Unverified Commit 4c30f00f authored by david-perez's avatar david-perez Committed by GitHub
Browse files

Refactor determining server error type when deserializing an `@httpPayload` (#3752) 

Determining the error type when deserializing an `@httpPayload` is a
protocol-specific concern, and as such should not live in
`ServerHttpBoundProtocolGenerator`, which should remain
protocol-agnostic. This commits makes that determination part of the
`ServerProtocol` interface.

As a drive-by improvement, the companion object in
`ServerHttpBoundProtocolGenerator` has also been removed, since its
members have been unused for a long time.

----

_By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice._
parent dc66ae4b

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/http/ServerRequestBindingGenerator.kt

+3 −5
Original line number Diff line number Diff line
@@ -5,7 +5,6 @@ 


package software.amazon.smithy.rust.codegen.server.smithy.generators.http



import software.amazon.smithy.codegen.core.Symbol

import software.amazon.smithy.model.shapes.OperationShape

import software.amazon.smithy.rust.codegen.core.rustlang.RustType

import software.amazon.smithy.rust.codegen.core.rustlang.RustWriter
@@ -20,12 +19,12 @@ import software.amazon.smithy.rust.codegen.core.smithy.generators.http.HttpBindi 
import software.amazon.smithy.rust.codegen.core.smithy.generators.http.HttpMessageType

import software.amazon.smithy.rust.codegen.core.smithy.mapRustType

import software.amazon.smithy.rust.codegen.core.smithy.protocols.HttpBindingDescriptor

import software.amazon.smithy.rust.codegen.core.smithy.protocols.Protocol

import software.amazon.smithy.rust.codegen.server.smithy.ServerCodegenContext

import software.amazon.smithy.rust.codegen.server.smithy.generators.protocol.ServerProtocol

import software.amazon.smithy.rust.codegen.server.smithy.targetCanReachConstrainedShape



class ServerRequestBindingGenerator(

    protocol: Protocol,

    val protocol: ServerProtocol,

    codegenContext: ServerCodegenContext,

    operationShape: OperationShape,

    additionalHttpBindingCustomizations: List<HttpBindingCustomization> = listOf(),
@@ -50,12 +49,11 @@ class ServerRequestBindingGenerator( 


    fun generateDeserializePayloadFn(

        binding: HttpBindingDescriptor,

        errorSymbol: Symbol,

        structuredHandler: RustWriter.(String) -> Unit,

    ): RuntimeType =

        httpBindingGenerator.generateDeserializePayloadFn(

            binding,

            errorSymbol,

            protocol.deserializePayloadErrorType(binding).toSymbol(),

            structuredHandler,

            HttpMessageType.REQUEST,

        )

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocol.kt

+64 −2
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ package software.amazon.smithy.rust.codegen.server.smithy.generators.protocol 
import software.amazon.smithy.model.shapes.MemberShape

import software.amazon.smithy.model.shapes.OperationShape

import software.amazon.smithy.model.shapes.Shape

import software.amazon.smithy.model.shapes.StringShape

import software.amazon.smithy.model.shapes.StructureShape

import software.amazon.smithy.rust.codegen.core.rustlang.Writable

import software.amazon.smithy.rust.codegen.core.rustlang.rust
@@ -17,7 +18,9 @@ import software.amazon.smithy.rust.codegen.core.smithy.RuntimeConfig 
import software.amazon.smithy.rust.codegen.core.smithy.RuntimeType

import software.amazon.smithy.rust.codegen.core.smithy.protocols.AwsJson

import software.amazon.smithy.rust.codegen.core.smithy.protocols.AwsJsonVersion

import software.amazon.smithy.rust.codegen.core.smithy.protocols.HttpBindingDescriptor

import software.amazon.smithy.rust.codegen.core.smithy.protocols.HttpBindingResolver

import software.amazon.smithy.rust.codegen.core.smithy.protocols.HttpLocation

import software.amazon.smithy.rust.codegen.core.smithy.protocols.Protocol

import software.amazon.smithy.rust.codegen.core.smithy.protocols.RestJson

import software.amazon.smithy.rust.codegen.core.smithy.protocols.RestXml
@@ -70,8 +73,8 @@ interface ServerProtocol : Protocol { 
    fun serverRouterRequestSpecType(requestSpecModule: RuntimeType): RuntimeType



    /**

     * In some protocols, such as restJson1,

     * when there is no modeled body input, content type must not be set and the body must be empty.

     * In some protocols, such as `restJson1` and `rpcv2Cbor`,

     * when there is no modeled body input, `content-type` must not be set and the body must be empty.

     * Returns a boolean indicating whether to perform this check.

     */

    fun serverContentTypeCheckNoModeledInput(): Boolean = false
@@ -90,6 +93,19 @@ interface ServerProtocol : Protocol { 
    fun runtimeError(runtimeConfig: RuntimeConfig): RuntimeType =

        ServerCargoDependency.smithyHttpServer(runtimeConfig)

            .toType().resolve("protocol::$protocolModulePath::runtime_error::RuntimeError")



    /**

     * The function that deserializes a payload-bound shape takes as input a byte slab and returns a `Result` holding

     * the deserialized shape if successful. What error type should we use in case of failure?

