/*
* Copyright (C) 2002-2011 XimpleWare, info@ximpleware.com
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
package com.ximpleware.extended;
import java.lang.IndexOutOfBoundsException;
import java.lang.NullPointerException;
import java.lang.IllegalArgumentException;
import java.util.ArrayList;
/**
* A fast, unsynchronized, chunk-based int buffer
* identical with com.ximpleware.FastIntBuffer
*
*/
public class FastIntBuffer implements IIntBuffer {
/* bufferArrayList is a resizable array list of int buffers
*
*/
private ArrayList bufferArrayList;
/**
* Total capacity of the IntBuffer
*/
private int capacity;
/**
* Page size of the incremental growth of the Int Buffer
*/
private int pageSize;
/**
* Total number of integers in the IntBuffer
*/
private int size;
private int exp;
private int r;
/**
* FastIntBuffer constructor comment.
*/
public FastIntBuffer() {
size = 0;
capacity = 0;
pageSize = 1024;
exp = 10;
r = 1023;
bufferArrayList = new ArrayList();
}
/**
* Constructor with adjustable buffer page size of the value bfz
* @param e int is the size of the internal buffer
*/
public FastIntBuffer(int e) {
if (e < 0) {
throw new IllegalArgumentException();
}
capacity = size = 0;
pageSize = 1<<e;
exp = e;
r = pageSize -1;
bufferArrayList = new ArrayList();
}
/**
* Append an int array to the end of this buffer instance
* @param int_array int[]
*/
public void append(int[] int_array) {
if (int_array == null) {
throw new NullPointerException();
}
// no additional buffer space needed
int lastBufferIndex;
int[] lastBuffer;
if (bufferArrayList.size() == 0) {
lastBuffer = new int[pageSize];
bufferArrayList.add(lastBuffer);
lastBufferIndex = 0;
capacity = pageSize;
} else {
lastBufferIndex = Math.min((size>>exp),//+(((size&r)==0)? 0:1),
bufferArrayList.size() - 1);
lastBuffer = (int[]) bufferArrayList.get(lastBufferIndex);
}
if ((this.size + int_array.length) < this.capacity) {
//get the last buffer from the bufferListArray
//obtain the starting offset in that buffer to which the data is to be copied
//update length
//System.arraycopy(input, 0, lastBuffer, size % pageSize, input.length);
if (this.size + int_array.length< ((lastBufferIndex+1)<<exp)){
System.arraycopy(int_array, 0, lastBuffer, size & r, int_array.length);
}
else {
int offset = pageSize -(size&r);
// copy the first part
System.arraycopy(int_array, 0, lastBuffer, size & r, offset);
// copy the middle part
int l = int_array.length - offset;
int k = (l)>> exp;
int z;
for (z=1;z<=k;z++){
System.arraycopy(int_array,offset,
(int[]) bufferArrayList.get(lastBufferIndex+z), 0, pageSize);
offset += pageSize;
}
// copy the last part
System.arraycopy(int_array, offset,
(int[]) bufferArrayList.get(lastBufferIndex+z), 0, l & r);
}
size += int_array.length;
return;
} else // new buffers needed
{
// compute the number of additional buffers needed
// int n =
// ((int) ((int_array.length + size) / pageSize))
// + (((int_array.length + size) % pageSize) > 0 ? 1 : 0)
// - (int) (capacity / pageSize);
int n =
((int_array.length + size) >> exp)
+ (((int_array.length + size) &r) > 0 ? 1 : 0)
- (capacity >> exp);
// create these buffers
// add to bufferArrayList
//System.arraycopy(int_array, 0, lastBuffer, size % pageSize, capacity - size);
System.arraycopy(int_array, 0, lastBuffer, size& r, capacity - size);
for (int i = 0; i < n; i++) {
int[] newBuffer = new int[pageSize];
if (i < n - 1) {
// full copy
System.arraycopy(
int_array,
pageSize * i + capacity - size,
newBuffer,
0,
pageSize);
} else {
// last page
System.arraycopy(
int_array,
pageSize * i + capacity - size,
newBuffer,
0,
int_array.length + this.size - capacity - pageSize*i);
}
bufferArrayList.add(newBuffer);
}
// update length
size += int_array.length;
// update capacity
capacity += n * pageSize;
// update
}
}
/**
* Append a single int to the end of this buffer Instance
* @param i int
*/
public void append(int i) {
int[] lastBuffer;
int lastBufferIndex;
if (bufferArrayList.size() == 0) {
lastBuffer = new int[pageSize];
bufferArrayList.add(lastBuffer);
capacity = pageSize;
} else {
lastBufferIndex = Math.min((size>>exp),//+(((size&r)==0)? 0:1),
bufferArrayList.size() - 1);
lastBuffer = (int[]) bufferArrayList.get(lastBufferIndex);
//lastBuffer = (int[]) bufferArrayList.get(bufferArrayList.size() - 1);
}
if ((this.size + 1) <= this.capacity) {
//get the last buffer from the bufferListArray
//obtain the starting offset in that buffer to which the data is to be copied
//update length
//System.arraycopy(long_array, 0, lastBuffer, size % pageSize, long_array.length);
lastBuffer[size & r] = i;
// lastBuffer[size % pageSize] = i;
size += 1;
} else // new buffers needed
{
int[] newBuffer = new int[pageSize];
size++;
capacity += pageSize;
bufferArrayList.add(newBuffer);
newBuffer[0] = i;
}
}
/**
* Returns the total allocated capacity of this buffer instance.
