org.jpedal.fonts.objects.FontData 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@
*
* ---------------
* FontData.java
* ---------------
*/
package org.jpedal.fonts.objects;
import java.io.IOException;
import java.io.RandomAccessFile;
import org.jpedal.utils.LogWriter;
/**
* provides access to font data and caches large objects
*/
public class FontData {
private byte[] fontData;
/**
* flag to show if all fontData in memory or just some
*/
private boolean isInMemory;
/**
* real size of font object
*/
private int fullLength;
/**
* offset to actual block loaded
*/
private int offset;
/**
* bytes size of font we keep in memory
*/
public static int maxSizeAllowedInMemory = -1;
/**
* max size of data kept in memory at any one point
*/
private int blockSize = 8192;
private RandomAccessFile fontFile;
/**
* pass in name of temp file on disk so we can just read part at a time -
* if not part of PDF user is responsible for deleting
*
* @param cachedFile
*/
public FontData(final String cachedFile) { //, byte[] stream) {
try {
fontFile = new RandomAccessFile(cachedFile, "r");
fullLength = (int) fontFile.length();
} catch (final Exception e) {
LogWriter.writeLog("Exception: " + e.getMessage());
}
//if small read all
if (fullLength < maxSizeAllowedInMemory) {
blockSize = maxSizeAllowedInMemory;
adjustForCache(0);
isInMemory = true;
}
}
public byte getByte(int pointer) {
if (!isInMemory) {
pointer = adjustForCache(pointer);
}
// System.err.println("Now="+pointer+" "+fontData.length+" inMemory="+isInMemory);
if (pointer >= fontData.length) {
return 0;
} else {
return fontData[pointer];
}
}
/**
* check block in memory, read if not and
* adjust pointer
*
* @param pointer
* @return
*/
private int adjustForCache(final int pointer) {
//see if in memory and load if not
if (fontData == null || pointer < offset || pointer >= (offset + blockSize - 1)) {
try {
fontFile.seek(pointer);
fontData = new byte[blockSize];
fontFile.read(fontData);
} catch (final IOException e) {
LogWriter.writeLog("Exception: " + e.getMessage());
}
offset = pointer;
}
//subtract offset to make it fall in loaded range
return pointer - offset;
}
private int adjustForCache(final int pointer, final int blockSize) {
//see if in memory and load if not
//if(fontData==null || pointer=(offset+blockSize-1)){
try {
fontFile.seek(pointer);
fontData = new byte[blockSize];
fontFile.read(fontData);
} catch (final IOException e) {
LogWriter.writeLog("Exception: " + e.getMessage());
}
offset = pointer;
//}
//subtract offset to make it fall in loaded range
return pointer - offset;
}
public byte[] getBytes(int startPointer, final int length) {
if (!isInMemory) {
startPointer = adjustForCache(startPointer, length + 1);
}
final byte[] block = new byte[length];
System.arraycopy(fontData, startPointer, block, 0, length);
return block;
}
/**
* total length of FontData in bytes
*/
public int length() {
if (isInMemory) {
return fontData.length;
} else {
return fullLength;
}
}
public void close() {
if (fontFile != null) {
try {
fontFile.close();
} catch (final IOException e) {
LogWriter.writeLog("Exception: " + e.getMessage());
}
}
}
}