| /* |
| * 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.toolbox; |
| |
| import android.os.SystemClock; |
| |
| import com.android.volley.Cache; |
| import com.android.volley.VolleyLog; |
| |
| import java.io.EOFException; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| |
| /** |
| * Cache implementation that caches files directly onto the hard disk in the specified |
| * directory. The default disk usage size is 5MB, but is configurable. |
| */ |
| public class DiskBasedCache implements Cache { |
| |
| /** Map of the Key, CacheHeader pairs */ |
| private final Map<String, CacheHeader> mEntries = |
| new LinkedHashMap<String, CacheHeader>(16, .75f, true); |
| |
| /** Total amount of space currently used by the cache in bytes. */ |
| private long mTotalSize = 0; |
| |
| /** The root directory to use for the cache. */ |
| private final File mRootDirectory; |
| |
| /** The maximum size of the cache in bytes. */ |
| private final int mMaxCacheSizeInBytes; |
| |
| /** Default maximum disk usage in bytes. */ |
| private static final int DEFAULT_DISK_USAGE_BYTES = 5 * 1024 * 1024; |
| |
| /** High water mark percentage for the cache */ |
| private static final float HYSTERESIS_FACTOR = 0.9f; |
| |
| /** Magic number for current version of cache file format. */ |
| private static final int CACHE_MAGIC = 0x20120504; |
| |
| /** |
| * Constructs an instance of the DiskBasedCache at the specified directory. |
| * @param rootDirectory The root directory of the cache. |
| * @param maxCacheSizeInBytes The maximum size of the cache in bytes. |
| */ |
| public DiskBasedCache(File rootDirectory, int maxCacheSizeInBytes) { |
| mRootDirectory = rootDirectory; |
| mMaxCacheSizeInBytes = maxCacheSizeInBytes; |
| } |
| |
| /** |
| * Constructs an instance of the DiskBasedCache at the specified directory using |
| * the default maximum cache size of 5MB. |
| * @param rootDirectory The root directory of the cache. |
| */ |
| public DiskBasedCache(File rootDirectory) { |
| this(rootDirectory, DEFAULT_DISK_USAGE_BYTES); |
| } |
| |
| /** |
| * Clears the cache. Deletes all cached files from disk. |
| */ |
| @Override |
| public synchronized void clear() { |
| File[] files = mRootDirectory.listFiles(); |
| if (files != null) { |
| for (File file : files) { |
| file.delete(); |
| } |
| } |
| mEntries.clear(); |
| mTotalSize = 0; |
| VolleyLog.d("Cache cleared."); |
| } |
| |
| /** |
| * Returns the cache entry with the specified key if it exists, null otherwise. |
| */ |
| @Override |
| public synchronized Entry get(String key) { |
| CacheHeader entry = mEntries.get(key); |
| // if the entry does not exist, return. |
| if (entry == null) { |
| return null; |
| } |
| |
| File file = getFileForKey(key); |
| CountingInputStream cis = null; |
| try { |
| cis = new CountingInputStream(new FileInputStream(file)); |
| CacheHeader.readHeader(cis); // eat header |
| byte[] data = streamToBytes(cis, (int) (file.length() - cis.bytesRead)); |
| return entry.toCacheEntry(data); |
| } catch (IOException e) { |
| VolleyLog.d("%s: %s", file.getAbsolutePath(), e.toString()); |
| remove(key); |
| return null; |
| } finally { |
| if (cis != null) { |
| try { |
| cis.close(); |
| } catch (IOException ioe) { |
| return null; |
| } |
| } |
| } |
| } |
| |
| /** |
| * Initializes the DiskBasedCache by scanning for all files currently in the |
| * specified root directory. Creates the root directory if necessary. |
| */ |
| @Override |
| public synchronized void initialize() { |
| if (!mRootDirectory.exists()) { |
| if (!mRootDirectory.mkdirs()) { |
| VolleyLog.e("Unable to create cache dir %s", mRootDirectory.getAbsolutePath()); |
| } |
| return; |
| } |
| |
