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/*
* Copyright 2007-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* or in the "license" file accompanying this file. This file 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.amazon.ion.impl;
import com.amazon.ion.IonException;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.SortedSet;
import java.util.TreeSet;
/**
* This implements a blocked byte buffer and both an input and output stream
* that operates over it. It is designed to be able to be randomly accessed.
* The output steam supports both inserting data (with "stretching") in the
* middle of the stream and over-write. The output steam also supports remove
* which shrinks the overall data buffer. The underlying buffer is backed by
* one or more byte arrays to minimize data movement.
*
* It is also meant to be reused, so that it does not have to pressure the
* GC, if that is desirable.
*/
final class BlockedBuffer
{
///////////////////////////////////////////////////////////////////////////////
//
// updatable, insertable, and possibly fragmented byte buffer
//
// these manage the set of memory (byte) buffers
ArrayList _blocks;
int _next_block_position; // next position in _blocks for active block, may be less than _blocks.size()
int _lastCapacity; // used to allocate new blocks
int _buf_limit; // high water mark of _position
int _version;
int _mutation_version;
Object _mutator;
// BUGBUG - this is just a test, it shouldn't be in checked in code
static final boolean test_with_no_version_checking = false;
void start_mutate(Object caller, int version) {
if (test_with_no_version_checking) return;
if (_mutation_version != 0 || _mutator != null)
throw new BlockedBufferException("lock conflict");
if (version != _version)
throw new BlockedBufferException("version conflict on update");
_mutator = caller;
_mutation_version = version;
}
int end_mutate(Object caller) {
if (test_with_no_version_checking) return _version;
if (_version != _mutation_version)
throw new BlockedBufferException("version mismatch failure");
if (caller != _mutator)
throw new BlockedBufferException("caller mismatch failure");
_version = _mutation_version + 1;
_mutation_version = 0;
_mutator = null;
return _version;
}
boolean mutation_in_progress(Object caller, int version) {
if (test_with_no_version_checking) return false;
if (_mutation_version != version)
throw new BlockedBufferException("unexpected update lock conflict");
if (caller != _mutator)
throw new BlockedBufferException("caller mismatch failure");
return true;
}
int getVersion() {
return _version;
}
static boolean debugValidation = false;
static int _defaultBlockSizeMin;
static int _defaultBlockSizeUpperLimit;
static {
resetParameters();
}
public static void resetParameters() {
debugValidation = false;
_defaultBlockSizeMin = 4096 * 8;
_defaultBlockSizeUpperLimit = 4096 * 8;
}
public int _blockSizeMin = _defaultBlockSizeMin;
public int _blockSizeUpperLimit = _defaultBlockSizeUpperLimit;
static void setBlockSizeParameters(int min, int max,
boolean intenseValidation) {
debugValidation = intenseValidation;
setBlockSizeParameters(min, max);
}
public static void setBlockSizeParameters(int min, int max) {
if (min < 0 || max < min) {
throw new IllegalArgumentException();
}
_defaultBlockSizeMin = min;
_defaultBlockSizeUpperLimit = max;
return;
}
///////////////////////////////////////////////////////////////////////////
/**
* Creates a new buffer without preallocating any space.
*/
public BlockedBuffer() {
start_mutate(this, 0);
init(0, null);
end_mutate(this);
}
/**
* Creates a new buffer, preallocating some initial capacity.
*
* @param initialSize the number of bytes to allocate.
*/
public BlockedBuffer(int initialSize) {
start_mutate(this, 0);
init(initialSize, null);
end_mutate(this);
}
/**
* Creates a new buffer, assuming ownership of given data.
* This method assumes ownership of the data array
* and will modify it at will.
*
* @param data the initial data to be buffered.
*
* @throws NullPointerException if buffer is null.
*/
public BlockedBuffer(byte[] data) {
start_mutate(this, 0);
init(0, new bbBlock(data));
_buf_limit = data.length;
end_mutate(this);
}
/**
* Creates a new buffer containing all data remaining on an
* {@link InputStream}. The stream is closed before returning.
*
* @param data must not be null.
*
* @throws IOException
*/
public BlockedBuffer(InputStream data)
throws IOException
{
IonBinary.Writer writer = new IonBinary.Writer(this);
try {
writer.write(data);
}
finally {
data.close();
}
}
/**
* creates a logical copy of the buffer. This does not preserve
* the position state and is equivalent to constructing a new
* buffer from the old by getting the bytes from the original
* and writing them to a new buffer.
*/
@Override
public BlockedBuffer clone()
{
BlockedBuffer clone = new BlockedBuffer(this._buf_limit);
int end = this._buf_limit;
bbBlock dst_block = clone._blocks.get(0);
int dst_offset = 0;
int dst_limit = dst_block.blockCapacity();
for (int ii=0; ii dst_limit - dst_offset) {
to_copy = dst_limit - dst_offset;
}
System.arraycopy(src_block._buffer, 0, dst_block._buffer, dst_offset, to_copy);
dst_offset += to_copy;
// the cloned BlockedBuffer should be able to hold all the data
// in it's single block
assert dst_offset <= dst_limit;
// see if we're done (and break out in that case)
if (src_end >= end) break;
}
dst_block._limit = dst_offset;
clone._buf_limit = dst_offset;
return clone;
}
/**
* Initializes the various members such as the block arraylist
* the initial block and the various values like the block size upper limit.
* @param initialSize or 0
* @param initialBlock or null
* @return bbBlock the initial current block
*/
private bbBlock init(int initialSize, bbBlock initialBlock)
{
this._lastCapacity = BlockedBuffer._defaultBlockSizeMin;
this._blockSizeUpperLimit = BlockedBuffer._defaultBlockSizeUpperLimit;
while (this._lastCapacity < initialSize &&
this._lastCapacity < this._blockSizeUpperLimit)
{
this.nextBlockSize(this, 0);
}
int count = initialSize / this._lastCapacity;
if (initialBlock != null) count = 1;
this._blocks = new ArrayList(count);
if (initialBlock == null) {
initialBlock = new bbBlock(this.nextBlockSize(this, 0));
}
this._blocks.add(initialBlock);
this._next_block_position = 1;
// create any preallocated blocks (following _next_block_position)
bbBlock b;
for (int need = initialSize - initialBlock.blockCapacity()
; need > 0
; need -= b.blockCapacity()
) {
b = new bbBlock(this.nextBlockSize(this, 0));
b._idx = -1;
this._blocks.add(b);
}
return initialBlock;
}
/**
* Gets the number of bytes of content in this buffer.
* This isn't the same as its capacity.
