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Read/write ByteString from/to ByteBuffer
Closes #269
1 parent 92e0214 commit 613f51b

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‎bytestring/api/kotlinx-io-bytestring.api

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@@ -64,8 +64,14 @@ public final class kotlinx/io/bytestring/ByteStringBuilderKt {
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}
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public final class kotlinx/io/bytestring/ByteStringJvmExtKt {
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public static final fun asReadOnlyByteBuffer (Lkotlinx/io/bytestring/ByteString;)Ljava/nio/ByteBuffer;
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public static final fun decodeToString (Lkotlinx/io/bytestring/ByteString;Ljava/nio/charset/Charset;)Ljava/lang/String;
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public static final fun encodeToByteString (Ljava/lang/String;Ljava/nio/charset/Charset;)Lkotlinx/io/bytestring/ByteString;
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public static final fun getByteString (Ljava/nio/ByteBuffer;I)Lkotlinx/io/bytestring/ByteString;
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public static final fun getByteString (Ljava/nio/ByteBuffer;II)Lkotlinx/io/bytestring/ByteString;
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public static synthetic fun getByteString$default (Ljava/nio/ByteBuffer;IILjava/lang/Object;)Lkotlinx/io/bytestring/ByteString;
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public static final fun putByteString (Ljava/nio/ByteBuffer;ILkotlinx/io/bytestring/ByteString;)V
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public static final fun putByteString (Ljava/nio/ByteBuffer;Lkotlinx/io/bytestring/ByteString;)V
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}
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public final class kotlinx/io/bytestring/ByteStringKt {

‎bytestring/jvm/src/ByteStringJvmExt.kt

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@@ -5,6 +5,10 @@
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package kotlinx.io.bytestring
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import kotlinx.io.bytestring.unsafe.UnsafeByteStringApi
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import kotlinx.io.bytestring.unsafe.UnsafeByteStringOperations
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import java.nio.BufferOverflowException
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import java.nio.ByteBuffer
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import java.nio.charset.Charset
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/**
@@ -20,3 +24,103 @@ public fun ByteString.decodeToString(charset: Charset): String = getBackingArray
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* @param charset the encoding.
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*/
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public fun String.encodeToByteString(charset: Charset): ByteString = ByteString.wrap(toByteArray(charset))
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/**
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* Returns a new read-only heap [ByteBuffer] wrapping [this] ByteString's content.
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*/
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@OptIn(UnsafeByteStringApi::class)
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public fun ByteString.asReadOnlyByteBuffer(): ByteBuffer {
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val data: ByteArray
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UnsafeByteStringOperations.withByteArrayUnsafe(this) {
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data = it
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}
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return ByteBuffer.wrap(data).asReadOnlyBuffer()
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}
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/**
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* Reads [length] bytes of data from [this] ByteBuffer starting from the current position and
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* wraps them into a new [ByteString].
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*
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* Upon successful execution, current position will advance by [length].
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*
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* @throws IndexOutOfBoundsException when [length] has negative value or its value exceeds [ByteBuffer.remaining]
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*/
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@OptIn(UnsafeByteStringApi::class)
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public fun ByteBuffer.getByteString(length: Int = remaining()): ByteString {
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if (length < 0) {
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throw IndexOutOfBoundsException("length should be non-negative (was $length)")
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}
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if (remaining() < length) {
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throw IndexOutOfBoundsException("length ($length) exceeds remaining bytes count ({${remaining()}})")
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}
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val bytes = ByteArray(length)
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get(bytes)
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return UnsafeByteStringOperations.wrapUnsafe(bytes)
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}
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/**
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* Reads [length] bytes of data from [this] ByteBuffer starting from [at] index and
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* wraps them into a new [ByteString].
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*
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* This function does not update [ByteBuffer.position].
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*
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* @throws IndexOutOfBoundsException when [at] is negative, greater or equal to [ByteBuffer.limit]
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* or [at] + [length] exceeds [ByteBuffer.limit].
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*/
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@OptIn(UnsafeByteStringApi::class)
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public fun ByteBuffer.getByteString(at: Int, length: Int): ByteString {
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checkIndexAndCapacity(at, length)
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val bytes = ByteArray(length)
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// Absolute get(byte[]) was added only in JDK 13
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for (i in 0..<length) {
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bytes[i] = get(at + i)
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}
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return UnsafeByteStringOperations.wrapUnsafe(bytes)
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}
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/**
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* Writes [string] into [this] ByteBuffer starting from the current position.
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*
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* Upon successfully execution [ByteBuffer.position] will advance by the length of [string].
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*
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* @throws java.nio.ReadOnlyBufferException when [this] buffer is read-only
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* @throws java.nio.BufferOverflowException when [string] can't fit into remaining space of this buffer
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*/
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@OptIn(UnsafeByteStringApi::class)
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public fun ByteBuffer.putByteString(string: ByteString) {
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UnsafeByteStringOperations.withByteArrayUnsafe(string) {
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put(it)
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}
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}
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/**
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* Writes [string] into [this] ByteBuffer starting from position [at].
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*
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* This function does not update [ByteBuffer.position].
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*
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* @throws java.nio.ReadOnlyBufferException when [this] buffer is read-only
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* @throws IndexOutOfBoundsException when [at] is negative, exceeds [ByteBuffer.limit], or
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* [at] + [ByteString.size] exceeds [ByteBuffer.limit]
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*/
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public fun ByteBuffer.putByteString(at: Int, string: ByteString) {
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checkIndexAndCapacity(at, string.size)
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// Absolute get(byte[]) was added only in JDK 13
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for (idx in string.indices) {
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put(at + idx, string[idx])
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}
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}
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private fun ByteBuffer.checkIndexAndCapacity(idx: Int, length: Int) {
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if (idx < 0 || idx >= limit()) {
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throw IndexOutOfBoundsException("Index $idx is out of this ByteBuffer's bounds: [0, ${limit()})")
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}
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if (length < 0) {
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throw IndexOutOfBoundsException("length should be non-negative (was $length)")
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}
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if (idx + length > limit()) {
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throw IndexOutOfBoundsException("There's not enough space to put ByteString of length $length starting" +
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" from index $idx")
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}
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}

