lostluck commented on code in PR #24081: URL: https://github.com/apache/beam/pull/24081#discussion_r1020614296
########## sdks/go/examples/wasm/wasm.go: ########## @@ -0,0 +1,159 @@ +// Licensed to the Apache Software Foundation (ASF) under one or more +// contributor license agreements. See the NOTICE file distributed with +// this work for additional information regarding copyright ownership. +// The ASF licenses this file to You under the Apache License, Version 2.0 +// (the "License"); you may not use this file except in compliance with +// the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// wasm is an EXPERIMENTAL simple example that loads and executes a wasm file function. +// greet.wasm, Cargo.toml and greet.rs were copied from the example provided by the wazero library: +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +// +// New Concepts: +// 1. Load a wasm file compiled from: cargo build --release --target wasm32-unknown-unknown +// 2. Execute a wasm function within a DoFn +package main + +import ( + "context" + _ "embed" + "flag" + "fmt" + "github.com/apache/beam/sdks/v2/go/pkg/beam" + "github.com/apache/beam/sdks/v2/go/pkg/beam/io/textio" + "github.com/apache/beam/sdks/v2/go/pkg/beam/register" + "github.com/apache/beam/sdks/v2/go/pkg/beam/x/beamx" + "github.com/tetratelabs/wazero" + "github.com/tetratelabs/wazero/api" + "log" +) + +const ( + wasmFunctionName = "greeting" + wasmAllocateFunctionName = "allocate" + wasmDeallocateFunctionName = "deallocate" +) + +//go:embed greet.wasm +var greetWasm []byte + +var ( + output = flag.String("output", "", "Output file (required).") +) + +func init() { + // register.DoFnXxY registers a struct DoFn so that it can be correctly + // serialized and does some optimization to avoid runtime reflection. Since + // embeddedWasmFn's ProcessElement func has 2 inputs (context.Context) and 2 outputs (string, error), + // we use register.DoFn2x2 and provide its input and output types as its constraints. + // Struct DoFns must be registered for a pipeline to run. + register.DoFn2x2[context.Context, string, string, error](&embeddedWasmFn{}) +} + +func preRun() error { + if *output == "" { + return fmt.Errorf("--output is required") + } + return nil +} + +func main() { + flag.Parse() + beam.Init() + ctx := context.Background() + if err := preRun(); err != nil { + panic(err) + } + if err := run(ctx); err != nil { + panic(err) + } +} + +func run(ctx context.Context) error { + p, s := beam.NewPipelineWithRoot() + + in := beam.Create(s, "a", "b", "c", "d", "e", "f", "g", "h") Review Comment: Only one comment: Also include "World" because then there's at least one word that isn't a single character, also, because it's traditional. Personally, I'd go with "World", "Wasm", "Beam", "Dolly", as it's more interesting to an example runner. (Hello Dolly is a musical) ########## sdks/go/examples/wasm/wasm.go: ########## @@ -0,0 +1,159 @@ +// Licensed to the Apache Software Foundation (ASF) under one or more +// contributor license agreements. See the NOTICE file distributed with +// this work for additional information regarding copyright ownership. +// The ASF licenses this file to You under the Apache License, Version 2.0 +// (the "License"); you may not use this file except in compliance with +// the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// wasm is an EXPERIMENTAL simple example that loads and executes a wasm file function. +// greet.wasm, Cargo.toml and greet.rs were copied from the example provided by the wazero library: +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +// +// New Concepts: +// 1. Load a wasm file compiled from: cargo build --release --target wasm32-unknown-unknown +// 2. Execute a wasm function within a DoFn +package main + +import ( + "context" + _ "embed" + "flag" + "fmt" + "github.com/apache/beam/sdks/v2/go/pkg/beam" + "github.com/apache/beam/sdks/v2/go/pkg/beam/io/textio" + "github.com/apache/beam/sdks/v2/go/pkg/beam/register" + "github.com/apache/beam/sdks/v2/go/pkg/beam/x/beamx" + "github.com/tetratelabs/wazero" + "github.com/tetratelabs/wazero/api" + "log" +) + +const ( + wasmFunctionName = "greeting" + wasmAllocateFunctionName = "allocate" + wasmDeallocateFunctionName = "deallocate" +) + +//go:embed greet.wasm +var greetWasm []byte + +var ( + output = flag.String("output", "", "Output file (required).") +) + +func init() { + // register.DoFnXxY registers a struct DoFn so that it can be correctly + // serialized and does some optimization to avoid runtime reflection. Since + // embeddedWasmFn's ProcessElement func has 2 inputs (context.Context) and 2 outputs (string, error), + // we use register.DoFn2x2 and provide its input and output types as its constraints. + // Struct DoFns must be registered for a pipeline to run. + register.DoFn2x2[context.Context, string, string, error](&embeddedWasmFn{}) +} + +func preRun() error { + if *output == "" { + return fmt.Errorf("--output is required") + } + return nil +} + +func main() { + flag.Parse() + beam.Init() + ctx := context.Background() + if err := preRun(); err != nil { + panic(err) + } + if err := run(ctx); err != nil { + panic(err) + } +} + +func run(ctx context.Context) error { + p, s := beam.NewPipelineWithRoot() + + in := beam.Create(s, "a", "b", "c", "d", "e", "f", "g", "h") + + out := beam.ParDo(s.Scope("embeddedWasm"), &embeddedWasmFn{}, in) Review Comment: I'd remove the sub scoping here. It doesn't add anything when it's a single function, and it dilutes the example. Folks may interpret this to mean "we always need to rename scopes for wasm using DoFns". ########## sdks/go/examples/wasm/wasm.go: ########## @@ -0,0 +1,159 @@ +// Licensed to the Apache Software Foundation (ASF) under one or more +// contributor license agreements. See the NOTICE file distributed with +// this work for additional information regarding copyright ownership. +// The ASF licenses this file to You under the Apache License, Version 2.0 +// (the "License"); you may not use this file except in compliance with +// the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// wasm is an EXPERIMENTAL simple example that loads and executes a wasm file function. +// greet.wasm, Cargo.toml and greet.rs were copied from the example provided by the wazero library: +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +// +// New Concepts: +// 1. Load a wasm file compiled from: cargo build --release --target wasm32-unknown-unknown +// 2. Execute a wasm function within a DoFn +package main + +import ( + "context" + _ "embed" + "flag" + "fmt" + "github.com/apache/beam/sdks/v2/go/pkg/beam" + "github.com/apache/beam/sdks/v2/go/pkg/beam/io/textio" + "github.com/apache/beam/sdks/v2/go/pkg/beam/register" + "github.com/apache/beam/sdks/v2/go/pkg/beam/x/beamx" + "github.com/tetratelabs/wazero" + "github.com/tetratelabs/wazero/api" + "log" +) + +const ( + wasmFunctionName = "greeting" + wasmAllocateFunctionName = "allocate" + wasmDeallocateFunctionName = "deallocate" +) + +//go:embed greet.wasm +var greetWasm []byte + +var ( + output = flag.String("output", "", "Output file (required).") +) + +func init() { + // register.DoFnXxY registers a struct DoFn so that it can be correctly + // serialized and does some optimization to avoid runtime reflection. Since + // embeddedWasmFn's ProcessElement func has 2 inputs (context.Context) and 2 outputs (string, error), + // we use register.DoFn2x2 and provide its input and output types as its constraints. + // Struct DoFns must be registered for a pipeline to