Unverified Commit 5455c4e9 authored by Matteo Bigoi's avatar Matteo Bigoi Committed by GitHub
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Fix bug in coroutine scheduling. Add ByteStream implementation and simplify... 


Fix bug in coroutine scheduling. Add ByteStream implementation and simplify Python symbol visitor. (#1633)

* Fix bug in coroutine scheduling. Add ByteStream implementation and simplify Python symbol visitor.

* Bug in coroutine scheduling:

In the previous iteration, the runtime crate aws-smithy-http-server-python
was exposing the python application implementation as a struct, which
was wrapped by the codegenerated App to allow to dynamically building
the router.

This caused scheduling of coroutines (handlers prefixed with async def)
to block becuse we were passing the Python eventloop of the parent
process that was stored pre-fork().

This commit changes the runtime PyApp to become a trait, allowing us to
dynamically build the router post-fork() and with the right event loop.

This change also allowed us to remove a bunch of unnecessary Arc(s).

* Add ByteStream implementation

Implementation of a ByteStream type for Python that can be roughly used like this:

let b = await ByteStream.from_path("file.txt")
async for chunk in b:
    print(chunk)

Implement futures_core::stream::Stream for Python ByteStream wrapper.

The BytesStream implementation in python can now use a sync Mutex from
parking_lot because we are now using pyo3_asyncio::tokio::local_future_into_py()
to read a chunk, which supports !Send futures.

This allows to simply forward the implementation of Stream (poll_next()
and size_hint()) directly to our inner SDK ByteStream.

* Simplify Python symbol visitor

Inherit from Symbol visitor and override just what is needed to swap Python complex
types.

Signed-off-by: default avatarBigo <1781140+crisidev@users.noreply.github.com>
parent 7e7d5718

codegen-server-test/python/model/pokemon.smithy

+18 −3
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ use aws.protocols#restJson1 
service PokemonService {

    version: "2021-12-01",

    resources: [PokemonSpecies],

    operations: [GetServerStatistics, EmptyOperation, HealthCheckOperation],

    operations: [GetServerStatistics, EmptyOperation, HealthCheckOperation, StreamPokemonRadioOperation],

}



/// A Pokémon species forms the basis for at least one Pokémon.
@@ -70,6 +70,22 @@ structure GetServerStatisticsOutput { 
    calls_count: Long,

}



/// Fetch the radio song from the database and stream it back as a playable audio.

@readonly

@http(uri: "/radio", method: "GET")

operation StreamPokemonRadioOperation {

    output: StreamPokemonRadioOutput,

}



@output

structure StreamPokemonRadioOutput {

    @httpPayload

    data: StreamingBlob,

}



@streaming

blob StreamingBlob



list FlavorTextEntries {

    member: FlavorText

}
@@ -127,8 +143,7 @@ structure EmptyOperationOutput { } 
/// Not yet a deep check

@readonly

@http(uri: "/ping", method: "GET")

operation HealthCheckOperation {

}

operation HealthCheckOperation { }



@error("client")

@httpError(404)

codegen-server/python/src/main/kotlin/software/amazon/smithy/rust/codegen/server/python/smithy/PythonCodegenServerPlugin.kt

+6 −10
Original line number Diff line number Diff line
@@ -12,13 +12,12 @@ import software.amazon.smithy.model.Model 
import software.amazon.smithy.model.shapes.ServiceShape

import software.amazon.smithy.rust.codegen.rustlang.RustReservedWordSymbolProvider

import software.amazon.smithy.rust.codegen.server.python.smithy.customizations.DECORATORS

import software.amazon.smithy.rust.codegen.server.python.smithy.generators.PythonServerSymbolProvider

import software.amazon.smithy.rust.codegen.server.python.smithy.generators.PythonServerSymbolVisitor

import software.amazon.smithy.rust.codegen.server.python.smithy.generators.PythonStreamingShapeMetadataProvider

import software.amazon.smithy.rust.codegen.server.smithy.customizations.ServerRequiredCustomizations

import software.amazon.smithy.rust.codegen.smithy.BaseSymbolMetadataProvider

import software.amazon.smithy.rust.codegen.smithy.EventStreamSymbolProvider

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

import software.amazon.smithy.rust.codegen.smithy.StreamingShapeMetadataProvider

import software.amazon.smithy.rust.codegen.smithy.StreamingShapeSymbolProvider

import software.amazon.smithy.rust.codegen.smithy.SymbolVisitor

import software.amazon.smithy.rust.codegen.smithy.SymbolVisitorConfig

import software.amazon.smithy.rust.codegen.smithy.customize.CombinedCodegenDecorator
@@ -68,20 +67,17 @@ class PythonCodegenServerPlugin : SmithyBuildPlugin { 
            serviceShape: ServiceShape,

            symbolVisitorConfig: SymbolVisitorConfig,

        ) =

            SymbolVisitor(model, serviceShape = serviceShape, config = symbolVisitorConfig)

            // Rename a set of symbols that do not implement `PyClass` and have been wrapped in

            // `aws_smithy_http_server_python::types`.

