package com.splout.db.common;
/*
* #%L
* Splout SQL Server
* %%
* Copyright (C) 2012 Datasalt Systems S.L.
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 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 Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
* #L%
*/
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import org.apache.thrift.TBase;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TBinaryProtocol;
import org.apache.thrift.transport.TIOStreamTransport;
/**
* A simple class for reading Thrift objects (of a single type) from a file.
*
* @author Joel Meyer - simplified & modified by us
*/
public class ThriftReader {
/** File containing the objects. */
protected final File file;
/** For reading the file. */
private BufferedInputStream bufferedIn;
/** For reading the binary thrift objects. */
private TBinaryProtocol binaryIn;
/**
* Constructor.
*
* @throws FileNotFoundException
*/
public ThriftReader(File file) throws FileNotFoundException {
this.file = file;
open();
}
/**
* Opens the file for reading. Must be called before {@link read()}.
*/
private void open() throws FileNotFoundException {
bufferedIn = new BufferedInputStream(new FileInputStream(file), 2048);
binaryIn = new TBinaryProtocol(new TIOStreamTransport(bufferedIn));
}
/**
* Checks if another objects is available by attempting to read another byte from the stream.
*/
public boolean hasNext() throws IOException {
bufferedIn.mark(1);
int val = bufferedIn.read();
bufferedIn.reset();
return val != -1;
}
/**
* Reads the next object from the file.
*/
@SuppressWarnings("rawtypes")
public <T extends TBase> T read(T t) throws IOException {
try {
t.read(binaryIn);
} catch(TException e) {
throw new IOException(e);
}
return (T) t;
}
/**
* Close the file.
*/
public ThriftReader close() throws IOException {
bufferedIn.close();
return this;
}
}