Roman Elizarov | 1f74a2d | 2018-06-29 19:19:45 +0300 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2016-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license. |
| 3 | */ |
| 4 | |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 5 | package kotlinx.coroutines.experimental.io.internal |
| 6 | |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 7 | import java.nio.ByteBuffer |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 8 | |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 9 | // this is MAGICAL constant that is tied to the code ByteBufferChannel (that is how much it needs extra) |
| 10 | internal const val RESERVED_SIZE = 8 |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 11 | |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 12 | internal val EmptyByteBuffer: ByteBuffer = ByteBuffer.allocate(0) |
Roman Elizarov | 469cad3 | 2017-08-15 15:54:56 +0300 | [diff] [blame] | 13 | internal val EmptyCapacity = RingBufferCapacity(0) |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 14 | |
| 15 | internal sealed class ReadWriteBufferState( |
Roman Elizarov | 469cad3 | 2017-08-15 15:54:56 +0300 | [diff] [blame] | 16 | @JvmField val backingBuffer: ByteBuffer, |
| 17 | @JvmField val capacity: RingBufferCapacity |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 18 | ) { |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 19 | open val idle: Boolean get() = false |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 20 | open val readBuffer: ByteBuffer get() = error("read buffer is not available in state $this") |
| 21 | open val writeBuffer: ByteBuffer get() = error("write buffer is not available in state $this") |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 22 | |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 23 | internal open fun startReading(): ReadWriteBufferState = error("Reading is not available in state $this") |
| 24 | internal open fun startWriting(): ReadWriteBufferState = error("Writing is not available in state $this") |
| 25 | internal open fun stopReading(): ReadWriteBufferState = error("Unable to stop reading in state $this") |
| 26 | internal open fun stopWriting(): ReadWriteBufferState = error("Unable to stop writing in state $this") |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 27 | |
Roman Elizarov | 469cad3 | 2017-08-15 15:54:56 +0300 | [diff] [blame] | 28 | object IdleEmpty : ReadWriteBufferState(EmptyByteBuffer, EmptyCapacity) { |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 29 | override val idle: Boolean get() = true |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 30 | override fun toString() = "IDLE(empty)" |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 31 | } |
| 32 | |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 33 | class Initial( |
| 34 | backingBuffer: ByteBuffer, |
| 35 | reservedSize: Int = RESERVED_SIZE |
| 36 | ) : ReadWriteBufferState(backingBuffer, RingBufferCapacity(backingBuffer.capacity() - reservedSize)) { |
| 37 | init { |
| 38 | require(backingBuffer.position() == 0) |
| 39 | require(backingBuffer.limit() == backingBuffer.capacity()) |
| 40 | } |
| 41 | override val writeBuffer: ByteBuffer = backingBuffer.duplicate() // defensive copy of buffer's state |
| 42 | override val readBuffer: ByteBuffer = backingBuffer.duplicate() // must have a separate buffer state here |
| 43 | // all other possible states |
| 44 | internal val idleState = IdleNonEmpty(this) |
| 45 | internal val readingState = Reading(this) |
| 46 | internal val writingState = Writing(this) |
| 47 | internal val readingWritingState = ReadingWriting(this) |
| 48 | // state transitions |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 49 | override fun startReading() = readingState |
| 50 | override fun startWriting() = writingState |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 51 | override val idle: Boolean get() = error("Not available for initial state") |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 52 | override fun toString() = "Initial" |
| 53 | } |
| 54 | |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 55 | class IdleNonEmpty internal constructor( |
| 56 | val initial: Initial // public here, so can release initial state when idle |
| 57 | ) : ReadWriteBufferState(initial.backingBuffer, initial.capacity) { |
| 58 | override fun startReading() = initial.readingState |
| 59 | override fun startWriting() = initial.writingState |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 60 | override val idle: Boolean get() = true |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 61 | override fun toString() = "IDLE(with buffer)" |
| 62 | } |
| 63 | |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 64 | class Reading internal constructor( |
| 65 | private val initial: Initial |
| 66 | ) : ReadWriteBufferState(initial.backingBuffer, initial.capacity) { |
| 67 | override val readBuffer: ByteBuffer get() = initial.readBuffer |
| 68 | override fun startWriting() = initial.readingWritingState |
| 69 | override fun stopReading() = initial.idleState |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 70 | override fun toString() = "Reading" |
| 71 | } |
| 72 | |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 73 | class Writing internal constructor( |
| 74 | private val initial: Initial |
| 75 | ) : ReadWriteBufferState(initial.backingBuffer, initial.capacity) { |
| 76 | override val writeBuffer: ByteBuffer get() = initial.writeBuffer |
| 77 | override fun startReading() = initial.readingWritingState |
| 78 | override fun stopWriting() = initial.idleState |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 79 | override fun toString() = "Writing" |
| 80 | } |
| 81 | |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 82 | class ReadingWriting internal constructor( |
| 83 | private val initial: Initial |
| 84 | ) : ReadWriteBufferState(initial.backingBuffer, initial.capacity) { |
| 85 | override val readBuffer: ByteBuffer get() = initial.readBuffer |
| 86 | override val writeBuffer: ByteBuffer get() = initial.writeBuffer |
| 87 | override fun stopReading() = initial.writingState |
| 88 | override fun stopWriting() = initial.readingState |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 89 | override fun toString() = "Reading+Writing" |
| 90 | } |
| 91 | |
Roman Elizarov | 469cad3 | 2017-08-15 15:54:56 +0300 | [diff] [blame] | 92 | object Terminated : ReadWriteBufferState(EmptyByteBuffer, EmptyCapacity) { |
Sergey Mashkov | 86f7061 | 2017-07-25 10:59:44 +0300 | [diff] [blame] | 93 | override fun toString() = "Terminated" |
| 94 | } |
Roman Elizarov | 8376203 | 2017-08-08 19:58:40 +0300 | [diff] [blame] | 95 | } |