*/
public final int size() {
return _buf_limit;
}
/**
* empties the entire contents of the buffer
*/
private void clear(Object caller, int version) {
assert mutation_in_progress(caller, version);
_buf_limit = 0;
for (int ii=0; ii<_blocks.size(); ii++) {
_blocks.get(ii).clearBlock();
// _blocks.get(ii)._idx = -1; this is done in clearBlock()
}
bbBlock first = _blocks.get(0);
first._idx = 0; // cas: 26 dec 2008
first._offset = 0;
first._limit = 0;
_next_block_position = 1;
return;
}
/**
* treat the limit as the end of file
*/
bbBlock truncate(Object caller, int version, int pos) {
assert mutation_in_progress(caller, version);
if (0 > pos || pos > this._buf_limit )
throw new IllegalArgumentException();
// clear out all the blocks in use from the last in use
// to the block where the eof will be located
bbBlock b = null;
for (int idx = this._next_block_position - 1; idx >= 0; idx--) {
b = this._blocks.get(idx);
if (b._offset <= pos) break;
b.clearBlock();
}
if (b == null) {
throw new IllegalStateException("block missing at position "+pos);
}
// reset the next block position to account for this.
this._next_block_position = b._idx + 1;
// on the block where eof is, set it's limit appropriately
b._limit = pos - b._offset;
// set the overall buffer limits
this._buf_limit = pos;
b = this.findBlockForRead(pos, version, b, pos);
return b;
}
private bbBlock addBlock(Object caller, int version, int idx, int offset,
int needed)
{
assert mutation_in_progress(caller, version);
bbBlock newblock = null;
for (int ii=this._next_block_position; ii < this._blocks.size(); ii++)
{
bbBlock tmpblock = this._blocks.get(this._next_block_position);
if (tmpblock._buffer.length >= needed) {
this._blocks.remove(this._next_block_position);
newblock = tmpblock;
break;
}
}
if (newblock == null) {
// if there's nothing big enough to recycle
// so we have to really make more space
int bufcapacity = 0;
if (needed > _blockSizeUpperLimit) {
bufcapacity = needed;
}
else {
while (bufcapacity < needed) {
bufcapacity = this.nextBlockSize(caller, version);
}
}
newblock = new bbBlock(bufcapacity);
}
// if the caller didn't specify an index
// we'll have to find out where this goes
if (idx == -1) {
for (idx = 0; idx < this._next_block_position; idx++) {
if (this._blocks.get(idx)._offset < 0) {
break;
}
if (offset >= this._blocks.get(idx)._offset) {
break;
}
}
}
// initialize the buffer and add it to the list in the right spot
newblock._idx = idx;
newblock._offset = offset;
_blocks.add(idx, newblock);
_next_block_position++;
// if this isn't the last buffer, bump the idx of the trailing buffers
for (int ii = idx + 1; ii < _next_block_position; ii++) {
this._blocks.get(ii)._idx = ii;
}
return newblock;
}
private int nextBlockSize(Object caller, int version)
{
assert mutation_in_progress(caller, version);
if (_lastCapacity == 0) {
_lastCapacity = _blockSizeMin;
}
else if (_lastCapacity < _blockSizeUpperLimit) {
_lastCapacity *= 2;
}
return _lastCapacity;
}
// starts with (pos, 0, _next_block_position) so we're really
// looking in blocks with indices from lo to (hi-1) inclusive
final bbBlock findBlockHelper(int pos, int lo, int hi)
{
bbBlock block;
int ii;
if ((hi - lo) <= 3) {
for (ii=lo; ii block._offset + block._limit) continue;
if (block.containsForRead(pos)) {
return block;
}
if (block._offset >= pos) break;
}
return this._blocks.get(ii - 1); // this will always be > 0
}
int mid = (hi + lo) / 2;
block = this._blocks.get(mid);
assert block != null;
if (block._offset > pos) {
return findBlockHelper(pos, lo, mid);
}
return findBlockHelper(pos, mid, hi);
}
/**
* find the block where this offset (newPosition) has already
* been written. Typically the caller will set _curr to be the
* returned block.
* @param pos global position to be read from
* @return curr block ready to be read from
*/
bbBlock findBlockForRead(Object caller, int version, bbBlock curr, int pos)
{
assert pos >= 0 && "buffer positions are never negative".length() > 0;
if (pos > this._buf_limit) {
throw new BlockedBufferException("invalid position");
}
assert _validate();
if (curr != null) {
if (curr.containsForRead(pos)) {
return curr;
}
if (pos == this._buf_limit && (pos - curr._offset) == curr._limit) {
return curr;
}
}
boolean at_eof = (pos == this._buf_limit);
if (at_eof) {
// if this is the last block actually in use
// and we're looking for the eof position then
// we can check for the "last byte not quite
// written yet" case, which is fine
bbBlock block = this._blocks.get(this._next_block_position - 1);
if (block.containsForWrite(pos)) return block;
}
else {
bbBlock block = this.findBlockHelper(pos, 0, this._next_block_position);
return block;
}
throw new BlockedBufferException("valid position can't be found!");
}
/**
* find the block where this offset (newPosition) should be written.
* typicall the caller will set _curr to be the returned block.