* @return int
*/
public int getCapacity() {
return capacity;
}
/**
* Returns a single int array representing every int in this buffer instance
* @return int[] (null if there isn't anything left in the buffer
* @param startingOffset int
* @param len int
* @return int[]
*/
public int[] getIntArray(int startingOffset, int len) {
if (size <= 0 || startingOffset < 0) {
throw (new IllegalArgumentException());
}
if ((startingOffset + len) > size()) {
throw (new IndexOutOfBoundsException());
}
int[] result = new int[len]; // allocate result array
// int first_index = (int) (startingOffset / pageSize);
// int last_index = (int) ((startingOffset + len) / pageSize);
// if ((startingOffset + len) % pageSize == 0) {
// last_index--;
// }
int first_index = startingOffset >> exp;
int last_index = (startingOffset + len)>> exp;
if (((startingOffset + len) & r) == 0) {
last_index--;
}
if (first_index == last_index) {
// to see if there is a need to go across buffer boundry
System.arraycopy(
(int[]) (bufferArrayList.get(first_index)),
// startingOffset % pageSize,
startingOffset & r,
result,
0,
len);
} else {
int int_array_offset = 0;
for (int i = first_index; i <= last_index; i++) {
int[] currentChunk = (int[]) bufferArrayList.get(i);
if (i == first_index) // first section
{
System.arraycopy(
currentChunk,
// startingOffset % pageSize,
startingOffset & r,
result,
0,
// pageSize - (startingOffset % pageSize));
pageSize - (startingOffset & r));
// int_array_offset += pageSize - (startingOffset) % pageSize;
int_array_offset += pageSize - (startingOffset & r);
} else if (i == last_index) // last sections
{
System.arraycopy(
currentChunk,
0,
result,
int_array_offset,
len - int_array_offset);
} else {
System.arraycopy(currentChunk, 0, result, int_array_offset, pageSize);
int_array_offset += pageSize;
}
}
}
return result;
}
/**
* Returns the page size of this buffer instance.
* Creation date: (7/17/03 6:38:02 PM)
* @return int
*/
public int getPageSize() {
return pageSize;
}
/**
* Get the int at the location specified by index.
* @return int
* @param index int
*/
public int intAt(int index) {
if (index < 0 || index > size()-1) {
throw new IndexOutOfBoundsException();
}
// int pageNum = (int) index / pageSize;
int pageNum = index>>exp;
//System.out.println("page Number is "+pageNum);
// int offset = index % pageSize;
int offset = index & r;
return ((int[]) bufferArrayList.get(pageNum))[offset];
}
/**
* Assigns a new int value to location index of the buffer instance.
* @param index int
* @param newValue int
*/
public void modifyEntry(int index, int newValue) {
if (index < 0 || index > size - 1) {
throw new IndexOutOfBoundsException();
}
// ((int[]) bufferArrayList.get((int) (index / pageSize)))[index % pageSize] =
((int[]) bufferArrayList.get((index >> exp)))[index & r] =
newValue;
}
/**
* Returns the total number of int values in the buffer instance
* @return int
*/
public int size() {
return size;
}
/**
*
* @param newSz
* @return status of resize
*
*/
public boolean resize(int newSz){
if (newSz <= capacity && newSz >=0){
size = newSz;
return true;
}
else
return false;
}
/**
* Returns the int array corresponding to all int values in this buffer instance
* @return int[] (null if the buffer is empty)
*/
public int[] toIntArray() {
if (size > 0) {
int s = size;
int[] resultArray = new int[size];
//copy all the content int into the resultArray
int array_offset = 0;
for (int i = 0; s>0; i++) {
System.arraycopy(
(int[]) bufferArrayList.get(i),
0,
resultArray,
array_offset,
(s<pageSize) ? s : pageSize);
// (i == (bufferArrayList.size() - 1)) ? size() % pageSize : pageSize);
s = s - pageSize;
array_offset += pageSize;
}
return resultArray;
}
return null;
}
/**
* set the size of int buffer to zero, capacity
* untouched so int buffer can be reused without
* any unnecessary and additional allocation
*
*/
public void clear(){
size = 0;
}
}