1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.gallery3d.data; 18 19 import android.content.Context; 20 21 import com.android.gallery3d.common.BlobCache; 22 import com.android.gallery3d.common.BlobCache.LookupRequest; 23 import com.android.gallery3d.common.Utils; 24 import com.android.gallery3d.data.BytesBufferPool.BytesBuffer; 25 import com.android.gallery3d.util.CacheManager; 26 import com.android.gallery3d.util.GalleryUtils; 27 28 import java.io.IOException; 29 import java.nio.ByteBuffer; 30 31 public class ImageCacheService { 32 @SuppressWarnings("unused") 33 private static final String TAG = "ImageCacheService"; 34 35 private static final String IMAGE_CACHE_FILE = "imgcache"; 36 private static final int IMAGE_CACHE_MAX_ENTRIES = 5000; 37 private static final int IMAGE_CACHE_MAX_BYTES = 200 * 1024 * 1024; 38 private static final int IMAGE_CACHE_VERSION = 7; 39 40 private BlobCache mCache; 41 ImageCacheService(Context context)42 public ImageCacheService(Context context) { 43 mCache = CacheManager.getCache(context, IMAGE_CACHE_FILE, 44 IMAGE_CACHE_MAX_ENTRIES, IMAGE_CACHE_MAX_BYTES, 45 IMAGE_CACHE_VERSION); 46 } 47 48 /** 49 * Gets the cached image data for the given <code>path</code> and <code>type</code>. 50 * 51 * The image data will be stored in <code>buffer.data</code>, started from 52 * <code>buffer.offset</code> for <code>buffer.length</code> bytes. If the 53 * buffer.data is not big enough, a new byte array will be allocated and returned. 54 * 55 * @return true if the image data is found; false if not found. 56 */ getImageData(Path path, int type, BytesBuffer buffer)57 public boolean getImageData(Path path, int type, BytesBuffer buffer) { 58 byte[] key = makeKey(path, type); 59 long cacheKey = Utils.crc64Long(key); 60 try { 61 LookupRequest request = new LookupRequest(); 62 request.key = cacheKey; 63 request.buffer = buffer.data; 64 synchronized (mCache) { 65 if (!mCache.lookup(request)) return false; 66 } 67 if (isSameKey(key, request.buffer)) { 68 buffer.data = request.buffer; 69 buffer.offset = key.length; 70 buffer.length = request.length - buffer.offset; 71 return true; 72 } 73 } catch (IOException ex) { 74 // ignore. 75 } 76 return false; 77 } 78 putImageData(Path path, int type, byte[] value)79 public void putImageData(Path path, int type, byte[] value) { 80 byte[] key = makeKey(path, type); 81 long cacheKey = Utils.crc64Long(key); 82 ByteBuffer buffer = ByteBuffer.allocate(key.length + value.length); 83 buffer.put(key); 84 buffer.put(value); 85 synchronized (mCache) { 86 try { 87 mCache.insert(cacheKey, buffer.array()); 88 } catch (IOException ex) { 89 // ignore. 90 } 91 } 92 } 93 clearImageData(Path path, int type)94 public void clearImageData(Path path, int type) { 95 byte[] key = makeKey(path, type); 96 long cacheKey = Utils.crc64Long(key); 97 synchronized (mCache) { 98 try { 99 mCache.clearEntry(cacheKey); 100 } catch (IOException ex) { 101 // ignore. 102 } 103 } 104 } 105 makeKey(Path path, int type)106 private static byte[] makeKey(Path path, int type) { 107 return GalleryUtils.getBytes(path.toString() + "+" + type); 108 } 109 isSameKey(byte[] key, byte[] buffer)110 private static boolean isSameKey(byte[] key, byte[] buffer) { 111 int n = key.length; 112 if (buffer.length < n) { 113 return false; 114 } 115 for (int i = 0; i < n; ++i) { 116 if (key[i] != buffer[i]) { 117 return false; 118 } 119 } 120 return true; 121 } 122 } 123