gRPC/Native: Add Wire Format encoder and decoder

grpc/grpc-core/build.gradle.kts

@@ -14,6 +14,8 @@ plugins {
     alias(libs.plugins.kotlinx.rpc)
 }
 
+
+
 kotlin {
     compilerOptions {
         freeCompilerArgs.add("-Xexpect-actual-classes")
@@ -27,6 +29,7 @@ kotlin {
                 api(libs.coroutines.core)
 
                 implementation(libs.atomicfu)
+                implementation(libs.kotlinx.io.core)
             }
         }
 
@@ -58,6 +61,12 @@ kotlin {
             }
         }
 
+        nativeMain {
+            dependencies {
+                implementation(libs.kotlinx.collections.immutable)
+            }
+        }
+
         nativeTest {
             dependencies {
                 implementation(kotlin("test"))
@@ -83,7 +92,7 @@ kotlin {
     val buildGrpcppCLib = tasks.register<Exec>("buildGrpcppCLib") {
         group = "build"
         workingDir = grpcppCLib
-        commandLine("bash", "-c", "bazel build :grpcpp_c_static --config=release")
+        commandLine("bash", "-c", "bazel build :grpcpp_c_static :protowire_static --config=release")
         inputs.files(fileTree(grpcppCLib) { exclude("bazel-*/**") })
         outputs.dir(grpcppCLib.resolve("bazel-bin"))
 
@@ -108,6 +117,22 @@ kotlin {
                 tasks.named(interopTask, CInteropProcess::class) {
                     dependsOn(buildGrpcppCLib)
                 }
+
+
+                val libprotowire by creating {
+                    includeDirs(
+                        grpcppCLib.resolve("include")
+                    )
+                    extraOpts(
+                        "-libraryPath", "${grpcppCLib.resolve("bazel-out/darwin_arm64-opt/bin")}",
+                    )
+                }
+
+                val libUpbTask = "cinterop${libprotowire.name.capitalized()}${it.targetName.capitalized()}"
+                tasks.named(libUpbTask, CInteropProcess::class) {
+                    dependsOn(buildGrpcppCLib)
+                }
+
             }
         }
     }

grpc/grpc-core/src/commonMain/kotlin/kotlinx/rpc/grpc/internal/KTag.kt

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+import kotlinx.rpc.grpc.internal.KTag.Companion.K_TAG_TYPE_BITS
+
+internal enum class WireType {
+    VARINT, // 0
+    FIXED64, // 1
+    LENGTH_DELIMITED, // 2
+    START_GROUP, // 3
+    END_GROUP, // 4
+    FIXED32, // 5
+}
+
+internal data class KTag(val fieldNr: Int, val wireType: WireType) {
+
+    init {
+        check(isValidFieldNr(fieldNr)) { "Invalid field number: $fieldNr" }
+    }
+
+    companion object {
+        // Number of bits in a tag which identify the wire type.
+        const val K_TAG_TYPE_BITS: Int = 3;
+
+        // Mask for those bits. (just 0b111)
+        val K_TAG_TYPE_MASK: UInt = (1u shl K_TAG_TYPE_BITS) - 1u
+    }
+}
+
+internal fun KTag.toRawKTag(): UInt {
+    return (fieldNr.toUInt() shl K_TAG_TYPE_BITS) or wireType.ordinal.toUInt()
+}
+
+internal fun KTag.Companion.fromOrNull(rawKTag: UInt): KTag? {
+    val type = (rawKTag and K_TAG_TYPE_MASK).toInt()
+    val field = (rawKTag shr K_TAG_TYPE_BITS).toInt()
+    if (!isValidFieldNr(field)) {
+        return null
+    }
+    if (type >= WireType.entries.size) {
+        return null
+    }
+    return KTag(field, WireType.entries[type])
+}
+
+internal fun KTag.Companion.isValidFieldNr(fieldNr: Int): Boolean {
+    return 1 <= fieldNr && fieldNr <= 536_870_911
+}