‎bytestring/jvm/test/ByteStringByteBufferExtensions.kt

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,98 @@
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/*
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* Copyright 2017-2024 JetBrains s.r.o. and respective authors and developers.
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* Use of this source code is governed by the Apache 2.0 license that can be found in the LICENCE file.
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*/
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package kotlinx.io.bytestring
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import org.junit.jupiter.api.Test
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import java.nio.BufferOverflowException
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import java.nio.ByteBuffer
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import java.nio.ReadOnlyBufferException
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import kotlin.test.assertContentEquals
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import kotlin.test.assertEquals
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import kotlin.test.assertFailsWith
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import kotlin.test.assertTrue
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public class ByteStringByteBufferExtensions {
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@Test
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fun asReadOnlyByteBuffer() {
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val buffer = ByteString(1, 2, 3, 4).asReadOnlyByteBuffer()
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assertTrue(buffer.isReadOnly)
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assertEquals(4, buffer.remaining())
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ByteArray(4).let {
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buffer.get(it)
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assertContentEquals(byteArrayOf(1, 2, 3, 4), it)
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}
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}
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@Test
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fun getByteString() {
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val bb = ByteBuffer.allocate(8)
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bb.put(byteArrayOf(1, 2, 3, 4, 5, 6, 7, 8))
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bb.flip()
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assertEquals(ByteString(1, 2, 3, 4, 5, 6, 7, 8), bb.getByteString())
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bb.flip()
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assertEquals(ByteString(1, 2, 3, 4), bb.getByteString(length = 4))
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assertEquals(ByteString(), bb.getByteString(length = 0))
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assertFailsWith<IndexOutOfBoundsException> { bb.getByteString(length = -1) }
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val p = bb.position()
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assertFailsWith<IndexOutOfBoundsException> { bb.getByteString(length = 5) }
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assertEquals(p, bb.position())
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bb.clear()
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assertEquals(ByteString(1, 2, 3, 4, 5, 6, 7, 8), bb.getByteString(at = 0, length = 8))
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assertEquals(0, bb.position())
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assertEquals(ByteString(2, 3, 4, 5), bb.getByteString(at = 1, length = 4))
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assertEquals(0, bb.position())
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assertFailsWith<IndexOutOfBoundsException> { bb.getByteString(at = -1, length = 8) }
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assertFailsWith<IndexOutOfBoundsException> { bb.getByteString(at = 9, length = 1) }
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assertFailsWith<IndexOutOfBoundsException> { bb.getByteString(at = 7, length = 2) }
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assertFailsWith<IndexOutOfBoundsException> { bb.getByteString(at = 0, length = -1) }
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}
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@Test
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fun putString() {
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val bb = ByteBuffer.allocate(8)
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val string = ByteString(1, 2, 3, 4, 5, 6, 7, 8)
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val shortString = ByteString(-1, -2, -3)
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bb.putByteString(string)
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assertEquals(8, bb.position())
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bb.flip()
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ByteArray(8).let {
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bb.get(it)
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assertContentEquals(byteArrayOf(1, 2, 3, 4, 5, 6, 7, 8), it)
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}
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bb.clear()
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bb.position(1)
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assertFailsWith<BufferOverflowException> { bb.putByteString(string) }
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assertEquals(1, bb.position())
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bb.putByteString(at = 0, string = shortString)
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bb.putByteString(at = 5, string = shortString)
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assertEquals(1, bb.position())
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bb.clear()
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ByteArray(8).let {
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bb.get(it)
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assertContentEquals(byteArrayOf(-1, -2, -3, 4, 5, -1, -2, -3), it)
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}
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assertFailsWith<IndexOutOfBoundsException> { bb.putByteString(at = 7, string = shortString) }
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assertFailsWith<IndexOutOfBoundsException> { bb.putByteString(at = -1, string = string) }
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assertFailsWith<IndexOutOfBoundsException> { bb.putByteString(at = 8, string = string) }
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assertFailsWith<ReadOnlyBufferException> {
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bb.asReadOnlyBuffer().putByteString(string)
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}
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assertFailsWith<ReadOnlyBufferException> {
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bb.asReadOnlyBuffer().putByteString(at = 0, string = string)
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}
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}
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}

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