diff --git a/Makefile b/Makefile index 2b128f58..f1821ade 100644 --- a/Makefile +++ b/Makefile @@ -15,22 +15,42 @@ LINT_SOURCES = \ examples/async_pi_estimate/sync.cc \ examples/async_pi_estimate/sync.h \ nan.h \ - nan_string_bytes.h \ + nan_callbacks.h \ + nan_callbacks_12_inl.h \ + nan_callbacks_pre_12_inl.h \ + nan_converters.h \ + nan_converters_43_inl.h \ + nan_converters_pre_43_inl.h \ nan_implementation_12_inl.h \ nan_implementation_pre_12_inl.h \ + nan_maybe_43_inl.h \ + nan_maybe_pre_43_inl.h \ nan_new.h \ + nan_persistent_12_inl.h \ + nan_persistent_pre_12_inl.h \ + nan_string_bytes.h \ + nan_weak.h \ + test/cpp/accessors.cpp \ + test/cpp/accessors2.cpp \ test/cpp/asyncworker.cpp \ test/cpp/asyncprogressworker.cpp \ test/cpp/asyncworkererror.cpp \ + test/cpp/buffer.cpp \ test/cpp/bufferworkerpersistent.cpp \ test/cpp/error.cpp \ test/cpp/gc.cpp \ + test/cpp/indexedinterceptors.cpp \ + test/cpp/isolatedata.cpp \ + test/cpp/makecallback.cpp \ + test/cpp/morenews.cpp \ + test/cpp/converters.cpp \ test/cpp/isolatedata.cpp \ test/cpp/makecallback.cpp \ test/cpp/morenews.cpp \ test/cpp/multifile1.cpp \ test/cpp/multifile2.cpp \ test/cpp/multifile2.h \ + test/cpp/namedinterceptors.cpp \ test/cpp/nancallback.cpp \ test/cpp/nannew.cpp \ test/cpp/news.cpp \ @@ -41,11 +61,12 @@ LINT_SOURCES = \ test/cpp/returnundefined.cpp \ test/cpp/returnvalue.cpp \ test/cpp/settemplate.cpp \ - test/cpp/settergetter.cpp \ test/cpp/strings.cpp \ test/cpp/symbols.cpp \ test/cpp/threadlocal.cpp \ + test/cpp/trycatch.cpp \ test/cpp/weak.cpp \ + test/cpp/weak2.cpp \ node_modules/node-gyp/gyp/data/win/large-pdb-shim.cc FILTER = -whitespace/parens @@ -62,5 +83,17 @@ forcetest: cd test/ && node-gyp rebuild && cd .. npm test -$(ADDONS): nan.h nan_string_bytes.h nan_new.h nan_implementation_pre_12_inl.h nan_implementation_12_inl.h test/binding.gyp $(SOURCES) +docs: README.md doc/.build.sh doc/asyncworker.md doc/buffers.md doc/callback.md \ + doc/converters.md doc/errors.md doc/maybe_types.md doc/methods.md doc/new.md \ + doc/node_misc.md doc/persistent.md doc/scopes.md doc/script.md doc/string_bytes.md \ + doc/v8_internals.md doc/v8_misc.md + doc/.build.sh + + +$(ADDONS): nan.h nan_new.h nan_implementation_pre_12_inl.h nan_implementation_12_inl.h \ + nan_callbacks.h nan_callbacks_12_inl.h nan_callbacks_pre_12_inl.h \ + nan_converters.h nan_converters_43_inl.h nan_converters_pre_43_inl.h \ + nan_maybe_43_inl.h nan_maybe_pre_43_inl.h \ + nan_persistent_12_inl.h nan_persistent_pre_12_inl.h nan_weak.h \ + nan_string_bytes.h test/binding.gyp $(SOURCES) cd test/ && ../node_modules/.bin/node-gyp rebuild diff --git a/README.md b/README.md index 8e155dcc..2deb9b7b 100644 --- a/README.md +++ b/README.md @@ -27,81 +27,6 @@ This project also contains some helper utilities that make addon development a b ## News & Updates -### Apr-2015: 1.8.0 release - -* Support V8 4.2 -* Removed support for creating `Signature`s with arguments -* Backported thread local storage routines for libuv - -### Feb-2015: 1.7.0 release - -* Made `NanCallback::Call` accept optional target -* Support atom-shell 0.21 - -Node 0.12.0 is out and supported by NAN. So is atom-shell 0.21. `NanCallback::Call` now accepts an optional `target` argument like `NanMakeCallback`. - -### Jan-2015: 1.6.0 release - -* Deprecated `NanNewContextHandle` in favor of `NanNew` -* Added `NanSetCounterFunction`, `NanSetCreateHistogramFunction`, `NanSetAddHistogramSampleFunction` -* Added `NanIdleNotification`, `NanLowMemoryNotification`, `NanContextDisposedNotification` -* Added `NanEncode`, `NanDecodeBytes` and `NanDecodeWrite` - -### Jan-2015: 1.5.0 release - -* Support [io.js](https://github.com/iojs/io.js) thanks to [Ben Noordhuis](bnoordhuis) -* Rewritten NanNew internals thanks to [David Siegel](agnat) -* NanAsyncWorker now supports progress reporting thanks to [Brett Lawson](brett19) - -### Aug-2014: 1.3.0 release - -* `NanCString()` and `NanRawString()` have been deprecated in favour of new NanAsciiString, NanUtf8String and NanUcs2String. These classes manage the underlying memory for you in a safer way than just handing off an allocated array. You should now `*NanAsciiString(handle)` to access the raw `char` data, you can also allocate on the heap if you need to keep a reference. -* Two more NanMakeCallback overloads have been added to for parity with Node core. -* You can now `NanNew(std::string)` (use `NanNew(std::string&)` to pass by reference) -* NanSetTemplate, NanSetPrototypeTemplate and NanSetInstanceTemplate have been added. - -### May-2014: 1.1.0 release - -* We've deprecated `NanSymbol()`, you should just use `NanNew()` now. -* `NanNull()`, `NanUndefined()`, `NanTrue()`, `NanFalse()` all return `Local`s now. -* `nan_isolate` is gone, it was intended to be internal-only but if you were using it then you should switch to `v8::Isolate::GetCurrent()`. -* `NanNew()` has received some additional overload-love so you should be able to give it many kinds of values without specifying the ``. -* Lots of small fixes and additions to expand the V8 API coverage, *use the source, Luke*. - - -### May-2014: Major changes for V8 3.25 / Node 0.11.13 - -Node 0.11.11 and 0.11.12 were both broken releases for native add-ons, you simply can't properly compile against either of them for different reasons. But we now have a 0.11.13 release that jumps a couple of versions of V8 ahead and includes some more, major (traumatic) API changes. - -Because we are now nearing Node 0.12 and estimate that the version of V8 we are using in Node 0.11.13 will be close to the API we get for 0.12, we have taken the opportunity to not only *fix* NAN for 0.11.13 but make some major changes to improve the NAN API. - -We have **removed support for Node 0.11 versions prior to 0.11.13**. As usual, our tests are run against (and pass) the last 5 versions of Node 0.8 and Node 0.10. We also include Node 0.11.13 obviously. - -The major change is something that [Benjamin Byholm](kkoopa) has put many hours in to. We now have a fantastic new `NanNew(args)` interface for creating new `Local`s, this replaces `NanNewLocal()` and much more. If you look in [./nan.h](nan.h) you'll see a large number of overloaded versions of this method. In general you should be able to `NanNew(arguments)` for any type you want to make a `Local` from. This includes `Persistent` types, so we now have a `Local NanNew(const Persistent arg)` to replace `NanPersistentToLocal()`. - -We also now have `NanUndefined()`, `NanNull()`, `NanTrue()` and `NanFalse()`. Mainly because of the new requirement for an `Isolate` argument for each of the native V8 versions of this. - -V8 has now introduced an `EscapableHandleScope` from which you `scope.Escape(Local value)` to *return* a value from a one scope to another. This replaces the standard `HandleScope` and `scope.Close(Local value)`, although `HandleScope` still exists for when you don't need to return a handle to the caller. For NAN we are exposing it as `NanEscapableScope()` and `NanEscapeScope()`, while `NanScope()` is still how you create