Remove MiniThumbFile (5312e4b0) · Commits · e / os / android_frameworks_base

media/java/android/media/MiniThumbFile.java

deleted100644 → 0

+0 −334

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		/*
		* Copyright (C) 2009 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 android.media;

		import android.annotation.UnsupportedAppUsage;
		import android.net.Uri;
		import android.os.Build;
		import android.os.Environment;
		import android.util.Log;

		import dalvik.system.VMRuntime;

		import java.io.File;
		import java.io.IOException;
		import java.io.RandomAccessFile;
		import java.nio.ByteBuffer;
		import java.nio.channels.FileChannel;
		import java.nio.channels.FileLock;
		import java.util.Hashtable;

		/**
		* This class handles the mini-thumb file. A mini-thumb file consists
		* of blocks, indexed by id. Each block has BYTES_PER_MINTHUMB bytes in the
		* following format:
		*
		* 1 byte status (0 = empty, 1 = mini-thumb available)
		* 8 bytes magic (a magic number to match what's in the database)
		* 4 bytes data length (LEN)
		* LEN bytes jpeg data
		* (the remaining bytes are unused)
		*
		* @hide This file is shared between MediaStore and MediaProvider and should remained internal use
		* only.
		* @deprecated thumbnails are now maintained in separate files, and this file
		* format is no longer used.
		*/
		@Deprecated
		public class MiniThumbFile {
		private static final String TAG = "MiniThumbFile";
		private static final int MINI_THUMB_DATA_FILE_VERSION = 4;
		public static final int BYTES_PER_MINTHUMB = 10000;
		private static final int HEADER_SIZE = 1 + 8 + 4;
		private Uri mUri;
		private RandomAccessFile mMiniThumbFile;
		private FileChannel mChannel;
		private ByteBuffer mBuffer;
		private ByteBuffer mEmptyBuffer;
		private static final Hashtable<String, MiniThumbFile> sThumbFiles =
		new Hashtable<String, MiniThumbFile>();

		/**
		* We store different types of thumbnails in different files. To remain backward compatibility,
		* we should hashcode of content://media/external/images/media remains the same.
		*/
		@UnsupportedAppUsage
		public static synchronized void reset() {
		for (MiniThumbFile file : sThumbFiles.values()) {
		file.deactivate();
		}
		sThumbFiles.clear();
		}

		public static synchronized MiniThumbFile instance(Uri uri) {
		if (VMRuntime.getRuntime().getTargetSdkVersion() >= Build.VERSION_CODES.Q) {
		throw new UnsupportedOperationException();
		}
		String type = uri.getPathSegments().get(1);
		MiniThumbFile file = sThumbFiles.get(type);
		// Log.v(TAG, "get minithumbfile for type: "+type);
		if (file == null) {
		file = new MiniThumbFile(
		Uri.parse("content://media/external/" + type + "/media"));
		sThumbFiles.put(type, file);
		}

		return file;
		}

		private String randomAccessFilePath(int version) {
		String directoryName =
		Environment.getExternalStorageDirectory().toString()
		+ "/DCIM/.thumbnails";
		return directoryName + "/.thumbdata" + version + "-" + mUri.hashCode();
		}

		private void removeOldFile() {
		String oldPath = randomAccessFilePath(MINI_THUMB_DATA_FILE_VERSION - 1);
		File oldFile = new File(oldPath);
		if (oldFile.exists()) {
		try {
		oldFile.delete();
		} catch (SecurityException ex) {
		// ignore
		}
		}
		}

		private RandomAccessFile miniThumbDataFile() {
		if (mMiniThumbFile == null) {
		removeOldFile();
		String path = randomAccessFilePath(MINI_THUMB_DATA_FILE_VERSION);
		File directory = new File(path).getParentFile();
		if (!directory.isDirectory()) {
		if (!directory.mkdirs()) {
		Log.e(TAG, "Unable to create .thumbnails directory "
		+ directory.toString());
		}
		}
		File f = new File(path);
		try {
		mMiniThumbFile = new RandomAccessFile(f, "rw");
		} catch (IOException ex) {
		// Open as read-only so we can at least read the existing
		// thumbnails.
		try {
		mMiniThumbFile = new RandomAccessFile(f, "r");
		} catch (IOException ex2) {
		// ignore exception
		}
		}
		if (mMiniThumbFile != null) {
		mChannel = mMiniThumbFile.getChannel();
		}
		}
		return mMiniThumbFile;
		}

		private MiniThumbFile(Uri uri) {
		mUri = uri;
		mBuffer = ByteBuffer.allocateDirect(BYTES_PER_MINTHUMB);
		mEmptyBuffer = ByteBuffer.allocateDirect(BYTES_PER_MINTHUMB);
		}

		public synchronized void deactivate() {
		if (mMiniThumbFile != null) {
		try {
		mMiniThumbFile.close();
		mMiniThumbFile = null;
		} catch (IOException ex) {
		// ignore exception
		}
		}
		}