run. + register.DoFn2x2[context.Context, string, string, error](&embeddedWasmFn{}) +} + +func preRun() error { + if *output == "" { + return fmt.Errorf("--output is required") + } + return nil +} + +func main() { + flag.Parse() + beam.Init() + ctx := context.Background() + if err := preRun(); err != nil { + panic(err) + } + if err := run(ctx); err != nil { + panic(err) + } +} + +func run(ctx context.Context) error { + p, s := beam.NewPipelineWithRoot() + + in := beam.Create(s, "a", "b", "c", "d", "e", "f", "g", "h") + + out := beam.ParDo(s.Scope("embeddedWasm"), &embeddedWasmFn{}, in) + + textio.Write(s, *output, out) + + if err := beamx.Run(ctx, p); err != nil { + return fmt.Errorf("failed to run pipeline: %v", err) + } + return nil +} + +// Concept #2 wrap wasm function execution within a DoFn. +// wasmFn wraps a DoFn to execute a Rust compiled wasm function +type embeddedWasmFn struct { + r wazero.Runtime + mod api.Module + greeting, allocate, deallocate api.Function +} + +// Setup loads and initializes the embedded wasm functions +// Concept #1: Load a compiled wasm file []byte content and function. +// This example is derived from +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +func (fn *embeddedWasmFn) Setup(ctx context.Context) error { + fn.r = wazero.NewRuntime(ctx) + _, err := fn.r.NewHostModuleBuilder("env"). + NewFunctionBuilder().WithFunc(logString).Export("log"). + Instantiate(ctx, fn.r) + if err != nil { + return fmt.Errorf("failed to instantiate host module: %w", err) + } + fn.mod, err = fn.r.InstantiateModuleFromBinary(ctx, greetWasm) + if err != nil { + return fmt.Errorf("failed to instantiate wasm module: %v", err) + } + fn.greeting = fn.mod.ExportedFunction(wasmFunctionName) + fn.allocate = fn.mod.ExportedFunction(wasmAllocateFunctionName) + fn.deallocate = fn.mod.ExportedFunction(wasmDeallocateFunctionName) + return nil +} + +// ProcessElement processes a string calling a wasm function written in Rust +// This example is derived from +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +func (fn *embeddedWasmFn) ProcessElement(ctx context.Context, s string) (string, error) { + size := uint64(len(s)) + results, err := fn.allocate.Call(ctx, size) + if err != nil { + return "", fmt.Errorf("error calling allocate: %w", err) + } + ptr := results[0] + defer fn.deallocate.Call(ctx, ptr, size) + if !fn.mod.Memory().Write(ctx, uint32(ptr), []byte(s)) { + return "", fmt.Errorf("Memory.Write(%d, %d) out of range of memory size %d", + ptr, size, fn.mod.Memory().Size(ctx)) + } + + ptrSize, err := fn.greeting.Call(ctx, ptr, size) + resultPtr := uint32(ptrSize[0] >> 32) + resultSize := uint32(ptrSize[0]) + defer fn.deallocate.Call(ctx, uint64(resultPtr), uint64(resultSize)) + bytes, ok := fn.mod.Memory().Read(ctx, resultPtr, resultSize) + if !ok { + return "", fmt.Errorf("Memory.Read(%d, %d) out of range of memory size %d", + resultPtr, resultSize, fn.mod.Memory().Size(ctx)) + } + return string(bytes), nil +} + +func logString(ctx context.Context, m api.Module, offset, byteCount uint32) { + buf, ok := m.Memory().Read(ctx, offset, byteCount) + if !ok { + log.Panicf("Memory.Read(%d, %d) out of range", offset, byteCount) + } + fmt.Println(string(buf)) Review Comment: I'd use the beam Log package instead of fmt.Println, so they're visible when using portable runners outside of Loopback mode. Note that this is different from the standard library "log" package. When the [new structure logging package for Go](https://go.googlesource.com/proposal/+/master/design/56345-structured-logging.md) comes out in ~1.20, we can add a proper "beam" backend to it so we become more compatible with the ecosystem (and deprecate the existing log package/ re-implement it in terms of the new structured logging, because it leaves plenty to be desired at