1049 lines
34 KiB
Java
1049 lines
34 KiB
Java
/* GENERATED SOURCE. DO NOT MODIFY. */
|
|
/*
|
|
* 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.okhttp.internal;
|
|
|
|
import com.android.okhttp.internal.io.FileSystem;
|
|
import java.io.Closeable;
|
|
import java.io.EOFException;
|
|
import java.io.File;
|
|
import java.io.FileNotFoundException;
|
|
import java.io.IOException;
|
|
import java.util.ArrayList;
|
|
import java.util.Arrays;
|
|
import java.util.Iterator;
|
|
import java.util.LinkedHashMap;
|
|
import java.util.NoSuchElementException;
|
|
import java.util.concurrent.Executor;
|
|
import java.util.concurrent.LinkedBlockingQueue;
|
|
import java.util.concurrent.ThreadPoolExecutor;
|
|
import java.util.concurrent.TimeUnit;
|
|
import java.util.regex.Matcher;
|
|
import java.util.regex.Pattern;
|
|
import com.android.okhttp.okio.Buffer;
|
|
import com.android.okhttp.okio.BufferedSink;
|
|
import com.android.okhttp.okio.BufferedSource;
|
|
import com.android.okhttp.okio.Okio;
|
|
import com.android.okhttp.okio.Sink;
|
|
import com.android.okhttp.okio.Source;
|
|
import com.android.okhttp.okio.Timeout;
|
|
|
|
/**
|
|
* A cache that uses a bounded amount of space on a filesystem. Each cache
|
|
* entry has a string key and a fixed number of values. Each key must match
|
|
* the regex <strong>[a-z0-9_-]{1,64}</strong>. Values are byte sequences,
|
|
* accessible as streams or files. Each value must be between {@code 0} and
|
|
* {@code Integer.MAX_VALUE} bytes in length.
|
|
*
|
|
* <p>The cache stores its data in a directory on the filesystem. This
|
|
* directory must be exclusive to the cache; the cache may delete or overwrite
|
|
* files from its directory. It is an error for multiple processes to use the
|
|
* same cache directory at the same time.
|
|
*
|
|
* <p>This cache limits the number of bytes that it will store on the
|
|
* filesystem. When the number of stored bytes exceeds the limit, the cache will
|
|
* remove entries in the background until the limit is satisfied. The limit is
|
|
* not strict: the cache may temporarily exceed it while waiting for files to be
|
|
* deleted. The limit does not include filesystem overhead or the cache
|
|
* journal so space-sensitive applications should set a conservative limit.
|
|
*
|
|
* <p>Clients call {@link #edit} to create or update the values of an entry. An
|
|
* entry may have only one editor at one time; if a value is not available to be
|
|
* edited then {@link #edit} will return null.
|
|
* <ul>
|
|
* <li>When an entry is being <strong>created</strong> it is necessary to
|
|
* supply a full set of values; the empty value should be used as a
|
|
* placeholder if necessary.
|
|
* <li>When an entry is being <strong>edited</strong>, it is not necessary
|
|
* to supply data for every value; values default to their previous
|
|
* value.
|
|
* </ul>
|
|
* Every {@link #edit} call must be matched by a call to {@link Editor#commit}
|
|
* or {@link Editor#abort}. Committing is atomic: a read observes the full set
|
|
* of values as they were before or after the commit, but never a mix of values.
|
|
*
|
|
* <p>Clients call {@link #get} to read a snapshot of an entry. The read will
|
|
* observe the value at the time that {@link #get} was called. Updates and
|
|
* removals after the call do not impact ongoing reads.
|
|
*
|
|
* <p>This class is tolerant of some I/O errors. If files are missing from the
|
|
* filesystem, the corresponding entries will be dropped from the cache. If
|
|
* an error occurs while writing a cache value, the edit will fail silently.
|
|
* Callers should handle other problems by catching {@code IOException} and
|
|
* responding appropriately.
|
|
* @hide This class is not part of the Android public SDK API
|
|
*/
|
|
public final class DiskLruCache implements Closeable {
|
|
static final String JOURNAL_FILE = "journal";
|
|
static final String JOURNAL_FILE_TEMP = "journal.tmp";
|
|
static final String JOURNAL_FILE_BACKUP = "journal.bkp";
|
|
static final String MAGIC = "libcore.io.DiskLruCache";
|
|
static final String VERSION_1 = "1";
|
|
static final long ANY_SEQUENCE_NUMBER = -1;
|
|
static final Pattern LEGAL_KEY_PATTERN = Pattern.compile("[a-z0-9_-]{1,120}");
|
|
private static final String CLEAN = "CLEAN";
|
|
private static final String DIRTY = "DIRTY";
|
|
private static final String REMOVE = "REMOVE";
|
|
private static final String READ = "READ";
|
|
|
|
/*
|
|
* This cache uses a journal file named "journal". A typical journal file
|
|
* looks like this:
|
|
* libcore.io.DiskLruCache
|
|
* 1
|
|
* 100
|
|
* 2
|
|
*
|
|
* CLEAN 3400330d1dfc7f3f7f4b8d4d803dfcf6 832 21054
|
|
* DIRTY 335c4c6028171cfddfbaae1a9c313c52
|
|
* CLEAN 335c4c6028171cfddfbaae1a9c313c52 3934 2342
|
|
* REMOVE 335c4c6028171cfddfbaae1a9c313c52
|
|
* DIRTY 1ab96a171faeeee38496d8b330771a7a
|
|
* CLEAN 1ab96a171faeeee38496d8b330771a7a 1600 234
|
|
* READ 335c4c6028171cfddfbaae1a9c313c52
|
|
* READ 3400330d1dfc7f3f7f4b8d4d803dfcf6
|
|
*
|
|
* The first five lines of the journal form its header. They are the
|
|
* constant string "libcore.io.DiskLruCache", the disk cache's version,
|
|
* the application's version, the value count, and a blank line.
