src.java.com.ctc.wstx.util.TextBuffer Maven / Gradle / Ivy
package com.ctc.wstx.util;
import java.io.*;
import java.util.ArrayList;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.ext.LexicalHandler;
import org.codehaus.stax2.validation.XMLValidationException;
import org.codehaus.stax2.validation.XMLValidator;
import com.ctc.wstx.api.ReaderConfig;
import com.ctc.wstx.dtd.DTDEventListener;
/**
* TextBuffer is a class similar to {@link StringBuffer}, with
* following differences:
*
* - TextBuffer uses segments character arrays, to avoid having
* to do additional array copies when array is not big enough. This
* means that only reallocating that is necessary is done only once --
* if and when caller
* wants to access contents in a linear array (char[], String).
*
* - TextBuffer is not synchronized.
*
*
*
* Notes about usage: for debugging purposes, it's suggested to use
* {@link #toString} method, as opposed to
* {@link #contentsAsArray} or {@link #contentsAsString}. Internally
* resulting code paths may or may not be different, WRT caching.
*/
public final class TextBuffer
{
/* 23-Mar-2006, TSa: After realizing that memory buffer clearing
* is a significant overhead for small documents, it occured to
* me that default size for this buffer was too big (4000 chars);
* no need to be that big.
*/
/**
* Size of the first text segment buffer to allocate; need not contain
* the biggest segment, since new ones will get allocated as needed.
* However, it's sensible to use something that often is big enough
* to contain segments.
*/
final static int DEF_INITIAL_BUFFER_SIZE = 500; // 1k
// // // Configuration:
private final ReaderConfig mConfig;
/**
* Initial allocation size to use, if/when temporary output buffer
* is needed.
*/
private final int mInitialBufSize;
// // // Shared read-only input buffer:
/**
* Shared input buffer; stored here in case some input can be returned
* as is, without being copied to collector's own buffers. Note that
* this is read-only for this Objet.
*/
private char[] mInputBuffer;
/**
* Character offset of first char in input buffer; -1 to indicate
* that input buffer currently does not contain any useful char data
*/
private int mInputStart;
private int mInputLen;
// // // Internal non-shared collector buffers:
/**
* List of segments prior to currently active segment.
*/
private ArrayList mSegments;
// // // Currently used segment; not (yet) contained in mSegments
/**
* Amount of characters in segments in {@link mSegments}
*/
private int mSegmentSize;
private char[] mCurrentSegment;
/**
* Number of characters in currently active (last) segment
*/
private int mCurrentSize;
// // // Temporary caching for Objects to return
/**
* String that will be constructed when the whole contents are
* needed; will be temporarily stored in case asked for again.
*/
private String mResultString;
private char[] mResultArray;
// // // Canonical indentation objects (up to 32 spaces, 8 tabs)
public final static int MAX_INDENT_SPACES = 32;
public final static int MAX_INDENT_TABS = 8;
// Let's add one more space at the end, for safety...
private final static String sIndSpaces =
// 123456789012345678901234567890123
"\n ";
private final static char[] sIndSpacesArray = sIndSpaces.toCharArray();
private final static String[] sIndSpacesStrings = new String[sIndSpacesArray.length];
private final static String sIndTabs =
// 1 2 3 4 5 6 7 8 9
"\n\t\t\t\t\t\t\t\t\t";
private final static char[] sIndTabsArray = sIndTabs.toCharArray();
private final static String[] sIndTabsStrings = new String[sIndTabsArray.length];
/*
//////////////////////////////////////////////
// Life-cycle
//////////////////////////////////////////////
*/
private TextBuffer(int initialSize, ReaderConfig cfg)
{
mInitialBufSize = initialSize;
mConfig = cfg;
}
public static TextBuffer createRecyclableBuffer(ReaderConfig cfg)
{
return new TextBuffer(DEF_INITIAL_BUFFER_SIZE, cfg);
}
public static TextBuffer createTemporaryBuffer(int initialSize)
{
return new TextBuffer(initialSize, null);
}
/**
* Method called to indicate that the underlying buffers should now
* be recycled if they haven't yet been recycled. Although caller
* can still use this text buffer, it is not advisable to call this
* method if that is likely, since next time a buffer is needed,
* buffers need to reallocated.
* Note: calling this method automatically also clears contents
* of the buffer.
