| /* |
| * Copyright 2016-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license. |
| */ |
| |
| package kotlinx.coroutines.experimental.io |
| |
| interface LookAheadSession { |
| /** |
| * Marks [n] bytes as consumed so the corresponding range becomes available for writing |
| */ |
| fun consumed(n: Int) |
| |
| /** |
| * Request byte buffer range skipping [skip] bytes and [atLeast] bytes length |
| * @return byte buffer for the requested range or null if it is impossible to provide such a buffer |
| * |
| * There are the following reasons for this function to return `null`: |
| * - not enough bytes available yet (should be at least `skip + atLeast` bytes available) |
| * - due to buffer fragmentation is is impossible to represent the requested range as a single byte buffer |
| * - end of stream encountered and all bytes were consumed |
| * - channel has been closed with an exception so buffer has been recycled |
| */ |
| fun request(skip: Int, atLeast: Int): ByteBuffer? |
| } |
| |
| interface LookAheadSuspendSession : LookAheadSession { |
| /** |
| * Suspend until [n] bytes become available or end of stream encountered (possibly due to exceptional close) |
| */ |
| suspend fun awaitAtLeast(n: Int): Boolean |
| } |
| |
| inline fun LookAheadSession.consumeEachRemaining(visitor: (ByteBuffer) -> Boolean) { |
| do { |
| val cont = request(0, 1)?.let { |
| val s = it.remaining() |
| val rc = visitor(it) |
| consumed(s) |
| rc |
| } ?: false |
| |
| if (!cont) break |
| } while (true) |
| } |
| |