|
|
*
|
|
* Each of the subsequent lines in the file is a record of the state of a
|
|
* cache entry. Each line contains space-separated values: a state, a key,
|
|
* and optional state-specific values.
|
|
* o DIRTY lines track that an entry is actively being created or updated.
|
|
* Every successful DIRTY action should be followed by a CLEAN or REMOVE
|
|
* action. DIRTY lines without a matching CLEAN or REMOVE indicate that
|
|
* temporary files may need to be deleted.
|
|
* o CLEAN lines track a cache entry that has been successfully published
|
|
* and may be read. A publish line is followed by the lengths of each of
|
|
* its values.
|
|
* o READ lines track accesses for LRU.
|
|
* o REMOVE lines track entries that have been deleted.
|
|
*
|
|
* The journal file is appended to as cache operations occur. The journal may
|
|
* occasionally be compacted by dropping redundant lines. A temporary file named
|
|
* "journal.tmp" will be used during compaction; that file should be deleted if
|
|
* it exists when the cache is opened.
|
|
*/
|
|
|
|
private final FileSystem fileSystem;
|
|
private final File directory;
|
|
private final File journalFile;
|
|
private final File journalFileTmp;
|
|
private final File journalFileBackup;
|
|
private final int appVersion;
|
|
private long maxSize;
|
|
private final int valueCount;
|
|
private long size = 0;
|
|
private BufferedSink journalWriter;
|
|
private final LinkedHashMap<String, Entry> lruEntries = new LinkedHashMap<>(0, 0.75f, true);
|
|
private int redundantOpCount;
|
|
private boolean hasJournalErrors;
|
|
|
|
// Must be read and written when synchronized on 'this'.
|
|
private boolean initialized;
|
|
private boolean closed;
|
|
|
|
/**
|
|
* To differentiate between old and current snapshots, each entry is given
|
|
* a sequence number each time an edit is committed. A snapshot is stale if
|
|
* its sequence number is not equal to its entry's sequence number.
|
|
*/
|
|
private long nextSequenceNumber = 0;
|
|
|
|
/** Used to run 'cleanupRunnable' for journal rebuilds. */
|
|
private final Executor executor;
|
|
private final Runnable cleanupRunnable = new Runnable() {
|
|
public void run() {
|
|
synchronized (DiskLruCache.this) {
|
|
if (!initialized | closed) {
|
|
return; // Nothing to do
|
|
}
|
|
try {
|
|
trimToSize();
|
|
if (journalRebuildRequired()) {
|
|
rebuildJournal();
|
|
redundantOpCount = 0;
|
|
}
|
|
} catch (IOException e) {
|
|
throw new RuntimeException(e);
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
DiskLruCache(FileSystem fileSystem, File directory, int appVersion, int valueCount, long maxSize,
|
|
Executor executor) {
|
|
this.fileSystem = fileSystem;
|
|
this.directory = directory;
|
|
this.appVersion = appVersion;
|
|
this.journalFile = new File(directory, JOURNAL_FILE);
|
|
this.journalFileTmp = new File(directory, JOURNAL_FILE_TEMP);
|
|
this.journalFileBackup = new File(directory, JOURNAL_FILE_BACKUP);
|
|
this.valueCount = valueCount;
|
|
this.maxSize = maxSize;
|
|
this.executor = executor;
|
|
}
|
|
|
|
public synchronized void initialize() throws IOException {
|
|
assert Thread.holdsLock(this);
|
|
|
|
if (initialized) {
|
|
return; // Already initialized.
|
|
}
|
|
|
|
// If a bkp file exists, use it instead.
|
|
if (fileSystem.exists(journalFileBackup)) {
|
|
// If journal file also exists just delete backup file.
|
|
if (fileSystem.exists(journalFile)) {
|
|
fileSystem.delete(journalFileBackup);
|
|
} else {
|
|
fileSystem.rename(journalFileBackup, journalFile);
|
|
}
|
|
}
|
|
|
|
// Prefer to pick up where we left off.
