grpc-pb: Address PR comments

Signed-off-by: Johannes Zottele <[email protected]>

Author: Jozott00

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

@@ -4,7 +4,7 @@
 
 package kotlinx.rpc.grpc.internal
 
-import kotlinx.rpc.grpc.ProtobufDecodingException
+import kotlinx.rpc.grpc.pb.ProtobufDecodingException
 import kotlinx.rpc.grpc.pb.WireDecoder
 
 internal expect fun WireDecoder.pushLimit(byteLen: Int): Int

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

@@ -40,10 +40,10 @@ internal fun KTag.Companion.from(rawKTag: UInt): KTag {
     val type = (rawKTag and K_TAG_TYPE_MASK).toInt()
     val field = (rawKTag shr K_TAG_TYPE_BITS).toInt()
     if (!isValidFieldNr(field)) {
-        error("Invalid field number: $field")
+        throw ProtobufDecodingException("Invalid field number: $field")
     }
     if (type >= WireType.entries.size) {
-        error("Invalid wire type: $type")
+        throw ProtobufDecodingException("Invalid wire type: $type")
     }
     return KTag(field, WireType.entries[type])
 }

grpc/grpc-core/src/commonMain/kotlin/kotlinx/rpc/grpc/GrpcException.kt renamed to grpc/grpc-core/src/commonMain/kotlin/kotlinx/rpc/grpc/pb/ProtobufException.kt

@@ -2,14 +2,14 @@
  * 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
+package kotlinx.rpc.grpc.pb
 
-public sealed class GrpcException : RuntimeException {
+public sealed class ProtobufException : RuntimeException {
     protected constructor(message: String, cause: Throwable? = null) : super(message, cause)
 }
 
 
-public class ProtobufDecodingException : GrpcException {
+public class ProtobufDecodingException : ProtobufException {
     internal constructor(message: String, cause: Throwable? = null) : super(message, cause)
 
     public companion object Companion {
@@ -35,6 +35,6 @@ public class ProtobufDecodingException : GrpcException {
     }
 }
 
-public class ProtobufEncodingException : GrpcException {
+public class ProtobufEncodingException : ProtobufException {
     internal constructor(message: String, cause: Throwable? = null) : super(message, cause)
 }

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

@@ -5,7 +5,6 @@
 package kotlinx.rpc.grpc.pb
 
 import kotlinx.io.Buffer
-import kotlinx.rpc.grpc.ProtobufDecodingException
 import kotlinx.rpc.grpc.internal.popLimit
 import kotlinx.rpc.grpc.internal.pushLimit
 import kotlinx.rpc.internal.utils.InternalRpcApi
@@ -20,10 +19,12 @@ internal const val MAX_PACKED_BULK_SIZE: Int = 1_000_000
  * 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`.
+ * All `read*()` methods will throw an exception if the expected value couldn't be decoded.
+ * Because of optimization reasons, the exception is platform-dependent. To unify them
+ * wrap the decoding in a [checkForPlatformDecodeException] call, which turn platform-specific exceptions
+ * into a [ProtobufDecodingException].
  *
- * NOTE: If the [hadError] after a call to `read*()` returns `false`, it doesn't mean that the
+ * NOTE: If a call to `read*()` doesn't throw an error, it doesn't mean that the
  * value is correctly decoded. E.g., the following test will pass:
  * ```kt
  * val fieldNr = 1
@@ -33,10 +34,12 @@ internal const val MAX_PACKED_BULK_SIZE: Int = 1_000_000
  * assertTrue(encoder.writeInt32(fieldNr, 12312))
  * encoder.flush()
  *
- * WireDecoder(buffer).use { decoder ->
- *     decoder.readTag()
- *     decoder.readBool()
- *     assertFalse(decoder.hasError())
+ * checkForPlatformDecodeException {
+ *  WireDecoder(buffer).use { decoder ->
+ *      decoder.readTag()
+ *      decoder.readBool()
+ *      assertFalse(decoder.hasError())
+ *  }
  * }
  * ```
  */
@@ -92,12 +95,16 @@ public interface WireDecoder : AutoCloseable {
             WireType.FIXED32 -> readFixed32()
             WireType.FIXED64 -> readFixed64()
             WireType.LENGTH_DELIMITED -> readBytes()
-            WireType.START_GROUP -> error("Unexpected START_GROUP wire type (KRPC-193)")
+            WireType.START_GROUP -> throw ProtobufDecodingException("Unexpected START_GROUP wire type (KRPC-193)")
             WireType.END_GROUP -> {} // nothing to do
         }
     }
 }
 