            PythonServerSymbolVisitor(model, serviceShape = serviceShape, config = symbolVisitorConfig)

                // Generate different types for EventStream shapes (e.g. transcribe streaming)

                .let {

                    EventStreamSymbolProvider(symbolVisitorConfig.runtimeConfig, it, model, CodegenTarget.SERVER)

                }

                // Generate [ByteStream] instead of `Blob` for streaming binary shapes (e.g. S3 GetObject)

                .let { StreamingShapeSymbolProvider(it, model) }

                // Rename a set of symbols that do not implement `PyClass` and have been wrapped in

                // `aws_smithy_http_server_python::types`.

                .let { PythonServerSymbolProvider(it, model) }

                // Add Rust attributes (like `#[derive(PartialEq)]`) to generated shapes

                .let { BaseSymbolMetadataProvider(it, model, additionalAttributes = listOf()) }

                // Streaming shapes need different derives (e.g. they cannot derive Eq)

                .let { StreamingShapeMetadataProvider(it, model) }

                .let { PythonStreamingShapeMetadataProvider(it, model) }

                // Rename shapes that clash with Rust reserved words & and other SDK specific features e.g. `send()` cannot

                // be the name of an operation input

                .let { RustReservedWordSymbolProvider(it, model) }

codegen-server/python/src/main/kotlin/software/amazon/smithy/rust/codegen/server/python/smithy/PythonServerCargoDependency.kt

+1 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ object PythonServerCargoDependency { 
    val TowerHttp: CargoDependency = CargoDependency("tower-http", CratesIo("0.3"), features = setOf("trace"))

    val Hyper: CargoDependency = CargoDependency("hyper", CratesIo("0.14.12"), features = setOf("server", "http1", "http2", "tcp", "stream"))

    val NumCpus: CargoDependency = CargoDependency("num_cpus", CratesIo("1.13"))

    val ParkingLot: CargoDependency = CargoDependency("parking_lot", CratesIo("0.12"))



    fun SmithyHttpServer(runtimeConfig: RuntimeConfig) = runtimeConfig.runtimeCrate("http-server")

    fun SmithyHttpServerPython(runtimeConfig: RuntimeConfig) = runtimeConfig.runtimeCrate("http-server-python")

codegen-server/python/src/main/kotlin/software/amazon/smithy/rust/codegen/server/python/smithy/PythonServerCodegenVisitor.kt

+0 −4
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ import software.amazon.smithy.rust.codegen.smithy.generators.BuilderGenerator 
import software.amazon.smithy.rust.codegen.smithy.generators.CodegenTarget

import software.amazon.smithy.rust.codegen.smithy.generators.implBlock

import software.amazon.smithy.rust.codegen.util.getTrait

import software.amazon.smithy.rust.codegen.util.hasStreamingMember



/**

 * Entrypoint for Python server-side code generation. This class will walk the in-memory model and
@@ -83,9 +82,6 @@ class PythonServerCodegenVisitor( 
     * This function _does not_ generate any serializers.

     */

    override fun structureShape(shape: StructureShape) {

        if (shape.hasStreamingMember(model)) {

            throw CodegenException("Streaming members are not supported in Python yet")

        }

        logger.info("[python-server-codegen] Generating a structure $shape")

        rustCrate.useShapeWriter(shape) { writer ->

            // Use Python specific structure generator that adds the #[pyclass] attribute

codegen-server/python/src/main/kotlin/software/amazon/smithy/rust/codegen/server/python/smithy/PythonServerRuntimeType.kt

+3 −0
Original line number Diff line number Diff line
@@ -21,6 +21,9 @@ object PythonServerRuntimeType { 
    fun Blob(runtimeConfig: RuntimeConfig) =

        RuntimeType("Blob", PythonServerCargoDependency.SmithyHttpServerPython(runtimeConfig), "${runtimeConfig.crateSrcPrefix}_http_server_python::types")



    fun ByteStream(runtimeConfig: RuntimeConfig) =

        RuntimeType("ByteStream", PythonServerCargoDependency.SmithyHttpServerPython(runtimeConfig), "${runtimeConfig.crateSrcPrefix}_http_server_python::types")



    fun DateTime(runtimeConfig: RuntimeConfig) =

        RuntimeType("DateTime", PythonServerCargoDependency.SmithyHttpServerPython(runtimeConfig), "${runtimeConfig.crateSrcPrefix}_http_server_python::types")