|
|
if (fileSystem.exists(journalFile)) {
|
|
try {
|
|
readJournal();
|
|
processJournal();
|
|
initialized = true;
|
|
return;
|
|
} catch (IOException journalIsCorrupt) {
|
|
Platform.get().logW("DiskLruCache " + directory + " is corrupt: "
|
|
+ journalIsCorrupt.getMessage() + ", removing");
|
|
delete();
|
|
closed = false;
|
|
}
|
|
}
|
|
|
|
rebuildJournal();
|
|
|
|
initialized = true;
|
|
}
|
|
|
|
/**
|
|
* Create a cache which will reside in {@code directory}. This cache is lazily initialized on
|
|
* first access and will be created if it does not exist.
|
|
*
|
|
* @param directory a writable directory
|
|
* @param valueCount the number of values per cache entry. Must be positive.
|
|
* @param maxSize the maximum number of bytes this cache should use to store
|
|
*/
|
|
public static DiskLruCache create(FileSystem fileSystem, File directory, int appVersion,
|
|
int valueCount, long maxSize) {
|
|
if (maxSize <= 0) {
|
|
throw new IllegalArgumentException("maxSize <= 0");
|
|
}
|
|
if (valueCount <= 0) {
|
|
throw new IllegalArgumentException("valueCount <= 0");
|
|
}
|
|
|
|
// Use a single background thread to evict entries.
|
|
Executor executor = new ThreadPoolExecutor(0, 1, 60L, TimeUnit.SECONDS,
|
|
new LinkedBlockingQueue<Runnable>(), Util.threadFactory("OkHttp DiskLruCache", true));
|
|
|
|
return new DiskLruCache(fileSystem, directory, appVersion, valueCount, maxSize, executor);
|
|
}
|
|
|
|
private void readJournal() throws IOException {
|
|
BufferedSource source = Okio.buffer(fileSystem.source(journalFile));
|
|
try {
|
|
String magic = source.readUtf8LineStrict();
|
|
String version = source.readUtf8LineStrict();
|
|
String appVersionString = source.readUtf8LineStrict();
|
|
String valueCountString = source.readUtf8LineStrict();
|
|
String blank = source.readUtf8LineStrict();
|
|
if (!MAGIC.equals(magic)
|
|
|| !VERSION_1.equals(version)
|
|
|| !Integer.toString(appVersion).equals(appVersionString)
|
|
|| !Integer.toString(valueCount).equals(valueCountString)
|
|
|| !"".equals(blank)) {
|
|
throw new IOException("unexpected journal header: [" + magic + ", " + version + ", "
|
|
+ valueCountString + ", " + blank + "]");
|
|
}
|
|
|
|
int lineCount = 0;
|
|
while (true) {
|
|
try {
|
|
readJournalLine(source.readUtf8LineStrict());
|
|
lineCount++;
|
|
} catch (EOFException endOfJournal) {
|
|
break;
|
|
}
|
|
}
|
|
redundantOpCount = lineCount - lruEntries.size();
|
|
|
|
// If we ended on a truncated line, rebuild the journal before appending to it.
|
|
if (!source.exhausted()) {
|
|
rebuildJournal();
|
|
} else {
|
|
journalWriter = newJournalWriter();
|
|
}
|
|
} finally {
|
|
Util.closeQuietly(source);
|
|
}
|
|
}
|
|
|
|
private BufferedSink newJournalWriter() throws FileNotFoundException {
|
|
Sink fileSink = fileSystem.appendingSink(journalFile);
|
|
Sink faultHidingSink = new FaultHidingSink(fileSink) {
|
|
@Override protected void onException(IOException e) {
|
|
assert (Thread.holdsLock(DiskLruCache.this));
|
|
hasJournalErrors = true;
|
|
}
|
|
};
|
|
return Okio.buffer(faultHidingSink);
|
|
}
|
|
|
|
private void readJournalLine(String line) throws IOException {
|
|
int firstSpace = line.indexOf(' ');
|
|
if (firstSpace == -1) {
|
|
throw new IOException("unexpected journal line: " + line);
|
|
}
|
|
|
|
int keyBegin = firstSpace + 1;
|
|
int secondSpace = line.indexOf(' ', keyBegin);
|
|
final String key;
|
|
if (secondSpace == -1) {
|
|
key = line.substring(keyBegin);
|
|
if (firstSpace == REMOVE.length() && line.startsWith(REMOVE)) {
|
|
lruEntries.remove(key);
|
|
return;
|
|
}
|
|
} else {
|
|
key = line.substring(keyBegin, secondSpace);
|
|
}
|
|
|
|
Entry entry = lruEntries.get(key);
|
|
if (entry == null) {
|
|
entry = new Entry(key);
|
|
lruEntries.put(key, entry);
|
|
}
|
|
|
|
if (secondSpace != -1 && firstSpace == CLEAN.length() && line.startsWith(CLEAN)) {
|
|
String[] parts = line.substring(secondSpace + 1).split(" ");
|
|
entry.readable = true;
|
|
entry.currentEditor = null;
|
|
entry.setLengths(parts);
|
|
} else if (secondSpace == -1 && firstSpace == DIRTY.length() && line.startsWith(DIRTY)) {
|
|
entry.currentEditor = new Editor(entry);
|
|
} else if (secondSpace == -1 && firstSpace == READ.length() && line.startsWith(READ)) {
|
|
// This work was already done by calling lruEntries.get().
