replicant-packages_apps_Email/src/com/android/email/service/ImapTempFileLiteral.java

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/*
* 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.email.service;
import android.util.Log;
import com.android.email.FixedLengthInputStream;
import com.android.email.mail.store.imap.ImapResponse;
import com.android.email.mail.store.imap.ImapResponseParser;
import com.android.email.mail.store.imap.ImapString;
import com.android.emailcommon.Logging;
import com.android.emailcommon.TempDirectory;
import com.android.emailcommon.utility.Utility;
import org.apache.commons.io.IOUtils;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
* Subclass of {@link ImapString} used for literals backed by a temp file.
*/
public class ImapTempFileLiteral extends ImapString {
/* package for test */ final File mFile;
/** Size is purely for toString() */
private final int mSize;
/* package */ ImapTempFileLiteral(FixedLengthInputStream stream) throws IOException {
mSize = stream.getLength();
mFile = File.createTempFile("imap", ".tmp", TempDirectory.getTempDirectory());
// Unfortunately, we can't really use deleteOnExit(), because temp filenames are random
// so it'd simply cause a memory leak.
// deleteOnExit() simply adds filenames to a static list and the list will never shrink.
// mFile.deleteOnExit();
OutputStream out = new FileOutputStream(mFile);
IOUtils.copy(stream, out);
out.close();
}
/**
* Make sure we delete the temp file.
*
* We should always be calling {@link ImapResponse#destroy()}, but it's here as a last resort.
*/
@Override
protected void finalize() throws Throwable {
try {
destroy();
} finally {
super.finalize();
}
}
@Override
public InputStream getAsStream() {
checkNotDestroyed();
try {
return new FileInputStream(mFile);
} catch (FileNotFoundException e) {
// It's probably possible if we're low on storage and the system clears the cache dir.
Log.w(Logging.LOG_TAG, "ImapTempFileLiteral: Temp file not found");
// Return 0 byte stream as a dummy...
return new ByteArrayInputStream(new byte[0]);
}
}
@Override
public String getString() {
checkNotDestroyed();
try {
byte[] bytes = IOUtils.toByteArray(getAsStream());
// Prevent crash from OOM; we've seen this, but only rarely and not reproducibly
if (bytes.length > ImapResponseParser.LITERAL_KEEP_IN_MEMORY_THRESHOLD) {
throw new IOException();
}
return Utility.fromAscii(bytes);
} catch (IOException e) {
Log.w(Logging.LOG_TAG, "ImapTempFileLiteral: Error while reading temp file", e);
return "";
}
}
@Override
public void destroy() {
try {
if (!isDestroyed() && mFile.exists()) {
mFile.delete();
}
} catch (RuntimeException re) {
// Just log and ignore.
Log.w(Logging.LOG_TAG, "Failed to remove temp file: " + re.getMessage());
}
super.destroy();
}
@Override
public String toString() {
return String.format("{%d byte literal(file)}", mSize);
}
public boolean tempFileExistsForTest() {
return mFile.exists();
}
}