	     HT_MALLOC(strlen(root) + strlen(HT_CACHE_LOCK) + 1)) == NULL)
	    HT_OUTOFMEM("HTCache_getLock");
	strcpy(location, root);
	strcat(location, HT_CACHE_LOCK);
	if ((fp = fopen(location, "r")) != NULL) {
	    HTAlertCallback *cbf = HTAlert_find(HT_A_CONFIRM);
	    HTTRACE(CACHE_TRACE, "Cache....... In `%s\' is already in use\n" _ root);
	    fclose(fp);
            if (cbf) {
                BOOL result = (*cbf)(NULL, HT_A_CONFIRM,
                                     HT_MSG_CACHE_LOCK,NULL,location,NULL);
                if (result == YES) {
                    REMOVE(location);
                } else {
                    HT_FREE(location);
                    return NO;
                }
            } else {
                HT_FREE(location);
                return NO;    
            }
	}
	if ((fp = fopen(location, "w")) == NULL) {
	    HTTRACE(CACHE_TRACE, "Cache....... Can't open `%s\' for writing\n" _ location);
	    HT_FREE(location);
	    return NO;
	}
	locked_open_file = fp;
	HT_FREE(location);
	return YES;
    }
    return NO;
}

/*
**	Release the single user lock
*/
PRIVATE BOOL HTCache_deleteSingleUserLock (const char * root)
{
    if (root) {
	char * location = NULL;
	if ((location = (char *)
	     HT_MALLOC(strlen(root) + strlen(HT_CACHE_LOCK) + 1)) == NULL)
	    HT_OUTOFMEM("HTCache_deleteLock");
	strcpy(location, root);
	strcat(location, HT_CACHE_LOCK);
	/* under UNIX you can remove an open file, not so under NT */
	if (locked_open_file) {
		fclose(locked_open_file);
	    locked_open_file = NULL;
	}
	REMOVE(location);
	HT_FREE(location);
	return YES;
    }
    return NO;
}

/*
**	If `cache_root' is NULL then reuse old value or use HT_CACHE_ROOT.
**	An empty string will make '/' as cache root
**	We can only enable the cache if the HTSecure flag is not set. This
**	is for example the case if using an application as a telnet shell.
*/
PUBLIC BOOL HTCacheInit (const char * cache_root, int size)
{
    if (!HTLib_secure() && !HTCacheRoot) {

	/*
	**  Find an appropriate root for the cache
	*/
	if (HTCacheMode_setRoot(cache_root) != YES) return NO;

	/*
	**  Set the max size of the cache 
	*/
	HTCacheMode_setMaxSize(size);

	/*
	**  Set a lock on the cache so that multiple users
	**  don't step on each other.
	*/
	if (HTCache_getSingleUserLock(HTCacheRoot) == NO)
	    return NO;

	/*
	**  Look for the cache index and read the contents
	*/
	HTCacheIndex_read(HTCacheRoot);

	/*
	**  Register the cache before and after filters
	*/
	HTNet_addBefore(HTCacheFilter, "http://*", NULL, HT_FILTER_MIDDLE);
	HTNet_addAfter(HTCacheUpdateFilter, "http://*", NULL,
		       HT_NOT_MODIFIED, HT_FILTER_MIDDLE);
	
	/*
	**  Register the cache AFTER filter for checking whether
        **  we should invalidate the cached entry
	*/
	HTNet_addAfter(HTCacheCheckFilter, "http://*",	NULL, HT_ALL,
		       HT_FILTER_MIDDLE);

	/*
	**  Do caching from now on
	*/
	HTCacheEnable = YES;
	HTCacheInitialized = YES;
	return YES;
    }
    return NO;
}

/*
**	Turns off the cache and updates entries on disk.
*/
PUBLIC BOOL HTCacheTerminate (void)
{
    if (HTCacheInitialized) {

	/*
	**  Write the index to file
	*/
	HTCacheIndex_write(HTCacheRoot);

	/*
	**  Unregister the cache before and after filters
	*/
	HTNet_deleteBefore(HTCacheFilter);
	HTNet_deleteAfter(HTCacheUpdateFilter);
	HTNet_deleteAfter(HTCacheCheckFilter);

	/*
	**  Remove the global cache lock.
	*/
	HTCache_deleteSingleUserLock(HTCacheRoot);

	/*
	**  Cleanup memory by deleting all HTCache objects
	*/
	HTCache_deleteAll();

	/*
	**  Don't do anymore caching from now on
	*/
	HT_FREE(HTCacheRoot);
	HTCacheEnable = NO;
	return YES;
    }
    return NO;
}

/*
**	The cache can be temporarily suspended by using the enable/disable
**	flag. This does not prevent the cache from being enabled/disable at
**	a later point in time.
*/
PUBLIC void HTCacheMode_setEnabled (BOOL mode)
{
    HTCacheEnable = mode;
}

PUBLIC BOOL HTCacheMode_enabled (void)
{
    return HTCacheEnable;
}

PUBLIC void HTCacheMode_setProtected (BOOL mode)
{
    HTCacheProtected = mode;
}

PUBLIC BOOL HTCacheMode_protected (void)
{
    return HTCacheProtected;
}

/*
**  We can set the cache to operate in disconnected mode in which we only
**  return (valid) responses from the cache. Disconnected mode does not
**  automatically deliver stale documents as this must be declared 
**  explicitly. 
*/
PUBLIC void HTCacheMode_setDisconnected (HTDisconnectedMode mode)
{
    DisconnectedMode = mode;
}

PUBLIC HTDisconnectedMode HTCacheMode_disconnected (void)
{
    return DisconnectedMode;
}

PUBLIC BOOL HTCacheMode_isDisconnected (HTReload mode)
{
    return (DisconnectedMode != HT_DISCONNECT_NONE);
}

/*
**  Set the mode for how we handle Expires header from the local history
**  list. The following modes are available:
**
**	HT_EXPIRES_IGNORE : No update in the history list
**	HT_EXPIRES_NOTIFY : The user is notified but no reload
**	HT_EXPIRES_AUTO   : Automatic reload
*/
PUBLIC void HTCacheMode_setExpires (HTExpiresMode mode)
{
    HTExpMode = mode;
}

PUBLIC HTExpiresMode HTCacheMode_expires (void)
{
    return HTExpMode;
}

/*
**  Cache size management. We set the default cache size to 20M.
**  We set the minimum size to 5M in order not to get into weird
**  problems while writing the cache. The size is indicated in Mega
**  bytes
*/
PUBLIC BOOL HTCacheMode_setMaxSize (int size)
{
    long new_size = size < HT_MIN_CACHE_TOTAL_SIZE ?
	HT_MIN_CACHE_TOTAL_SIZE*MEGA : size*MEGA;
    long old_size = HTCacheTotalSize;
    HTCacheTotalSize = new_size;
    HTCacheFolderSize = HTCacheTotalSize/HT_CACHE_FOLDER_PCT;
    HTCacheGCBuffer = HTCacheTotalSize/HT_CACHE_GC_PCT;
    if (new_size < old_size) HTCacheGarbage();
    HTTRACE(CACHE_TRACE, "Cache....... Total cache size: %ld with %ld bytes for metainformation and folders and at least %ld bytes free after every gc\n" _ 
		HTCacheTotalSize _ HTCacheFolderSize _ HTCacheGCBuffer);
    return YES;
}

PUBLIC int HTCacheMode_maxSize (void)
{
    return HTCacheTotalSize / MEGA;
}

/*
**  How big can a single cached entry be in Mbytes. The default is 3M
**  
*/
PUBLIC BOOL HTCacheMode_setMaxCacheEntrySize (int size)
{