| File[] files = mRootDirectory.listFiles(); |
| if (files == null) { |
| return; |
| } |
| for (File file : files) { |
| FileInputStream fis = null; |
| try { |
| fis = new FileInputStream(file); |
| CacheHeader entry = CacheHeader.readHeader(fis); |
| entry.size = file.length(); |
| putEntry(entry.key, entry); |
| } catch (IOException e) { |
| if (file != null) { |
| file.delete(); |
| } |
| } finally { |
| try { |
| if (fis != null) { |
| fis.close(); |
| } |
| } catch (IOException ignored) { } |
| } |
| } |
| } |
| |
| /** |
| * Invalidates an entry in the cache. |
| * @param key Cache key |
| * @param fullExpire True to fully expire the entry, false to soft expire |
| */ |
| @Override |
| public synchronized void invalidate(String key, boolean fullExpire) { |
| Entry entry = get(key); |
| if (entry != null) { |
| entry.softTtl = 0; |
| if (fullExpire) { |
| entry.ttl = 0; |
| } |
| put(key, entry); |
| } |
| |
| } |
| |
| /** |
| * Puts the entry with the specified key into the cache. |
| */ |
| @Override |
| public synchronized void put(String key, Entry entry) { |
| pruneIfNeeded(entry.data.length); |
| File file = getFileForKey(key); |
| try { |
| FileOutputStream fos = new FileOutputStream(file); |
| CacheHeader e = new CacheHeader(key, entry); |
| e.writeHeader(fos); |
| fos.write(entry.data); |
| fos.close(); |
| putEntry(key, e); |
| return; |
| } catch (IOException e) { |
| } |
| boolean deleted = file.delete(); |
| if (!deleted) { |
| VolleyLog.d("Could not clean up file %s", file.getAbsolutePath()); |
| } |
| } |
| |
| /** |
| * Removes the specified key from the cache if it exists. |
| */ |
| @Override |
| public synchronized void remove(String key) { |
| boolean deleted = getFileForKey(key).delete(); |
| removeEntry(key); |
| if (!deleted) { |
| VolleyLog.d("Could not delete cache entry for key=%s, filename=%s", |
| key, getFilenameForKey(key)); |
| } |
| } |
| |
| /** |
| * Creates a pseudo-unique filename for the specified cache key. |
| * @param key The key to generate a file name for. |
| * @return A pseudo-unique filename. |
| */ |
| private String getFilenameForKey(String key) { |
| int firstHalfLength = key.length() / 2; |
| String localFilename = String.valueOf(key.substring(0, firstHalfLength).hashCode()); |
| localFilename += String.valueOf(key.substring(firstHalfLength).hashCode()); |
| return localFilename; |
| } |
| |
| /** |
| * Returns a file object for the given cache key. |
| */ |
| public File getFileForKey(String key) { |
| return new File(mRootDirectory, getFilenameForKey(key)); |
| } |
| |
| /** |
| * Prunes the cache to fit the amount of bytes specified. |
| * @param neededSpace The amount of bytes we are trying to fit into the cache. |
| */ |
| private void pruneIfNeeded(int neededSpace) { |
| if ((mTotalSize + neededSpace) < mMaxCacheSizeInBytes) { |
| return; |
| } |
| if (VolleyLog.DEBUG) { |
| VolleyLog.v("Pruning old cache entries."); |
| } |
| |
| long before = mTotalSize; |
| int prunedFiles = 0; |
| long startTime = SystemClock.elapsedRealtime(); |
| |
| Iterator<Map.Entry<String, CacheHeader>> iterator = mEntries.entrySet().iterator(); |
| while (iterator.hasNext()) { |
| Map.Entry<String, CacheHeader> entry = iterator.next(); |
| CacheHeader e = entry.getValue(); |
| boolean deleted = getFileForKey(e.key).delete(); |
| if (deleted) { |
| mTotalSize -= e.size; |
| } else { |
| VolleyLog.d("Could not delete cache entry for key=%s, filename=%s", |
| e.key, getFilenameForKey(e.key)); |
| } |
| iterator.remove(); |
| prunedFiles++; |
| |
| if ((mTotalSize + neededSpace) < mMaxCacheSizeInBytes * HYSTERESIS_FACTOR) { |
| break; |
| } |
| } |
| |
| if (VolleyLog.DEBUG) { |
| VolleyLog.v("pruned %d files, %d bytes, %d ms", |