present). ########## sdks/go/examples/wasm/wasm.go: ########## @@ -0,0 +1,159 @@ +// Licensed to the Apache Software Foundation (ASF) under one or more +// contributor license agreements. See the NOTICE file distributed with +// this work for additional information regarding copyright ownership. +// The ASF licenses this file to You under the Apache License, Version 2.0 +// (the "License"); you may not use this file except in compliance with +// the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// wasm is an EXPERIMENTAL simple example that loads and executes a wasm file function. +// greet.wasm, Cargo.toml and greet.rs were copied from the example provided by the wazero library: +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +// +// New Concepts: +// 1. Load a wasm file compiled from: cargo build --release --target wasm32-unknown-unknown +// 2. Execute a wasm function within a DoFn +package main + +import ( + "context" + _ "embed" + "flag" + "fmt" + "github.com/apache/beam/sdks/v2/go/pkg/beam" + "github.com/apache/beam/sdks/v2/go/pkg/beam/io/textio" + "github.com/apache/beam/sdks/v2/go/pkg/beam/register" + "github.com/apache/beam/sdks/v2/go/pkg/beam/x/beamx" + "github.com/tetratelabs/wazero" + "github.com/tetratelabs/wazero/api" + "log" +) + +const ( + wasmFunctionName = "greeting" + wasmAllocateFunctionName = "allocate" + wasmDeallocateFunctionName = "deallocate" +) + +//go:embed greet.wasm +var greetWasm []byte + +var ( + output = flag.String("output", "", "Output file (required).") +) + +func init() { + // register.DoFnXxY registers a struct DoFn so that it can be correctly + // serialized and does some optimization to avoid runtime reflection. Since + // embeddedWasmFn's ProcessElement func has 2 inputs (context.Context) and 2 outputs (string, error), + // we use register.DoFn2x2 and provide its input and output types as its constraints. + // Struct DoFns must be registered for a pipeline to run. + register.DoFn2x2[context.Context, string, string, error](&embeddedWasmFn{}) +} + +func preRun() error { + if *output == "" { + return fmt.Errorf("--output is required") + } + return nil +} + +func main() { + flag.Parse() + beam.Init() + ctx := context.Background() + if err := preRun(); err != nil { + panic(err) + } + if err := run(ctx); err != nil { + panic(err) + } +} + +func run(ctx context.Context) error { + p, s := beam.NewPipelineWithRoot() + + in := beam.Create(s, "a", "b", "c", "d", "e", "f", "g", "h") + + out := beam.ParDo(s.Scope("embeddedWasm"), &embeddedWasmFn{}, in) + + textio.Write(s, *output, out) + + if err := beamx.Run(ctx, p); err != nil { + return fmt.Errorf("failed to run pipeline: %v", err) + } + return nil +} + +// Concept #2 wrap wasm function execution within a DoFn. +// wasmFn wraps a DoFn to execute a Rust compiled wasm function +type embeddedWasmFn struct { + r wazero.Runtime + mod api.Module + greeting, allocate, deallocate api.Function +} + +// Setup loads and initializes the embedded wasm functions +// Concept #1: Load a compiled wasm file []byte content and function. +// This example is derived from +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +func (fn *embeddedWasmFn) Setup(ctx context.Context) error { + fn.r = wazero.NewRuntime(ctx) + _, err := fn.r.NewHostModuleBuilder("env"). + NewFunctionBuilder().WithFunc(logString).Export("log"). + Instantiate(ctx, fn.r) + if err != nil { + return fmt.Errorf("failed to instantiate host module: %w", err) + } + fn.mod, err = fn.r.InstantiateModuleFromBinary(ctx, greetWasm) + if err != nil { + return fmt.Errorf("failed to instantiate wasm module: %v", err) + } + fn.greeting = fn.mod.ExportedFunction(wasmFunctionName) + fn.allocate = fn.mod.ExportedFunction(wasmAllocateFunctionName) + fn.deallocate = fn.mod.ExportedFunction(wasmDeallocateFunctionName) + return