/* Copyright (c) 2001-2011, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
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* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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package org.hsqldb.persist;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.lib.HsqlByteArrayOutputStream;
import org.hsqldb.rowio.RowInputInterface;
import org.hsqldb.rowio.RowInputText;
/**
* Reader for text files.
*
* @author Bob Preston (sqlbob@users dot sourceforge.net)
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.3.0
* @since 2.2.7
*/
public class TextFileReader {
private RandomAccessInterface dataFile;
private RowInputInterface rowIn;
private TextFileSettings textFileSettings;
private String header;
private boolean isReadOnly;
private HsqlByteArrayOutputStream buffer;
TextFileReader(RandomAccessInterface dataFile,
TextFileSettings textFileSettings, RowInputInterface rowIn,
boolean isReadOnly) {
this.dataFile = dataFile;
this.textFileSettings = textFileSettings;
this.rowIn = rowIn;
this.isReadOnly = isReadOnly;
this.buffer = new HsqlByteArrayOutputStream(128);
}
public RowInputInterface readObject(long pos) {
boolean hasQuote = false;
boolean complete = false;
boolean wasCR = false;
boolean wasNormal = false;
buffer.reset();
pos = findNextUsedLinePos(pos);
if (pos == -1) {
return null;
}
try {
dataFile.seek(pos);
while (!complete) {
int c = dataFile.read();
wasNormal = false;
if (c == -1) {
if (buffer.size() == 0) {
return null;
}
complete = true;
if (wasCR) {
break;
}
if (!isReadOnly) {
dataFile.write(TextFileSettings.BYTES_LINE_SEP, 0,
TextFileSettings.BYTES_LINE_SEP.length);
buffer.write(TextFileSettings.BYTES_LINE_SEP);
}
break;
}
switch (c) {
case TextFileSettings.DOUBLE_QUOTE_CHAR :
wasNormal = true;
complete = wasCR;
wasCR = false;
if (textFileSettings.isQuoted) {
hasQuote = !hasQuote;
}
break;
case TextFileSettings.CR_CHAR :
wasCR = !hasQuote;
break;
case TextFileSettings.LF_CHAR :
complete = !hasQuote;
break;
default :
wasNormal = true;
complete = wasCR;
wasCR = false;
}
buffer.write(c);
}
if (complete) {
if (wasNormal) {
buffer.setPosition(buffer.size() - 1);
}
String rowString;
try {
rowString =
buffer.toString(textFileSettings.stringEncoding);
} catch (UnsupportedEncodingException e) {
rowString = buffer.toString();
}
((RowInputText) rowIn).setSource(rowString, pos,
buffer.size());
return rowIn;
}
return null;
} catch (IOException e) {
throw Error.error(ErrorCode.TEXT_FILE_IO, e);
}
}
public int readHeaderLine() {
boolean complete = false;
boolean wasCR = false;
boolean wasNormal = false;
buffer.reset();
try {
dataFile.seek(0);
} catch (IOException e) {
throw Error.error(ErrorCode.TEXT_FILE_IO, e);
}
while (!complete) {
wasNormal = false;
int c;
try {
c = dataFile.read();
if (c == -1) {
if (buffer.size() == 0) {
return 0;
}
complete = true;
if (!isReadOnly) {
dataFile.write(TextFileSettings.BYTES_LINE_SEP, 0,
TextFileSettings.BYTES_LINE_SEP.length);
buffer.write(TextFileSettings.BYTES_LINE_SEP);
}
break;
}
} catch (IOException e) {
throw Error.error(ErrorCode.TEXT_FILE);
}
switch (c) {
case TextFileSettings.CR_CHAR :
wasCR = true;
break;
case TextFileSettings.LF_CHAR :
complete = true;
break;
default :
wasNormal = true;
complete = wasCR;
wasCR = false;
}
if (wasCR || complete) {
continue;
}
buffer.write(c);
}
if (wasNormal) {
buffer.setPosition(buffer.size() - 1);
}
try {
header = buffer.toString(textFileSettings.stringEncoding);
} catch (UnsupportedEncodingException e) {
header = buffer.toString();
}
return buffer.size();
}
// fredt - new method
/**
* Searches from file pointer, pos, and finds the beginning of the first
* line that contains any non-space character. Increments the row counter
* when a blank line is skipped.
*
* If none found return -1
*/
private long findNextUsedLinePos(long pos) {
try {
long firstPos = pos;
long currentPos = pos;
boolean wasCR = false;
dataFile.seek(pos);
while (true) {
int c = dataFile.read();
currentPos++;
switch (c) {
case TextFileSettings.CR_CHAR :
wasCR = true;
break;
case TextFileSettings.LF_CHAR :
wasCR = false;
((RowInputText) rowIn).skippedLine();
firstPos = currentPos;
break;
case ' ' :
if (wasCR) {
wasCR = false;
((RowInputText) rowIn).skippedLine();
}
break;
case -1 :
return -1;
default :
if (wasCR) {
wasCR = false;
((RowInputText) rowIn).skippedLine();
}
return firstPos;
}
}
} catch (IOException e) {
throw Error.error(ErrorCode.TEXT_FILE_IO, e);
}
}
public String getHeaderLine() {
return header;
}
public int getLineNumber() {
return ((RowInputText) rowIn).getLineNumber();
}
}