*/
public void recycle(boolean force)
{
if (mConfig != null && mCurrentSegment != null) {
if (force) {
/* If we are allowed to wipe out all existing data, it's
* quite easy; we'll just wipe out contents, and return
* biggest buffer:
*/
resetWithEmpty();
} else {
/* But if there's non-shared data (ie. buffer is still
* in use), can't return it yet:
*/
if (mInputStart < 0 && (mSegmentSize + mCurrentSize) > 0) {
return;
}
// If no data (or only shared data), can continue
if (mSegments != null && mSegments.size() > 0) {
// No need to use anything from list, curr segment not null
mSegments.clear();
mSegmentSize = 0;
}
}
char[] buf = mCurrentSegment;
mCurrentSegment = null;
mConfig.freeMediumCBuffer(buf);
}
}
/**
* Method called to clear out any content text buffer may have, and
* initializes buffer to use non-shared data.
*/
public void resetWithEmpty()
{
//System.out.println("[DEBUG] resetWithEmpty");
mInputBuffer = null;
mInputStart = -1; // indicates shared buffer not used
mInputLen = 0;
mResultString = null;
mResultArray = null;
// And then reset internal input buffers, if necessary:
if (mSegments != null && mSegments.size() > 0) {
/* Let's start using _last_ segment from list; for one, it's
* the biggest one, and it's also most likely to be cached
*/
mCurrentSegment = (char[]) mSegments.get(mSegments.size() - 1);
mSegments.clear();
mSegmentSize = 0;
}
mCurrentSize = 0;
}
/**
* Method called to initialize the buffer with a shared copy of data;
* this means that buffer will just have pointers to actual data. It
* also means that if anything is to be appended to the buffer, it
* will first have to unshare it (make a local copy).
*/
public void resetWithShared(char[] buf, int start, int len)
{
//System.out.println("[DEBUG] resetWithShared, "+len+" chars ("+new String(buf, start, len)+")");
// Let's first mark things we need about input buffer
mInputBuffer = buf;
mInputStart = start;
mInputLen = len;
// Then clear intermediate values, if any:
mResultString = null;
mResultArray = null;
// And then reset internal input buffers, if necessary:
if (mSegments != null && mSegments.size() > 0) {
/* Let's start using _last_ segment from list; for one, it's
* the biggest one, and it's also most likely to be cached
*/
mCurrentSegment = (char[]) mSegments.get(mSegments.size() - 1);
mSegments.clear();
mCurrentSize = mSegmentSize = 0;
}
}
public void resetWithCopy(char[] buf, int start, int len)
{
//System.out.println("[DEBUG] resetWithCopy, start "+start+", len "+len);
mInputBuffer = null;
mInputStart = -1; // indicates shared buffer not used
mInputLen = 0;
mResultString = null;
mResultArray = null;
// And then reset internal input buffers, if necessary:
if (mSegments != null && mSegments.size() > 0) {
/* Let's start using _last_ segment from list; for one, it's
* the biggest one, and it's also most likely to be cached
*/
mCurrentSegment = (char[]) mSegments.get(mSegments.size() - 1);
mSegments.clear();
} else {
if (mCurrentSegment == null) {
mCurrentSegment = allocBuffer(mInitialBufSize);
}
}
mCurrentSize = mSegmentSize = 0;
append(buf, start, len);
}
/**
* Method called to make sure there is a non-shared segment to use, without
* appending any content yet.
*/
public void resetInitialized()
{
resetWithEmpty();
if (mCurrentSegment == null) {
mCurrentSegment = allocBuffer(mInitialBufSize);
}
}
private final char[] allocBuffer(int needed)
{
char[] buf = null;
if (mConfig != null) {
buf = mConfig.allocMediumCBuffer(needed);
if (buf != null) {
return buf;
}
}
return new char[needed];
}
public void resetWithIndentation(int indCharCount, char indChar)
{
mInputStart = 0;
mInputLen = indCharCount+1;
String text;
if (indChar == '\t') { // tabs?
mInputBuffer = sIndTabsArray;
text = sIndTabsStrings[indCharCount];
if (text == null) {
sIndTabsStrings[indCharCount] = text = sIndTabs.substring(0, mInputLen);
}
} else { // nope, spaces (should assert indChar?)