     *

     * The shape could be payload-bound either because of the `@httpPayload` trait, or because it's part of an event

     * stream.

     *

     * Note that despite the trait (https://smithy.io/2.0/spec/http-bindings.html#httppayload-trait) being able to

     * target any structure member shape, AWS Protocols only support binding the following shape types to the payload

     * (and Smithy does indeed enforce this at model build-time): string, blob, structure, union, and document

     */

    fun deserializePayloadErrorType(binding: HttpBindingDescriptor): RuntimeType

}



fun returnSymbolToParseFn(codegenContext: ServerCodegenContext): (Shape) -> ReturnSymbolToParse {
@@ -185,6 +201,18 @@ class ServerAwsJsonProtocol( 
    override fun runtimeError(runtimeConfig: RuntimeConfig): RuntimeType =

        ServerCargoDependency.smithyHttpServer(runtimeConfig)

            .toType().resolve("protocol::aws_json::runtime_error::RuntimeError")



    /*

     * Note that despite the AWS JSON 1.x protocols not supporting the `@httpPayload` trait, event streams are bound

     * to the payload.

     */

    override fun deserializePayloadErrorType(binding: HttpBindingDescriptor): RuntimeType =

        deserializePayloadErrorType(

            codegenContext,

            binding,

            requestRejection(runtimeConfig),

            RuntimeType.smithyJson(codegenContext.runtimeConfig).resolve("deserialize::error::DeserializeError"),

        )

}



private fun restRouterType(runtimeConfig: RuntimeConfig) =
@@ -227,6 +255,14 @@ class ServerRestJsonProtocol( 
    override fun serverRouterRuntimeConstructor() = "new_rest_json_router"



    override fun serverContentTypeCheckNoModeledInput() = true



    override fun deserializePayloadErrorType(binding: HttpBindingDescriptor): RuntimeType =

        deserializePayloadErrorType(

            codegenContext,

            binding,

            requestRejection(runtimeConfig),

            RuntimeType.smithyJson(codegenContext.runtimeConfig).resolve("deserialize::error::DeserializeError"),

        )

}



class ServerRestXmlProtocol(
@@ -252,6 +288,32 @@ class ServerRestXmlProtocol( 
    override fun serverRouterRuntimeConstructor() = "new_rest_xml_router"



    override fun serverContentTypeCheckNoModeledInput() = true



    override fun deserializePayloadErrorType(binding: HttpBindingDescriptor): RuntimeType =

        deserializePayloadErrorType(

            codegenContext,

            binding,

            requestRejection(runtimeConfig),

            RuntimeType.smithyXml(runtimeConfig).resolve("decode::XmlDecodeError"),

        )

}



/** Just a common function to keep things DRY. **/

fun deserializePayloadErrorType(

    codegenContext: CodegenContext,

    binding: HttpBindingDescriptor,

    requestRejection: RuntimeType,

    protocolSerializationFormatError: RuntimeType,

): RuntimeType {

    check(binding.location == HttpLocation.PAYLOAD)



    if (codegenContext.model.expectShape(binding.member.target) is StringShape) {

        // The only way deserializing a string can fail is if the HTTP body does not contain valid UTF-8.

        // TODO(https://github.com/smithy-lang/smithy-rs/issues/3750): we're returning an incorrect `RequestRejection` variant here.

        return requestRejection

    }



    return protocolSerializationFormatError

}



/**

codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/protocols/ServerHttpBoundProtocolGenerator.kt

+8 −49
Original line number Diff line number Diff line
@@ -5,10 +5,6 @@ 


package software.amazon.smithy.rust.codegen.server.smithy.protocols



import software.amazon.smithy.aws.traits.protocols.AwsJson1_0Trait

import software.amazon.smithy.aws.traits.protocols.AwsJson1_1Trait

import software.amazon.smithy.aws.traits.protocols.RestJson1Trait

import software.amazon.smithy.aws.traits.protocols.RestXmlTrait

import software.amazon.smithy.codegen.core.Symbol

import software.amazon.smithy.model.knowledge.HttpBindingIndex

import software.amazon.smithy.model.node.ExpectationNotMetException
@@ -20,7 +16,6 @@ import software.amazon.smithy.model.shapes.MemberShape 
import software.amazon.smithy.model.shapes.NumberShape

import software.amazon.smithy.model.shapes.OperationShape

import software.amazon.smithy.model.shapes.Shape

import software.amazon.smithy.model.shapes.StringShape

import software.amazon.smithy.model.shapes.StructureShape

import software.amazon.smithy.model.traits.ErrorTrait

import software.amazon.smithy.model.traits.HttpErrorTrait
@@ -124,13 +119,7 @@ class ServerHttpBoundProtocolGenerator( 
) : ServerProtocolGenerator(

        protocol,

        ServerHttpBoundProtocolTraitImplGenerator(codegenContext, protocol, customizations, additionalHttpBindingCustomizations),