| prunedFiles, (mTotalSize - before), SystemClock.elapsedRealtime() - startTime); |
| } |
| } |
| |
| /** |
| * Puts the entry with the specified key into the cache. |
| * @param key The key to identify the entry by. |
| * @param entry The entry to cache. |
| */ |
| private void putEntry(String key, CacheHeader entry) { |
| if (!mEntries.containsKey(key)) { |
| mTotalSize += entry.size; |
| } else { |
| CacheHeader oldEntry = mEntries.get(key); |
| mTotalSize += (entry.size - oldEntry.size); |
| } |
| mEntries.put(key, entry); |
| } |
| |
| /** |
| * Removes the entry identified by 'key' from the cache. |
| */ |
| private void removeEntry(String key) { |
| CacheHeader entry = mEntries.get(key); |
| if (entry != null) { |
| mTotalSize -= entry.size; |
| mEntries.remove(key); |
| } |
| } |
| |
| /** |
| * Reads the contents of an InputStream into a byte[]. |
| * */ |
| private static byte[] streamToBytes(InputStream in, int length) throws IOException { |
| byte[] bytes = new byte[length]; |
| int count; |
| int pos = 0; |
| while (pos < length && ((count = in.read(bytes, pos, length - pos)) != -1)) { |
| pos += count; |
| } |
| if (pos != length) { |
| throw new IOException("Expected " + length + " bytes, read " + pos + " bytes"); |
| } |
| return bytes; |
| } |
| |
| /** |
| * Handles holding onto the cache headers for an entry. |
| */ |
| // Visible for testing. |
| static class CacheHeader { |
| /** The size of the data identified by this CacheHeader. (This is not |
| * serialized to disk. */ |
| public long size; |
| |
| /** The key that identifies the cache entry. */ |
| public String key; |
| |
| /** ETag for cache coherence. */ |
| 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; |
| |
| /** Headers from the response resulting in this cache entry. */ |
| public Map<String, String> responseHeaders; |
| |
| private CacheHeader() { } |
| |
| /** |
| * Instantiates a new CacheHeader object |
| * @param key The key that identifies the cache entry |
| * @param entry The cache entry. |
| */ |
| public CacheHeader(String key, Entry entry) { |
| this.key = key; |
| this.size = entry.data.length; |
| this.etag = entry.etag; |
| this.serverDate = entry.serverDate; |
| this.ttl = entry.ttl; |
| this.softTtl = entry.softTtl; |
| this.responseHeaders = entry.responseHeaders; |
| } |
| |
| /** |
| * Reads the header off of an InputStream and returns a CacheHeader object. |
| * @param is The InputStream to read from. |
| * @throws IOException |
| */ |
| public static CacheHeader readHeader(InputStream is) throws IOException { |
| CacheHeader entry = new CacheHeader(); |
| int magic = readInt(is); |
| if (magic != CACHE_MAGIC) { |
| // don't bother deleting, it'll get pruned eventually |
| throw new IOException(); |
| } |
| entry.key = readString(is); |
| entry.etag = readString(is); |
| if (entry.etag.equals("")) { |
| entry.etag = null; |
| } |
| entry.serverDate = readLong(is); |
| entry.ttl = readLong(is); |
| entry.softTtl = readLong(is); |
| entry.responseHeaders = readStringStringMap(is); |
| return entry; |
| } |
| |
| /** |
| * Creates a cache entry for the specified data. |
| */ |
| public Entry toCacheEntry(byte[] data) { |
| Entry e = new Entry(); |
| e.data = data; |
| e.etag = etag; |
| e.serverDate = serverDate; |
| e.ttl = ttl; |
| e.softTtl = softTtl; |
| e.responseHeaders = responseHeaders; |
| return e; |
| } |
| |
| |
| /** |
| * Writes the contents of this CacheHeader to the specified OutputStream. |
| */ |
| public boolean writeHeader(OutputStream os) { |
| try { |
| writeInt(os, CACHE_MAGIC); |
| writeString(os, key); |
| writeString(os, etag == null ? "" : etag); |
| writeLong(os, serverDate); |
| writeLong(os, ttl); |