|
|
} else {
|
|
throw new IOException("unexpected journal line: " + line);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Computes the initial size and collects garbage as a part of opening the
|
|
* cache. Dirty entries are assumed to be inconsistent and will be deleted.
|
|
*/
|
|
private void processJournal() throws IOException {
|
|
fileSystem.delete(journalFileTmp);
|
|
for (Iterator<Entry> i = lruEntries.values().iterator(); i.hasNext(); ) {
|
|
Entry entry = i.next();
|
|
if (entry.currentEditor == null) {
|
|
for (int t = 0; t < valueCount; t++) {
|
|
size += entry.lengths[t];
|
|
}
|
|
} else {
|
|
entry.currentEditor = null;
|
|
for (int t = 0; t < valueCount; t++) {
|
|
fileSystem.delete(entry.cleanFiles[t]);
|
|
fileSystem.delete(entry.dirtyFiles[t]);
|
|
}
|
|
i.remove();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Creates a new journal that omits redundant information. This replaces the
|
|
* current journal if it exists.
|
|
*/
|
|
private synchronized void rebuildJournal() throws IOException {
|
|
if (journalWriter != null) {
|
|
journalWriter.close();
|
|
}
|
|
|
|
BufferedSink writer = Okio.buffer(fileSystem.sink(journalFileTmp));
|
|
try {
|
|
writer.writeUtf8(MAGIC).writeByte('\n');
|
|
writer.writeUtf8(VERSION_1).writeByte('\n');
|
|
writer.writeDecimalLong(appVersion).writeByte('\n');
|
|
writer.writeDecimalLong(valueCount).writeByte('\n');
|
|
writer.writeByte('\n');
|
|
|
|
for (Entry entry : lruEntries.values()) {
|
|
if (entry.currentEditor != null) {
|
|
writer.writeUtf8(DIRTY).writeByte(' ');
|
|
writer.writeUtf8(entry.key);
|
|
writer.writeByte('\n');
|
|
} else {
|
|
writer.writeUtf8(CLEAN).writeByte(' ');
|
|
writer.writeUtf8(entry.key);
|
|
entry.writeLengths(writer);
|
|
writer.writeByte('\n');
|
|
}
|
|
}
|
|
} finally {
|
|
writer.close();
|
|
}
|
|
|
|
if (fileSystem.exists(journalFile)) {
|
|
fileSystem.rename(journalFile, journalFileBackup);
|
|
}
|
|
fileSystem.rename(journalFileTmp, journalFile);
|
|
fileSystem.delete(journalFileBackup);
|
|
|
|
journalWriter = newJournalWriter();
|
|
hasJournalErrors = false;
|
|
}
|
|
|
|
/**
|
|
* Returns a snapshot of the entry named {@code key}, or null if it doesn't
|
|
* exist is not currently readable. If a value is returned, it is moved to
|
|
* the head of the LRU queue.
|
|
*/
|
|
public synchronized Snapshot get(String key) throws IOException {
|
|
initialize();
|
|
|
|
checkNotClosed();
|
|
validateKey(key);
|
|
Entry entry = lruEntries.get(key);
|
|
if (entry == null || !entry.readable) return null;
|
|
|
|
Snapshot snapshot = entry.snapshot();
|
|
if (snapshot == null) return null;
|
|
|
|
redundantOpCount++;
|
|
journalWriter.writeUtf8(READ).writeByte(' ').writeUtf8(key).writeByte('\n');
|
|
if (journalRebuildRequired()) {
|
|
executor.execute(cleanupRunnable);
|
|
}
|
|
|
|
return snapshot;
|
|
}
|
|
|
|
/**
|
|
* Returns an editor for the entry named {@code key}, or null if another
|
|
* edit is in progress.
|
|
*/
|
|
public Editor edit(String key) throws IOException {
|
|
return edit(key, ANY_SEQUENCE_NUMBER);
|
|
}
|
|
|
|
private synchronized Editor edit(String key, long expectedSequenceNumber) throws IOException {
|
|
initialize();
|
|
|
|
checkNotClosed();
|
|
validateKey(key);
|
|
Entry entry = lruEntries.get(key);
|
|
if (expectedSequenceNumber != ANY_SEQUENCE_NUMBER && (entry == null
|
|
|| entry.sequenceNumber != expectedSequenceNumber)) {
|
|
return null; // Snapshot is stale.
|
|
}
|
|
if (entry != null && entry.currentEditor != null) {
|
|
return null; // Another edit is in progress.
|
|
}
|
|
|
|
// Flush the journal before creating files to prevent file leaks.