+/**
+ * Turns exceptions thrown by different platforms during decoding into [ProtobufDecodingException].
+ */
+@InternalRpcApi
 public expect fun checkForPlatformDecodeException(block: () -> Unit)
 
 /**
@@ -110,4 +117,5 @@ public expect fun checkForPlatformDecodeException(block: () -> Unit)
  *
  * @param source The buffer containing the encoded wire-format data.
  */
+@InternalRpcApi
 public expect fun WireDecoder(source: Buffer): WireDecoder

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

@@ -10,8 +10,11 @@ import kotlinx.rpc.internal.utils.InternalRpcApi
 /**
  * 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].
+ * If one `write*()` method fails to encode the value in the buffer,
+ * it will throw a platform-specific exception.
+ *
+ * Wrap the encoding of a message with [checkForPlatformEncodeException] to
+ * turn all thrown platform-specific exceptions into [ProtobufEncodingException]s.
  *
  * [flush] must be called to ensure that all data is written to the [Sink].
  */
@@ -59,7 +62,11 @@ public interface WireEncoder {
 
 }
 
-
+/**
+ * Turns exceptions thrown by different platforms during encoding into [ProtobufEncodingException].
+ */
+@InternalRpcApi
 public expect fun checkForPlatformEncodeException(block: () -> Unit)
 
+@InternalRpcApi
 public expect fun WireEncoder(sink: Sink): WireEncoder

grpc/grpc-core/src/commonTest/kotlin/kotlinx/rpc/grpc/pb/ProtosTest.kt

@@ -13,7 +13,6 @@ import asInternal
 import encodeWith
 import invoke
 import kotlinx.io.Buffer
-import kotlinx.rpc.grpc.ProtobufDecodingException
 import kotlinx.rpc.grpc.codec.MessageCodec
 import kotlinx.rpc.grpc.test.*
 import kotlinx.rpc.grpc.test.common.*

grpc/grpc-core/src/commonTest/kotlin/kotlinx/rpc/grpc/pb/WireCodecTest.kt

@@ -5,7 +5,6 @@
 package kotlinx.rpc.grpc.pb
 
 import kotlinx.io.Buffer
-import kotlinx.rpc.grpc.ProtobufDecodingException
 import kotlin.test.*
 
 enum class TestPlatform {

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

@@ -33,7 +33,7 @@ private fun io.grpc.Server.toKotlin(): Server {
         override val isTerminated: Boolean
             get() = this@toKotlin.isTerminated
 
-        override fun start() : Server {
+        override fun start(): Server {
             this@toKotlin.start()
             return this
         }

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

@@ -8,7 +8,6 @@ import com.google.protobuf.CodedInputStream
 import com.google.protobuf.InvalidProtocolBufferException
 import kotlinx.io.Buffer
 import kotlinx.io.asInputStream
-import kotlinx.rpc.grpc.ProtobufDecodingException
 import kotlinx.rpc.grpc.internal.readPackedVarInternal
 
 internal class WireDecoderJvm(source: Buffer) : WireDecoder {
@@ -119,14 +118,10 @@ public actual fun checkForPlatformDecodeException(block: () -> Unit) {
     try {
         return block()
     } catch (e: InvalidProtocolBufferException) {
-        throw e.toDecodingException()
+        throw ProtobufDecodingException(e.message ?: "Failed to decode protobuf message.", e)
     }
 }
 
 public actual fun WireDecoder(source: Buffer): WireDecoder {
     return WireDecoderJvm(source)
 }
-
-private fun InvalidProtocolBufferException.toDecodingException(): ProtobufDecodingException {
-    return ProtobufDecodingException(message ?: "Failed to decode protobuf message.", cause)
-}

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

@@ -8,7 +8,6 @@ import com.google.protobuf.CodedOutputStream
 import kotlinx.io.IOException
 import kotlinx.io.Sink
 import kotlinx.io.asOutputStream
-import kotlinx.rpc.grpc.ProtobufEncodingException
 
 private class WireEncoderJvm(sink: Sink) : WireEncoder {
     private val codedOutputStream = CodedOutputStream.newInstance(sink.asOutputStream())