hadoop DataBlocks 源码
haddop DataBlocks 代码
文件路径：/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/store/DataBlocks.java
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.hadoop.fs.store;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.EOFException;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.hadoop.util.Preconditions;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeys;
import org.apache.hadoop.fs.FSExceptionMessages;
import org.apache.hadoop.fs.LocalDirAllocator;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.util.DirectBufferPool;
import static java.util.Objects.requireNonNull;
import static org.apache.hadoop.fs.CommonConfigurationKeys.HADOOP_TMP_DIR;
import static org.apache.hadoop.fs.store.DataBlocks.DataBlock.DestState.Closed;
import static org.apache.hadoop.fs.store.DataBlocks.DataBlock.DestState.Upload;
import static org.apache.hadoop.fs.store.DataBlocks.DataBlock.DestState.Writing;
import static org.apache.hadoop.io.IOUtils.cleanupWithLogger;
/**
* A class to provide disk, byteBuffer and byteArray option for Filesystem
* OutputStreams.
* <ul>
* <li>
* Disk: Uses Disk space to write the blocks. Is suited best to avoid
* OutOfMemory Errors in Java heap space.
* </li>
* <li>
* byteBuffer: Uses DirectByteBuffer to allocate memory off-heap to
* provide faster writing of DataBlocks with some risk of running
* OutOfMemory.
* </li>
* <li>
* byteArray: Uses byte[] to write a block of data. On heap and does have
* risk of running OutOfMemory fairly easily.
* </li>
* </ul>
* <p>
* Implementation of DataBlocks taken from HADOOP-13560 to support huge file
* uploads in S3A with different options rather than one.
*/
public final class DataBlocks {
private static final Logger LOG =
LoggerFactory.getLogger(DataBlocks.class);
/**
* Buffer blocks to disk.
* Capacity is limited to available disk space.
*/
public static final String DATA_BLOCKS_BUFFER_DISK = "disk";
/**
* Use a byte buffer.
*/
public static final String DATA_BLOCKS_BYTEBUFFER = "bytebuffer";
/**
* Use an in-memory array. Fast but will run of heap rapidly.
*/
public static final String DATA_BLOCKS_BUFFER_ARRAY = "array";
private DataBlocks() {
}
/**
* Validate args to a write command. These are the same validation checks
* expected for any implementation of {@code OutputStream.write()}.
*
* @param b byte array containing data.
* @param off offset in array where to start.
* @param len number of bytes to be written.
* @throws NullPointerException for a null buffer
* @throws IndexOutOfBoundsException if indices are out of range
* @throws IOException raised on errors performing I/O.
*/
public static void validateWriteArgs(byte[] b, int off, int len)
throws IOException {
Preconditions.checkNotNull(b);
if ((off < 0) || (off > b.length) || (len < 0) ||
((off + len) > b.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException(
"write (b[" + b.length + "], " + off + ", " + len + ')');
}
}
/**
* Create a factory.
*
* @param keyToBufferDir Key to buffer directory config for a FS.
* @param configuration factory configurations.
* @param name factory name -the option from {@link CommonConfigurationKeys}.
* @return the factory, ready to be initialized.
* @throws IllegalArgumentException if the name is unknown.
*/
public static BlockFactory createFactory(String keyToBufferDir,
Configuration configuration,
String name) {
LOG.debug("Creating DataFactory of type : {}", name);
switch (name) {
case DATA_BLOCKS_BUFFER_ARRAY:
return new ArrayBlockFactory(keyToBufferDir, configuration);
case DATA_BLOCKS_BUFFER_DISK:
return new DiskBlockFactory(keyToBufferDir, configuration);
case DATA_BLOCKS_BYTEBUFFER:
return new ByteBufferBlockFactory(keyToBufferDir, configuration);
default:
throw new IllegalArgumentException("Unsupported block buffer" +
" \"" + name + '"');
}
}
/**
* The output information for an upload.
* It can be one of a file, an input stream or a byteArray.
* {@link #toByteArray()} method to be used to convert the data into byte
* array to be done in this class as well.
* When closed, any stream is closed. Any source file is untouched.
*/
public static final class BlockUploadData implements Closeable {
private final File file;
private InputStream uploadStream;
private byte[] byteArray;
private boolean isClosed;
/**
* Constructor for byteArray upload data block. File and uploadStream
* would be null.
*
* @param byteArray byteArray used to construct BlockUploadData.
