okhttp3.internal.cache2.FileOperator.kt Maven / Gradle / Ivy
/*
* Copyright (C) 2016 Square, Inc.
*
* 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 okhttp3.internal.cache2
import java.io.IOException
import java.nio.channels.FileChannel
import okio.Buffer
/**
* Read and write a target file. Unlike Okio's built-in `Okio.source(java.io.File file)` and `Okio.sink(java.io.File file)`
* this class offers:
*
* * **Read/write:** read and write using the same operator.
* * **Random access:** access any position within the file.
* * **Shared channels:** read and write a file channel that's shared between
* multiple operators. Note that although the underlying [FileChannel] may be shared,
* each [FileOperator] should not be.
*/
internal class FileOperator(
private val fileChannel: FileChannel
) {
/** Write [byteCount] bytes from [source] to the file at [pos]. */
@Throws(IOException::class)
fun write(pos: Long, source: Buffer, byteCount: Long) {
if (byteCount < 0L || byteCount > source.size) {
throw IndexOutOfBoundsException()
}
var mutablePos = pos
var mutableByteCount = byteCount
while (mutableByteCount > 0L) {
val bytesWritten = fileChannel.transferFrom(source, mutablePos, mutableByteCount)
mutablePos += bytesWritten
mutableByteCount -= bytesWritten
}
}
/**
* Copy [byteCount] bytes from the file at [pos] into `source`. It is the
* caller's responsibility to make sure there are sufficient bytes to read: if there aren't this
* method throws an `EOFException`.
*/
fun read(pos: Long, sink: Buffer, byteCount: Long) {
if (byteCount < 0L) {
throw IndexOutOfBoundsException()
}
var mutablePos = pos
var mutableByteCount = byteCount
while (mutableByteCount > 0L) {
val bytesRead = fileChannel.transferTo(mutablePos, mutableByteCount, sink)
mutablePos += bytesRead
mutableByteCount -= bytesRead
}
}
}