mInputBuffer = sIndSpacesArray;
text = sIndSpacesStrings[indCharCount];
if (text == null) {
sIndSpacesStrings[indCharCount] = text = sIndSpaces.substring(0, mInputLen);
}
}
mResultString = text;
/* Should not need the explicit non-shared array; no point in
* pre-populating it (can be changed if this is not true)
*/
mResultArray = null;
// And then reset internal input buffers, if necessary:
if (mSegments != null && mSegments.size() > 0) {
mCurrentSegment = (char[]) mSegments.get(mSegments.size() - 1);
mSegments.clear();
mCurrentSize = mSegmentSize = 0;
}
}
/*
//////////////////////////////////////////////
// Accessors for implementing StAX interface:
//////////////////////////////////////////////
*/
/**
* @return Number of characters currently stored by this collector
*/
public int size() {
if (mInputStart >= 0) { // shared copy from input buf
return mInputLen;
}
// local segmented buffers
return mSegmentSize + mCurrentSize;
}
public int getTextStart()
{
/* Only shared input buffer can have non-zero offset; buffer
* segments start at 0, and if we have to create a combo buffer,
* that too will start from beginning of the buffer
*/
return (mInputStart >= 0) ? mInputStart : 0;
}
public char[] getTextBuffer()
{
// Are we just using shared input buffer?
if (mInputStart >= 0) {
return mInputBuffer;
}
// Nope; but does it fit in just one segment?
if (mSegments == null || mSegments.size() == 0) {
return mCurrentSegment;
}
// Nope, need to have/create a non-segmented array and return it
return contentsAsArray();
}
/*
//////////////////////////////////////////////
// Accessors:
//////////////////////////////////////////////
*/
public String contentsAsString()
{
if (mResultString == null) {
// Has array been requested? Can make a shortcut, if so:
if (mResultArray != null) {
mResultString = new String(mResultArray);
} else {
// Do we use shared array?
if (mInputStart >= 0) {
if (mInputLen < 1) {
return (mResultString = "");
}
mResultString = new String(mInputBuffer, mInputStart, mInputLen);
} else { // nope... need to copy
// But first, let's see if we have just one buffer
int segLen = mSegmentSize;
int currLen = mCurrentSize;
if (segLen == 0) { // yup
mResultString = (currLen == 0) ? "" : new String(mCurrentSegment, 0, currLen);
} else { // no, need to combine
StringBuffer sb = new StringBuffer(segLen + currLen);
// First stored segments
if (mSegments != null) {
for (int i = 0, len = mSegments.size(); i < len; ++i) {
char[] curr = (char[]) mSegments.get(i);
sb.append(curr, 0, curr.length);
}
}
// And finally, current segment:
sb.append(mCurrentSegment, 0, mCurrentSize);
mResultString = sb.toString();
}
}
}
}
return mResultString;
}
public char[] contentsAsArray()
{
char[] result = mResultArray;
if (result == null) {
mResultArray = result = buildResultArray();
}
return result;
}
public int contentsToArray(int srcStart, char[] dst, int dstStart, int len) {
//System.out.println("[DEBUG]: TextBuffer, contentsToArray, src "+srcStart+", dst "+dstStart+", len "+len);
// Easy to copy from shared buffer:
if (mInputStart >= 0) {
//System.out.println("[DEBUG]: is shared, start: "+mInputStart);
int amount = mInputLen - srcStart;
if (amount > len) {
amount = len;
} else if (amount < 0) {
amount = 0;
}
if (amount > 0) {
System.arraycopy(mInputBuffer, mInputStart+srcStart,
dst, dstStart, amount);
}
return amount;
}
/* Could also check if we have array, but that'd only help with
* braindead clients that get full array first, then segments...
* which hopefully aren't that common
*/
//System.out.println("[DEBUG]: is NOT shared, segs: "+((mSegments == null) ? 0 : mSegments.size()));
// Copying from segmented array is bit more involved:
int totalAmount = 0;
if (mSegments != null) {
for (int i = 0, segc = mSegments.size(); i < segc; ++i) {
char[] segment = (char[]) mSegments.get(i);
int segLen = segment.length;
int amount = segLen - srcStart;
if (amount < 1) { // nothing from this segment?
srcStart -= segLen;
continue;
}
if (amount >= len) { // can get rest from this segment?