nil +} + +// ProcessElement processes a string calling a wasm function written in Rust +// This example is derived from +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +func (fn *embeddedWasmFn) ProcessElement(ctx context.Context, s string) (string, error) { + size := uint64(len(s)) + results, err := fn.allocate.Call(ctx, size) + if err != nil { + return "", fmt.Errorf("error calling allocate: %w", err) + } + ptr := results[0] + defer fn.deallocate.Call(ctx, ptr, size) + if !fn.mod.Memory().Write(ctx, uint32(ptr), []byte(s)) { + return "", fmt.Errorf("Memory.Write(%d, %d) out of range of memory size %d", + ptr, size, fn.mod.Memory().Size(ctx)) + } + + ptrSize, err := fn.greeting.Call(ctx, ptr, size) + resultPtr := uint32(ptrSize[0] >> 32) + resultSize := uint32(ptrSize[0]) + defer fn.deallocate.Call(ctx, uint64(resultPtr), uint64(resultSize)) + bytes, ok := fn.mod.Memory().Read(ctx, resultPtr, resultSize) + if !ok { + return "", fmt.Errorf("Memory.Read(%d, %d) out of range of memory size %d", + resultPtr, resultSize, fn.mod.Memory().Size(ctx)) + } + return string(bytes), nil +} Review Comment: Given the direct pointer/offset + size uses, it would be good to add comments. I tried just wraping in methods, but that didn't help very much, so I propose doing something like... ```suggestion func (fn *embeddedWasmFn) ProcessElement(ctx context.Context, s string) (string, error) { // Write the string to wasm size := uint64(len(s)) results, err := fn.allocate.Call(ctx, size) if err != nil { return "", fmt.Errorf("error calling allocate: %w", err) } ptr := results[0] defer fn.deallocate.Call(ctx, ptr, size) if !fn.mod.Memory().Write(ctx, uint32(ptr), []byte(s)) { return "", fmt.Errorf("Memory.Write(%d, %d) out of range of memory size %d", ptr, size, fn.mod.Memory().Size(ctx)) } // Call the wasm function and read the updated string ptrSize, err := fn.greeting.Call(ctx, ptr, size) resultPtr := uint32(ptrSize[0] >> 32) resultSize := uint32(ptrSize[0]) defer fn.deallocate.Call(ctx, uint64(resultPtr), uint64(resultSize)) bytes, ok := fn.mod.Memory().Read(ctx, resultPtr, resultSize) if !ok { return "", fmt.Errorf("Memory.Read(%d, %d) out of range of memory size %d", resultPtr, resultSize, fn.mod.Memory().Size(ctx)) } return string(bytes), nil } ``` ########## sdks/go/examples/wasm/wasm.go: ########## @@ -0,0 +1,159 @@ +// Licensed to the Apache Software Foundation (ASF) under one or more +// contributor license agreements. See the NOTICE file distributed with +// this work for additional information regarding copyright ownership. +// The ASF licenses this file to You under the Apache License, Version 2.0 +// (the "License"); you may not use this file except in compliance with +// the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// wasm is an EXPERIMENTAL simple example that loads and executes a wasm file function. +// greet.wasm, Cargo.toml and greet.rs were copied from the example provided by the wazero library: +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +// +// New Concepts: +// 1. Load a wasm file compiled from: cargo build --release --target wasm32-unknown-unknown +// 2. Execute a wasm function within a DoFn +package main + +import ( + "context" + _ "embed" + "flag" + "fmt" + "github.com/apache/beam/sdks/v2/go/pkg/beam" + "github.com/apache/beam/sdks/v2/go/pkg/beam/io/textio" + "github.com/apache/beam/sdks/v2/go/pkg/beam/register" + "github.com/apache/beam/sdks/v2/go/pkg/beam/x/beamx" + "github.com/tetratelabs/wazero" + "github.com/tetratelabs/wazero/api" + "log" +) + +const ( + wasmFunctionName = "greeting" + wasmAllocateFunctionName = "allocate" + wasmDeallocateFunctionName = "deallocate" +) + +//go:embed greet.wasm +var greetWasm []byte + +var ( + output = flag.String("output", "", "Output