com.evernote.thrift.transport.TTransport Maven / Gradle / Ivy
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/*
* 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 com.evernote.thrift.transport;
/**
* Generic class that encapsulates the I/O layer. This is basically a thin
* wrapper around the combined functionality of Java input/output streams.
*
*/
public abstract class TTransport {
/**
* Queries whether the transport is open.
*
* @return True if the transport is open.
*/
public abstract boolean isOpen();
/**
* Is there more data to be read?
*
* @return True if the remote side is still alive and feeding us
*/
public boolean peek() {
return isOpen();
}
/**
* Opens the transport for reading/writing.
*
* @throws TTransportException if the transport could not be opened
*/
public abstract void open()
throws TTransportException;
/**
* Closes the transport.
*/
public abstract void close();
/**
* Reads up to len bytes into buffer buf, starting att offset off.
*
* @param buf Array to read into
* @param off Index to start reading at
* @param len Maximum number of bytes to read
* @return The number of bytes actually read
* @throws TTransportException if there was an error reading data
*/
public abstract int read(byte[] buf, int off, int len)
throws TTransportException;
/**
* Guarantees that all of len bytes are actually read off the transport.
*
* @param buf Array to read into
* @param off Index to start reading at
* @param len Maximum number of bytes to read
* @return The number of bytes actually read, which must be equal to len
* @throws TTransportException if there was an error reading data
*/
public int readAll(byte[] buf, int off, int len)
throws TTransportException {
int got = 0;
int ret = 0;
while (got < len) {
ret = read(buf, off+got, len-got);
if (ret <= 0) {
throw new TTransportException("Cannot read. Remote side has closed. Tried to read " + len + " bytes, but only got " + got + " bytes.");
}
got += ret;
}
return got;
}
/**
* Writes the buffer to the output
*
* @param buf The output data buffer
* @throws TTransportException if an error occurs writing data
*/
public void write(byte[] buf) throws TTransportException {
write(buf, 0, buf.length);
}
/**
* Writes up to len bytes from the buffer.
*
* @param buf The output data buffer
* @param off The offset to start writing from
* @param len The number of bytes to write
* @throws TTransportException if there was an error writing data
*/
public abstract void write(byte[] buf, int off, int len)
throws TTransportException;
/**
* Flush any pending data out of a transport buffer.
*
* @throws TTransportException if there was an error writing out data.
*/
public void flush()
throws TTransportException {}
/**
* Access the protocol's underlying buffer directly. If this is not a
* buffered transport, return null.
* @return
*/
public byte[] getBuffer() {
return null;
}
/**
* Return the index within the underlying buffer that specifies the next spot
* that should be read from.
* @return
*/
public int getBufferPosition() {
return 0;
}
/**
* Get the number of bytes remaining in the underlying buffer. Returns -1 if
* this is a non-buffered transport.
* @return
*/
public int getBytesRemainingInBuffer() {
return -1;
}
/**
* Consume len bytes from the underlying buffer.
* @param len
*/
public void consumeBuffer(int len) {}
}