grpc/grpc-core/src/commonMain/kotlin/kotlinx/rpc/grpc/internal/WireDecoder.kt

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+import kotlinx.io.Buffer
+
+/**
+ * A platform-specific decoder for wire format data.
+ *
+ * This decoder is used by first calling [readTag], than looking up the field based on the field number in the returned,
+ * tag and then calling the actual `read*()` method to read the value to the corresponding field.
+ *
+ * [hadError] indicates an error during decoding. While calling `read*()` is safe, the returned values
+ * are meaningless if [hadError] returns `true`.
+ *
+ * NOTE: If the [hadError] after a call to `read*()` returns `false`, it doesn't mean that the
+ * value is correctly decoded. E.g., the following test will pass:
+ * ```kt
+ * val fieldNr = 1
+ * val buffer = Buffer()
+ *
+ * val encoder = WireEncoder(buffer)
+ * assertTrue(encoder.writeInt32(fieldNr, 12312))
+ * encoder.flush()
+ *
+ * WireDecoder(buffer).use { decoder ->
+ *     decoder.readTag()
+ *     decoder.readBool()
+ *     assertFalse(decoder.hasError())
+ * }
+ * ```
+ */
+internal interface WireDecoder : AutoCloseable {
+    fun hadError(): Boolean
+    fun readTag(): KTag?
+    fun readBool(): Boolean
+    fun readInt32(): Int
+    fun readInt64(): Long
+    fun readUInt32(): UInt
+    fun readUInt64(): ULong
+    fun readSInt32(): Int
+    fun readSInt64(): Long
+    fun readFixed32(): UInt
+    fun readFixed64(): ULong
+    fun readSFixed32(): Int
+    fun readSFixed64(): Long
+    fun readFloat(): Float
+    fun readDouble(): Double
+
+    fun readEnum(): Int
+    fun readString(): String
+    fun readBytes(): ByteArray
+    fun readPackedBool(): List<Boolean>
+    fun readPackedInt32(): List<Int>
+    fun readPackedInt64(): List<Long>
+    fun readPackedSInt32(): List<Int>
+    fun readPackedSInt64(): List<Long>
+    fun readPackedUInt32(): List<UInt>
+    fun readPackedUInt64(): List<ULong>
+    fun readPackedFixed32(): List<UInt>
+    fun readPackedFixed64(): List<ULong>
+    fun readPackedSFixed32(): List<Int>
+    fun readPackedSFixed64(): List<Long>
+    fun readPackedFloat(): List<Float>
+    fun readPackedDouble(): List<Double>
+    fun readPackedEnum(): List<Int>
+}
+
+/**
+ * Creates a platform-specific [WireDecoder].
+ *
+ * This constructor takes a [Buffer] instead of a [kotlinx.io.Source] because
+ * the native implementation (`WireDecoderNative`) depends on [Buffer]'s internal structure.
+ *
+ * NOTE: Do not use the [source] buffer while the [WireDecoder] is still open.
+ *
+ * @param source The buffer containing the encoded wire-format data.
+ */
+internal expect fun WireDecoder(source: Buffer): WireDecoder

grpc/grpc-core/src/commonMain/kotlin/kotlinx/rpc/grpc/internal/WireEncoder.kt

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+import kotlinx.io.Sink
+
+/**
+ * A platform-specific class that encodes values into protobuf's wire format.
+ *
+ * If one `write*()` method returns false, the encoding of the value failed
+ * and no further encodings can be performed on this [WireEncoder].
+ *
+ * [flush] must be called to ensure that all data is written to the [Sink].
+ */
+@OptIn(ExperimentalUnsignedTypes::class)
+internal interface WireEncoder {
+    fun flush()
+    fun writeBool(field: Int, value: Boolean): Boolean
+    fun writeInt32(fieldNr: Int, value: Int): Boolean
+    fun writeInt64(fieldNr: Int, value: Long): Boolean
+    fun writeUInt32(fieldNr: Int, value: UInt): Boolean
+    fun writeUInt64(fieldNr: Int, value: ULong): Boolean
+    fun writeSInt32(fieldNr: Int, value: Int): Boolean
+    fun writeSInt64(fieldNr: Int, value: Long): Boolean
+    fun writeFixed32(fieldNr: Int, value: UInt): Boolean
+    fun writeFixed64(fieldNr: Int, value: ULong): Boolean
+    fun writeSFixed32(fieldNr: Int, value: Int): Boolean
+    fun writeSFixed64(fieldNr: Int, value: Long): Boolean
+    fun writeFloat(fieldNr: Int, value: Float): Boolean
+    fun writeDouble(fieldNr: Int, value: Double): Boolean
+    fun writeEnum(fieldNr: Int, value: Int): Boolean
+    fun writeBytes(fieldNr: Int, value: ByteArray): Boolean
+    fun writeString(fieldNr: Int, value: String): Boolean
+    fun writePackedBool(fieldNr: Int, value: List<Boolean>, fieldSize: Int): Boolean
+    fun writePackedInt32(fieldNr: Int, value: List<Int>, fieldSize: Int): Boolean
+    fun writePackedInt64(fieldNr: Int, value: List<Long>, fieldSize: Int): Boolean
+    fun writePackedUInt32(fieldNr: Int, value: List<UInt>, fieldSize: Int): Boolean
+    fun writePackedUInt64(fieldNr: Int, value: List<ULong>, fieldSize: Int): Boolean
+    fun writePackedSInt32(fieldNr: Int, value: List<Int>, fieldSize: Int): Boolean
+    fun writePackedSInt64(fieldNr: Int, value: List<Long>, fieldSize: Int): Boolean
+    fun writePackedFixed32(fieldNr: Int, value: List<UInt>): Boolean
+    fun writePackedFixed64(fieldNr: Int, value: List<ULong>): Boolean
+    fun writePackedSFixed32(fieldNr: Int, value: List<Int>): Boolean
+    fun writePackedSFixed64(fieldNr: Int, value: List<Long>): Boolean
+    fun writePackedFloat(fieldNr: Int, value: List<Float>): Boolean
+    fun writePackedDouble(fieldNr: Int, value: List<Double>): Boolean
+    fun writePackedEnum(fieldNr: Int, value: List<Int>, fieldSize: Int) =
+        writePackedInt32(fieldNr, value, fieldSize)
+}
+
+
+internal expect fun WireEncoder(sink: Sink): WireEncoder

