Files
go-away/lib/challenge/wasm/runner.go
2025-04-06 12:51:27 +02:00

123 lines
3.3 KiB
Go

package wasm
import (
"context"
"errors"
"fmt"
"github.com/tetratelabs/wazero"
"github.com/tetratelabs/wazero/api"
"github.com/tetratelabs/wazero/imports/wasi_snapshot_preview1"
"slices"
)
type Runner struct {
context context.Context
runtime wazero.Runtime
modules map[string]wazero.CompiledModule
}
func NewRunner(useNativeCompiler bool) *Runner {
var r Runner
r.context = context.Background()
var runtimeConfig wazero.RuntimeConfig
if useNativeCompiler {
runtimeConfig = wazero.NewRuntimeConfigCompiler()
} else {
runtimeConfig = wazero.NewRuntimeConfigInterpreter()
}
r.runtime = wazero.NewRuntimeWithConfig(r.context, runtimeConfig)
wasi_snapshot_preview1.MustInstantiate(r.context, r.runtime)
r.modules = make(map[string]wazero.CompiledModule)
return &r
}
func (r *Runner) Compile(key string, binary []byte) error {
module, err := r.runtime.CompileModule(r.context, binary)
if err != nil {
return err
}
// check interface
functions := module.ExportedFunctions()
if f, ok := functions["MakeChallenge"]; ok {
if slices.Compare(f.ParamTypes(), []api.ValueType{api.ValueTypeI64}) != 0 {
return fmt.Errorf("MakeChallenge does not follow parameter interface")
}
if slices.Compare(f.ResultTypes(), []api.ValueType{api.ValueTypeI64}) != 0 {
return fmt.Errorf("MakeChallenge does not follow result interface")
}
} else {
module.Close(r.context)
return errors.New("no MakeChallenge exported")
}
if f, ok := functions["VerifyChallenge"]; ok {
if slices.Compare(f.ParamTypes(), []api.ValueType{api.ValueTypeI64}) != 0 {
return fmt.Errorf("VerifyChallenge does not follow parameter interface")
}
if slices.Compare(f.ResultTypes(), []api.ValueType{api.ValueTypeI64}) != 0 {
return fmt.Errorf("VerifyChallenge does not follow result interface")
}
} else {
module.Close(r.context)
return errors.New("no VerifyChallenge exported")
}
if f, ok := functions["malloc"]; ok {
if slices.Compare(f.ParamTypes(), []api.ValueType{api.ValueTypeI32}) != 0 {
return fmt.Errorf("malloc does not follow parameter interface")
}
if slices.Compare(f.ResultTypes(), []api.ValueType{api.ValueTypeI32}) != 0 {
return fmt.Errorf("malloc does not follow result interface")
}
} else {
module.Close(r.context)
return errors.New("no malloc exported")
}
if f, ok := functions["free"]; ok {
if slices.Compare(f.ParamTypes(), []api.ValueType{api.ValueTypeI32}) != 0 {
return fmt.Errorf("free does not follow parameter interface")
}
if slices.Compare(f.ResultTypes(), []api.ValueType{}) != 0 {
return fmt.Errorf("free does not follow result interface")
}
} else {
module.Close(r.context)
return errors.New("no free exported")
}
r.modules[key] = module
return nil
}
func (r *Runner) Close() {
for _, module := range r.modules {
module.Close(r.context)
}
r.runtime.Close(r.context)
}
var ErrModuleNotFound = errors.New("module not found")
func (r *Runner) Instantiate(key string, f func(ctx context.Context, mod api.Module) error) (err error) {
compiledModule, ok := r.modules[key]
if !ok {
return ErrModuleNotFound
}
mod, err := r.runtime.InstantiateModule(
r.context,
compiledModule,
wazero.NewModuleConfig().WithName(key).WithStartFunctions("_initialize"),
)
if err != nil {
return err
}
defer mod.Close(r.context)
return f(r.context, mod)
}