* @param pos global position to be written to
* @return curr block ready to be written to
*/
bbBlock findBlockForWrite(Object caller, int version, bbBlock curr, int pos)
{
assert mutation_in_progress(caller, version);
assert (pos >= 0 && "invalid position, positions must be >= 0".length() > 0);
if (pos > this._buf_limit + 1) {
throw new BlockedBufferException("writes must be contiguous");
}
assert _validate();
if (curr != null && curr.hasRoomToWrite(pos, 1) == true) {
if (curr._offset + curr._limit == pos && curr._idx < this._next_block_position) {
bbBlock b = this._blocks.get(curr._idx + 1);
if (b.containsForWrite(pos)) {
curr = b;
}
}
return curr;
}
// we're not going to write into curr, so find out the right block
bbBlock block;
if (pos == this._buf_limit) {
// if we're at the limit the only possible (existing) block
// will be the very last block - shortcut to optimize append
assert this._next_block_position > 0;
block = this._blocks.get(this._next_block_position - 1);
}
else if (curr != null && pos == curr._offset + curr._limit) {
// if our current position is exactly at the end (and we already know
// we can't write into this block if we can write at all we'll have
// to write into the next block (inner blocks can't be 0 bytes long)
block = this._blocks.get(curr._idx + 1);
}
else {
// since we're not at the limit and we don't have a current block
// we'll go find the block in the list (this is an abnormal case)
// since append if usual for writing
block = findBlockHelper(pos, 0, this._next_block_position);
}
assert block != null;
assert block.containsForWrite(pos);
// chech our candidate block to see if it's the one we'd write into
if (block.hasRoomToWrite(pos, 1)) {
return block;
}
// at this point, we can't use _curr in any event so we can just
// move on to the next block since findHelper will have returned
// either the right block (which it didn't) or the one just in
// front of the right block - so let's see if there is an allocated
// block just following this
if (block._idx < this._next_block_position - 1) {
block = this._blocks.get(block._idx + 1);
return block;
}
// there wasn't a following block (actually a common case when
// you're appending) so we have to go ahead an actually add a new block
int newIdx = block._idx + 1;
assert newIdx == this._next_block_position;
bbBlock ret = this.addBlock(caller
,version
,newIdx
,pos
,this.nextBlockSize(caller, version)
);
return ret;
}
/**
* dispatcher for the various forms of insert we encounter
* calls one of the four helpers depending on the case
* that is needed to inser here
* @param len number of bytes to make space for
* @return int number of bytes inserted
*/
int insert(Object caller, int version, bbBlock curr, int pos, int len)
{
assert mutation_in_progress(caller, version);
// DEBUG: int amountMoved = 0;
// DEBUG: int before = this._buf_limit;
// DEBUG: assert _validate();
// if there's room in the current block - just
// move the "trailing" bytes down and we're done
int neededSpace = len - curr.unusedBlockCapacity();
if (neededSpace <= 0) {
// we have all the space we need in the current block
// DEBUG: amountMoved =
insertInCurrOnly(caller, version, curr, pos, len);
}
else {
// we'll need at least some additional space beyond the curr
// block, see if there's room in the
// next one, otherwise we'll make more (blocks)
bbBlock next = null;
if (curr._idx < this._next_block_position - 1) {
// if there is another block
next = this._blocks.get(curr._idx + 1);
}
if (next != null &&
(neededSpace <= next.unusedBlockCapacity())
) {
// with the addition of the free space in the following block we have enough
// DEBUG: amountMoved =
insertInCurrAndNext(caller, version, curr, pos, len, next);
}
else {
// we'll have to make one or more new blocks
// first figure out much will be in the first
// and last blocks (i.e. ignoring the whole
// blocks
int lenNeededInLastAddedBlock = neededSpace % _blockSizeUpperLimit;
int tailLen = curr.bytesAvailableToRead(pos);
if (lenNeededInLastAddedBlock < tailLen) lenNeededInLastAddedBlock = tailLen;
if (lenNeededInLastAddedBlock < neededSpace
&& neededSpace < this._blockSizeUpperLimit) {
// if we need less than the largest block then we should
// make *one* block with all of the needed space
lenNeededInLastAddedBlock = neededSpace;
}
bbBlock newblock = insertMakeNewTailBlock(caller, version, curr, lenNeededInLastAddedBlock);
// now see if the curr block and this newblock have enough
// available space to do the job, and if there's some trailing
// data from curr that will end up staying in curr
if (len <= (curr.unusedBlockCapacity()
+ newblock.unusedBlockCapacity())
) {
// insert this as a zero length block immediately after _curr
// insertBlock also adjusts the trailing blocks idx values
insertBlock(newblock);
// now pretend we just have the "push into the next block" case
// DEBUG: amountMoved =
insertInCurrAndNext(caller, version, curr, pos, len, newblock);
}
else {
// and last we have the case of having to insert more than 1 block
// which means all of the trailing bytes in _curr move into the last
// block
// DEBUG: amountMoved =
insertAsManyBlocksAsNeeded(caller, version, curr, pos, len, newblock);
}
}
}
// DEBUG: if (this._buf_limit - before != len
// DEBUG: || amountMoved != len) {
// DEBUG: throw new BlockedBufferException("insert went wrong #1 !!!");
// DEBUG: }
assert _validate();
return len;
}
/**
* this handles insert when there's enough room in the
* current block
*/
private int insertInCurrOnly(Object caller, int version, bbBlock curr, int pos, int len)
{
assert mutation_in_progress(caller, version);
// the space we need is available right in the block
assert curr.unusedBlockCapacity() >= len;
System.arraycopy(curr._buffer, curr.blockOffsetFromAbsolute(pos)
,curr._buffer, curr.blockOffsetFromAbsolute(pos) + len, curr.bytesAvailableToRead(pos));
curr._limit += len;
this.adjustOffsets(curr._idx, len, 0);
notifyInsert(pos, len);
return len;
}
private int insertInCurrAndNext(Object caller, int version, bbBlock curr, int pos, int len, bbBlock next)
{
assert mutation_in_progress(caller, version);
// DEBUG: int amountMoved = 0;
// all the space we need (len) fits in these two blocks
assert curr.unusedBlockCapacity() + next.unusedBlockCapacity() >= len;
// and we need to use space in both of these blocks
assert curr.unusedBlockCapacity() < len;
int availableToRead = curr.bytesAvailableToRead(pos);
int tailInCurr = availableToRead;
int deltaOfNextData = len - curr.unusedBlockCapacity();
int tailCopiedToNext = deltaOfNextData;
if (tailCopiedToNext > availableToRead) {
tailCopiedToNext = availableToRead;
}
// first we copy the data in the next block down to make room
// for data we're pushing off the end of the _curr block
// if we need to, there may not be any data in the next block
if (next._limit > 0) {
System.arraycopy(next._buffer, 0, next._buffer, deltaOfNextData, next._limit);
}
next._limit += deltaOfNextData;
// DEBUG: amountMoved += deltaOfNextData;
// next we copy the data from the tail of _curr into the front of next
// since we don't have room for it any longer in the _curr block
// but it is possible that there is not tail at all (pos == limit)
if (tailCopiedToNext > 0) {
System.arraycopy(curr._buffer, curr._limit - tailCopiedToNext
, next._buffer, deltaOfNextData - tailCopiedToNext, tailCopiedToNext);
}
// finally if there's any tail left in the _curr block we copy that
// down to the end of the _curr block (if all of the tail moved into
// the next block nothing happens here
int leftInCurr = tailInCurr - tailCopiedToNext;
if (leftInCurr > 0) {
int blockPosition = curr.blockOffsetFromAbsolute(pos);
System.arraycopy(curr._buffer, blockPosition
,curr._buffer, blockPosition + len, leftInCurr);
}
// finally if we reused from space in _curr (between _limit and the unreserved capacity)
// we adjust for that as well as the space adjusted in the newblock
int addedInCurr = curr.unusedBlockCapacity();
if (addedInCurr > 0) {