grpc/grpc-core/src/commonMain/kotlin/kotlinx/rpc/grpc/internal/WireSize.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+internal object WireSize
+
+internal expect fun WireSize.int32(value: Int): UInt
+internal expect fun WireSize.int64(value: Long): UInt
+internal expect fun WireSize.uInt32(value: UInt): UInt
+internal expect fun WireSize.uInt64(value: ULong): UInt
+internal expect fun WireSize.sInt32(value: Int): UInt
+internal expect fun WireSize.sInt64(value: Long): UInt
+
+internal fun WireSize.bool(value: Boolean) = int32(if (value) 1 else 0)
+internal fun WireSize.enum(value: Int) = int32(value)
+internal fun WireSize.packedInt32(value: List<Int>) = value.sumOf { int32(it) }
+internal fun WireSize.packedInt64(value: List<Long>) = value.sumOf { int64(it) }
+internal fun WireSize.packedUInt32(value: List<UInt>) = value.sumOf { uInt32(it) }
+internal fun WireSize.packedUInt64(value: List<ULong>) = value.sumOf { uInt64(it) }
+internal fun WireSize.packedSInt32(value: List<Int>) = value.sumOf { sInt32(it) }
+internal fun WireSize.packedSInt64(value: List<Long>) = value.sumOf { sInt64(it) }
+internal fun WireSize.packedEnum(value: List<Int>) = value.sumOf { enum(it) }

grpc/grpc-core/src/jsMain/kotlin/kotlinx/rpc/grpc/internal/WireDecoder.js.kt

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+import kotlinx.io.Buffer
+import kotlinx.io.Source
+
+internal actual fun WireDecoder(source: Buffer): WireDecoder {
+    TODO("Not yet implemented")
+}

grpc/grpc-core/src/jsMain/kotlin/kotlinx/rpc/grpc/internal/WireEncoder.js.kt

@@ -0,0 +1,11 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+import kotlinx.io.Sink
+
+internal actual fun WireEncoder(sink: Sink): WireEncoder {
+    TODO("Not yet implemented")
+}

grpc/grpc-core/src/jsMain/kotlin/kotlinx/rpc/grpc/internal/WireSize.js.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+internal actual fun WireSize.int32(value: Int): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.int64(value: Long): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.uInt32(value: UInt): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.uInt64(value: ULong): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.sInt32(value: Int): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.sInt64(value: Long): UInt {
+    TODO("Not yet implemented")
+}

grpc/grpc-core/src/jvmMain/kotlin/kotlinx/rpc/grpc/internal/WireDecoder.jvm.kt

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+import kotlinx.io.Buffer
+import kotlinx.io.Source
+
+internal actual fun WireDecoder(source: Buffer): WireDecoder {
+    TODO("Not yet implemented")
+}

grpc/grpc-core/src/jvmMain/kotlin/kotlinx/rpc/grpc/internal/WireEncoder.jvm.kt

@@ -0,0 +1,11 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+import kotlinx.io.Sink
+
+internal actual fun WireEncoder(sink: Sink): WireEncoder {
+    TODO("Not yet implemented")
+}

grpc/grpc-core/src/jvmMain/kotlin/kotlinx/rpc/grpc/internal/WireSize.jvm.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2023-2025 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.rpc.grpc.internal
+
+internal actual fun WireSize.int32(value: Int): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.int64(value: Long): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.uInt32(value: UInt): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.uInt64(value: ULong): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.sInt32(value: Int): UInt {
+    TODO("Not yet implemented")
+}
+
+internal actual fun WireSize.sInt64(value: Long): UInt {
+    TODO("Not yet implemented")
+}