IO: add byte packet readBytes and readText utility functions + tests

Author: Sergey Mashkov

core/kotlinx-coroutines-io/src/main/kotlin/kotlinx/coroutines/experimental/io/packet/ByteReadPacket.kt

@@ -38,4 +38,6 @@ interface ByteReadPacket {
 
     fun inputStream(): InputStream
     fun readerUTF8(): Reader
+
+    fun readText(): CharSequence
 }

core/kotlinx-coroutines-io/src/main/kotlin/kotlinx/coroutines/experimental/io/packet/ByteReadPacketEmpty.kt

@@ -53,6 +53,8 @@ object ByteReadPacketEmpty : ByteReadPacket {
     override fun inputStream(): InputStream = EmptyInputStream
     override fun readerUTF8(): Reader = EmptyReader
 
+    override fun readText() = ""
+
     private object EmptyInputStream : InputStream() {
         override fun available() = 0
 

core/kotlinx-coroutines-io/src/main/kotlin/kotlinx/coroutines/experimental/io/packet/ByteReadPacketImpl.kt

@@ -2,11 +2,9 @@
 
 package kotlinx.coroutines.experimental.io.packet
 
-import kotlinx.coroutines.experimental.io.internal.ObjectPool
-import kotlinx.coroutines.experimental.io.internal.decodeUTF8
+import kotlinx.coroutines.experimental.io.internal.*
 import java.io.*
-import java.nio.BufferOverflowException
-import java.nio.ByteBuffer
+import java.nio.*
 import java.nio.charset.*
 import java.util.*
 
@@ -145,6 +143,25 @@ internal class ByteReadPacketImpl(private val packets: ArrayDeque<ByteBuffer>, i
         return rc
     }
 
+    override fun readText(): CharSequence {
+        val sb = StringBuilder(remaining)
+
+        var size = 0
+
+        reading(1) { bb ->
+            size = bb.decodeUTF8 { ch ->
+                sb.append(ch)
+                true
+            }
+
+            size == 0
+        }
+
+        if (size > 0) throw CharacterCodingException()
+
+        return sb
+    }
+
     override fun skip(n: Int): Int {
         var skipped = 0
 

core/kotlinx-coroutines-io/src/main/kotlin/kotlinx/coroutines/experimental/io/packet/ByteReadPacketSingle.kt

@@ -5,7 +5,7 @@ import kotlinx.coroutines.experimental.io.internal.decodeUTF8
 import java.io.*
 import java.nio.BufferOverflowException
 import java.nio.ByteBuffer
-import java.nio.charset.MalformedInputException
+import java.nio.charset.*
 
 internal class ByteReadPacketSingle(private var buffer: ByteBuffer?, internal val pool: ObjectPool<ByteBuffer>) : ByteReadPacket {
     override val remaining: Int
@@ -138,6 +138,25 @@ internal class ByteReadPacketSingle(private var buffer: ByteBuffer?, internal va
         }
     }
 
+    override fun readText(): CharSequence {
+        val sb = StringBuilder(remaining)
+
+        var size = 0
+
+        reading { bb ->
+            size = bb.decodeUTF8 { ch ->
+                sb.append(ch)
+                true
+            }
+
+            size == 0
+        }
+
+        if (size > 0) throw CharacterCodingException()
+
+        return sb
+    }
+
     override fun skip(n: Int): Int {
         var skipped = 0
 

core/kotlinx-coroutines-io/src/main/kotlin/kotlinx/coroutines/experimental/io/packet/Packets.kt

@@ -1,8 +1,6 @@
 package kotlinx.coroutines.experimental.io.packet
 
-import kotlinx.coroutines.experimental.io.internal.ObjectPool
-import kotlinx.coroutines.experimental.io.internal.ObjectPoolImpl
-import kotlinx.coroutines.experimental.io.internal.getIOIntProperty
+import kotlinx.coroutines.experimental.io.internal.*
 import java.nio.ByteBuffer
 
 internal val PACKET_BUFFER_SIZE = getIOIntProperty("PacketBufferSize", 4096)
@@ -22,3 +20,5 @@ fun ByteReadPacket.readUTF8Line(estimate: Int = 16, limit: Int = Int.MAX_VALUE):
     val sb = StringBuilder(estimate)
     return if (readUTF8LineTo(sb, limit)) sb.toString() else null
 }
+
+fun ByteReadPacket.readBytes() = inputStream().readBytes(remaining)

core/kotlinx-coroutines-io/src/test/kotlin/kotlinx/coroutines/experimental/io/BytePacketReaderWriterTest.kt

@@ -2,6 +2,7 @@ package kotlinx.coroutines.experimental.io
 
 import kotlinx.coroutines.experimental.io.packet.*
 import org.junit.*
+import java.util.*
 import kotlin.test.*
 
 class BytePacketReaderWriterTest {
@@ -225,4 +226,52 @@ class BytePacketReaderWriterTest {
 
         assertNull(p.readUTF8Line())
     }
+
+    @Test
+    fun testSingleBufferReadText() {
+        val p = buildPacket {
+            append("ABC")
+        }
+
+        assertEquals("ABC", p.readText().toString())
+    }
+
+    @Test
+    fun testMultiBufferReadText() {
+        val s = buildString {
+            repeat(100000) {
+                append("x")
+            }
+        }
+
+        val packet = buildPacket {
+            writeFully(s.toByteArray())
+        }
+
+        assertEquals(s, packet.readText().toString())
+    }
+
+    @Test
+    fun testSingleBufferReadAll() {
+        val bb = ByteArray(100)
+        Random().nextBytes(bb)
+
+        val p = buildPacket {
+            writeFully(bb)
+        }
+
+        assertTrue { bb.contentEquals(p.readBytes()) }
+    }
+
+    @Test
+    fun testMultiBufferReadAll() {
+        val bb = ByteArray(100000)
+        Random().nextBytes(bb)
+
+        val p = buildPacket {
+            writeFully(bb)
+        }
+
+        assertTrue { bb.contentEquals(p.readBytes()) }
+    }
 }