curr._limit += addedInCurr;
// DEBUG: amountMoved += addedInCurr;
next._offset += addedInCurr;
}
assert (curr.blockOffsetFromAbsolute(pos) + tailCopiedToNext + addedInCurr + leftInCurr) == curr._limit;
this.adjustOffsets(next._idx, len, 0);
notifyInsert(pos, len);
// DEBUG: if (amountMoved != len) {
// DEBUG: throw new BlockedBufferException("insert went wrong #4 !!!");
// DEBUG: }
return len;
}
private bbBlock insertMakeNewTailBlock(Object caller, int version, bbBlock curr, int minimumBlockSize)
{
assert mutation_in_progress(caller, version);
// needed is the amount of data we'll put into the
// final added block (which is actually added first)
int newblocksize = minimumBlockSize;
if (newblocksize < _blockSizeUpperLimit) {
// if we don't need an oversize block then find a block
// size that will be big enough
while ((newblocksize = this.nextBlockSize(caller, version)) < minimumBlockSize) {
// bump up requested block capacity until we get
// at least enough to hold the request, or we
// hit the max blocksize whichever comes first
}
}
// allocate and initialize a new block that will be the
// tail of our interesting blocks
bbBlock newblock = new bbBlock(newblocksize);
newblock._idx = curr._idx + 1;
newblock._offset = curr._offset + curr._limit; // we'll adjust this later like any existing block
return newblock;
}
private int insertAsManyBlocksAsNeeded(Object caller, int version, bbBlock curr, int pos, int len, bbBlock newLastBlock)
{
assert mutation_in_progress(caller, version);
// DEBUG: int amountAllocated = 0;
// DEBUG: int origPos = this._buf_position;
// this is the case where the old tail is pushed entirely out of the
// old block into a new trailing block and then as many whole new
// blocks as needed (which maybe none) are inserted between these two
bbBlock oldCurr = curr;
int oldPosition = curr.blockOffsetFromAbsolute(pos);
int oldBlockTail = curr._limit - oldPosition;
int newSpaceInCurr = curr.unusedBlockCapacity();
// adjust the curr blocks limit
curr._limit += newSpaceInCurr;
// DEBUG: amountAllocated += newSpaceInCurr;
int newoffset = curr._offset + curr._limit;
int spaceNeededInMiddle = len - newSpaceInCurr - newLastBlock._buffer.length;
int addedblocks = 0;
bbBlock newblock = null;
assert (spaceNeededInMiddle > 0); // this is the "as many as needed" case not "this and next"
// add blocks until we're ready for the last block
while (spaceNeededInMiddle > 0) {
addedblocks++;
newblock = new bbBlock(this.nextBlockSize(caller, version));
newblock._limit = newblock._buffer.length;
if (newblock._limit > spaceNeededInMiddle) newblock._limit = spaceNeededInMiddle;
// DEBUG: amountAllocated += newblock._limit;
newblock._idx = curr._idx + addedblocks;
newblock._offset = newoffset;
this._blocks.add(newblock._idx, newblock);
spaceNeededInMiddle -= newblock._limit;
newoffset += newblock._limit;
}
// add the last block
addedblocks++;
newblock = newLastBlock;
newblock._limit = newblock._buffer.length;
// DEBUG: amountAllocated += newblock._limit;
newblock._idx = curr._idx + addedblocks;
newblock._offset = newoffset;
this._blocks.add(newblock._idx, newblock);
// DEBUG: assert (amountAllocated == len);
// now adjust the trailing blocks
adjustOffsets(newblock._idx, len, addedblocks);
notifyInsert(pos, len);
// now we copy the tail of the _curr block to the end of the space
// note that this only works because the tail is being copied to
// an altogether different block in the buffer, so it can't overlap
if (oldBlockTail > 0) {
System.arraycopy(oldCurr._buffer, oldPosition, newLastBlock._buffer, newLastBlock._limit - oldBlockTail, oldBlockTail);
}
// DEBUG: assert this.position() == origPos;
// DEBUG: assert (amountAllocated == len);
return len;
}
private void insertBlock(bbBlock newblock) {
// in both cases we need to insert the new block after _curr
// and adjust the idx values to go with that
this._blocks.add(newblock._idx, newblock);
_next_block_position++;
for (int ii=newblock._idx + 1; ii < this._next_block_position; ii++) {
this._blocks.get(ii)._idx++;
}
}
private void adjustOffsets(int lastidx, int addedBytes, int addedBlocks) {
bbBlock b;
// now we adjust the trailing offsets
if (addedBytes != 0 || addedBlocks != 0) {
this._next_block_position += addedBlocks;
for (int ii=lastidx + 1; ii < this._next_block_position; ii++) {
b = this._blocks.get(ii);
b._offset += addedBytes;
b._idx += addedBlocks;
}
this._buf_limit += addedBytes;
}
}
bbBlock remove(Object caller, int version, bbBlock curr, int pos, int len)
{
assert mutation_in_progress(caller, version);
if (len == 0) return curr;
if (len < 0 || (pos + len) > this._buf_limit) {
throw new IllegalArgumentException();
}
int amountToRemove = len;
int removedBlocks = 0;
int startingIdx = curr._idx;
int currIdx = curr._idx;
bbBlock currBlock = curr;
assert (curr._offset <= pos);
assert (pos - curr._offset <= curr._limit);
assert _validate();
// this is to simply eliminate a big edge case
if (pos == 0 && len == this._buf_limit) {
this.clear(caller, version);
notifyRemove(0, len);
return null;
}
// remove from the initial block
int currBlockPosition = currBlock.blockOffsetFromAbsolute(pos);
int removedFromThisBlock = currBlock._limit - currBlockPosition;
if (removedFromThisBlock > amountToRemove) removedFromThisBlock = amountToRemove;
if (removedFromThisBlock == currBlock._limit) {
// we'll be removing the whole block in the whole block loop below
startingIdx--; // so we have to back up on to fix the next block that will
// "fall" down into the soon to be emptied slot here
}
else {
// we always copy into position, and we copy whatever is still
// left in the end of the block
int moveAmount = currBlock._limit - currBlockPosition - removedFromThisBlock;
if (moveAmount > 0) {
System.arraycopy(currBlock._buffer, currBlock._limit - moveAmount
,currBlock._buffer, currBlockPosition, moveAmount);
}
amountToRemove -= removedFromThisBlock;
currBlock._limit -= removedFromThisBlock;
if (amountToRemove > 0) {
// when we're on the last block, there'll be nothing to remove,
// and no block to get either
currIdx = currBlock._idx + 1;
currBlock = this._blocks.get(currIdx);
}
}
while (amountToRemove > 0 && amountToRemove >= currBlock._limit) {
amountToRemove -= currBlock._limit;
// remove the whole block - so first hang onto a reference
bbBlock temp = currBlock;
this._blocks.remove(currIdx);
removedBlocks++;
temp.clearBlock();
this._blocks.add(temp); // dump it at the end (marked as not in use)
// and we don't move currIdx because we bumped it out of the whole array
if (currIdx < this._next_block_position - removedBlocks) {
currBlock = this._blocks.get(currIdx);
}
else if (currIdx > 0) {
currIdx--;
currBlock = this._blocks.get(currIdx);
}
else {
throw new BlockedBufferException("fatal - no current block!");
}
}
if (amountToRemove > 0) {
assert amountToRemove < currBlock._limit;
System.arraycopy(currBlock._buffer, amountToRemove
,currBlock._buffer, 0, currBlock._limit - amountToRemove);
assert amountToRemove < currBlock._limit;
currBlock._limit -= amountToRemove;
currBlock._offset += amountToRemove;
}
// we'll even adjust the offset of the first block (if it's the last as well)
adjustOffsets(startingIdx, -len, -removedBlocks);
notifyRemove(pos, len);
// DEBUG: int shouldBe = 0;
// DEBUG: int is = currBlock._offset;
// DEBUG: if (currBlock._idx > 0) {
// DEBUG: shouldBe = this._blocks.get(currBlock._idx - 1)._offset + this._blocks.get(currBlock._idx - 1)._limit;
// DEBUG: if (currIdx != startingIdx) assert (shouldBe == this._buf_position);
// DEBUG: }
// DEBUG: int delta = shouldBe - is;
// DEBUG: assert(delta == 0);
assert _validate();
return currBlock;
}
static int _validate_count;
public boolean _validate() {
int pos = 0;
int idx;
boolean err = false;
_validate_count++;
if ((_validate_count % 128) != 0) return true;
// you can change the 0 below (in from of the -2) to be the validation counter
// which reported the failure and the test will be true when _validate() is
// called on the last GOOD check.