file (required).") +) + +func init() { + // register.DoFnXxY registers a struct DoFn so that it can be correctly + // serialized and does some optimization to avoid runtime reflection. Since + // embeddedWasmFn's ProcessElement func has 2 inputs (context.Context) and 2 outputs (string, error), + // we use register.DoFn2x2 and provide its input and output types as its constraints. + // Struct DoFns must be registered for a pipeline to run. + register.DoFn2x2[context.Context, string, string, error](&embeddedWasmFn{}) +} + +func preRun() error { + if *output == "" { + return fmt.Errorf("--output is required") + } + return nil +} + +func main() { + flag.Parse() + beam.Init() + ctx := context.Background() + if err := preRun(); err != nil { + panic(err) + } + if err := run(ctx); err != nil { + panic(err) + } +} + +func run(ctx context.Context) error { + p, s := beam.NewPipelineWithRoot() + + in := beam.Create(s, "a", "b", "c", "d", "e", "f", "g", "h") + + out := beam.ParDo(s.Scope("embeddedWasm"), &embeddedWasmFn{}, in) + + textio.Write(s, *output, out) + + if err := beamx.Run(ctx, p); err != nil { + return fmt.Errorf("failed to run pipeline: %v", err) + } + return nil +} + +// Concept #2 wrap wasm function execution within a DoFn. +// wasmFn wraps a DoFn to execute a Rust compiled wasm function +type embeddedWasmFn struct { + r wazero.Runtime + mod api.Module + greeting, allocate, deallocate api.Function +} + +// Setup loads and initializes the embedded wasm functions +// Concept #1: Load a compiled wasm file []byte content and function. +// This example is derived from +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +func (fn *embeddedWasmFn) Setup(ctx context.Context) error { + fn.r = wazero.NewRuntime(ctx) + _, err := fn.r.NewHostModuleBuilder("env"). + NewFunctionBuilder().WithFunc(logString).Export("log"). + Instantiate(ctx, fn.r) + if err != nil { + return fmt.Errorf("failed to instantiate host module: %w", err) + } + fn.mod, err = fn.r.InstantiateModuleFromBinary(ctx, greetWasm) + if err != nil { + return fmt.Errorf("failed to instantiate wasm module: %v", err) + } + fn.greeting = fn.mod.ExportedFunction(wasmFunctionName) + fn.allocate = fn.mod.ExportedFunction(wasmAllocateFunctionName) + fn.deallocate = fn.mod.ExportedFunction(wasmDeallocateFunctionName) + return nil +} + +// ProcessElement processes a string calling a wasm function written in Rust +// This example is derived from +// https://github.com/tetratelabs/wazero/blob/v1.0.0-pre.3/examples/allocation/rust/greet.go +func (fn *embeddedWasmFn) ProcessElement(ctx context.Context, s string) (string, error) { + size := uint64(len(s)) + results, err := fn.allocate.Call(ctx, size) + if err != nil { + return "", fmt.Errorf("error calling allocate: %w", err) + } + ptr := results[0] + defer fn.deallocate.Call(ctx, ptr, size) + if !fn.mod.Memory().Write(ctx, uint32(ptr), []byte(s)) { + return "", fmt.Errorf("Memory.Write(%d, %d) out of range of memory size %d", + ptr, size, fn.mod.Memory().Size(ctx)) + } + + ptrSize, err := fn.greeting.Call(ctx, ptr, size) + resultPtr := uint32(ptrSize[0] >> 32) + resultSize := uint32(ptrSize[0]) + defer fn.deallocate.Call(ctx, uint64(resultPtr), uint64(resultSize)) + bytes, ok := fn.mod.Memory().Read(ctx, resultPtr, resultSize) + if !ok { + return "", fmt.Errorf("Memory.Read(%d, %d) out of range of memory size %d", + resultPtr, resultSize, fn.mod.Memory().Size(ctx)) + } + return string(bytes), nil +} + +func logString(ctx context.Context, m api.Module, offset, byteCount uint32) { Review Comment: Please add a comment to this saying that it's being used as a foreign function to the wasm code. It's easy to miss that when reading the code, and it's not used elsewhere. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