*/
public BlockUploadData(byte[] byteArray) {
this.file = null;
this.uploadStream = null;
this.byteArray = requireNonNull(byteArray);
}
/**
* File constructor; input stream and byteArray will be null.
*
* @param file file to upload
*/
BlockUploadData(File file) {
Preconditions.checkArgument(file.exists(), "No file: %s", file);
this.file = file;
this.uploadStream = null;
this.byteArray = null;
}
/**
* Stream constructor, file and byteArray field will be null.
*
* @param uploadStream stream to upload.
*/
BlockUploadData(InputStream uploadStream) {
requireNonNull(uploadStream, "rawUploadStream");
this.uploadStream = uploadStream;
this.file = null;
this.byteArray = null;
}
/**
* Predicate: does this instance contain a file reference.
*
* @return true if there is a file.
*/
boolean hasFile() {
return file != null;
}
/**
* Get the file, if there is one.
*
* @return the file for uploading, or null.
*/
File getFile() {
return file;
}
/**
* Get the raw upload stream, if the object was
* created with one.
*
* @return the upload stream or null.
*/
InputStream getUploadStream() {
return uploadStream;
}
/**
* Convert to a byte array.
* If the data is stored in a file, it will be read and returned.
* If the data was passed in via an input stream (which happens if the
* data is stored in a bytebuffer) then it will be converted to a byte
* array -which will then be cached for any subsequent use.
*
* @return byte[] after converting the uploadBlock.
* @throws IOException throw if an exception is caught while reading
* File/InputStream or closing InputStream.
*/
public byte[] toByteArray() throws IOException {
Preconditions.checkState(!isClosed, "Block is closed");
if (byteArray != null) {
return byteArray;
}
if (file != null) {
// Need to save byteArray here so that we don't read File if
// byteArray() is called more than once on the same file.
byteArray = FileUtils.readFileToByteArray(file);
return byteArray;
}
byteArray = IOUtils.toByteArray(uploadStream);
IOUtils.close(uploadStream);
uploadStream = null;
return byteArray;
}
/**
* Close: closes any upload stream and byteArray provided in the
* constructor.
*
* @throws IOException inherited exception.
*/
@Override
public void close() throws IOException {
isClosed = true;
cleanupWithLogger(LOG, uploadStream);
byteArray = null;
if (file != null) {
LOG.debug("File deleted in BlockUploadData close: {}", file.delete());
}
}
}
/**
* Base class for block factories.
*/
public static abstract class BlockFactory implements Closeable {
private final String keyToBufferDir;
private final Configuration conf;
protected BlockFactory(String keyToBufferDir, Configuration conf) {
this.keyToBufferDir = keyToBufferDir;
this.conf = conf;
}
/**
* Create a block.
*
* @param index index of block
* @param limit limit of the block.
* @param statistics stats to work with
* @return a new block.
* @throws IOException raised on errors performing I/O.
*/
public abstract DataBlock create(long index, int limit,
BlockUploadStatistics statistics)
throws IOException;
/**
* Implement any close/cleanup operation.
* Base class is a no-op.
*
* @throws IOException Inherited exception; implementations should
* avoid raising it.
*/
@Override
public void close() throws IOException {
}
/**
* Configuration.
*
* @return config passed to create the factory.
*/
protected Configuration getConf() {
return conf;
}
/**
* Key to Buffer Directory config for a FS instance.
*
* @return String containing key to Buffer dir.
*/
public String getKeyToBufferDir() {
return keyToBufferDir;
}
}
/**
* This represents a block being uploaded.
*/
public static abstract class DataBlock implements Closeable {
enum DestState {Writing, Upload, Closed}
private volatile DestState state = Writing;
private final long index;
private final BlockUploadStatistics statistics;
protected DataBlock(long index,
BlockUploadStatistics statistics) {
this.index = index;
this.statistics = statistics;
}
/**
* Atomically enter a state, verifying current state.
*
* @param current current state. null means "no check"
* @param next next state
* @throws IllegalStateException if the current state is not as expected
*/
protected synchronized final void enterState(DestState current,
DestState next)
throws IllegalStateException {
verifyState(current);
LOG.debug("{}: entering state {}", this, next);
state = next;
}
/**
* Verify that the block is in the declared state.
*
* @param expected expected state.
* @throws IllegalStateException if the DataBlock is in the wrong state
*/
protected final void verifyState(DestState expected)
throws IllegalStateException {
if (expected != null && state != expected) {
throw new IllegalStateException("Expected stream state " + expected
+ " -but actual state is " + state + " in " + this);
}
}
/**
* Current state.