a new scope that doesn't need to return handles. For older versions of Node/V8, it'll still map to the older `HandleScope` functionality. - -`NanFromV8String()` was deprecated and has now been removed. You should use `NanCString()` or `NanRawString()` instead. - -Because `node::MakeCallback()` now takes an `Isolate`, and because it doesn't exist in older versions of Node, we've introduced `NanMakeCallback()`. You should *always* use this when calling a JavaScript function from C++. - -There's lots more, check out the Changelog in nan.h or look through [#86](https://github.com/nodejs/nan/pull/86) for all the gory details. - -### Dec-2013: NanCString and NanRawString - -Two new functions have been introduced to replace the functionality that's been provided by `NanFromV8String` until now. NanCString has sensible defaults so it's super easy to fetch a null-terminated c-style string out of a `v8::String`. `NanFromV8String` is still around and has defaults that allow you to pass a single handle to fetch a `char*` while `NanRawString` requires a little more attention to arguments. - -### Nov-2013: Node 0.11.9+ breaking V8 change - -The version of V8 that's shipping with Node 0.11.9+ has changed the signature for new `Local`s to: `v8::Local::New(isolate, value)`, i.e. introducing the `isolate` argument and therefore breaking all new `Local` declarations for previous versions. NAN 0.6+ now includes a `NanNewLocal(value)` that can be used in place to work around this incompatibility and maintain compatibility with 0.8->0.11.9+ (minus a few early 0.11 releases). - -For example, if you wanted to return a `null` on a callback you will have to change the argument from `v8::Local::New(v8::Null())` to `NanNewLocal(v8::Null())`. - -### Nov-2013: Change to binding.gyp `"include_dirs"` for NAN - -Inclusion of NAN in a project's binding.gyp is now greatly simplified. You can now just use `" ## Usage @@ -127,1186 +52,243 @@ This works like a `-I` when compiling your addon. Just getting started with Nan? Refer to a [quick-start **Nan** Boilerplate](https://github.com/fcanas/node-native-boilerplate) for a ready-to-go project that utilizes basic Nan functionality. -See **[LevelDOWN](https://github.com/rvagg/node-leveldown/pull/48)** for a full example of **NAN** in use. - For a simpler example, see the **[async pi estimation example](https://github.com/nodejs/nan/tree/master/examples/async_pi_estimate)** in the examples directory for full code and an explanation of what this Monte Carlo Pi estimation example does. Below are just some parts of the full example that illustrate the use of **NAN**. For another example, see **[nan-example-eol](https://github.com/CodeCharmLtd/nan-example-eol)**. It shows newline detection implemented as a native addon. -Compare to the current 0.10 version of this example, found in the [node-addon-examples](https://github.com/iojs/node-addon-examples/tree/master/9_async_work) repository and also a 0.11 version of the same found [here](https://github.com/kkoopa/node-addon-examples/tree/5c01f58fc993377a567812597e54a83af69686d7/9_async_work). - -Note that there is no embedded version sniffing going on here and also the async work is made much simpler, see below for details on the `NanAsyncWorker` class. - -```c++ -// addon.cc -#include -#include -// ... - -using v8::FunctionTemplate; -using v8::Handle; -using v8::Object; -using v8::String; - -void InitAll(Handle