		// Get the magic number for the specified id in the mini-thumb file.
		// Returns 0 if the magic is not available.
		public synchronized long getMagic(long id) {
		// check the mini thumb file for the right data. Right is
		// defined as having the right magic number at the offset
		// reserved for this "id".
		RandomAccessFile r = miniThumbDataFile();
		if (r != null) {
		long pos = id * BYTES_PER_MINTHUMB;
		FileLock lock = null;
		try {
		mBuffer.clear();
		mBuffer.limit(1 + 8);

		lock = mChannel.lock(pos, 1 + 8, true);
		// check that we can read the following 9 bytes
		// (1 for the "status" and 8 for the long)
		if (mChannel.read(mBuffer, pos) == 9) {
		mBuffer.position(0);
		if (mBuffer.get() == 1) {
		return mBuffer.getLong();
		}
		}
		} catch (IOException ex) {
		Log.v(TAG, "Got exception checking file magic: ", ex);
		} catch (RuntimeException ex) {
		// Other NIO related exception like disk full, read only channel..etc
		Log.e(TAG, "Got exception when reading magic, id = " + id +
		", disk full or mount read-only? " + ex.getClass());
		} finally {
		try {
		if (lock != null) lock.release();
		}
		catch (IOException ex) {
		// ignore it.
		}
		}
		}
		return 0;
		}

		public synchronized void eraseMiniThumb(long id) {
		RandomAccessFile r = miniThumbDataFile();
		if (r != null) {
		long pos = id * BYTES_PER_MINTHUMB;
		FileLock lock = null;
		try {
		mBuffer.clear();
		mBuffer.limit(1 + 8);

		lock = mChannel.lock(pos, BYTES_PER_MINTHUMB, false);
		// check that we can read the following 9 bytes
		// (1 for the "status" and 8 for the long)
		if (mChannel.read(mBuffer, pos) == 9) {
		mBuffer.position(0);
		if (mBuffer.get() == 1) {
		long currentMagic = mBuffer.getLong();
		if (currentMagic == 0) {
		// there is no thumbnail stored here
		Log.i(TAG, "no thumbnail for id " + id);
		return;
		}
		// zero out the thumbnail slot
		// Log.v(TAG, "clearing slot " + id + ", magic " + currentMagic
		// + " at offset " + pos);
		mChannel.write(mEmptyBuffer, pos);
		}
		} else {
		// Log.v(TAG, "No slot");
		}
		} catch (IOException ex) {
		Log.v(TAG, "Got exception checking file magic: ", ex);
		} catch (RuntimeException ex) {
		// Other NIO related exception like disk full, read only channel..etc
		Log.e(TAG, "Got exception when reading magic, id = " + id +
		", disk full or mount read-only? " + ex.getClass());
		} finally {
		try {
		if (lock != null) lock.release();
		}
		catch (IOException ex) {
		// ignore it.
		}
		}
		} else {
		// Log.v(TAG, "No data file");
		}
		}

		public synchronized void saveMiniThumbToFile(byte[] data, long id, long magic)
		throws IOException {
		RandomAccessFile r = miniThumbDataFile();
		if (r == null) return;

		long pos = id * BYTES_PER_MINTHUMB;
		FileLock lock = null;
		try {
		if (data != null) {
		if (data.length > BYTES_PER_MINTHUMB - HEADER_SIZE) {
		// not enough space to store it.
		return;
		}
		mBuffer.clear();
		mBuffer.put((byte) 1);
		mBuffer.putLong(magic);
		mBuffer.putInt(data.length);
		mBuffer.put(data);
		mBuffer.flip();

		lock = mChannel.lock(pos, BYTES_PER_MINTHUMB, false);
		mChannel.write(mBuffer, pos);
		}
		} catch (IOException ex) {
		Log.e(TAG, "couldn't save mini thumbnail data for "
		+ id + "; ", ex);
		throw ex;
		} catch (RuntimeException ex) {
		// Other NIO related exception like disk full, read only channel..etc
		Log.e(TAG, "couldn't save mini thumbnail data for "
		+ id + "; disk full or mount read-only? " + ex.getClass());
		} finally {
		try {
		if (lock != null) lock.release();
		}
		catch (IOException ex) {
		// ignore it.
		}
		}
		}

		/**
		* Gallery app can use this method to retrieve mini-thumbnail. Full size
		* images share the same IDs with their corresponding thumbnails.
		*
		* @param id the ID of the image (same of full size image).
		* @param data the buffer to store mini-thumbnail.
		*/
		public synchronized byte [] getMiniThumbFromFile(long id, byte [] data) {
		RandomAccessFile r = miniThumbDataFile();
		if (r == null) return null;

		long pos = id * BYTES_PER_MINTHUMB;
		FileLock lock = null;
		try {
		mBuffer.clear();
		lock = mChannel.lock(pos, BYTES_PER_MINTHUMB, true);
		int size = mChannel.read(mBuffer, pos);
		if (size > 1 + 8 + 4) { // flag, magic, length
		mBuffer.position(0);
		byte flag = mBuffer.get();
		long magic = mBuffer.getLong();
		int length = mBuffer.getInt();

		if (size >= 1 + 8 + 4 + length && length != 0 && magic != 0 && flag == 1 &&
		data.length >= length) {
		mBuffer.get(data, 0, length);
		return data;
		}
		}
		} catch (IOException ex) {
		Log.w(TAG, "got exception when reading thumbnail id=" + id + ", exception: " + ex);
		} catch (RuntimeException ex) {
		// Other NIO related exception like disk full, read only channel..etc
		Log.e(TAG, "Got exception when reading thumbnail, id = " + id +
		", disk full or mount read-only? " + ex.getClass());
		} finally {
		try {
		if (lock != null) lock.release();
		}
		catch (IOException ex) {
		// ignore it.
		}
		}
		return null;
		}
		}