*
* @return the current state.
*/
final DestState getState() {
return state;
}
/**
* Return the current data size.
*
* @return the size of the data.
*/
public abstract int dataSize();
/**
* Predicate to verify that the block has the capacity to write
* the given set of bytes.
*
* @param bytes number of bytes desired to be written.
* @return true if there is enough space.
*/
abstract boolean hasCapacity(long bytes);
/**
* Predicate to check if there is data in the block.
*
* @return true if there is
*/
public boolean hasData() {
return dataSize() > 0;
}
/**
* The remaining capacity in the block before it is full.
*
* @return the number of bytes remaining.
*/
public abstract int remainingCapacity();
/**
* Write a series of bytes from the buffer, from the offset.
* Returns the number of bytes written.
* Only valid in the state {@code Writing}.
* Base class verifies the state but does no writing.
*
* @param buffer buffer.
* @param offset offset.
* @param length length of write.
* @return number of bytes written.
* @throws IOException trouble
*/
public int write(byte[] buffer, int offset, int length) throws IOException {
verifyState(Writing);
Preconditions.checkArgument(buffer != null, "Null buffer");
Preconditions.checkArgument(length >= 0, "length is negative");
Preconditions.checkArgument(offset >= 0, "offset is negative");
Preconditions.checkArgument(
!(buffer.length - offset < length),
"buffer shorter than amount of data to write");
return 0;
}
/**
* Flush the output.
* Only valid in the state {@code Writing}.
* In the base class, this is a no-op
*
* @throws IOException any IO problem.
*/
public void flush() throws IOException {
verifyState(Writing);
}
/**
* Switch to the upload state and return a stream for uploading.
* Base class calls {@link #enterState(DestState, DestState)} to
* manage the state machine.
*
* @return the stream.
* @throws IOException trouble
*/
public BlockUploadData startUpload() throws IOException {
LOG.debug("Start datablock[{}] upload", index);
enterState(Writing, Upload);
return null;
}
/**
* Enter the closed state.
*
* @return true if the class was in any other state, implying that
* the subclass should do its close operations.
*/
protected synchronized boolean enterClosedState() {
if (!state.equals(Closed)) {
enterState(null, Closed);
return true;
} else {
return false;
}
}
@Override
public void close() throws IOException {
if (enterClosedState()) {
LOG.debug("Closed {}", this);
innerClose();
}
}
/**
* Inner close logic for subclasses to implement.
*
* @throws IOException raised on errors performing I/O.
*/
protected void innerClose() throws IOException {
}
/**
* A block has been allocated.
*/
protected void blockAllocated() {
if (statistics != null) {
statistics.blockAllocated();
}
}
/**
* A block has been released.
*/
protected void blockReleased() {
if (statistics != null) {
statistics.blockReleased();
}
}
protected BlockUploadStatistics getStatistics() {
return statistics;
}
public long getIndex() {
return index;
}
}
// ====================================================================
/**
* Use byte arrays on the heap for storage.
*/
static class ArrayBlockFactory extends BlockFactory {
ArrayBlockFactory(String keyToBufferDir, Configuration conf) {
super(keyToBufferDir, conf);
}
@Override
public DataBlock create(long index, int limit,
BlockUploadStatistics statistics)
throws IOException {
return new ByteArrayBlock(0, limit, statistics);
}
}
static class DataBlockByteArrayOutputStream extends ByteArrayOutputStream {
DataBlockByteArrayOutputStream(int size) {
super(size);
}
/**
* InputStream backed by the internal byte array.
*
* @return ByteArrayInputStream instance.
*/
ByteArrayInputStream getInputStream() {
ByteArrayInputStream bin = new ByteArrayInputStream(this.buf, 0, count);
this.reset();
this.buf = null;
return bin;
}
}
/**
* Stream to memory via a {@code ByteArrayOutputStream}.
* <p>
* It can consume a lot of heap space
* proportional to the mismatch between writes to the stream and
* the JVM-wide upload bandwidth to a Store's endpoint.
* The memory consumption can be limited by tuning the filesystem settings
* to restrict the number of queued/active uploads.