|
|
journalWriter.writeUtf8(DIRTY).writeByte(' ').writeUtf8(key).writeByte('\n');
|
|
journalWriter.flush();
|
|
|
|
if (hasJournalErrors) {
|
|
return null; // Don't edit; the journal can't be written.
|
|
}
|
|
|
|
if (entry == null) {
|
|
entry = new Entry(key);
|
|
lruEntries.put(key, entry);
|
|
}
|
|
Editor editor = new Editor(entry);
|
|
entry.currentEditor = editor;
|
|
return editor;
|
|
}
|
|
|
|
/** Returns the directory where this cache stores its data. */
|
|
public File getDirectory() {
|
|
return directory;
|
|
}
|
|
|
|
/**
|
|
* Returns the maximum number of bytes that this cache should use to store
|
|
* its data.
|
|
*/
|
|
public synchronized long getMaxSize() {
|
|
return maxSize;
|
|
}
|
|
|
|
/**
|
|
* Changes the maximum number of bytes the cache can store and queues a job
|
|
* to trim the existing store, if necessary.
|
|
*/
|
|
public synchronized void setMaxSize(long maxSize) {
|
|
this.maxSize = maxSize;
|
|
if (initialized) {
|
|
executor.execute(cleanupRunnable);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns the number of bytes currently being used to store the values in
|
|
* this cache. This may be greater than the max size if a background
|
|
* deletion is pending.
|
|
*/
|
|
public synchronized long size() throws IOException {
|
|
initialize();
|
|
return size;
|
|
}
|
|
|
|
private synchronized void completeEdit(Editor editor, boolean success) throws IOException {
|
|
Entry entry = editor.entry;
|
|
if (entry.currentEditor != editor) {
|
|
throw new IllegalStateException();
|
|
}
|
|
|
|
// If this edit is creating the entry for the first time, every index must have a value.
|
|
if (success && !entry.readable) {
|
|
for (int i = 0; i < valueCount; i++) {
|
|
if (!editor.written[i]) {
|
|
editor.abort();
|
|
throw new IllegalStateException("Newly created entry didn't create value for index " + i);
|
|
}
|
|
if (!fileSystem.exists(entry.dirtyFiles[i])) {
|
|
editor.abort();
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
for (int i = 0; i < valueCount; i++) {
|
|
File dirty = entry.dirtyFiles[i];
|
|
if (success) {
|
|
if (fileSystem.exists(dirty)) {
|
|
File clean = entry.cleanFiles[i];
|
|
fileSystem.rename(dirty, clean);
|
|
long oldLength = entry.lengths[i];
|
|
long newLength = fileSystem.size(clean);
|
|
entry.lengths[i] = newLength;
|
|
size = size - oldLength + newLength;
|
|
}
|
|
} else {
|
|
fileSystem.delete(dirty);
|
|
}
|
|
}
|
|
|
|
redundantOpCount++;
|
|
entry.currentEditor = null;
|
|
if (entry.readable | success) {
|
|
entry.readable = true;
|
|
journalWriter.writeUtf8(CLEAN).writeByte(' ');
|
|
journalWriter.writeUtf8(entry.key);
|
|
entry.writeLengths(journalWriter);
|
|
journalWriter.writeByte('\n');
|
|
if (success) {
|
|
entry.sequenceNumber = nextSequenceNumber++;
|
|
}
|
|
} else {
|
|
lruEntries.remove(entry.key);
|
|
journalWriter.writeUtf8(REMOVE).writeByte(' ');
|
|
journalWriter.writeUtf8(entry.key);
|
|
journalWriter.writeByte('\n');
|
|
}
|
|
journalWriter.flush();
|
|
|
|
if (size > maxSize || journalRebuildRequired()) {
|
|
executor.execute(cleanupRunnable);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* We only rebuild the journal when it will halve the size of the journal
|
|
* and eliminate at least 2000 ops.
|
|
*/
|
|
private boolean journalRebuildRequired() {
|
|
final int redundantOpCompactThreshold = 2000;
|
|
return redundantOpCount >= redundantOpCompactThreshold
|
|
&& redundantOpCount >= lruEntries.size();
|
|
}
|
|
|
|
/**
|
|
* Drops the entry for {@code key} if it exists and can be removed. If the
|
|
* entry for {@code key} is currently being edited, that edit will complete
|
|
* normally but its value will not be stored.
|
|
*
|
|
* @return true if an entry was removed.
|
|
*/
|
|
public synchronized boolean remove(String key) throws IOException {
|
|
initialize();
|
|
|
|
checkNotClosed();
|
|
validateKey(key);
|
|
Entry entry = lruEntries.get(key);
|
|
if (entry == null) return false;
|
|
return removeEntry(entry);
|
|
}
|
|
|
|
private boolean removeEntry(Entry entry) throws IOException {
|
|
if (entry.currentEditor != null) {
|
|
entry.currentEditor.detach(); // Prevent the edit from completing normally.
