01: // Copyright 2006 The Apache Software Foundation
02: //
03: // Licensed under the Apache License, Version 2.0 (the "License");
04: // you may not use this file except in compliance with the License.
05: // You may obtain a copy of the License at
06: //
07: // http://www.apache.org/licenses/LICENSE-2.0
08: //
09: // Unless required by applicable law or agreed to in writing, software
10: // distributed under the License is distributed on an "AS IS" BASIS,
11: // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12: // See the License for the specific language governing permissions and
13: // limitations under the License.
14:
15: package org.apache.tapestry.internal.services;
16:
17: import org.apache.tapestry.internal.event.InvalidationEventHub;
18: import org.apache.tapestry.ioc.Resource;
19: import org.apache.tapestry.services.ResourceDigestGenerator;
20:
21: /**
22: * Caches information about resources on the classpath. In addition, acts as an invalidation hub for
23: * any resources for which information is obtained (when any of the resources are changed,
24: * invalidation listeners are notified so they can clear their caches).
25: */
26: public interface ResourceCache extends InvalidationEventHub {
27: /**
28: * Returns true if the path requires that the client URL for the resource include a digest to
29: * validate that the client is authorized to access the resource.
30: *
31: * @param resource
32: * @return true if digest is required for the resource
33: * @see ResourceDigestGenerator#requiresDigest(String)
34: */
35: boolean requiresDigest(Resource resource);
36:
37: /**
38: * Returns the digest for the given path.
39: *
40: * @param resource
41: * @return the digest, or null if the resource does not exist
42: */
43: String getDigest(Resource resource);
44:
45: /**
46: * Returns the time modified for the resource.
47: *
48: * @param resource
49: * @return the date time modified for the path, or a negative value if the resource does not
50: * exist
51: */
52: long getTimeModified(Resource resource);
53: }
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