*/
static class ByteArrayBlock extends DataBlock {
private DataBlockByteArrayOutputStream buffer;
private final int limit;
// cache data size so that it is consistent after the buffer is reset.
private Integer dataSize;
ByteArrayBlock(long index,
int limit,
BlockUploadStatistics statistics) {
super(index, statistics);
this.limit = limit;
this.buffer = new DataBlockByteArrayOutputStream(limit);
blockAllocated();
}
/**
* Get the amount of data; if there is no buffer then the size is 0.
*
* @return the amount of data available to upload.
*/
@Override
public int dataSize() {
return dataSize != null ? dataSize : buffer.size();
}
@Override
public BlockUploadData startUpload() throws IOException {
super.startUpload();
dataSize = buffer.size();
ByteArrayInputStream bufferData = buffer.getInputStream();
buffer = null;
return new BlockUploadData(bufferData);
}
@Override
boolean hasCapacity(long bytes) {
return dataSize() + bytes <= limit;
}
@Override
public int remainingCapacity() {
return limit - dataSize();
}
@Override
public int write(byte[] b, int offset, int len) throws IOException {
super.write(b, offset, len);
int written = Math.min(remainingCapacity(), len);
buffer.write(b, offset, written);
return written;
}
@Override
protected void innerClose() {
buffer = null;
blockReleased();
}
@Override
public String toString() {
return "ByteArrayBlock{"
+ "index=" + getIndex() +
", state=" + getState() +
", limit=" + limit +
", dataSize=" + dataSize +
'}';
}
}
// ====================================================================
/**
* Stream via Direct ByteBuffers; these are allocated off heap
* via {@link DirectBufferPool}.
*/
static class ByteBufferBlockFactory extends BlockFactory {
private final DirectBufferPool bufferPool = new DirectBufferPool();
private final AtomicInteger buffersOutstanding = new AtomicInteger(0);
ByteBufferBlockFactory(String keyToBufferDir, Configuration conf) {
super(keyToBufferDir, conf);
}
@Override public ByteBufferBlock create(long index, int limit,
BlockUploadStatistics statistics)
throws IOException {
return new ByteBufferBlock(index, limit, statistics);
}
private ByteBuffer requestBuffer(int limit) {
LOG.debug("Requesting buffer of size {}", limit);
buffersOutstanding.incrementAndGet();
return bufferPool.getBuffer(limit);
}
private void releaseBuffer(ByteBuffer buffer) {
LOG.debug("Releasing buffer");
bufferPool.returnBuffer(buffer);
buffersOutstanding.decrementAndGet();
}
/**
* Get count of outstanding buffers.
*
* @return the current buffer count.
*/
public int getOutstandingBufferCount() {
return buffersOutstanding.get();
}
@Override
public String toString() {
return "ByteBufferBlockFactory{"
+ "buffersOutstanding=" + buffersOutstanding +
'}';
}
/**
* A DataBlock which requests a buffer from pool on creation; returns
* it when it is closed.
*/
class ByteBufferBlock extends DataBlock {
private ByteBuffer blockBuffer;
private final int bufferSize;
// cache data size so that it is consistent after the buffer is reset.
private Integer dataSize;
/**
* Instantiate. This will request a ByteBuffer of the desired size.
*
* @param index block index.
* @param bufferSize buffer size.
* @param statistics statistics to update.
*/
ByteBufferBlock(long index,
int bufferSize,
BlockUploadStatistics statistics) {
super(index, statistics);
this.bufferSize = bufferSize;
this.blockBuffer = requestBuffer(bufferSize);
blockAllocated();
}
/**
* Get the amount of data; if there is no buffer then the size is 0.
*
* @return the amount of data available to upload.
*/
@Override public int dataSize() {
return dataSize != null ? dataSize : bufferCapacityUsed();
}
@Override
public BlockUploadData startUpload() throws IOException {
super.startUpload();
dataSize = bufferCapacityUsed();
// set the buffer up from reading from the beginning
blockBuffer.limit(blockBuffer.position());
blockBuffer.position(0);
return new BlockUploadData(
new ByteBufferInputStream(dataSize, blockBuffer));
}
@Override
public boolean hasCapacity(long bytes) {
return bytes <= remainingCapacity();
}
@Override
public int remainingCapacity() {
return blockBuffer != null ? blockBuffer.remaining() : 0;
}
private int bufferCapacityUsed() {
return blockBuffer.capacity() - blockBuffer.remaining();
}
@Override
public int write(byte[] b, int offset, int len) throws IOException {
super.write(b, offset, len);
int written = Math.min(remainingCapacity(), len);
blockBuffer.put(b, offset, written);
return written;
}
/**
* Closing the block will release the buffer.