| writeLong(os, softTtl); |
| writeStringStringMap(responseHeaders, os); |
| os.flush(); |
| return true; |
| } catch (IOException e) { |
| VolleyLog.d("%s", e.toString()); |
| return false; |
| } |
| } |
| |
| } |
| |
| private static class CountingInputStream extends FilterInputStream { |
| private int bytesRead = 0; |
| |
| private CountingInputStream(InputStream in) { |
| super(in); |
| } |
| |
| @Override |
| public int read() throws IOException { |
| int result = super.read(); |
| if (result != -1) { |
| bytesRead++; |
| } |
| return result; |
| } |
| |
| @Override |
| public int read(byte[] buffer, int offset, int count) throws IOException { |
| int result = super.read(buffer, offset, count); |
| if (result != -1) { |
| bytesRead += result; |
| } |
| return result; |
| } |
| } |
| |
| /* |
| * Homebrewed simple serialization system used for reading and writing cache |
| * headers on disk. Once upon a time, this used the standard Java |
| * Object{Input,Output}Stream, but the default implementation relies heavily |
| * on reflection (even for standard types) and generates a ton of garbage. |
| */ |
| |
| /** |
| * Simple wrapper around {@link InputStream#read()} that throws EOFException |
| * instead of returning -1. |
| */ |
| private static int read(InputStream is) throws IOException { |
| int b = is.read(); |
| if (b == -1) { |
| throw new EOFException(); |
| } |
| return b; |
| } |
| |
| static void writeInt(OutputStream os, int n) throws IOException { |
| os.write((n >> 0) & 0xff); |
| os.write((n >> 8) & 0xff); |
| os.write((n >> 16) & 0xff); |
| os.write((n >> 24) & 0xff); |
| } |
| |
| static int readInt(InputStream is) throws IOException { |
| int n = 0; |
| n |= (read(is) << 0); |
| n |= (read(is) << 8); |
| n |= (read(is) << 16); |
| n |= (read(is) << 24); |
| return n; |
| } |
| |
| static void writeLong(OutputStream os, long n) throws IOException { |
| os.write((byte)(n >>> 0)); |
| os.write((byte)(n >>> 8)); |
| os.write((byte)(n >>> 16)); |
| os.write((byte)(n >>> 24)); |
| os.write((byte)(n >>> 32)); |
| os.write((byte)(n >>> 40)); |
| os.write((byte)(n >>> 48)); |
| os.write((byte)(n >>> 56)); |
| } |
| |
| static long readLong(InputStream is) throws IOException { |
| long n = 0; |
| n |= ((read(is) & 0xFFL) << 0); |
| n |= ((read(is) & 0xFFL) << 8); |
| n |= ((read(is) & 0xFFL) << 16); |
| n |= ((read(is) & 0xFFL) << 24); |
| n |= ((read(is) & 0xFFL) << 32); |
| n |= ((read(is) & 0xFFL) << 40); |
| n |= ((read(is) & 0xFFL) << 48); |
| n |= ((read(is) & 0xFFL) << 56); |
| return n; |
| } |
| |
| static void writeString(OutputStream os, String s) throws IOException { |
| byte[] b = s.getBytes("UTF-8"); |
| writeLong(os, b.length); |
| os.write(b, 0, b.length); |
| } |
| |
| static String readString(InputStream is) throws IOException { |
| int n = (int) readLong(is); |
| byte[] b = streamToBytes(is, n); |
| return new String(b, "UTF-8"); |
| } |
| |
| static void writeStringStringMap(Map<String, String> map, OutputStream os) throws IOException { |
| if (map != null) { |
| writeInt(os, map.size()); |
| for (Map.Entry<String, String> entry : map.entrySet()) { |
| writeString(os, entry.getKey()); |
| writeString(os, entry.getValue()); |
| } |
| } else { |
| writeInt(os, 0); |
| } |
| } |
| |
| static Map<String, String> readStringStringMap(InputStream is) throws IOException { |
| int size = readInt(is); |
| Map<String, String> result = (size == 0) |
| ? Collections.<String, String>emptyMap() |
| : new HashMap<String, String>(size); |
| for (int i = 0; i < size; i++) { |
| String key = readString(is).intern(); |
| String value = readString(is).intern(); |
| result.put(key, value); |
| } |
| return result; |
| } |
| |
| |
| } |