if (_validate_count == 30 -2) {
// used to set breakpoints on particular calls for validation
err = (_validate_count < 0);
}
for (idx=0; idx b._buffer.length /* - b._reserved */ ) {
System.out.println("block "+idx+": "+
"limit is out of range"+
", it is "+b._limit+
" should be between 0 and "+ (b._buffer.length /* - b._reserved */));
err = true;
}
else if (b._limit == 0) {
if ( ! (b._idx == (this._next_block_position - 1)
&& b._offset == this._buf_limit)
) {
System.out.println("block "+idx+": "+
"has a ZERO limit");
err = true;
}
}
pos += b._limit;
}
if (idx != this._next_block_position) {
System.out.println("next block position is wrong, is "+this._next_block_position+" should be "+idx);
err = true;
}
for (idx++; idx 0) {
bbBlock last = this._blocks.get(this._next_block_position - 1);
if (last._offset + last._limit != this._buf_limit){
System.out.println("last block "+last._idx+" limit isn't "+
"_buf_limit ("+this._buf_limit+"): "+
" calc'd last block limit is "
+ last._offset +" + "+ last._limit
+" = "+(last._offset + last._limit)
);
err = true;
}
}
if (this._buf_limit < 0 || (this._buf_limit > 0 && this._next_block_position < 1)){
System.out.println("this._buf_limit "+ this._buf_limit+ " is invalid");
err = true;
}
if (err == true) {
System.out.println("failed with validation count = " + _validate_count);
}
return err == false; // validate is true if all is ok so that assert _validate(); works as expected
}
final static class bbBlock {
public int _idx;
public int _offset;
public int _limit;
public byte[] _buffer;
public bbBlock(int capacity) {
_buffer = new byte[capacity];
}
/**
* Assumes ownership of an array to create a new block. The data
* within the buffer is maintained.
*
* @param buffer contains the data for the block.
*
* @throws NullPointerException if buffer is null.
*/
bbBlock(byte[] buffer) {
_buffer = buffer;
_limit = buffer.length;
}
public bbBlock clearBlock() {
_idx = -1;
_offset = -1;
_limit = 0;
return this;
}
/**
* maximimum number of bytes that can be held in this block.
*/
final int blockCapacity() {
assert this._offset >= 0;
return this._buffer.length ;
}
/**
* maximimum number of bytes that can be appended in this block currently.
*/
final int unusedBlockCapacity() {
assert this._offset >= 0;
return this._buffer.length - this._limit;
}
/**
* Gets the number of bytes between the current position and the
* writable capacity of this block.
* @param pos absolute position
*/
final int bytesAvailableToWrite(int pos) {
assert this._offset >= 0;
return this._buffer.length - (pos - _offset);
}
/**
* Gets the number of, as yet, unused bytes in this block. That's the number
* of bytes that can be inserted into this block without overflowing, or the
* number of bytes between the current position and the end of the written bytes
* in this block
* @param pos absolute position
*/
public final int bytesAvailableToRead(int pos) {
assert this._offset >= 0;
return this._limit - (pos - _offset);
}
/**
* is there space between position and capacity?
* @param pos absolute position
* @param needed
* @return boolean
*/
final boolean hasRoomToWrite(int pos, int needed) {
assert this._offset >= 0;
return (needed <= (this._buffer.length - (pos - _offset)));
}
final boolean containsForRead(int pos) {
assert this._offset >= 0;
return (pos >= _offset && pos < _offset + _limit);
}
final boolean containsForWrite(int pos) {
assert this._offset >= 0;
return (pos >= _offset && pos <= _offset + _limit);
}
final int blockOffsetFromAbsolute(int pos) {
assert this._offset >= 0;
return pos - _offset;
}
}
public interface Monitor
{
public boolean notifyInsert(int pos, int len);
public boolean notifyRemove(int pos, int len);
public int getMemberIdOffset();
}
private final static class PositionMonitor implements Monitor
{
int _pos;
PositionMonitor(int pos) { _pos = pos; }
public int getMemberIdOffset() { return _pos; }
public boolean notifyInsert(int pos, int len) { return false; }
public boolean notifyRemove(int pos, int len) { return false; }
}
private final static class CompareMonitor implements Comparator {
static CompareMonitor instance = new CompareMonitor();
private CompareMonitor() {}
static CompareMonitor getComparator()
{
return instance;
}
public int compare(Monitor arg0, Monitor arg1)
{
return arg0.getMemberIdOffset() - arg1.getMemberIdOffset();
}
}
TreeSet _updatelist = new TreeSet(CompareMonitor.getComparator());
public void notifyRegister(Monitor item) {
_updatelist.add(item);
}
public void notifyUnregister(Monitor item) {
_updatelist.remove(item);
}
public void notifyInsert(int pos, int len) {
if (len == 0) return;
PositionMonitor pm = new PositionMonitor(pos);
SortedSet follows = _updatelist.tailSet(pm);
for (Monitor m : follows) {
if (m.notifyInsert(pos, len)) {
follows.remove(m);
}
}
}
public void notifyRemove(int pos, int len) {
if (len == 0) return;
PositionMonitor pm = new PositionMonitor(pos);
SortedSet follows = _updatelist.tailSet(pm);
for (Monitor m : follows) {
if (m.notifyRemove(pos, len)) {
follows.remove(m);
}
}
}
/**
* Reads data from a byte buffer, keeps a local position and
* a current block. Snaps a buffer length on creation;
*/
public static class BlockedByteInputStream extends java.io.InputStream
{
BlockedBuffer _buf;
int _pos;
int _mark;
bbBlock _curr;
int _blockPosition;
int _version;
/**
* @param bb blocked buffer to read from
*/
public BlockedByteInputStream(BlockedBuffer bb)
{
this(0, bb);
}
/**
* @param bb blocked buffer to read from
* @param pos initial offset to read
*/
public BlockedByteInputStream(BlockedBuffer bb, int pos)
{
this(pos, bb);
}
/**
* @param pos initial offset to read
* @param end is the local limit, or -1 (_end_unspecified)
* @param bb blocked buffer to read from
*/
private BlockedByteInputStream(int pos, BlockedBuffer bb)
{
if (bb == null) throw new IllegalArgumentException();
_version = bb.getVersion();
_buf = bb;
_set_position(pos);
_mark = -1;
}
@Override
public final void mark(int readlimit) {
this._mark = this._pos;
}
@Override
public final void reset() throws IOException {
if (this._mark == -1) throw new IOException("mark not set");
_set_position(this._mark);
}
/**
* the current offset in the buffer
*/
public final int position() {
return this._pos;
}
/**
* this forces a version sync with the underlying blocked buffer.