System.arraycopy(segment, srcStart, dst, dstStart, len);
return (totalAmount + len);
}
// Can get some from this segment, offset becomes zero:
System.arraycopy(segment, srcStart, dst, dstStart, amount);
totalAmount += amount;
dstStart += amount;
len -= amount;
srcStart = 0;
}
}
// Need to copy anything from last segment?
if (len > 0) {
int maxAmount = mCurrentSize - srcStart;
if (len > maxAmount) {
len = maxAmount;
}
if (len > 0) { // should always be true
System.arraycopy(mCurrentSegment, srcStart, dst, dstStart, len);
totalAmount += len;
}
}
return totalAmount;
}
/**
* Method that will stream contents of this buffer into specified
* Writer.
*/
public int rawContentsTo(Writer w)
throws IOException
{
// Let's first see if we have created helper objects:
if (mResultArray != null) {
w.write(mResultArray);
return mResultArray.length;
}
if (mResultString != null) {
w.write(mResultString);
return mResultString.length();
}
// Do we use shared array?
if (mInputStart >= 0) {
if (mInputLen > 0) {
w.write(mInputBuffer, mInputStart, mInputLen);
}
return mInputLen;
}
// Nope, need to do full segmented output
int rlen = 0;
if (mSegments != null) {
for (int i = 0, len = mSegments.size(); i < len; ++i) {
char[] ch = (char[]) mSegments.get(i);
w.write(ch);
rlen += ch.length;
}
}
if (mCurrentSize > 0) {
w.write(mCurrentSegment, 0, mCurrentSize);
rlen += mCurrentSize;
}
return rlen;
}
public Reader rawContentsViaReader()
throws IOException
{
// Let's first see if we have created helper objects:
if (mResultArray != null) {
return new CharArrayReader(mResultArray);
}
if (mResultString != null) {
return new StringReader(mResultString);
}
// Do we use shared array?
if (mInputStart >= 0) {
if (mInputLen > 0) {
return new CharArrayReader(mInputBuffer, mInputStart, mInputLen);
}
return new StringReader("");
}
// or maybe it's all in the current segment
if (mSegments == null || mSegments.size() == 0) {
return new CharArrayReader(mCurrentSegment, 0, mCurrentSize);
}
// Nope, need to do full segmented output
return new BufferReader(mSegments, mCurrentSegment, mCurrentSize);
}
public boolean isAllWhitespace()
{
if (mInputStart >= 0) { // using single shared buffer?
char[] buf = mInputBuffer;
int i = mInputStart;
int last = i + mInputLen;
for (; i < last; ++i) {
if (buf[i] > 0x0020) {
return false;
}
}
return true;
}
// Nope, need to do full segmented output
if (mSegments != null) {
for (int i = 0, len = mSegments.size(); i < len; ++i) {
char[] buf = (char[]) mSegments.get(i);
for (int j = 0, len2 = buf.length; j < len2; ++j) {
if (buf[j] > 0x0020) {
return false;
}
}
}
}
char[] buf = mCurrentSegment;
for (int i = 0, len = mCurrentSize; i < len; ++i) {
if (buf[i] > 0x0020) {
return false;
}
}
return true;
}
/**
* Method that can be used to check if the contents of the buffer end
* in specified String.
*
* @return True if the textual content buffer contains ends with the
* specified String; false otherwise
*/
public boolean endsWith(String str)
{
/* Let's just play this safe; should seldom if ever happen...
* and because of that, can be sub-optimal, performancewise, to
* alternatives.
*/
if (mInputStart >= 0) {
unshare(16);
}
int segIndex = (mSegments == null) ? 0 : mSegments.size();
int inIndex = str.length() - 1;
char[] buf = mCurrentSegment;
int bufIndex = mCurrentSize-1;
while (inIndex >= 0) {
if (str.charAt(inIndex) != buf[bufIndex]) {
return false;
}
if (--inIndex == 0) {
break;
}
if (--bufIndex < 0) {
if (--segIndex < 0) { // no more data?
return false;
}
buf = (char[]) mSegments.get(segIndex);
bufIndex = buf.length-1;
}
}
return true;
}
/**
* Note: it is assumed that this method is not used often enough to
* be a bottleneck, or for long segments. Based on this, it is optimized
* for common simple cases where there is only one single character
* segment to use; fallback for other cases is to create such segment.
