01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one or more
03: * contributor license agreements. See the NOTICE file distributed with
04: * this work for additional information regarding copyright ownership.
05: * The ASF licenses this file to You under the Apache License, Version 2.0
06: * (the "License"); you may not use this file except in compliance with
07: * the License. You may obtain a copy of the License at
08: *
09: * http://www.apache.org/licenses/LICENSE-2.0
10: *
11: * Unless required by applicable law or agreed to in writing, software
12: * distributed under the License is distributed on an "AS IS" BASIS,
13: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14: * See the License for the specific language governing permissions and
15: * limitations under the License.
16: */
17: package org.apache.cocoon.components.source.impl.validity;
18:
19: import org.apache.excalibur.source.SourceValidity;
20:
21: /**
22: * Delays validity check for a specified interval.
23: *
24: * <p>
25: * This is wrapper validity which can be used to reduce count of
26: * filesystem (or network) accesses just to check the source
27: * validity.
28: *
29: * @since 2.1.8
30: * @version $Id: DelayedValidity.java 433543 2006-08-22 06:22:54Z crossley $
31: */
32: public class DelayedValidity implements SourceValidity {
33:
34: private long delay;
35: private long expires;
36:
37: private SourceValidity delegate;
38:
39: public DelayedValidity(long delay, SourceValidity validity) {
40: this .delay = delay;
41: this .expires = System.currentTimeMillis() + delay;
42: this .delegate = validity;
43: }
44:
45: public int isValid() {
46: final long currentTime = System.currentTimeMillis();
47: if (currentTime <= this .expires) {
48: // The delay has not passed yet - assuming source is valid.
49: return SourceValidity.VALID;
50: }
51:
52: // The delay has passed, prepare for the next interval.
53: this .expires = currentTime + this .delay;
54:
55: return this .delegate.isValid();
56: }
57:
58: public int isValid(SourceValidity newValidity) {
59: // Always delegate
60: return this.delegate.isValid(newValidity);
61: }
62: }
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