package duktape
/*
#cgo !windows CFLAGS: -std=c99 -O3 -Wall -fomit-frame-pointer -fstrict-aliasing
#cgo windows CFLAGS: -O3 -Wall -fomit-frame-pointer -fstrict-aliasing
#cgo linux LDFLAGS: -lm
#cgo freebsd LDFLAGS: -lm
#cgo openbsd LDFLAGS: -lm
#include "duktape.h"
#include "duk_logging.h"
#include "duk_print_alert.h"
#include "duk_module_duktape.h"
#include "duk_console.h"
extern duk_ret_t goFunctionCall(duk_context *ctx);
extern void goFinalizeCall(duk_context *ctx);
*/
import "C"
import (
"errors"
"fmt"
"regexp"
"sync"
"unsafe"
)
var reFuncName = regexp.MustCompile("^[a-z_][a-z0-9_]*([A-Z_][a-z0-9_]*)*$")
const (
goFunctionPtrProp = "\xff" + "goFunctionPtrProp"
goContextPtrProp = "\xff" + "goContextPtrProp"
)
type Context struct {
*context
}
// transmute replaces the value from Context with the value of pointer
func (c *Context) transmute(p unsafe.Pointer) {
*c = *(*Context)(p)
}
// this is a pojo containing only the values of the Context
type context struct {
sync.Mutex
duk_context *C.duk_context
fnIndex *functionIndex
timerIndex *timerIndex
}
// New returns plain initialized duktape context object
// See: http://duktape.org/api.html#duk_create_heap_default
func New() *Context {
d := &Context{
&context{
duk_context: C.duk_create_heap(nil, nil, nil, nil, nil),
fnIndex: newFunctionIndex(),
timerIndex: &timerIndex{},
},
}
ctx := d.duk_context
C.duk_logging_init(ctx, 0)
C.duk_print_alert_init(ctx, 0)
C.duk_module_duktape_init(ctx)
C.duk_console_init(ctx, 0)
return d
}
// Flags is a set of flags for controlling the behaviour of duktape.
type Flags struct {
Logging uint
PrintAlert uint
Console uint
}
// FlagConsoleProxyWrapper is a Console flag.
// Use a proxy wrapper to make undefined methods (console.foo()) no-ops.
const FlagConsoleProxyWrapper = 1 << 0
// FlagConsoleFlush is a Console flag.
// Flush output after every call.
const FlagConsoleFlush = 1 << 1
// NewWithFlags returns plain initialized duktape context object
// You can control the behaviour of duktape by setting flags.
// See: http://duktape.org/api.html#duk_create_heap_default
func NewWithFlags(flags *Flags) *Context {
d := &Context{
&context{
duk_context: C.duk_create_heap(nil, nil, nil, nil, nil),
fnIndex: newFunctionIndex(),
timerIndex: &timerIndex{},
},
}
ctx := d.duk_context
C.duk_logging_init(ctx, C.duk_uint_t(flags.Logging))
C.duk_print_alert_init(ctx, C.duk_uint_t(flags.PrintAlert))
C.duk_module_duktape_init(ctx)
C.duk_console_init(ctx, C.duk_uint_t(flags.Console))
return d
}
func contextFromPointer(ctx *C.duk_context) *Context {
return &Context{&context{duk_context: ctx}}
}
// PushGlobalGoFunction push the given function into duktape global object
// Returns non-negative index (relative to stack bottom) of the pushed function
// also returns error if the function name is invalid
func (d *Context) PushGlobalGoFunction(name string, fn func(*Context) int) (int, error) {
if !reFuncName.MatchString(name) {
return -1, errors.New("Malformed function name '" + name + "'")
}
d.PushGlobalObject()
idx := d.PushGoFunction(fn)
d.PutPropString(-2, name)
d.Pop()
return idx, nil
}
// PushGoFunction push the given function into duktape stack, returns non-negative
// index (relative to stack bottom) of the pushed function
func (d *Context) PushGoFunction(fn func(*Context) int) int {
funPtr := d.fnIndex.add(fn)
ctxPtr := contexts.add(d)
idx := d.PushCFunction((*[0]byte)(C.goFunctionCall), C.DUK_VARARGS)
d.PushCFunction((*[0]byte)(C.goFinalizeCall), 1)
d.PushPointer(funPtr)
d.PutPropString(-2, goFunctionPtrProp)
d.PushPointer(ctxPtr)
d.PutPropString(-2, goContextPtrProp)
d.SetFinalizer(-2)
d.PushPointer(funPtr)
d.PutPropString(-2, goFunctionPtrProp)
d.PushPointer(ctxPtr)
d.PutPropString(-2, goContextPtrProp)