*/
public boolean equalsString(String str)
{
int expLen = str.length();
// First the easy check; if we have a shared buf:
if (mInputStart >= 0) {
if (mInputLen != expLen) {
return false;
}
for (int i = 0; i < expLen; ++i) {
if (str.charAt(i) != mInputBuffer[mInputStart+i]) {
return false;
}
}
return true;
}
// Otherwise, segments:
if (expLen != size()) {
return false;
}
char[] seg;
if (mSegments == null || mSegments.size() == 0) {
// just one segment, still easy
seg = mCurrentSegment;
} else {
/* Ok; this is the sub-optimal case. Could obviously juggle through
* segments, but probably not worth the hassle, we seldom if ever
* get here...
*/
seg = contentsAsArray();
}
for (int i = 0; i < expLen; ++i) {
if (seg[i] != str.charAt(i)) {
return false;
}
}
return true;
}
/*
//////////////////////////////////////////////
// Access using SAX handlers:
//////////////////////////////////////////////
*/
public void fireSaxCharacterEvents(ContentHandler h)
throws SAXException
{
if (mResultArray != null) { // already have single array?
h.characters(mResultArray, 0, mResultArray.length);
} else if (mInputStart >= 0) { // sharing input buffer?
h.characters(mInputBuffer, mInputStart, mInputLen);
} else {
if (mSegments != null) {
for (int i = 0, len = mSegments.size(); i < len; ++i) {
char[] ch = (char[]) mSegments.get(i);
h.characters(ch, 0, ch.length);
}
}
if (mCurrentSize > 0) {
h.characters(mCurrentSegment, 0, mCurrentSize);
}
}
}
public void fireSaxSpaceEvents(ContentHandler h)
throws SAXException
{
if (mResultArray != null) { // only happens for indentation
h.ignorableWhitespace(mResultArray, 0, mResultArray.length);
} else if (mInputStart >= 0) { // sharing input buffer?
h.ignorableWhitespace(mInputBuffer, mInputStart, mInputLen);
} else {
if (mSegments != null) {
for (int i = 0, len = mSegments.size(); i < len; ++i) {
char[] ch = (char[]) mSegments.get(i);
h.ignorableWhitespace(ch, 0, ch.length);
}
}
if (mCurrentSize > 0) {
h.ignorableWhitespace(mCurrentSegment, 0, mCurrentSize);
}
}
}
public void fireSaxCommentEvent(LexicalHandler h)
throws SAXException
{
// Comment can not be split, so may need to combine the array
if (mResultArray != null) { // only happens for indentation
h.comment(mResultArray, 0, mResultArray.length);
} else if (mInputStart >= 0) { // sharing input buffer?
h.comment(mInputBuffer, mInputStart, mInputLen);
} else if (mSegments != null && mSegments.size() > 0) {
char[] ch = contentsAsArray();
h.comment(ch, 0, ch.length);
} else {
h.comment(mCurrentSegment, 0, mCurrentSize);
}
}
public void fireDtdCommentEvent(DTDEventListener l)
{
// Comment can not be split, so may need to combine the array
if (mResultArray != null) { // only happens for indentation
l.dtdComment(mResultArray, 0, mResultArray.length);
} else if (mInputStart >= 0) { // sharing input buffer?
l.dtdComment(mInputBuffer, mInputStart, mInputLen);
} else if (mSegments != null && mSegments.size() > 0) {
char[] ch = contentsAsArray();
l.dtdComment(ch, 0, ch.length);
} else {
l.dtdComment(mCurrentSegment, 0, mCurrentSize);
}
}
/*
//////////////////////////////////////////////
// Support for validation
//////////////////////////////////////////////
*/
public void validateText(XMLValidator vld, boolean lastSegment)
throws XMLValidationException
{
// Shared buffer? Let's just pass that
if (mInputStart >= 0) {
vld.validateText(mInputBuffer, mInputStart, mInputStart + mInputLen, lastSegment);
} else {
/* Otherwise, can either create a combine buffer, or construct
* a String. While former could be more efficient, let's do latter
* for now since current validator implementations work better
* with Strings.
*/
vld.validateText(contentsAsString(), lastSegment);
}
}
/*
//////////////////////////////////////////////
// Public mutators:
//////////////////////////////////////////////
*/
/**
* Method called to make sure that buffer is not using shared input
* buffer; if it is, it will copy such contents to private buffer.
