/*
Derby - Class org.apache.derbyDemo.vtis.example.SubversionLogVTI
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package org.apache.derbyDemo.vtis.example;
import java.io.*;
import java.sql.*;
import java.text.SimpleDateFormat;
import org.apache.derbyDemo.vtis.core.*;
/**
* <p>
* This VTI makes a table out of the output of the subversion log ("svn log") command.
* </p>
*/
public class SubversionLogVTI extends FlatFileVTI
{
///////////////////////////////////////////////////////////////////////////////////
//
// CONSTANTS
//
///////////////////////////////////////////////////////////////////////////////////
private static final String[] COLUMN_NAMES =
{
"XID", "committer", "commit_time", "line_count", "description"
};
private static final int XID = 0;
private static final int COMMITTER = XID + 1;
private static final int COMMIT_TIME = COMMITTER + 1;
private static final int LINE_COUNT = COMMIT_TIME + 1;
private static final int DESCRIPTION = LINE_COUNT + 1;
private static final String RECORD_HEADER = "------------------------------------------------------------------------";
///////////////////////////////////////////////////////////////////////////////////
//
// STATE
//
///////////////////////////////////////////////////////////////////////////////////
private SimpleDateFormat _dateFormatter;
///////////////////////////////////////////////////////////////////////////////////
//
// CONSTRUCTORS
//
///////////////////////////////////////////////////////////////////////////////////
/**
* <p>
* Build a SubversionLogVTI given the name of the output file created by the
* "svn log" command.
* </p>
*/
public SubversionLogVTI( String logFileName )
{
super( COLUMN_NAMES, logFileName );
}
///////////////////////////////////////////////////////////////////////////////////
//
// TABLE FUNCTION METHOD
//
///////////////////////////////////////////////////////////////////////////////////
/**
* <p>
* This is the method which is registered as a table function.
* </p>
*/
public static ResultSet subversionLogVTI( String logFileName )
throws SQLException
{
return new SubversionLogVTI( logFileName );
}
///////////////////////////////////////////////////////////////////////////////////
//
// FlatFileVTI BEHAVIOR TO BE IMPLEMENTED BY SUBCLASSES
//
///////////////////////////////////////////////////////////////////////////////////
/**
* <p>
* Parse the next chunk of text, using readLine(), and return the next row.
* Returns null if the file is exhausted.
* </p>
*/
protected String[] parseRow( ) throws SQLException
{
String[] newRow = new String[ COLUMN_NAMES.length ];
String headerLine = readNextLine();
if ( headerLine == null ) { return null; }
if ( !isRecordHeader( headerLine ) )
{
throw new SQLException( "Badly formatted record header: " + headerLine );
}
// the next line has all of the columns except for DESCRIPTION
String mainline = readNextLine();
if ( mainline == null ) { return null; }
int oldIdx[] = new int[ 1 ];
oldIdx[ 0 ] = 0;
for ( int i = 0; i < DESCRIPTION; i++ ) { newRow[ i ] = readField( mainline, oldIdx ); }
// get the number of lines in the DESCRIPTION
int descriptionLineCount = 0;
try {
String lineCountField = newRow[ LINE_COUNT ];
if ( lineCountField != null )
{
lineCountField = lineCountField.trim();
String numberString = lineCountField.substring( 0, lineCountField.indexOf( ' ' ) );
descriptionLineCount = Integer.parseInt( numberString );
}
}
catch ( Throwable t )
{
throw wrap( "Error parsing description line count at line " + getLineNumber() + ": " + mainline, t );
}
// account for extra blank line
descriptionLineCount++;
// the rest of the record is the DESCRIPTION
StringBuffer buffer = new StringBuffer();
for ( int i = 0; i < descriptionLineCount; i++ )
{
String nextLine = readNextLine();
buffer.append( nextLine );
}
newRow[ DESCRIPTION ] = buffer.toString();
return newRow;
}
///////////////////////////////////////////////////////////////////////////////////
//
// ResultSet METHOD
//
///////////////////////////////////////////////////////////////////////////////////
/**
* <p>
* Subversion formats timestamps thusly: "2007-09-16 11:17:37 -0700 (Sun, 16 Sep 2007)"
* </p>
*/
public java.sql.Timestamp getTimestamp(int columnIndex) throws SQLException
{
String columnValue = getString( columnIndex ).trim();
try {
SimpleDateFormat dateFormatter = getDateFormatter();
java.util.Date rawDate = dateFormatter.parse( columnValue );
long time = rawDate.getTime();
return new java.sql.Timestamp( time );
} catch (Throwable t) { throw new SQLException( t.getMessage() ); }
}
///////////////////////////////////////////////////////////////////////////////////
//
// MINIONS
//
///////////////////////////////////////////////////////////////////////////////////
/**
* <p>
* Read the next field in the main line of the record. Fields are delimited
* by | or line-end.
* </p>
*/
private String readField( String mainline, int[] oldIdx )
throws SQLException
{
String result = null;
int fieldStart = oldIdx[ 0 ];
int fieldEnd = mainline.indexOf( "|", fieldStart );
if ( fieldEnd < 0 ) { fieldEnd = mainline.length(); }
// this can happen, if for instance, we encounter a badly formatted record
if ( fieldStart > fieldEnd ) { return null; }
try {
result = mainline.substring( fieldStart, fieldEnd );
if ( result != null ) { result = result.trim(); }
} catch (Throwable t)
{
throw wrap( "Bad record at line " + getLineNumber() + ". Field start = " + fieldStart + ", fieldEnd = " + fieldEnd + ": " + mainline, t );
}
oldIdx[ 0 ] = fieldEnd + 1;
return result;
}
/**
* <p>
* Returns true if a line is a record header.
* </p>
*/
private boolean isRecordHeader( String line )
{
if ( line.startsWith( RECORD_HEADER ) ) { return true; }
else { return false; }
}
/**
* <p>
* Read a line, possibly just using the last line that was pushed back.
* </p>
*/
private String readNextLine() throws SQLException
{
String retval;
retval = readLine();
return retval;
}
/**
* <p>
* Subversion formats timestamps thusly: "2007-09-16 11:17:37 -0700 (Sun, 16 Sep 2007)"
* </p>
*/
private SimpleDateFormat getDateFormatter()
{
if ( _dateFormatter == null )
{
_dateFormatter = new SimpleDateFormat( "yyyy-MM-dd HH:mm:ss Z (EEE, dd MMM yyyy)" );
}
return _dateFormatter;
}
}