    ) {

    // Define suffixes for operation input / output / error wrappers

    companion object {

        const val OPERATION_INPUT_WRAPPER_SUFFIX = "OperationInputWrapper"

        const val OPERATION_OUTPUT_WRAPPER_SUFFIX = "OperationOutputWrapper"

    }

}

    )



class ServerHttpBoundProtocolPayloadGenerator(

    codegenContext: CodegenContext,
@@ -697,8 +686,6 @@ class ServerHttpBoundProtocolTraitImplGenerator( 
        inputShape: StructureShape,

        bindings: List<HttpBindingDescriptor>,

    ) {

        val httpBindingGenerator =

            ServerRequestBindingGenerator(protocol, codegenContext, operationShape, additionalHttpBindingCustomizations)

        val structuredDataParser = protocol.structuredDataParser()

        Attribute.AllowUnusedMut.render(this)

        rust(
@@ -740,7 +727,7 @@ class ServerHttpBoundProtocolTraitImplGenerator( 
        for (binding in bindings) {

            val member = binding.member

            val parsedValue =

                serverRenderBindingParser(binding, operationShape, httpBindingGenerator, structuredDataParser)

                serverRenderBindingParser(binding, operationShape, httpBindingGenerator(operationShape), structuredDataParser)

            val valueToSet =

                if (symbolProvider.toSymbol(binding.member).isOptional()) {

                    "Some(value)"
@@ -801,13 +788,8 @@ class ServerHttpBoundProtocolTraitImplGenerator( 
                val structureShapeHandler: RustWriter.(String) -> Unit = { body ->

                    rust("#T($body)", structuredDataParser.payloadParser(binding.member))

                }

                val errorSymbol = getDeserializePayloadErrorSymbol(binding)

                val deserializer =

                    httpBindingGenerator.generateDeserializePayloadFn(

                        binding,

                        errorSymbol,

                        structuredHandler = structureShapeHandler,

                    )

                    httpBindingGenerator.generateDeserializePayloadFn(binding, structuredHandler = structureShapeHandler)

                return writable {

                    if (binding.member.isStreaming(model)) {

                        rustTemplate(
@@ -1196,9 +1178,7 @@ class ServerHttpBoundProtocolTraitImplGenerator( 
        binding: HttpBindingDescriptor,

        operationShape: OperationShape,

    ) {

        val httpBindingGenerator =

            ServerRequestBindingGenerator(protocol, codegenContext, operationShape, additionalHttpBindingCustomizations)

        val deserializer = httpBindingGenerator.generateDeserializeHeaderFn(binding)

        val deserializer = httpBindingGenerator(operationShape).generateDeserializeHeaderFn(binding)

        writer.rustTemplate(

            """

            #{deserializer}(&headers)?
@@ -1215,8 +1195,7 @@ class ServerHttpBoundProtocolTraitImplGenerator( 
    ) {

        check(binding.location == HttpLocation.PREFIX_HEADERS)



        val httpBindingGenerator = ServerRequestBindingGenerator(protocol, codegenContext, operationShape)

        val deserializer = httpBindingGenerator.generateDeserializePrefixHeadersFn(binding)

        val deserializer = httpBindingGenerator(operationShape).generateDeserializePrefixHeadersFn(binding)

        writer.rustTemplate(

            """

            #{deserializer}(&headers)?
@@ -1300,33 +1279,13 @@ class ServerHttpBoundProtocolTraitImplGenerator( 
        }

    }



    /**

     * Returns the error type of the function that deserializes a non-streaming HTTP payload (a byte slab) into the

     * shape targeted by the `httpPayload` trait.

     */

    private fun getDeserializePayloadErrorSymbol(binding: HttpBindingDescriptor): Symbol {

        check(binding.location == HttpLocation.PAYLOAD)



        if (model.expectShape(binding.member.target) is StringShape) {

            return protocol.requestRejection(runtimeConfig).toSymbol()

        }

        return when (codegenContext.protocol) {

            RestJson1Trait.ID, AwsJson1_0Trait.ID, AwsJson1_1Trait.ID -> {

                RuntimeType.smithyJson(runtimeConfig).resolve("deserialize::error::DeserializeError").toSymbol()

            }

            RestXmlTrait.ID -> {

                RuntimeType.smithyXml(runtimeConfig).resolve("decode::XmlDecodeError").toSymbol()

            }

            else -> {

                TODO("Protocol ${codegenContext.protocol} not supported yet")

            }

        }

    }



    private fun streamingBodyTraitBounds(operationShape: OperationShape) =

        if (operationShape.inputShape(model).hasStreamingMember(model)) {

            "\n B: Into<#{SmithyTypes}::byte_stream::ByteStream>,"

        } else {

            ""

        }



    private fun httpBindingGenerator(operationShape: OperationShape) =

        ServerRequestBindingGenerator(protocol, codegenContext, operationShape, additionalHttpBindingCustomizations)

}