wvlet.airframe.msgpack.spi.MessageSink.scala Maven / Gradle / Ivy
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/*
* Licensed 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 wvlet.airframe.msgpack.spi
import java.io.{Flushable, IOException}
/**
* Provides a buffered output stream that writes sequence of [[WriteBuffer]] instances.
*
* A Sink implementation has total control of the buffer memory so that it can reuse buffer memory, use buffer pools,
* or use memory-mapped files.
*/
trait MessageSink extends AutoCloseable with Flushable {
/**
* Allocates the next buffer for writing MessagePack data. This method returns an [[WriteBuffer]] instance that
* has specified size of capacity at least.
When this method is called twice, the previously returned buffer is
* no longer used. This method may be called twice without call of [[writeBuffer(int)]] in between. In this case, the
* buffer should be discarded without flushing it to the output.
*
* @param minimumSize
* the minimum required buffer size to allocate
* @return
* a Buffer instance with at least minimumSize bytes of capacity
* @throws IOException
*/
@throws[IOException]
def next(minimumSize: Int): WriteBuffer
/**
* Writes the previously allocated buffer(s).
This method should write the buffer previously returned from
* [[next(int)]] method until specified number of bytes. Once the entire buffer contents is totally written to the
* sink, the buffer should not be used because a BufferSink implementation might reuse the buffer.
This method is
* not always called for each [[next(int)]] call. In this case, the buffer should be discarded without flushing it to
* the output when the next [[next(int)]] is called.
*
* @param length
* the number of bytes to write
* @throws IOException
*/
@throws[IOException]
def writeBuffer(length: Int): Unit
/**
* Writes an external payload data. This method should follow semantics of OutputStream.
*
* @param buffer
* the data to write
* @param offset
* the start offset in the data
* @param length
* the number of bytes to write
* @throws IOException
*/
@throws[IOException]
def write(buffer: Array[Byte], offset: Int, length: Int): Unit
/**
* Writes an external payload data.
Unlike [[write(byte[], int, int)]] method, the buffer is given - this
* BufferSink implementation gets ownership of the buffer and may modify contents of the buffer. Contents of this
* buffer won't be modified by the caller.
*
* @param buffer
* the data to add
* @param offset
* the start offset in the data
* @param length
* the number of bytes to add
* @throws IOException
*/
@throws[IOException]
def add(buffer: Array[Byte], offset: Int, length: Int): Unit
}