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Merge change Ide90d0cc into eclair

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* changes:
  Unify Java NIO to read/write MiniThumbFile.
This commit is contained in:
Android (Google) Code Review
2009-09-29 16:24:22 -04:00
parent 4fbf81bc94 ecc97cc949
commit 0167263bf4
1 changed files with 33 additions and 37 deletions
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70
media/java/android/media/MiniThumbFile.java
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@@ -25,6 +25,7 @@ import android.util.Log;
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;
@@ -44,12 +45,6 @@ import java.util.Hashtable;
* only.
*/
public class MiniThumbFile {
public static final int THUMBNAIL_TARGET_SIZE = 320;
public static final int MINI_THUMB_TARGET_SIZE = 96;
public static final int THUMBNAIL_MAX_NUM_PIXELS = 512 * 384;
public static final int MINI_THUMB_MAX_NUM_PIXELS = 128 * 128;
public static final int UNCONSTRAINED = -1;
private static final String TAG = "MiniThumbFile";
private static final int MINI_THUMB_DATA_FILE_VERSION = 3;
public static final int BYTES_PER_MINTHUMB = 10000;
@@ -57,6 +52,7 @@ public class MiniThumbFile {
private Uri mUri;
private RandomAccessFile mMiniThumbFile;
private FileChannel mChannel;
private ByteBuffer mBuffer;
private static Hashtable<String, MiniThumbFile> sThumbFiles =
new Hashtable<String, MiniThumbFile>();
@@ -130,6 +126,7 @@ public class MiniThumbFile {
public MiniThumbFile(Uri uri) {
mUri = uri;
mBuffer = ByteBuffer.allocateDirect(BYTES_PER_MINTHUMB);
}
public synchronized void deactivate() {
@@ -154,14 +151,16 @@ public class MiniThumbFile {
long pos = id * BYTES_PER_MINTHUMB;
FileLock lock = null;
try {
lock = mChannel.lock();
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 (r.length() >= pos + 1 + 8) {
r.seek(pos);
if (r.readByte() == 1) {
long fileMagic = r.readLong();
return fileMagic;
if (mChannel.read(mBuffer, pos) == 9) {
mBuffer.position(0);
if (mBuffer.get() == 1) {
return mBuffer.getLong();
}
}
} catch (IOException ex) {
@@ -196,25 +195,20 @@ public class MiniThumbFile {
long pos = id * BYTES_PER_MINTHUMB;
FileLock lock = null;
try {
lock = mChannel.lock();
if (data != null) {
if (data.length > BYTES_PER_MINTHUMB - HEADER_SIZE) {
// not enough space to store it.
return;
}
r.seek(pos);
r.writeByte(0); // we have no data in this slot
mBuffer.clear();
mBuffer.put((byte) 1);
mBuffer.putLong(magic);
mBuffer.putInt(data.length);
mBuffer.put(data);
mBuffer.flip();
// if magic is 0 then leave it alone
if (magic == 0) {
r.skipBytes(8);
} else {
r.writeLong(magic);
}
r.writeInt(data.length);
r.write(data);
r.seek(pos);
r.writeByte(1); // we have data in this slot
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 "
@@ -248,20 +242,22 @@ public class MiniThumbFile {
long pos = id * BYTES_PER_MINTHUMB;
FileLock lock = null;
try {
lock = mChannel.lock();
r.seek(pos);
if (r.readByte() == 1) {
long magic = r.readLong();
int length = r.readInt();
int got = r.read(data, 0, length);
if (got != length) return null;
return data;
} else {
return null;
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 && data.length >= length) {
mBuffer.get(data, 0, length);
return data;
}
}
} catch (IOException ex) {
Log.w(TAG, "got exception when reading thumbnail: " + ex);
return null;
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 +