grpc: Support sub-messages

grpc/grpc-core/src/commonMain/kotlin/kotlinx/rpc/grpc/pb/InternalMessage.kt

@@ -6,8 +6,41 @@ package kotlinx.rpc.grpc.pb
 
 import kotlinx.rpc.grpc.utils.BitSet
 import kotlinx.rpc.internal.utils.InternalRpcApi
+import kotlin.properties.ReadWriteProperty
+import kotlin.reflect.KProperty
 
 @InternalRpcApi
 public abstract class InternalMessage(fieldsWithPresence: Int) {
     public val presenceMask: BitSet = BitSet(fieldsWithPresence)
+
+    @Suppress("PropertyName")
+    public abstract val _size: Int
+}
+
+@InternalRpcApi
+public class MsgFieldDelegate<T : Any>(
+    private val presenceIdx: Int? = null,
+    private val defaultProvider: (() -> T)? = null
+) : ReadWriteProperty<InternalMessage, T> {
+
+    private var valueSet = false
+    private var value: T? = null
+
+    override operator fun getValue(thisRef: InternalMessage, property: KProperty<*>): T {
+        if (!valueSet) {
+            if (defaultProvider != null) {
+                value = defaultProvider.invoke()
+                valueSet = true
+            } else {
+                error("Property ${property.name} not initialized")
+            }
+        }
+        return value as T
+    }
+
+    override operator fun setValue(thisRef: InternalMessage, property: KProperty<*>, value: T) {
+        presenceIdx?.let { thisRef.presenceMask[it] = true }
+        this@MsgFieldDelegate.value = value
+        valueSet = true
+    }
 }

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

@@ -5,6 +5,8 @@
 package kotlinx.rpc.grpc.pb
 
 import kotlinx.io.Buffer
+import kotlinx.rpc.grpc.internal.popLimit
+import kotlinx.rpc.grpc.internal.pushLimit
 import kotlinx.rpc.internal.utils.InternalRpcApi
 
 // TODO: Evaluate if this buffer size is suitable for all targets (KRPC-186)
@@ -76,6 +78,16 @@ public interface WireDecoder : AutoCloseable {
     public fun readPackedFloat(): List<Float>
     public fun readPackedDouble(): List<Double>
     public fun readPackedEnum(): List<Int>
+
+    // TODO: Throw error instead of just returning
+    public fun <T : InternalMessage> readMessage(msg: T, decoder: (T, WireDecoder) -> Unit) {
+        val len = readInt32()
+        if (hadError()) return
+        if (len <= 0) return
+        val limit = pushLimit(len)
+        decoder(msg, this)
+        popLimit(limit)
+    }
 }
 
 /**

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

@@ -50,6 +50,13 @@ public interface WireEncoder {
     public fun writePackedDouble(fieldNr: Int, value: List<Double>): Boolean
     public fun writePackedEnum(fieldNr: Int, value: List<Int>, fieldSize: Int): Boolean =
         writePackedInt32(fieldNr, value, fieldSize)
+
+    public fun <T : InternalMessage> writeMessage(
+        fieldNr: Int,
+        value: T,
+        encode: T.(WireEncoder) -> Unit
+    )
+
 }
 
 

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

@@ -4,11 +4,15 @@
 
 package kotlinx.rpc.grpc.pb
 
+import kotlinx.io.bytestring.encodeToByteString
 import kotlinx.rpc.internal.utils.InternalRpcApi
 
 @InternalRpcApi
 public object WireSize
 
+public fun WireSize.tag(fieldNumber: Int, wireType: WireType): Int =
+    uInt32(KTag(fieldNumber, wireType).toRawKTag())
+
 @InternalRpcApi
 public expect fun WireSize.int32(value: Int): Int
 
@@ -27,12 +31,36 @@ public expect fun WireSize.sInt32(value: Int): Int
 @InternalRpcApi
 public expect fun WireSize.sInt64(value: Long): Int
 
+@InternalRpcApi
+public fun WireSize.float(value: Float): Int = 32
+
+@InternalRpcApi
+public fun WireSize.double(value: Double): Int = 64
+
+@InternalRpcApi
+public fun WireSize.fixed32(value: UInt): Int = 32
+
+@InternalRpcApi
+public fun WireSize.fixed64(value: ULong): Int = 64
+
+@InternalRpcApi
+public fun WireSize.sFixed32(value: Int): Int = 32
+
+@InternalRpcApi
+public fun WireSize.sFixed64(value: Long): Int = 64
+
 @InternalRpcApi
 public fun WireSize.bool(value: Boolean): Int = int32(if (value) 1 else 0)
 
 @InternalRpcApi
 public fun WireSize.enum(value: Int): Int = int32(value)
 
+@InternalRpcApi
+public fun WireSize.bytes(value: ByteArray): Int = value.size
+
+@InternalRpcApi
+public fun WireSize.string(value: String): Int = value.encodeToByteString().size
+
 @InternalRpcApi
 public fun WireSize.packedInt32(value: List<Int>): Int = value.sumOf { int32(it) }
 
@@ -53,3 +81,21 @@ public fun WireSize.packedSInt64(value: List<Long>): Int = value.sumOf { sInt64(
 
 @InternalRpcApi
 public fun WireSize.packedEnum(value: List<Int>): Int = value.sumOf { enum(it) }
+
+@InternalRpcApi
+public fun WireSize.packedFloat(value: List<Float>): Int = value.size * 32
+
+@InternalRpcApi
+public fun WireSize.packedDouble(value: List<Double>): Int = value.size * 64
+
+@InternalRpcApi
+public fun WireSize.packedFixed32(value: List<UInt>): Int = value.size * 32
+
+@InternalRpcApi
+public fun WireSize.packedFixed64(value: List<ULong>): Int = value.size * 64
+
+@InternalRpcApi
+public fun WireSize.packedSFixed32(value: List<Int>): Int = value.size * 32
+
+@InternalRpcApi
+public fun WireSize.packedSFixed64(value: List<Long>): Int = value.size * 64