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revert recent changes 

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1887682 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
PJ Fanning 2021-03-15 18:21:37 +00:00
parent 08a88d6a68
commit bfa026e35f
1 changed files with 30 additions and 68 deletions
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98
src/java/org/apache/poi/poifs/filesystem/POIFSStream.java
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@ -32,28 +32,29 @@ import org.apache.poi.poifs.storage.HeaderBlock;
/**
* This handles reading and writing a stream within a
* {@link POIFSFileSystem}. It can supply an iterator
* to read blocks, and way to write out to existing and
* new blocks.
* {@link POIFSFileSystem}. It can supply an iterator
* to read blocks, and way to write out to existing and
* new blocks.
* Most users will want a higher level version of this,
* which deals with properties to track which stream
* this is.
* which deals with properties to track which stream
* this is.
* This only works on big block streams, it doesn't
* handle small block ones.
* handle small block ones.
* This uses the new NIO code
* <p>
*
* TODO Implement a streaming write method, and append
*/
public class POIFSStream implements Iterable<ByteBuffer> {
public class POIFSStream implements Iterable<ByteBuffer>
{
private final BlockStore blockStore;
private int startBlock;
private OutputStream outStream;
/**
* Constructor for an existing stream. It's up to you
* to know how to get the start block (eg from a
* {@link HeaderBlock} or a {@link Property})
* to know how to get the start block (eg from a
* {@link HeaderBlock} or a {@link Property})
*/
public POIFSStream(BlockStore blockStore, int startBlock) {
this.blockStore = blockStore;
@ -62,7 +63,7 @@ public class POIFSStream implements Iterable<ByteBuffer> {
/**
* Constructor for a new stream. A start block won't
* be allocated until you begin writing to it.
* be allocated until you begin writing to it.
*/
public POIFSStream(BlockStore blockStore) {
this.blockStore = blockStore;
@ -72,7 +73,7 @@ public class POIFSStream implements Iterable<ByteBuffer> {
/**
* What block does this stream start at?
* Will be {@link POIFSConstants#END_OF_CHAIN} for a
* new stream that hasn't been written to yet.
* new stream that hasn't been written to yet.
*/
public int getStartBlock() {
return startBlock;
@ -80,14 +81,14 @@ public class POIFSStream implements Iterable<ByteBuffer> {
/**
* Returns an iterator that'll supply one {@link ByteBuffer}
* per block in the stream.
* per block in the stream.
*/
public Iterator<ByteBuffer> iterator() {
return getBlockIterator();
}
Iterator<ByteBuffer> getBlockIterator() {
if (startBlock == POIFSConstants.END_OF_CHAIN) {
if(startBlock == POIFSConstants.END_OF_CHAIN) {
throw new IllegalStateException(
"Can't read from a new stream before it has been written to"
);
@ -95,20 +96,11 @@ public class POIFSStream implements Iterable<ByteBuffer> {
return new StreamBlockByteBufferIterator(startBlock);
}
Iterator<Integer> getBlockOffsetIterator() {
if (startBlock == POIFSConstants.END_OF_CHAIN) {
throw new IllegalStateException(
"Can't read from a new stream before it has been written to"
);
}
return new StreamBlockOffsetIterator(startBlock);
}
/**
* Updates the contents of the stream to the new
* set of bytes.
* set of bytes.
