org.jpedal.io.RandomAccessMemoryMapBuffer Maven / Gradle / Ivy
/*
* ===========================================
* Java Pdf Extraction Decoding Access Library
* ===========================================
*
* Project Info: http://www.idrsolutions.com
* Help section for developers at http://www.idrsolutions.com/support/
*
* (C) Copyright 1997-2017 IDRsolutions and Contributors.
*
* This file is part of JPedal/JPDF2HTML5
*
@LICENSE@
*
* ---------------
* RandomAccessMemoryMapBuffer.java
* ---------------
*/
package org.jpedal.io;
import java.io.*;
import org.jpedal.utils.LogWriter;
public class RandomAccessMemoryMapBuffer implements RandomAccessBuffer {
//private byte[] data;
private long pointer;
private int length;
private File file;
private RandomAccessFile buf;
public RandomAccessMemoryMapBuffer(final InputStream in) {
this.pointer = -1;
length = 0;
FileOutputStream to = null;
BufferedInputStream from = null;
try {
file = File.createTempFile("page", ".bin", new File(ObjectStore.temp_dir));
to = new java.io.FileOutputStream(file);
from = new BufferedInputStream(in);
//write
final byte[] buffer = new byte[65535];
int bytes_read;
while ((bytes_read = from.read(buffer)) != -1) {
to.write(buffer, 0, bytes_read);
length += bytes_read;
}
} catch (final Exception e) {
LogWriter.writeLog("Exception: " + e.getMessage());
}
//close streams
try {
if (to != null) {
to.close();
}
if (from != null) {
from.close();
}
} catch (final Exception e) {
LogWriter.writeLog("Exception " + e + " closing files");
}
try {
init();
} catch (final Exception e) {
LogWriter.writeLog("Exception: " + e.getMessage());
}
}
private void init() throws Exception {
// Create a read-only memory-mapped file
buf = new RandomAccessFile(file, "r");
}
@Override
public long getFilePointer() throws IOException {
return pointer;
}
@Override
public void seek(final long pos) throws IOException {
if (checkPos(pos)) {
this.pointer = pos;
} else {
throw new IOException("Position out of bounds");
}
}
@Override
public void close() throws IOException {
if (buf != null) {
buf.close();
buf = null;
}
this.pointer = -1;
if (file != null && file.exists()) {
file.delete();
}
}
/**/
@Override
protected void finalize() {
try {
super.finalize();
} catch (final Throwable e) {
LogWriter.writeLog("Exception: " + e.getMessage());
}
//ensure removal actual file
try {
close();
} catch (final IOException e) {
LogWriter.writeLog("Exception: " + e.getMessage());
}
} /**/
@Override
public long length() throws IOException {
if (buf != null) {
return length;
} else {
throw new IOException("Data buffer not initialized.");
}
}
@Override
public int read() throws IOException {
if (checkPos(this.pointer)) {
buf.seek(pointer++);
return b2i(buf.readByte());
} else {
return -1;
}
}
private int peek() throws IOException {
if (checkPos(this.pointer)) {
buf.seek(pointer++);
final int returnInt = b2i(buf.readByte());
pointer--; //needs to roll bakc - peek should not increment as it stops readLine working
return returnInt;
} else {
return -1;
}
}
/**
* return next line (returns null if no line)
*/
@Override
public String readLine() throws IOException {
if (this.pointer >= this.length - 1) {
return null;
} else {
final StringBuilder buf = new StringBuilder();
int c;
while ((c = read()) >= 0) {
if ((c == 10) || (c == 13)) {
if (((peek() == 10) || (peek() == 13)) && (peek() != c)) {
read();
}
break;
}
buf.append((char) c);
}
return buf.toString();
}
}
@Override
public int read(final byte[] b) throws IOException {
if (buf == null) {
throw new IOException("Data buffer not initialized.");
}
if (pointer < 0 || pointer >= length) {
return -1;
}
int length = this.length - (int) pointer;
if (length > b.length) {
length = b.length;
}
//replaced inefficient code with an improved performance version (up to ~60 %)
//buf.seek(pointer);
//buf.read(b);
//pointer += b.length;
for (int i = 0; i < length; i++) {
buf.seek(pointer++);
b[i] = buf.readByte();
}
return length;
}
private static int b2i(final byte b) {
if (b >= 0) {
return b;
}
return 256 + b;
}
private boolean checkPos(final long pos) throws IOException {
return ((pos >= 0) && (pos < length()));
}
/* returns the byte data*/
@Override
public byte[] getPdfBuffer() {
final byte[] bytes = new byte[length];
try {
buf.seek(0);
buf.read(bytes);
} catch (final IOException e) {
LogWriter.writeLog("Exception: " + e.getMessage());
}
return bytes;
}
}