* The current position is lost during this call.
*
*/
public final void sync() throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
_version = _buf.getVersion();
_curr = null;
_pos = 0;
}
/**
* debug api to force check for internal validity of the
* underlying buffer
*/
public final boolean _validate() {
return this._buf._validate();
}
/**
* sets the position of the stream to be pos. The next operation
* (such as read) will return the byte at that offset.
* @param pos new offset to read from
* @return this stream
*/
public final BlockedByteInputStream setPosition(int pos) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
fail_on_version_change();
if (pos < 0 || pos > _buf.size()) {
throw new IllegalArgumentException();
}
// call our unfailing private method to do the real work
_set_position(pos);
fail_on_version_change();
return this;
}
private final void _set_position(int pos)
{
_pos = pos;
_curr = _buf.findBlockForRead(this, _version, _curr, pos);
_blockPosition = _pos - _curr._offset;
}
/**
* closes the steam and clears its reference to the
* byte buffer. Once closed it cannot be used.
*/
@Override
public final void close() throws IOException
{
this._buf = null;
this._pos = -1;
}
public final int writeTo(OutputStream out, int len) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
fail_on_version_change();
if (_pos > _buf.size()) throw new IllegalArgumentException();
int startingPos = _pos;
int localEnd = _pos + len;
if (localEnd > _buf.size()) localEnd = _buf.size();
assert(_curr.blockOffsetFromAbsolute(_pos) == _blockPosition);
while (_pos < localEnd) {
int available = _curr._limit - _blockPosition;
boolean partial_read = available > localEnd - _pos;
if (partial_read) {
available = localEnd - _pos;
}
out.write(_curr._buffer, _blockPosition, available);
_pos += available;
if (partial_read) {
_blockPosition += available;
break;
}
_curr = _buf.findBlockForRead(this, _version, _curr, _pos);
_blockPosition =_curr.blockOffsetFromAbsolute(_pos);
}
fail_on_version_change();
return _pos - startingPos;
}
public final int writeTo(ByteWriter out, int len) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
fail_on_version_change();
if (_pos > _buf.size()) throw new IllegalArgumentException();
int startingPos = _pos;
int localEnd = _pos + len;
if (localEnd > _buf.size()) localEnd = _buf.size();
assert(_curr.blockOffsetFromAbsolute(_pos) == _blockPosition);
while (_pos < localEnd) {
int available = _curr._limit - _blockPosition;
boolean partial_read = available > localEnd - _pos;
if (partial_read) {
available = localEnd - _pos;
}
out.write(_curr._buffer, _blockPosition, available);
_pos += available;
if (partial_read) {
_blockPosition += available;
break;
}
_curr = _buf.findBlockForRead(this, _version, _curr, _pos);
_blockPosition =_curr.blockOffsetFromAbsolute(_pos);
}
fail_on_version_change();
return _pos - startingPos;
}
/**
* reads (up to) {@code len} bytes from the buffer and copies them into
* the user supplied byte array (bytes) starting at offset
* off in the users array. This returns the number of bytes
* read, which may be less than the number requested if
* there is not enough data available in the buffer.
*
* @throws IndexOutOfBoundsException
* if {@code (dst.length - offset) < len}
*/
@Override
public final int read(byte[] bytes, int offset, int len) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
fail_on_version_change();
if (_pos > _buf.size()) throw new IllegalArgumentException();
int startingPos = _pos;
int localEnd = _pos + len;
if (localEnd > _buf.size()) localEnd = _buf.size();
while (_pos < localEnd) {
bbBlock block = _curr;
int block_offset = _blockPosition;
int available = block._limit - _blockPosition;
if (available > localEnd - _pos) {
// we aren't emptying this block so adjust our location
available = localEnd - _pos;
_blockPosition += available;
}
else {
// TODO can't we just move to the next block?
_curr = _buf.findBlockForRead(this, _version, _curr, _pos + available);
_blockPosition = 0;
}
System.arraycopy(block._buffer, block_offset, bytes, offset, available);
_pos += available;
offset += available;
}
fail_on_version_change();
return _pos - startingPos;
}
/**
* reads the next byte in the buffer. This returns -1
* if there is no data available to be read.