* Note - if this is property based, you'll still
* need to update the size in the property yourself
* need to update the size in the property yourself
*/
void updateContents(byte[] contents) throws IOException {
OutputStream os = getOutputStream();
@ -134,10 +126,9 @@ public class POIFSStream implements Iterable<ByteBuffer> {
ChainLoopDetector loopDetector = blockStore.getChainLoopDetector();
free(loopDetector);
}
private void free(ChainLoopDetector loopDetector) {
int nextBlock = startBlock;
while (nextBlock != POIFSConstants.END_OF_CHAIN) {
while(nextBlock != POIFSConstants.END_OF_CHAIN) {
int thisBlock = nextBlock;
loopDetector.claim(thisBlock);
nextBlock = blockStore.getNextBlock(thisBlock);
@ -149,15 +140,15 @@ public class POIFSStream implements Iterable<ByteBuffer> {
/**
* Class that handles a streaming read of one stream
*/
private class StreamBlockOffsetIterator implements Iterator<Integer> {
private class StreamBlockByteBufferIterator implements Iterator<ByteBuffer> {
private final ChainLoopDetector loopDetector;
private int nextBlock;
StreamBlockOffsetIterator(int firstBlock) {
StreamBlockByteBufferIterator(int firstBlock) {
this.nextBlock = firstBlock;
try {
this.loopDetector = blockStore.getChainLoopDetector();
} catch (IOException e) {
} catch(IOException e) {
throw new RuntimeException(e);
}
}
@ -166,44 +157,17 @@ public class POIFSStream implements Iterable<ByteBuffer> {
return nextBlock != POIFSConstants.END_OF_CHAIN;
}
public Integer next() {
if (!hasNext()) {
throw new NoSuchElementException("Can't read past the end of the stream");
}
loopDetector.claim(nextBlock);
int currentBlock = nextBlock;
nextBlock = blockStore.getNextBlock(nextBlock);
return currentBlock;
}
public void remove() {
throw new UnsupportedOperationException();
}
}
/**
* Class that handles a streaming read of one stream
*/
private class StreamBlockByteBufferIterator implements Iterator<ByteBuffer> {
private final StreamBlockOffsetIterator offsetIterator;
StreamBlockByteBufferIterator(int firstBlock) {
offsetIterator = new StreamBlockOffsetIterator(firstBlock);
}
public boolean hasNext() {
return offsetIterator.hasNext();
}
public ByteBuffer next() {
if (!hasNext()) {
throw new NoSuchElementException("Can't read past the end of the stream");
}
try {
return blockStore.getBlockAt(offsetIterator.next());
} catch (IOException e) {
loopDetector.claim(nextBlock);
ByteBuffer data = blockStore.getBlockAt(nextBlock);
nextBlock = blockStore.getNextBlock(nextBlock);
return data;
} catch(IOException e) {
throw new RuntimeException(e);
}
}
@ -213,7 +177,6 @@ public class POIFSStream implements Iterable<ByteBuffer> {
}
}
protected class StreamBlockByteBuffer extends OutputStream {
byte[] oneByte = new byte[1];
ByteBuffer buffer;
@ -235,7 +198,7 @@ public class POIFSStream implements Iterable<ByteBuffer> {
// Allocate a block if needed, otherwise figure
// out what the next block will be
if (thisBlock == POIFSConstants.END_OF_CHAIN) {
if(thisBlock == POIFSConstants.END_OF_CHAIN) {
thisBlock = blockStore.getFreeBlock();
loopDetector.claim(thisBlock);
@ -243,14 +206,14 @@ public class POIFSStream implements Iterable<ByteBuffer> {
nextBlock = POIFSConstants.END_OF_CHAIN;
// Mark the previous block as carrying on to us if needed
if (prevBlock != POIFSConstants.END_OF_CHAIN) {
if(prevBlock != POIFSConstants.END_OF_CHAIN) {
blockStore.setNextBlock(prevBlock, thisBlock);
}
blockStore.setNextBlock(thisBlock, POIFSConstants.END_OF_CHAIN);
// If we've just written the first block on a
// new stream, save the start block offset
if (startBlock == POIFSConstants.END_OF_CHAIN) {
if(startBlock == POIFSConstants.END_OF_CHAIN) {
startBlock = thisBlock;
}
} else {
@ -269,7 +232,7 @@ public class POIFSStream implements Iterable<ByteBuffer> {
@Override
public void write(int b) throws IOException {
oneByte[0] = (byte) (b & 0xFF);
oneByte[0] = (byte)(b & 0xFF);
write(oneByte);
}
@ -303,4 +266,3 @@ public class POIFSStream implements Iterable<ByteBuffer> {
}
}
}