return idx
}
//export goFunctionCall
func goFunctionCall(cCtx *C.duk_context) C.duk_ret_t {
d := contextFromPointer(cCtx)
funPtr, ctx := d.getFunctionPtrs()
d.transmute(unsafe.Pointer(ctx))
result := d.fnIndex.get(funPtr)(d)
return C.duk_ret_t(result)
}
//export goFinalizeCall
func goFinalizeCall(cCtx *C.duk_context) {
d := contextFromPointer(cCtx)
funPtr, ctx := d.getFunctionPtrs()
d.transmute(unsafe.Pointer(ctx))
d.fnIndex.delete(funPtr)
}
func (d *Context) getFunctionPtrs() (unsafe.Pointer, *Context) {
d.PushCurrentFunction()
d.GetPropString(-1, goFunctionPtrProp)
funPtr := d.GetPointer(-1)
d.Pop()
d.GetPropString(-1, goContextPtrProp)
ctx := contexts.get(d.GetPointer(-1))
d.Pop2()
return funPtr, ctx
}
// Destroy destroy all the references to the functions and freed the pointers
func (d *Context) Destroy() {
d.fnIndex.destroy()
contexts.delete(d)
}
type Error struct {
Type string
Message string
FileName string
LineNumber int
Stack string
}
func (e *Error) Error() string {
return fmt.Sprintf("%s: %s", e.Type, e.Message)
}
type Type int
func (t Type) IsNone() bool { return t == TypeNone }
func (t Type) IsUndefined() bool { return t == TypeUndefined }
func (t Type) IsNull() bool { return t == TypeNull }
func (t Type) IsBool() bool { return t == TypeBoolean }
func (t Type) IsNumber() bool { return t == TypeNumber }
func (t Type) IsString() bool { return t == TypeString }
func (t Type) IsObject() bool { return t == TypeObject }
func (t Type) IsBuffer() bool { return t == TypeBuffer }
func (t Type) IsPointer() bool { return t == TypePointer }
func (t Type) IsLightFunc() bool { return t == TypeLightFunc }
func (t Type) String() string {
switch t {
case TypeNone:
return "None"
case TypeUndefined:
return "Undefined"
case TypeNull:
return "Null"
case TypeBoolean:
return "Boolean"
case TypeNumber:
return "Number"
case TypeString:
return "String"
case TypeObject:
return "Object"
case TypeBuffer:
return "Buffer"
case TypePointer:
return "Pointer"
case TypeLightFunc:
return "LightFunc"
default:
return "Unknown"
}
}
type functionIndex struct {
functions map[unsafe.Pointer]func(*Context) int
sync.RWMutex
}
type timerIndex struct {
c float64
sync.Mutex
}
func (t *timerIndex) get() float64 {
t.Lock()
defer t.Unlock()
t.c++
return t.c
}
func newFunctionIndex() *functionIndex {
return &functionIndex{
functions: make(map[unsafe.Pointer]func(*Context) int, 0),
}
}
func (i *functionIndex) add(fn func(*Context) int) unsafe.Pointer {
ptr := C.malloc(1)
i.Lock()
i.functions[ptr] = fn
i.Unlock()
return ptr
}
func (i *functionIndex) get(ptr unsafe.Pointer) func(*Context) int {
i.RLock()
fn := i.functions[ptr]
i.RUnlock()
return fn
}
func (i *functionIndex) delete(ptr unsafe.Pointer) {
i.Lock()
delete(i.functions, ptr)
i.Unlock()
C.free(ptr)
}
func (i *functionIndex) destroy() {
i.Lock()
for ptr, _ := range i.functions {
delete(i.functions, ptr)
C.free(ptr)
}
i.Unlock()
}
type ctxIndex struct {
sync.RWMutex
ctxs map[unsafe.Pointer]*Context
}
func (ci *ctxIndex) add(ctx *Context) unsafe.Pointer {
ci.RLock()
for ptr, ctxPtr := range ci.ctxs {
if ctxPtr == ctx {
ci.RUnlock()
return ptr
}
}
ci.RUnlock()
ci.Lock()
for ptr, ctxPtr := range ci.ctxs {
if ctxPtr == ctx {
ci.Unlock()
return ptr
}
}
ptr := C.malloc(1)
ci.ctxs[ptr] = ctx
ci.Unlock()
return ptr
}
func (ci *ctxIndex) get(ptr unsafe.Pointer) *Context {
ci.RLock()
ctx := ci.ctxs[ptr]
ci.RUnlock()
return ctx
}
func (ci *ctxIndex) delete(ctx *Context) {
ci.Lock()
for ptr, ctxPtr := range ci.ctxs {
if ctxPtr == ctx {
delete(ci.ctxs, ptr)
C.free(ptr)
ci.Unlock()
return
}
}
panic(fmt.Sprintf("context (%p) doesn't exist", ctx))
}
var contexts *ctxIndex
func init() {
contexts = &ctxIndex{
ctxs: make(map[unsafe.Pointer]*Context),
}
}