*/
@Override
public final int read() throws IOException
{
if (_buf == null) {
throw new IOException("input stream is closed");
}
fail_on_version_change();
if (_pos >= _buf.size()) return -1;
if (_blockPosition >= _curr._limit) {
_curr = this._buf.findBlockForRead(this, _version, _curr, _pos);
_blockPosition = 0;
}
int nextByte = (0xff & _curr._buffer[_blockPosition]);
_blockPosition++;
_pos++;
fail_on_version_change();
return nextByte;
}
private final void fail_on_version_change() throws IOException
{
if (_buf.getVersion() != _version) {
this.close();
throw new BlockedBufferException("buffer has been changed!");
}
}
@Override
public final long skip(long n) throws IOException
{
if (n < 0 || n > Integer.MAX_VALUE) throw new IllegalArgumentException("we only handle buffer less than "+Integer.MAX_VALUE+" bytes in length");
if (_buf == null) throw new IOException("stream is closed");
fail_on_version_change();
if (_pos >= _buf.size()) return -1;
int len = (int)n;
if (len == 0) return 0;
int startingPos = _pos;
int localEnd = _pos + len;
if (localEnd > _buf.size()) localEnd = _buf.size();
// if we run off the end of this block, we need to update
// our current block ( _curr ) we'll update the block position
// in any event (once we know the right block, of course)
if (localEnd > _blockPosition + _curr._offset) {
_curr = _buf.findBlockForRead(this, _version, _curr, localEnd);
}
_blockPosition = localEnd - _curr._offset;
_pos = localEnd;
fail_on_version_change();
return _pos - startingPos;
}
}
/**
* Reads data from a byte buffer, keeps a local position and
* a current block. Snaps a buffer length on creation;
*/
public static class BlockedByteOutputStream extends java.io.OutputStream
{
BlockedBuffer _buf;
int _pos;
bbBlock _curr;
int _blockPosition;
int _version;
/**
* creates writable stream (OutputStream) that writes
* to a fresh blocked buffer. The stream is initially
* position at offset 0.
*/
public BlockedByteOutputStream() {
_buf = new BlockedBuffer();
_version = _buf.getVersion();
_set_position(0);
}
/**
* creates writable stream (OutputStream) that writes
* to the supplied byte buffer. The stream is initially
* position at offset 0.
* @param bb blocked buffer to write to
*/
public BlockedByteOutputStream(BlockedBuffer bb) {
_buf = bb;
_version = _buf.getVersion();
_set_position(0);
}
/**
* creates writable stream (OutputStream) that can write
* to the supplied byte buffer. The stream is initially
* position at offset off.
* @param bb blocked buffer to write to
* @param off initial offset to write to
*/
public BlockedByteOutputStream(BlockedBuffer bb, int off) {
if (bb == null || off < 0 || off > bb.size() ) {
throw new IllegalArgumentException();
}
_buf = bb;
_version = _buf.getVersion();
_set_position(0);
}
/**
* the current offset in the buffer
*/
public final int position() {
return this._pos;
}
/**
* this forces a version sync with the underlying blocked buffer.
* The current position is lost during this call.
*
*/
public final void sync() throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
_version = _buf.getVersion();
_pos = 0;
_curr = null;
}
/**
* debug api to force check for internal validity of the
* underlying buffer
*/
public final boolean _validate() {
return this._buf._validate();
}
/**
* repositions this stream in the buffer. The next
* read, write, or insert operation will take place
* at the specified position. The position must
* be within the contiguous range of written bytes,
* including the pseudo end of file character just
* past the end, which can be written on and returns
* -1 if read.
*/
public final BlockedByteOutputStream setPosition(int pos) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
fail_on_version_change();
if (pos < 0 || pos > _buf.size()) {
throw new IllegalArgumentException();
}
this._set_position(pos);
fail_on_version_change();
return this;
}
private final void _set_position(int pos)
{
_pos = pos;
_curr = _buf.findBlockForRead(this, _version, _curr, pos);
_blockPosition = _pos - _curr._offset;
return;
}
/**
* closes the steam and clears its reference to the
* byte buffer. Once closed it cannot be used.
*/
@Override
public final void close() throws IOException
{
this._buf = null;
this._pos = -1;
return;
}
/**
* Inserts space and writes 1 byte to the current
* position in this output stream. Only the low
* order byte of the passed in int is written the
* high order bits are ignored.
*/
@Override
public final void write(int b) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
_buf.start_mutate(this, _version);
_write(b);
_version = _buf.end_mutate(this);
return;
}
final void start_write() {
_buf.start_mutate(this, _version);
}
final void end_write() {
_version = _buf.end_mutate(this);
}
final void _write(int b) throws IOException
{
if (bytesAvailableToWriteInCurr(_pos) < 1) {
_curr = _buf.findBlockForWrite(this, _version, _curr, _pos);
assert _curr._offset == _pos;
_blockPosition = 0;
}
_curr._buffer[_blockPosition++] = (byte)(b & 0xff);
_pos++;
if (_blockPosition > _curr._limit) {
_curr._limit = _blockPosition;
if (_pos > _buf._buf_limit ) _buf._buf_limit = _pos;
}
}
private final int bytesAvailableToWriteInCurr(int pos) {
assert _curr != null;
assert _curr._offset <= pos;
assert _curr._offset + _curr._limit >= pos;
if (_curr._idx < this._buf._next_block_position - 1) {
return _curr.bytesAvailableToRead(pos);
}
int ret = _curr._buffer.length - (pos - _curr._offset);
return ret; // _curr.bytesAvailableToWrite(pos);
}
/**
* Writes len bytes from the specified byte array starting
* at in the user array at offset off to the current position
* in this output stream.
*/
@Override
public final void write(byte[] b, int off, int len) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
_buf.start_mutate(this, _version);
_write(b, off, len);
_version = _buf.end_mutate(this);
}
private final void _write(byte[] b, int off, int len)
{
int end_b = off + len;
while (off < end_b)
{
int writeInThisBlock = bytesAvailableToWriteInCurr(_pos);
if (writeInThisBlock > end_b - off) {
writeInThisBlock = end_b - off;
}
assert writeInThisBlock >= 0;
if (writeInThisBlock > 0) {
System.arraycopy(b, off, _curr._buffer, _blockPosition, writeInThisBlock);
off += writeInThisBlock;
_pos += writeInThisBlock;
_blockPosition += writeInThisBlock;
if (_blockPosition > _curr._limit) {
_curr._limit = _blockPosition;
if (_pos > _buf._buf_limit) _buf._buf_limit = _pos;
}
else {
assert _pos <= _buf._buf_limit;
}
}
if (off >= end_b) break;
_curr = _buf.findBlockForWrite(this, _version, _curr, _pos);
_blockPosition = _curr.blockOffsetFromAbsolute(_pos);
assert _curr._offset == _pos || off >= end_b;
}
}
/**
* Writes bytes from the specified byte stream from its current
* stream position to the end of the stream. Writing the bytes
* to the current position in this output stream.
* @throws IOException
*/
public final void write(InputStream bytestream) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
_buf.start_mutate(this, _version);
_write(bytestream, -1);
_version = _buf.end_mutate(this);
}
/**
* Writes bytes from the specified byte stream from its current
* stream position up to length bytes from the stream. Writing the
* bytes to the current position in this output stream.
* @throws IOException
*/
public final void write(InputStream bytestream, int len) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
_buf.start_mutate(this, _version);
_write(bytestream, len);
_version = _buf.end_mutate(this);
}
/**
* helper to write data. This does not check input arguments.
