88 lines
2.0 KiB
Go
88 lines
2.0 KiB
Go
// Copyright (C) 2019 Storj Labs, Inc.
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// See LICENSE for copying information.
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package luacfg
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import (
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"fmt"
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"io"
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"io/ioutil"
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"sync"
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lua "github.com/Shopify/go-lua"
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luar "github.com/jtolds/go-luar"
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)
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// Scope represents a collection of values registered in a Lua namespace.
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type Scope struct {
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mu sync.Mutex
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registrations map[string]func(*lua.State) error
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}
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// NewScope creates an empty Scope.
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func NewScope() *Scope {
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return &Scope{
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registrations: map[string]func(*lua.State) error{},
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}
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}
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// RegisterType allows you to add a Lua function that creates new
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// values of the given type to the scope.
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func (scope *Scope) RegisterType(name string, example interface{}) error {
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return scope.register(name, example, luar.PushType)
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}
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// RegisterVal adds the Go value 'value', including Go functions, to the Lua
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// scope.
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func (scope *Scope) RegisterVal(name string, value interface{}) error {
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return scope.register(name, value, luar.PushValue)
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}
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func (scope *Scope) register(name string, val interface{}, pusher func(l *lua.State, val interface{}) error) error {
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scope.mu.Lock()
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defer scope.mu.Unlock()
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if _, exists := scope.registrations[name]; exists {
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return fmt.Errorf("registration %#v already exists", name)
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}
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scope.registrations[name] = func(l *lua.State) error {
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err := pusher(l, val)
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if err != nil {
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return err
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}
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l.SetGlobal(name)
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return nil
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}
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return nil
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}
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// Run runs the Lua source represented by in
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func (scope *Scope) Run(in io.Reader) error {
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l := lua.NewState()
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lua.OpenLibraries(l)
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luar.SetOptions(l, luar.Options{AllowUnexportedAccess: true})
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scope.mu.Lock()
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registrations := make([]func(l *lua.State) error, 0, len(scope.registrations))
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for _, reg := range scope.registrations {
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registrations = append(registrations, reg)
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}
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scope.mu.Unlock()
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for _, reg := range registrations {
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err := reg(l)
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if err != nil {
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return err
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}
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}
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data, err := ioutil.ReadAll(in)
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if err != nil {
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return err
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}
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err = lua.DoString(l, string(data))
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return err
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}
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