*/
@Override
protected void innerClose() {
if (blockBuffer != null) {
blockReleased();
releaseBuffer(blockBuffer);
blockBuffer = null;
}
}
@Override
public String toString() {
return "ByteBufferBlock{"
+ "index=" + getIndex() +
", state=" + getState() +
", dataSize=" + dataSize() +
", limit=" + bufferSize +
", remainingCapacity=" + remainingCapacity() +
'}';
}
/**
* Provide an input stream from a byte buffer; supporting
* {@link #mark(int)}, which is required to enable replay of failed
* PUT attempts.
*/
class ByteBufferInputStream extends InputStream {
private final int size;
private ByteBuffer byteBuffer;
ByteBufferInputStream(int size,
ByteBuffer byteBuffer) {
LOG.debug("Creating ByteBufferInputStream of size {}", size);
this.size = size;
this.byteBuffer = byteBuffer;
}
/**
* After the stream is closed, set the local reference to the byte
* buffer to null; this guarantees that future attempts to use
* stream methods will fail.
*/
@Override
public synchronized void close() {
LOG.debug("ByteBufferInputStream.close() for {}",
ByteBufferBlock.super.toString());
byteBuffer = null;
}
/**
* Verify that the stream is open.
*
* @throws IOException if the stream is closed
*/
private void verifyOpen() throws IOException {
if (byteBuffer == null) {
throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
}
}
public synchronized int read() throws IOException {
if (available() > 0) {
return byteBuffer.get() & 0xFF;
} else {
return -1;
}
}
@Override
public synchronized long skip(long offset) throws IOException {
verifyOpen();
long newPos = position() + offset;
if (newPos < 0) {
throw new EOFException(FSExceptionMessages.NEGATIVE_SEEK);
}
if (newPos > size) {
throw new EOFException(FSExceptionMessages.CANNOT_SEEK_PAST_EOF);
}
byteBuffer.position((int) newPos);
return newPos;
}
@Override
public synchronized int available() {
Preconditions.checkState(byteBuffer != null,
FSExceptionMessages.STREAM_IS_CLOSED);
return byteBuffer.remaining();
}
/**
* Get the current buffer position.
*
* @return the buffer position
*/
public synchronized int position() {
return byteBuffer.position();
}
/**
* Check if there is data left.
*
* @return true if there is data remaining in the buffer.
*/
public synchronized boolean hasRemaining() {
return byteBuffer.hasRemaining();
}
@Override
public synchronized void mark(int readlimit) {
LOG.debug("mark at {}", position());
byteBuffer.mark();
}
@Override
public synchronized void reset() throws IOException {
LOG.debug("reset");
byteBuffer.reset();
}
@Override
public boolean markSupported() {
return true;
}
/**
* Read in data.
*
* @param b destination buffer.
* @param offset offset within the buffer.
* @param length length of bytes to read.
* @throws EOFException if the position is negative
* @throws IndexOutOfBoundsException if there isn't space for the
* amount of data requested.
* @throws IllegalArgumentException other arguments are invalid.
*/
@SuppressWarnings("NullableProblems")
public synchronized int read(byte[] b, int offset, int length)
throws IOException {
Preconditions.checkArgument(length >= 0, "length is negative");
Preconditions.checkArgument(b != null, "Null buffer");
if (b.length - offset < length) {
throw new IndexOutOfBoundsException(
FSExceptionMessages.TOO_MANY_BYTES_FOR_DEST_BUFFER
+ ": request length =" + length
+ ", with offset =" + offset
+ "; buffer capacity =" + (b.length - offset));
}
verifyOpen();
if (!hasRemaining()) {
return -1;
}
int toRead = Math.min(length, available());
byteBuffer.get(b, offset, toRead);
return toRead;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder(
"ByteBufferInputStream{");
sb.append("size=").append(size);
ByteBuffer buf = this.byteBuffer;
if (buf != null) {
sb.append(", available=").append(buf.remaining());
}
sb.append(", ").append(ByteBufferBlock.super.toString());
sb.append('}');
return sb.toString();
}
}
}
}
// ====================================================================
/**
* Buffer blocks to disk.
*/
static class DiskBlockFactory extends BlockFactory {
private LocalDirAllocator directoryAllocator;
DiskBlockFactory(String keyToBufferDir, Configuration conf) {
super(keyToBufferDir, conf);
String bufferDir = conf.get(keyToBufferDir) != null
? keyToBufferDir : HADOOP_TMP_DIR;
directoryAllocator = new LocalDirAllocator(bufferDir);
}
/**
* Create a temp file and a {@link DiskBlock} instance to manage it.