|
|
}
|
|
|
|
for (int i = 0; i < valueCount; i++) {
|
|
fileSystem.delete(entry.cleanFiles[i]);
|
|
size -= entry.lengths[i];
|
|
entry.lengths[i] = 0;
|
|
}
|
|
|
|
redundantOpCount++;
|
|
journalWriter.writeUtf8(REMOVE).writeByte(' ').writeUtf8(entry.key).writeByte('\n');
|
|
lruEntries.remove(entry.key);
|
|
|
|
if (journalRebuildRequired()) {
|
|
executor.execute(cleanupRunnable);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/** Returns true if this cache has been closed. */
|
|
public synchronized boolean isClosed() {
|
|
return closed;
|
|
}
|
|
|
|
private synchronized void checkNotClosed() {
|
|
if (isClosed()) {
|
|
throw new IllegalStateException("cache is closed");
|
|
}
|
|
}
|
|
|
|
/** Force buffered operations to the filesystem. */
|
|
public synchronized void flush() throws IOException {
|
|
if (!initialized) return;
|
|
|
|
checkNotClosed();
|
|
trimToSize();
|
|
journalWriter.flush();
|
|
}
|
|
|
|
/** Closes this cache. Stored values will remain on the filesystem. */
|
|
public synchronized void close() throws IOException {
|
|
if (!initialized || closed) {
|
|
closed = true;
|
|
return;
|
|
}
|
|
// Copying for safe iteration.
|
|
for (Entry entry : lruEntries.values().toArray(new Entry[lruEntries.size()])) {
|
|
if (entry.currentEditor != null) {
|
|
entry.currentEditor.abort();
|
|
}
|
|
}
|
|
trimToSize();
|
|
journalWriter.close();
|
|
journalWriter = null;
|
|
closed = true;
|
|
}
|
|
|
|
private void trimToSize() throws IOException {
|
|
while (size > maxSize) {
|
|
Entry toEvict = lruEntries.values().iterator().next();
|
|
removeEntry(toEvict);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Closes the cache and deletes all of its stored values. This will delete
|
|
* all files in the cache directory including files that weren't created by
|
|
* the cache.
|
|
*/
|
|
public void delete() throws IOException {
|
|
close();
|
|
fileSystem.deleteContents(directory);
|
|
}
|
|
|
|
/**
|
|
* Deletes all stored values from the cache. In-flight edits will complete
|
|
* normally but their values will not be stored.
|
|
*/
|
|
public synchronized void evictAll() throws IOException {
|
|
initialize();
|
|
// Copying for safe iteration.
|
|
for (Entry entry : lruEntries.values().toArray(new Entry[lruEntries.size()])) {
|
|
removeEntry(entry);
|
|
}
|
|
}
|
|
|
|
private void validateKey(String key) {
|
|
Matcher matcher = LEGAL_KEY_PATTERN.matcher(key);
|
|
if (!matcher.matches()) {
|
|
throw new IllegalArgumentException(
|
|
"keys must match regex [a-z0-9_-]{1,120}: \"" + key + "\"");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns an iterator over the cache's current entries. This iterator doesn't throw {@code
|
|
* ConcurrentModificationException}, but if new entries are added while iterating, those new
|
|
* entries will not be returned by the iterator. If existing entries are removed during iteration,
|
|
* they will be absent (unless they were already returned).
|
|
*
|
|
* <p>If there are I/O problems during iteration, this iterator fails silently. For example, if
|
|
* the hosting filesystem becomes unreachable, the iterator will omit elements rather than
|
|
* throwing exceptions.
|
|
*
|
|
* <p><strong>The caller must {@link Snapshot#close close}</strong> each snapshot returned by
|
|
* {@link Iterator#next}. Failing to do so leaks open files!
|
|
*
|
|
* <p>The returned iterator supports {@link Iterator#remove}.
|
|
*/
|
|
public synchronized Iterator<Snapshot> snapshots() throws IOException {
|
|
initialize();
|
|
return new Iterator<Snapshot>() {
|
|
/** Iterate a copy of the entries to defend against concurrent modification errors. */
|
|
final Iterator<Entry> delegate = new ArrayList<>(lruEntries.values()).iterator();
|
|
|
|
/** The snapshot to return from {@link #next}. Null if we haven't computed that yet. */
|
|
Snapshot nextSnapshot;
|
|
|
|
/** The snapshot to remove with {@link #remove}. Null if removal is illegal. */
|
|
Snapshot removeSnapshot;
|
|
|
|
@Override public boolean hasNext() {
|
|
if (nextSnapshot != null) return true;
|
|
|
|
synchronized (DiskLruCache.this) {
|
|
// If the cache is closed, truncate the iterator.
|
|
if (closed) return false;
|
|
|
|
while (delegate.hasNext()) {
|
|
Entry entry = delegate.next();
|
|
Snapshot snapshot = entry.snapshot();
|
|
if (snapshot == null) continue; // Evicted since we copied the entries.