* @param bytestream source of the data
* @param len number of bytes to read from the input stream, -1 for all
* @throws IOException
*/
private final void _write(InputStream bytestream, int len) throws IOException
{
if (len == 0) return;
int written = 0;
boolean read_all = (len == -1);
for (;;)
{
int writeInThisBlock = bytesAvailableToWriteInCurr(_pos);
assert writeInThisBlock >= 0;
int to_read = read_all ? writeInThisBlock : len;
if (to_read > writeInThisBlock) {
to_read = writeInThisBlock;
}
int len_read = bytestream.read(_curr._buffer, _blockPosition, to_read);
if (len_read == -1) break;
if (len_read > 0) {
_pos += len_read;
_blockPosition += len_read;
if (_blockPosition > _curr._limit) {
_curr._limit = _blockPosition;
if (_pos > _buf._buf_limit) _buf._buf_limit = _pos;
}
else {
assert _pos <= _buf._buf_limit;
}
}
if (len_read == writeInThisBlock) {
_curr = _buf.findBlockForWrite(this, _version, _curr, _pos);
_blockPosition = _curr.blockOffsetFromAbsolute(_pos);
assert _curr._offset == _pos || written < len_read;
}
else {
assert len_read < writeInThisBlock;
}
if (!read_all) {
len -= len_read;
if (len < 1) break;
}
}
}
/**
* Inserts the amount space requested at the current
* position in this output stream. No data is written
* into the output stream.
*/
public final void insert(int len) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
if (len < 0) {
throw new IllegalArgumentException();
}
if (len > 0) {
_buf.start_mutate(this, _version);
_buf.insert(this, _version, _curr, _pos, len);
_version = _buf.end_mutate(this);
}
return;
}
/**
* Inserts space and writes 1 byte to the current
* position in this output stream. Only the low
* order byte of the passed in int is written the
* high order bits are ignored.
*/
public final void insert(byte b) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
_buf.start_mutate(this, _version);
_buf.insert(this, _version, _curr, _pos, 1);
_write(b);
_version = _buf.end_mutate(this);
}
/**
* Inserts space and writes len bytes from the specified
* byte array starting at in the user array at offset off
* to the current position in this output stream.
*/
public final void insert(byte[] b, int off, int len) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
_buf.start_mutate(this, _version);
_buf.insert(this, _version, _curr, _pos, len);
_write(b, off, len);
_version = _buf.end_mutate(this);
}
/**
* Inserts space and writes len bytes from the specified
* byte array starting at in the user array at offset off
* to the current position in this output stream.
*/
public final void remove(int len) throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
_buf.start_mutate(this, _version);
_curr = _buf.remove(this, _version, _curr, _pos, len);
_version = _buf.end_mutate(this);
}
/**
* trucates the buffer at the current location after this
* call the last previously written or read byte will be
* the end of the buffer.
*/
public final void truncate() throws IOException
{
if (_buf == null) throw new IOException("stream is closed");
if (this._buf._buf_limit == _pos) return;
_buf.start_mutate(this, _version);
_curr = _buf.truncate(this, _version, _pos);
_version = _buf.end_mutate(this);
}
private final void fail_on_version_change() throws IOException
{
if (_buf.getVersion() != _version) {
this.close();
throw new BlockedBufferException("buffer has been changed!");
}
}
}
public static class BlockedBufferException extends IonException
{
private static final long serialVersionUID = 1582507845614969389L;
public BlockedBufferException() { super(); }
public BlockedBufferException(String message) { super(message); }
public BlockedBufferException(String message, Throwable cause) {
super(message, cause);
}
public BlockedBufferException(Throwable cause) { super(cause); }
}
public static class BufferedOutputStream
extends OutputStream
{
BlockedBuffer _buffer;
BlockedByteOutputStream _writer;
public BufferedOutputStream() {
this(new BlockedBuffer());
}
public BufferedOutputStream(BlockedBuffer buffer) {
_buffer = buffer;
_writer = new BlockedByteOutputStream(_buffer);
}
/**
* Gets the size in bytes of this binary data.
* This is generally needed before calling {@link #getBytes()} or
* {@link #getBytes(byte[], int, int)}.
*
* @return the size in bytes.
*/
public int byteSize()
{
return _buffer.size();
}
/**
* Copies the current contents of this writer as a new byte array holding
* Ion binary-encoded data.
* This allocates an array of the size needed to exactly
* hold the output and copies the entire value to it.
*
* @return the byte array with the writers output
* @throws IOException
*/
public byte[] getBytes()
throws IOException
{
int size = byteSize();
ByteArrayOutputStream byteStream = new ByteArrayOutputStream(size);
writeBytes(byteStream);
byte[] bytes = byteStream.toByteArray();
return bytes;
}
/**
* Copies the current contents of the writer to a given byte array
* array. This starts writing to the array at offset and writes
* up to len bytes.
* If this writer is not able to stop in the middle of its
* work this may overwrite the array and later throw and exception.
*
* @param bytes users byte array to write into
* @param offset initial offset in the array to write into
* @param len maximum number of bytes to write from offset on
* @return number of bytes written
* @throws IOException
*/
public int getBytes(byte[] bytes, int offset, int len)
throws IOException
{
SimpleByteBuffer outbuf = new SimpleByteBuffer(bytes, offset, len);
OutputStream writer = (OutputStream)outbuf.getWriter();
int written = writeBytes(writer);
return written;
}
/**
* Writes the current contents of the writer to the output
* stream. This is only valid if the writer is not in the
* middle of writing a container.
*
* @param userstream OutputStream to write the bytes to
* @return int length of bytes written
* @throws IOException
*/
public int writeBytes(OutputStream userstream)
throws IOException
{
int limit = _buffer.size();
int pos = 0;
int version = _buffer.getVersion();
bbBlock curr = null;
_buffer.start_mutate(this, version);
while (pos < limit) {
curr = _buffer.findBlockForRead(this, version, curr, pos);
if (curr == null) {
throw new IOException("buffer missing expected bytes");
}
int len = curr.bytesAvailableToRead(pos);
if (len <= 0) {
throw new IOException("buffer missing expected bytes");
}
userstream.write(curr._buffer, 0, len);
pos += len;
}
_buffer.end_mutate(this);
return pos;
}
@Override
public void write(int b) throws IOException
{
_writer.write(b);
}
@Override
public void write(byte[] bytes) throws IOException
{
write(bytes, 0, bytes.length);
}
@Override
public void write(byte[] bytes, int off, int len) throws IOException
{
_writer.write(bytes, off, len);
}
}
}