*
* @param index block index.
* @param limit limit of the block.
* @param statistics statistics to update.
* @return the new block.
* @throws IOException IO problems
*/
@Override
public DataBlock create(long index,
int limit,
BlockUploadStatistics statistics)
throws IOException {
File destFile = createTmpFileForWrite(String.format("datablock-%04d-",
index),
limit, getConf());
return new DiskBlock(destFile, limit, index, statistics);
}
/**
* Demand create the directory allocator, then create a temporary file.
* This does not mark the file for deletion when a process exits.
* {@link LocalDirAllocator#createTmpFileForWrite(String, long, Configuration)}.
*
* @param pathStr prefix for the temporary file.
* @param size the size of the file that is going to be written.
* @param conf the Configuration object.
* @return a unique temporary file.
* @throws IOException IO problems
*/
File createTmpFileForWrite(String pathStr, long size,
Configuration conf) throws IOException {
Path path = directoryAllocator.getLocalPathForWrite(pathStr,
size, conf);
File dir = new File(path.getParent().toUri().getPath());
String prefix = path.getName();
// create a temp file on this directory
return File.createTempFile(prefix, null, dir);
}
}
/**
* Stream to a file.
* This will stop at the limit; the caller is expected to create a new block.
*/
static class DiskBlock extends DataBlock {
private int bytesWritten;
private final File bufferFile;
private final int limit;
private BufferedOutputStream out;
private final AtomicBoolean closed = new AtomicBoolean(false);
DiskBlock(File bufferFile,
int limit,
long index,
BlockUploadStatistics statistics)
throws FileNotFoundException {
super(index, statistics);
this.limit = limit;
this.bufferFile = bufferFile;
blockAllocated();
out = new BufferedOutputStream(new FileOutputStream(bufferFile));
}
@Override public int dataSize() {
return bytesWritten;
}
@Override
boolean hasCapacity(long bytes) {
return dataSize() + bytes <= limit;
}
@Override public int remainingCapacity() {
return limit - bytesWritten;
}
@Override
public int write(byte[] b, int offset, int len) throws IOException {
super.write(b, offset, len);
int written = Math.min(remainingCapacity(), len);
out.write(b, offset, written);
bytesWritten += written;
return written;
}
@Override
public BlockUploadData startUpload() throws IOException {
super.startUpload();
try {
out.flush();
} finally {
out.close();
out = null;
}
return new BlockUploadData(bufferFile);
}
/**
* The close operation will delete the destination file if it still
* exists.
*
* @throws IOException IO problems
*/
@SuppressWarnings("UnnecessaryDefault")
@Override
protected void innerClose() throws IOException {
final DestState state = getState();
LOG.debug("Closing {}", this);
switch (state) {
case Writing:
if (bufferFile.exists()) {
// file was not uploaded
LOG.debug("Block[{}]: Deleting buffer file as upload did not start",
getIndex());
closeBlock();
}
break;
case Upload:
LOG.debug("Block[{}]: Buffer file {} exists —close upload stream",
getIndex(), bufferFile);
break;
case Closed:
closeBlock();
break;
default:
// this state can never be reached, but checkstyle complains, so
// it is here.
}
}
/**
* Flush operation will flush to disk.
*
* @throws IOException IOE raised on FileOutputStream
*/
@Override public void flush() throws IOException {
super.flush();
out.flush();
}
@Override
public String toString() {
String sb = "FileBlock{"
+ "index=" + getIndex()
+ ", destFile=" + bufferFile +
", state=" + getState() +
", dataSize=" + dataSize() +
", limit=" + limit +
'}';
return sb;
}
/**
* Close the block.
* This will delete the block's buffer file if the block has
* not previously been closed.
*/
void closeBlock() {
LOG.debug("block[{}]: closeBlock()", getIndex());
if (!closed.getAndSet(true)) {
blockReleased();
if (!bufferFile.delete() && bufferFile.exists()) {
LOG.warn("delete({}) returned false",
bufferFile.getAbsoluteFile());
}
} else {
LOG.debug("block[{}]: skipping re-entrant closeBlock()", getIndex());
}
}
}
}
相关信息
相关文章
0
赞
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
8、 golang
-
9、 openharmony
-
10、 Vue中input框自动聚焦