exports) { - exports->Set(NanNew("calculateSync"), - NanNew(CalculateSync)->GetFunction()); - - exports->Set(NanNew("calculateAsync"), - NanNew(CalculateAsync)->GetFunction()); -} - -NODE_MODULE(addon, InitAll) -``` - -```c++ -// sync.h -#include -#include - -NAN_METHOD(CalculateSync); -``` - -```c++ -// sync.cc -#include -#include -#include "./sync.h" -// ... - -using v8::Number; - -// Simple synchronous access to the `Estimate()` function -NAN_METHOD(CalculateSync) { - NanScope(); - - // expect a number as the first argument - int points = args[0]->Uint32Value(); - double est = Estimate(points); - - NanReturnValue(NanNew(est)); -} -``` - -```c++ -// async.h -#include -#include - -NAN_METHOD(CalculateAsync); -``` - -```c++ -// async.cc -#include -#include -#include "./async.h" - -// ... - -using v8::Function; -using v8::Local; -using v8::Null; -using v8::Number; -using v8::Value; - -class PiWorker : public NanAsyncWorker { - public: - PiWorker(NanCallback *callback, int points) - : NanAsyncWorker(callback), points(points) {} - ~PiWorker() {} - - // Executed inside the worker-thread. - // It is not safe to access V8, or V8 data structures - // here, so everything we need for input and output - // should go on `this`. - void Execute () { - estimate = Estimate(points); - } - - // Executed when the async work is complete - // this function will be run inside the main event loop - // so it is safe to use V8 again - void HandleOKCallback () { - NanScope(); - - Local argv[] = { - NanNull() - , NanNew(estimate) - }; - - callback->Call(2, argv); - }; - - private: - int points; - double estimate; -}; - -// Asynchronous access to the `Estimate()` function -NAN_METHOD(CalculateAsync) { - NanScope(); - - int points = args[0]->Uint32Value(); - NanCallback *callback = new NanCallback(args[1].As()); - - NanAsyncQueueWorker(new PiWorker(callback, points)); - NanReturnUndefined(); -} -``` - ## API - * NAN_METHOD - * NAN_GETTER - * NAN_SETTER - * NAN_PROPERTY_GETTER - * NAN_PROPERTY_SETTER - * NAN_PROPERTY_ENUMERATOR - * NAN_PROPERTY_DELETER - * NAN_PROPERTY_QUERY - * NAN_INDEX_GETTER - * NAN_INDEX_SETTER - * NAN_INDEX_ENUMERATOR - * NAN_INDEX_DELETER - * NAN_INDEX_QUERY - * NAN_GC_CALLBACK - * NAN_WEAK_CALLBACK - * NAN_DEPRECATED - * NAN_INLINE - * NanNew - * NanUndefined - * NanNull - * NanTrue - * NanFalse - * NanReturnValue - * NanReturnUndefined - * NanReturnNull - * NanReturnEmptyString - * NanReturnThis - * NanReturnHolder - * NanScope - * NanEscapableScope - * NanEscapeScope - * NanLocker - * NanUnlocker - * NanGetInternalFieldPointer - * NanSetInternalFieldPointer - * NanObjectWrapHandle - * NanSymbol - * NanGetPointerSafe - * NanSetPointerSafe - * NanRawString - * NanCString - * NanAsciiString - * NanUtf8String - * NanUcs2String - * NanBooleanOptionValue - * NanUInt32OptionValue - * NanError, NanRangeError, NanReferenceError, NanSyntaxError, NanTypeError - * NanThrowError, NanThrowRangeError, NanThrowReferenceError, NanThrowSyntaxError, NanThrowTypeError, NanThrowError(Handle), NanThrowError(Handle, int) - * NanNewBufferHandle(char *, size_t, FreeCallback, void *), NanNewBufferHandle(char *, uint32_t), NanNewBufferHandle(uint32_t) - * NanBufferUse(char *, uint32_t) - * NanNewContextHandle - * NanGetCurrentContext - * NanHasInstance - * NanDisposePersistent - * NanAssignPersistent - * NanMakeWeakPersistent - * NanSetTemplate - * NanSetPrototypeTemplate - * NanSetInstanceTemplate - * NanMakeCallback - * NanFatalException - * NanErrnoException - * NanGetIsolateData - * NanSetIsolateData - * NanEncode - * NanDecodeBytes - * NanDecodeWrite - * NanCompileScript - * NanRunScript - * NanAdjustExternalMemory - * NanAddGCEpilogueCallback - * NanAddGCPrologueCallback - * NanRemoveGCEpilogueCallback - * NanRemoveGCPrologueCallback - * NanGetHeapStatistics - * NanSetCounterFunction - * NanSetCreateHistogramFunction - * NanSetAddHistogramSampleFunction - * NanIdleNotification - * NanLowMemoryNotification - * NanContextDisposedNotification - * NanCallback - * NanAsyncWorker - * NanAsyncQueueWorker - - -### NAN_METHOD(methodname) - -Use `NAN_METHOD` to define your V8 accessible methods: - -```c++ -// .h: -class Foo : public node::ObjectWrap { - ... - - static NAN_METHOD(Bar); - static NAN_METHOD(Baz); -} - - -// .cc: -NAN_METHOD(Foo::Bar) { - ... -} - -NAN_METHOD(Foo::Baz) { - ... -} -``` - -The reason for this macro is because of the method signature change in 0.11: - -```c++ -// 0.10 and below: -Handle name(const Arguments& args) - -// 0.11 and above -void name(const FunctionCallbackInfo& args) -``` - -The introduction of `FunctionCallbackInfo` brings additional complications: - - -### NAN_GETTER(methodname) - -Use `NAN_GETTER` to declare your V8 accessible getters. You get a `Local` `property` and an appropriately typed `args` object that can act like the `args` argument to a `NAN_METHOD` call. - -You can use `NanReturnNull()`, `NanReturnEmptyString()`, `NanReturnUndefined()` and `NanReturnValue()` in a `NAN_GETTER`. - - -### NAN_SETTER(methodname) - -Use `NAN_SETTER` to declare your V8 accessible setters. Same as `NAN_GETTER` but you also get a `Local` `value` object to work with. - - -### NAN_PROPERTY_GETTER(cbname) -Use `NAN_PROPERTY_GETTER` to declare your V8 accessible property getters. You get a `Local` `property` and an appropriately typed `args` object that can act similar to the `args` argument to a `NAN_METHOD` call. - -You can use `NanReturnNull()`, `NanReturnEmptyString()`, `NanReturnUndefined()` and `NanReturnValue()` in a `NAN_PROPERTY_GETTER`. - - -### NAN_PROPERTY_SETTER(cbname) -Use `NAN_PROPERTY_SETTER` to declare your V8 accessible property setters. Same as `NAN_PROPERTY_GETTER` but you also get a `Local` `value` object to work with. - - -### NAN_PROPERTY_ENUMERATOR(cbname) -Use `NAN_PROPERTY_ENUMERATOR` to declare your V8 accessible property enumerators. You get an appropriately typed `args` object like the `args` argument to a `NAN_PROPERTY_GETTER` call. - -You can use `NanReturnNull()`, `NanReturnEmptyString()`, `NanReturnUndefined()` and `NanReturnValue()` in a `NAN_PROPERTY_ENUMERATOR`. - - -### NAN_PROPERTY_DELETER(cbname) -Use `NAN_PROPERTY_DELETER` to declare your V8 accessible property deleters. Same as `NAN_PROPERTY_GETTER`. - -You can use `NanReturnNull()`, `NanReturnEmptyString()`, `NanReturnUndefined()` and `NanReturnValue()` in a `NAN_PROPERTY_DELETER`. - - -### NAN_PROPERTY_QUERY(cbname) -Use `NAN_PROPERTY_QUERY` to declare your V8 accessible property queries. Same as `NAN_PROPERTY_GETTER`. - -You can use `NanReturnNull()`, `NanReturnEmptyString()`, `NanReturnUndefined()` and `NanReturnValue()` in a `NAN_PROPERTY_QUERY`. - - -### NAN_INDEX_GETTER(cbname) -Use `NAN_INDEX_GETTER` to declare your V8 accessible index getters. You get a `uint32_t` `index` and an appropriately typed `args` object that can act similar to the `args` argument to a `NAN_METHOD` call. - -You can use `NanReturnNull()`, `NanReturnEmptyString()`, `NanReturnUndefined()` and `NanReturnValue()` in a `NAN_INDEX_GETTER`. - - -### NAN_INDEX_SETTER(cbname) -Use `NAN_INDEX_SETTER` to declare your V8 accessible index setters. Same as `NAN_INDEX_GETTER` but you