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Diffstat (limited to 'src/main/java/com/android/volley/Cache.java')
-rw-r--r-- | src/main/java/com/android/volley/Cache.java | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/src/main/java/com/android/volley/Cache.java b/src/main/java/com/android/volley/Cache.java new file mode 100644 index 0000000..eafd118 --- /dev/null +++ b/src/main/java/com/android/volley/Cache.java @@ -0,0 +1,97 @@ +/* + * Copyright (C) 2011 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.android.volley; + +import java.util.Collections; +import java.util.Map; + +/** + * An interface for a cache keyed by a String with a byte array as data. + */ +public interface Cache { + /** + * Retrieves an entry from the cache. + * @param key Cache key + * @return An {@link Entry} or null in the event of a cache miss + */ + public Entry get(String key); + + /** + * Adds or replaces an entry to the cache. + * @param key Cache key + * @param entry Data to store and metadata for cache coherency, TTL, etc. + */ + public void put(String key, Entry entry); + + /** + * Performs any potentially long-running actions needed to initialize the cache; + * will be called from a worker thread. + */ + public void initialize(); + + /** + * Invalidates an entry in the cache. + * @param key Cache key + * @param fullExpire True to fully expire the entry, false to soft expire + */ + public void invalidate(String key, boolean fullExpire); + + /** + * Removes an entry from the cache. + * @param key Cache key + */ + public void remove(String key); + + /** + * Empties the cache. + */ + public void clear(); + + /** + * Data and metadata for an entry returned by the cache. + */ + public static class Entry { + /** The data returned from cache. */ + public byte[] data; + + /** ETag for cache coherency. */ + public String etag; + + /** Date of this response as reported by the server. */ + public long serverDate; + + /** TTL for this record. */ + public long ttl; + + /** Soft TTL for this record. */ + public long softTtl; + + /** Immutable response headers as received from server; must be non-null. */ + public Map<String, String> responseHeaders = Collections.emptyMap(); + + /** True if the entry is expired. */ + public boolean isExpired() { + return this.ttl < System.currentTimeMillis(); + } + + /** True if a refresh is needed from the original data source. */ + public boolean refreshNeeded() { + return this.softTtl < System.currentTimeMillis(); + } + } + +} |