*/
public void ensureNotShared() {
if (mInputStart >= 0) {
unshare(16);
}
}
public void append(char c) {
// Using shared buffer so far?
if (mInputStart >= 0) {
unshare(16);
}
mResultString = null;
mResultArray = null;
// Room in current segment?
char[] curr = mCurrentSegment;
if (mCurrentSize >= curr.length) {
expand(1);
}
curr[mCurrentSize++] = c;
}
public void append(char[] c, int start, int len)
{
// Can't append to shared buf (sanity check)
if (mInputStart >= 0) {
unshare(len);
}
mResultString = null;
mResultArray = null;
// Room in current segment?
char[] curr = mCurrentSegment;
int max = curr.length - mCurrentSize;
if (max >= len) {
System.arraycopy(c, start, curr, mCurrentSize, len);
mCurrentSize += len;
} else {
// No room for all, need to copy part(s):
if (max > 0) {
System.arraycopy(c, start, curr, mCurrentSize, max);
start += max;
len -= max;
}
/* And then allocate new segment; we are guaranteed to now
* have enough room in segment.
*/
expand(len); // note: curr != mCurrentSegment after this
System.arraycopy(c, start, mCurrentSegment, 0, len);
mCurrentSize = len;
}
}
public void append(String str)
{
// Can't append to shared buf (sanity check)
int len = str.length();
if (mInputStart >= 0) {
unshare(len);
}
mResultString = null;
mResultArray = null;
// Room in current segment?
char[] curr = mCurrentSegment;
int max = curr.length - mCurrentSize;
if (max >= len) {
str.getChars(0, len, curr, mCurrentSize);
mCurrentSize += len;
} else {
// No room for all, need to copy part(s):
if (max > 0) {
str.getChars(0, max, curr, mCurrentSize);
len -= max;
}
/* And then allocate new segment; we are guaranteed to now
* have enough room in segment.
*/
expand(len);
str.getChars(max, len, mCurrentSegment, 0);
mCurrentSize = len;
}
}
/*
//////////////////////////////////////////////
// Raw access, for high-performance use:
//////////////////////////////////////////////
*/
public char[] getCurrentSegment()
{
/* Since the intention of the caller is to directly add stuff into
* buffers, we should NOT have anything in shared buffer... ie. may
* need to unshare contents.
*/
if (mInputStart >= 0) {
unshare(1);
} else {
char[] curr = mCurrentSegment;
if (curr == null) {
mCurrentSegment = allocBuffer(mInitialBufSize);
} else if (mCurrentSize >= curr.length) {
// Plus, we better have room for at least one more char
expand(1);
}
}
return mCurrentSegment;
}
public int getCurrentSegmentSize() {
return mCurrentSize;
}
public void setCurrentLength(int len) {
mCurrentSize = len;
}
public char[] finishCurrentSegment()
{
if (mSegments == null) {
mSegments = new ArrayList();
}
mSegments.add(mCurrentSegment);
int oldLen = mCurrentSegment.length;
mSegmentSize += oldLen;
// Let's grow segments by 50%
char[] curr = new char[oldLen + (oldLen >> 1)];
mCurrentSize = 0;
mCurrentSegment = curr;
return curr;
}
/*
//////////////////////////////////////////////
// Standard methods:
//////////////////////////////////////////////
*/
/**
* Note: calling this method may not be as efficient as calling
* {@link #contentsAsString}, since it's not guaranteed that resulting
* String is cached.
*/
public String toString() {
return contentsAsString();
}
/*
//////////////////////////////////////////////
// Internal methods:
//////////////////////////////////////////////
*/
/**
* Method called if/when we need to append content when we have been
* initialized to use shared buffer.
*/
public void unshare(int needExtra)
{
//System.out.println("[DEBUG] unshare");
int len = mInputLen;
mInputLen = 0;
char[] inputBuf = mInputBuffer;
mInputBuffer = null;
int start = mInputStart;
mInputStart = -1;
// Is buffer big enough, or do we need to reallocate?
int needed = len+needExtra;
if (mCurrentSegment == null || needed > mCurrentSegment.length) {
mCurrentSegment = allocBuffer((needed > mInitialBufSize) ?
needed : mInitialBufSize);
}
if (len > 0) {
System.arraycopy(inputBuf, start, mCurrentSegment, 0, len);
}
mSegmentSize = 0;
mCurrentSize = len;
}
/**
* Method called when current segment is full, to allocate new
* segment.