|
|
nextSnapshot = snapshot;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
@Override public Snapshot next() {
|
|
if (!hasNext()) throw new NoSuchElementException();
|
|
removeSnapshot = nextSnapshot;
|
|
nextSnapshot = null;
|
|
return removeSnapshot;
|
|
}
|
|
|
|
@Override public void remove() {
|
|
if (removeSnapshot == null) throw new IllegalStateException("remove() before next()");
|
|
try {
|
|
DiskLruCache.this.remove(removeSnapshot.key);
|
|
} catch (IOException ignored) {
|
|
// Nothing useful to do here. We failed to remove from the cache. Most likely that's
|
|
// because we couldn't update the journal, but the cached entry will still be gone.
|
|
} finally {
|
|
removeSnapshot = null;
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
/** A snapshot of the values for an entry.
|
|
* @hide This class is not part of the Android public SDK API*/
|
|
public final class Snapshot implements Closeable {
|
|
private final String key;
|
|
private final long sequenceNumber;
|
|
private final Source[] sources;
|
|
private final long[] lengths;
|
|
|
|
private Snapshot(String key, long sequenceNumber, Source[] sources, long[] lengths) {
|
|
this.key = key;
|
|
this.sequenceNumber = sequenceNumber;
|
|
this.sources = sources;
|
|
this.lengths = lengths;
|
|
}
|
|
|
|
public String key() {
|
|
return key;
|
|
}
|
|
|
|
/**
|
|
* Returns an editor for this snapshot's entry, or null if either the
|
|
* entry has changed since this snapshot was created or if another edit
|
|
* is in progress.
|
|
*/
|
|
public Editor edit() throws IOException {
|
|
return DiskLruCache.this.edit(key, sequenceNumber);
|
|
}
|
|
|
|
/** Returns the unbuffered stream with the value for {@code index}. */
|
|
public Source getSource(int index) {
|
|
return sources[index];
|
|
}
|
|
|
|
/** Returns the byte length of the value for {@code index}. */
|
|
public long getLength(int index) {
|
|
return lengths[index];
|
|
}
|
|
|
|
public void close() {
|
|
for (Source in : sources) {
|
|
Util.closeQuietly(in);
|
|
}
|
|
}
|
|
}
|
|
|
|
private static final Sink NULL_SINK = new Sink() {
|
|
@Override public void write(Buffer source, long byteCount) throws IOException {
|
|
source.skip(byteCount);
|
|
}
|
|
|
|
@Override public void flush() throws IOException {
|
|
}
|
|
|
|
@Override public Timeout timeout() {
|
|
return Timeout.NONE;
|
|
}
|
|
|
|
@Override public void close() throws IOException {
|
|
}
|
|
};
|
|
|
|
/** Edits the values for an entry.
|
|
* @hide This class is not part of the Android public SDK API*/
|
|
public final class Editor {
|
|
private final Entry entry;
|
|
private final boolean[] written;
|
|
private boolean done;
|
|
|
|
private Editor(Entry entry) {
|
|
this.entry = entry;
|
|
this.written = (entry.readable) ? null : new boolean[valueCount];
|
|
}
|
|
|
|
/**
|
|
* Prevents this editor from completing normally. This is necessary either when the edit causes
|
|
* an I/O error, or if the target entry is evicted while this editor is active. In either case
|
|
* we delete the editor's created files and prevent new files from being created. Note that once
|
|
* an editor has been detached it is possible for another editor to edit the entry.
|
|
*/
|
|
void detach() {
|
|
if (entry.currentEditor == this) {
|
|
for (int i = 0; i < valueCount; i++) {
|
|
try {
|
|
fileSystem.delete(entry.dirtyFiles[i]);
|
|
} catch (IOException e) {
|
|
// This file is potentially leaked. Not much we can do about that.
|
|
}
|
|
}
|
|
entry.currentEditor = null;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns an unbuffered input stream to read the last committed value,
|
|
* or null if no value has been committed.
|
|
*/
|
|
public Source newSource(int index) throws IOException {
|
|
synchronized (DiskLruCache.this) {
|
|
if (done) {
|
|
throw new IllegalStateException();
|
|
}
|
|
if (!entry.readable || entry.currentEditor != this) {
|
|
return null;
|
|
}
|
|
try {
|
|
return fileSystem.source(entry.cleanFiles[index]);
|
|
} catch (FileNotFoundException e) {
|
|
return null;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns a new unbuffered output stream to write the value at
|
|
* {@code index}. If the underlying output stream encounters errors
|
|
* when writing to the filesystem, this edit will be aborted when
|
|
* {@link #commit} is called. The returned output stream does not throw
|
|
* IOExceptions.
