/*
* Copyright (C) 2010 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.gallery3d.data;
import android.content.Context;
import com.android.gallery3d.common.BlobCache;
import com.android.gallery3d.common.BlobCache.LookupRequest;
import com.android.gallery3d.common.Utils;
import com.android.gallery3d.data.BytesBufferPool.BytesBuffer;
import com.android.gallery3d.util.CacheManager;
import com.android.gallery3d.util.GalleryUtils;
import java.io.IOException;
import java.nio.ByteBuffer;
public class ImageCacheService {
@SuppressWarnings("unused")
private static final String TAG = "ImageCacheService";
private static final String IMAGE_CACHE_FILE = "imgcache";
private static final int IMAGE_CACHE_MAX_ENTRIES = 5000;
private static final int IMAGE_CACHE_MAX_BYTES = 200 * 1024 * 1024;
private static final int IMAGE_CACHE_VERSION = 7;
private BlobCache mCache;
public ImageCacheService(Context context) {
mCache = CacheManager.getCache(context, IMAGE_CACHE_FILE,
IMAGE_CACHE_MAX_ENTRIES, IMAGE_CACHE_MAX_BYTES,
IMAGE_CACHE_VERSION);
}
/**
* Gets the cached image data for the given path
and type
.
*
* The image data will be stored in buffer.data
, started from
* buffer.offset
for buffer.length
bytes. If the
* buffer.data is not big enough, a new byte array will be allocated and returned.
*
* @return true if the image data is found; false if not found.
*/
public boolean getImageData(Path path, int type, BytesBuffer buffer) {
byte[] key = makeKey(path, type);
long cacheKey = Utils.crc64Long(key);
try {
LookupRequest request = new LookupRequest();
request.key = cacheKey;
request.buffer = buffer.data;
synchronized (mCache) {
if (!mCache.lookup(request)) return false;
}
if (isSameKey(key, request.buffer)) {
buffer.data = request.buffer;
buffer.offset = key.length;
buffer.length = request.length - buffer.offset;
return true;
}
} catch (IOException ex) {
// ignore.
}
return false;
}
public void putImageData(Path path, int type, byte[] value) {
byte[] key = makeKey(path, type);
long cacheKey = Utils.crc64Long(key);
ByteBuffer buffer = ByteBuffer.allocate(key.length + value.length);
buffer.put(key);
buffer.put(value);
synchronized (mCache) {
try {
mCache.insert(cacheKey, buffer.array());
} catch (IOException ex) {
// ignore.
}
}
}
public void clearImageData(Path path, int type) {
byte[] key = makeKey(path, type);
long cacheKey = Utils.crc64Long(key);
synchronized (mCache) {
try {
mCache.clearEntry(cacheKey);
} catch (IOException ex) {
// ignore.
}
}
}
private static byte[] makeKey(Path path, int type) {
return GalleryUtils.getBytes(path.toString() + "+" + type);
}
private static boolean isSameKey(byte[] key, byte[] buffer) {
int n = key.length;
if (buffer.length < n) {
return false;
}
for (int i = 0; i < n; ++i) {
if (key[i] != buffer[i]) {
return false;
}
}
return true;
}
}