*/
private void expand(int minNewSegmentSize)
{
// First, let's move current segment to segment list:
if (mSegments == null) {
mSegments = new ArrayList();
}
char[] curr = mCurrentSegment;
mSegments.add(curr);
mSegmentSize += curr.length;
int oldLen = curr.length;
// Let's grow segments by 50% minimum
int sizeAddition = oldLen >> 1;
if (sizeAddition < minNewSegmentSize) {
sizeAddition = minNewSegmentSize;
}
curr = new char[oldLen + sizeAddition];
mCurrentSize = 0;
mCurrentSegment = curr;
}
private char[] buildResultArray()
{
if (mResultString != null) { // Can take a shortcut...
return mResultString.toCharArray();
}
char[] result;
// Do we use shared array?
if (mInputStart >= 0) {
if (mInputLen < 1) {
return EmptyIterator.getEmptyCharArray();
}
result = new char[mInputLen];
System.arraycopy(mInputBuffer, mInputStart, result, 0,
mInputLen);
} else { // nope
int size = size();
if (size < 1) {
return EmptyIterator.getEmptyCharArray();
}
int offset = 0;
result = new char[size];
if (mSegments != null) {
for (int i = 0, len = mSegments.size(); i < len; ++i) {
char[] curr = (char[]) mSegments.get(i);
int currLen = curr.length;
System.arraycopy(curr, 0, result, offset, currLen);
offset += currLen;
}
}
System.arraycopy(mCurrentSegment, 0, result, offset, mCurrentSize);
}
return result;
}
private final static class BufferReader
extends Reader
{
ArrayList _Segments;
char[] _CurrentSegment;
final int _CurrentLength;
int _SegmentIndex;
int _SegmentOffset;
int _CurrentOffset;
public BufferReader(ArrayList segs, char[] currSeg, int currSegLen)
{
_Segments = segs;
_CurrentSegment = currSeg;
_CurrentLength = currSegLen;
_SegmentIndex = 0;
_SegmentOffset = _CurrentOffset = 0;
}
public void close() {
_Segments = null;
_CurrentSegment = null;
}
public void mark(int x)
throws IOException
{
throw new IOException("mark() not supported");
}
public boolean markSupported() {
return false;
}
public int read(char[] cbuf, int offset, int len)
{
if (len < 1) {
return 0;
}
int origOffset = offset;
// First need to copy stuff from previous segments
while (_Segments != null) {
char[] curr = (char[]) _Segments.get(_SegmentIndex);
int max = curr.length - _SegmentOffset;
if (len <= max) { // this is enough
System.arraycopy(curr, _SegmentOffset, cbuf, offset, len);
_SegmentOffset += len;
offset += len;
return (offset - origOffset);
}
// Not enough, but helps...
if (max > 0) {
System.arraycopy(curr, _SegmentOffset, cbuf, offset, max);
offset += max;
}
if (++_SegmentIndex >= _Segments.size()) { // last one
_Segments = null;
} else {
_SegmentOffset = 0;
}
}
// ok, anything to copy from the active segment?
if (len > 0 && _CurrentSegment != null) {
int max = _CurrentLength - _CurrentOffset;
if (len >= max) { // reading it all
len = max;
System.arraycopy(_CurrentSegment, _CurrentOffset,
cbuf, offset, len);
_CurrentSegment = null;
} else {
System.arraycopy(_CurrentSegment, _CurrentOffset,
cbuf, offset, len);
_CurrentOffset += len;
}
offset += len;
}
return (origOffset == offset) ? -1 : (offset - origOffset);
}
public boolean ready() {
return true;
}
public void reset()
throws IOException
{
throw new IOException("reset() not supported");
}
public long skip(long amount)
{
/* Note: implementation is almost identical to that of read();
* difference being that no data is copied.
*/
if (amount < 0) {
return 0L;
}
long origAmount= amount;
while (_Segments != null) {
char[] curr = (char[]) _Segments.get(_SegmentIndex);
int max = curr.length - _SegmentOffset;
if (max >= amount) { // this is enough
_SegmentOffset += (int) amount;
return origAmount;
}
// Not enough, but helps...
amount -= max;
if (++_SegmentIndex >= _Segments.size()) { // last one
_Segments = null;
} else {
_SegmentOffset = 0;
}
}
// ok, anything left in the active segment?
if (amount > 0 && _CurrentSegment != null) {
int max = _CurrentLength - _CurrentOffset;
if (amount >= max) { // reading it all
amount -= max;
_CurrentSegment = null;
} else {
amount = 0L;
_CurrentOffset += (int) amount;
}
}
return (amount == origAmount) ? -1L : (origAmount - amount);
}
}
}