|
|
*/
|
|
public Sink newSink(int index) throws IOException {
|
|
synchronized (DiskLruCache.this) {
|
|
if (done) {
|
|
throw new IllegalStateException();
|
|
}
|
|
if (entry.currentEditor != this) {
|
|
return NULL_SINK;
|
|
}
|
|
if (!entry.readable) {
|
|
written[index] = true;
|
|
}
|
|
File dirtyFile = entry.dirtyFiles[index];
|
|
Sink sink;
|
|
try {
|
|
sink = fileSystem.sink(dirtyFile);
|
|
} catch (FileNotFoundException e) {
|
|
return NULL_SINK;
|
|
}
|
|
return new FaultHidingSink(sink) {
|
|
@Override protected void onException(IOException e) {
|
|
synchronized (DiskLruCache.this) {
|
|
detach();
|
|
}
|
|
}
|
|
};
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Commits this edit so it is visible to readers. This releases the
|
|
* edit lock so another edit may be started on the same key.
|
|
*/
|
|
public void commit() throws IOException {
|
|
synchronized (DiskLruCache.this) {
|
|
if (done) {
|
|
throw new IllegalStateException();
|
|
}
|
|
if (entry.currentEditor == this) {
|
|
completeEdit(this, true);
|
|
}
|
|
done = true;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Aborts this edit. This releases the edit lock so another edit may be
|
|
* started on the same key.
|
|
*/
|
|
public void abort() throws IOException {
|
|
synchronized (DiskLruCache.this) {
|
|
if (done) {
|
|
throw new IllegalStateException();
|
|
}
|
|
if (entry.currentEditor == this) {
|
|
completeEdit(this, false);
|
|
}
|
|
done = true;
|
|
}
|
|
}
|
|
|
|
public void abortUnlessCommitted() {
|
|
synchronized (DiskLruCache.this) {
|
|
if (!done && entry.currentEditor == this) {
|
|
try {
|
|
completeEdit(this, false);
|
|
} catch (IOException ignored) {
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
private final class Entry {
|
|
private final String key;
|
|
|
|
/** Lengths of this entry's files. */
|
|
private final long[] lengths;
|
|
private final File[] cleanFiles;
|
|
private final File[] dirtyFiles;
|
|
|
|
/** True if this entry has ever been published. */
|
|
private boolean readable;
|
|
|
|
/** The ongoing edit or null if this entry is not being edited. */
|
|
private Editor currentEditor;
|
|
|
|
/** The sequence number of the most recently committed edit to this entry. */
|
|
private long sequenceNumber;
|
|
|
|
private Entry(String key) {
|
|
this.key = key;
|
|
|
|
lengths = new long[valueCount];
|
|
cleanFiles = new File[valueCount];
|
|
dirtyFiles = new File[valueCount];
|
|
|
|
// The names are repetitive so re-use the same builder to avoid allocations.
|
|
StringBuilder fileBuilder = new StringBuilder(key).append('.');
|
|
int truncateTo = fileBuilder.length();
|
|
for (int i = 0; i < valueCount; i++) {
|
|
fileBuilder.append(i);
|
|
cleanFiles[i] = new File(directory, fileBuilder.toString());
|
|
fileBuilder.append(".tmp");
|
|
dirtyFiles[i] = new File(directory, fileBuilder.toString());
|
|
fileBuilder.setLength(truncateTo);
|
|
}
|
|
}
|
|
|
|
/** Set lengths using decimal numbers like "10123". */
|
|
private void setLengths(String[] strings) throws IOException {
|
|
if (strings.length != valueCount) {
|
|
throw invalidLengths(strings);
|
|
}
|
|
|
|
try {
|
|
for (int i = 0; i < strings.length; i++) {
|
|
lengths[i] = Long.parseLong(strings[i]);
|
|
}
|
|
} catch (NumberFormatException e) {
|
|
throw invalidLengths(strings);
|
|
}
|
|
}
|
|
|
|
/** Append space-prefixed lengths to {@code writer}. */
|
|
void writeLengths(BufferedSink writer) throws IOException {
|
|
for (long length : lengths) {
|
|
writer.writeByte(' ').writeDecimalLong(length);
|
|
}
|
|
}
|
|
|
|
private IOException invalidLengths(String[] strings) throws IOException {
|
|
throw new IOException("unexpected journal line: " + Arrays.toString(strings));
|
|
}
|
|
|
|
/**
|
|
* Returns a snapshot of this entry. This opens all streams eagerly to guarantee that we see a
|
|
* single published snapshot. If we opened streams lazily then the streams could come from
|
|
* different edits.
|
|
*/
|
|
Snapshot snapshot() {
|
|
if (!Thread.holdsLock(DiskLruCache.this)) throw new AssertionError();
|
|
|
|
Source[] sources = new Source[valueCount];
|
|
long[] lengths = this.lengths.clone(); // Defensive copy since these can be zeroed out.
|
|
try {
|
|
for (int i = 0; i < valueCount; i++) {
|
|
sources[i] = fileSystem.source(cleanFiles[i]);
|
|
}
|
|
return new Snapshot(key, sequenceNumber, sources, lengths);
|
|
} catch (FileNotFoundException e) {
|
|
// A file must have been deleted manually!
|
|
for (int i = 0; i < valueCount; i++) {
|
|
if (sources[i] != null) {
|
|
Util.closeQuietly(sources[i]);
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
return null;
|
|
}
|
|
}
|
|
}
|
|
}
|