also get a `Local` `value` object to work with. - - -### NAN_INDEX_ENUMERATOR(cbname) -Use `NAN_INDEX_ENUMERATOR` to declare your V8 accessible index enumerators. You get an appropriately typed `args` object like the `args` argument to a `NAN_INDEX_GETTER` call. - -You can use `NanReturnNull()`, `NanReturnEmptyString()`, `NanReturnUndefined()` and `NanReturnValue()` in a `NAN_INDEX_ENUMERATOR`. - - -### NAN_INDEX_DELETER(cbname) -Use `NAN_INDEX_DELETER` to declare your V8 accessible index deleters. Same as `NAN_INDEX_GETTER`. - -You can use `NanReturnNull()`, `NanReturnEmptyString()`, `NanReturnUndefined()` and `NanReturnValue()` in a `NAN_INDEX_DELETER`. - - -### NAN_INDEX_QUERY(cbname) -Use `NAN_INDEX_QUERY` to declare your V8 accessible index queries. Same as `NAN_INDEX_GETTER`. - -You can use `NanReturnNull()`, `NanReturnEmptyString()`, `NanReturnUndefined()` and `NanReturnValue()` in a `NAN_INDEX_QUERY`. - - -### NAN_GC_CALLBACK(cbname) -Use `NAN_GC_CALLBACK` to declare your callbacks for `NanAddGCEpilogueCallback` and `NanAddGCPrologueCallback`. You get arguments `GCType type` and `GCCallbackFlags flags`. - -```c++ -static Persistent callback; - -NAN_GC_CALLBACK(gcPrologueCallback) { - Local argv[] = {NanNew("prologue")}; - NanMakeCallback(NanGetCurrentContext()->Global(), NanNew(callback), 1, argv); -} - -NAN_METHOD(Hook) { - NanScope(); - NanAssignPersistent(callback, args[0].As()); - NanAddGCPrologueCallback(gcPrologueCallback); - NanReturnValue(args.Holder()); -} -``` - - -### NAN_WEAK_CALLBACK(cbname) - -Use `NAN_WEAK_CALLBACK` to define your V8 WeakReference callbacks. There is an argument object `const _NanWeakCallbackData &data` allowing access to the weak object and the supplied parameter through its `GetValue` and `GetParameter` methods. You can even access the weak callback info object through the `GetCallbackInfo()`method, but you probably should not. `Revive()` keeps the weak object alive until the next GC round. - -```c++ -NAN_WEAK_CALLBACK(weakCallback) { - int *parameter = data.GetParameter(); - NanMakeCallback(NanGetCurrentContext()->Global(), data.GetValue(), 0, NULL); - if ((*parameter)++ == 0) { - data.Revive(); - } else { - delete parameter; - } -} -``` - - -### NAN_DEPRECATED -Declares a function as deprecated. - -```c++ -static NAN_DEPRECATED NAN_METHOD(foo) { - ... -} -``` - - -### NAN_INLINE -Inlines a function. - -```c++ -NAN_INLINE int foo(int bar) { - ... -} -``` - - -### Local<T> NanNew<T>( ... ) - -Use `NanNew` to construct almost all v8 objects (bound `Script`s are constructed with `NanCompileScript(Handle)`) and make new local handles. - -```c++ -Local s = NanNew("value"); - -... - -Persistent o; - -... - -Local lo = NanNew(o); - -``` - - -### Local<Primitive> NanUndefined() - -Use instead of `Undefined()` - - -### Local<Primitive> NanNull() - -Use instead of `Null()` - - -### Local<Boolean> NanTrue() - -Use instead of `True()` - - -### Local<Boolean> NanFalse() - -Use instead of `False()` - - -### NanReturnValue(Handle<Value>) - -Use `NanReturnValue` when you want to return a value from your V8 accessible method: - -```c++ -NAN_METHOD(Foo::Bar) { - ... - - NanReturnValue(NanNew("FooBar!")); -} -``` - -No `return` statement required. - -For convenience, `NanReturnValue` also accepts common primitives directly by implicitly performing an overloaded `NanNew(T)`. - -```c++ -NanReturnValue("FooBar!"); -NanReturnValue(true); -NanReturnValue(12); -NanReturnValue(3.14); -``` - - -### NanReturnUndefined() - -Use `NanReturnUndefined` when you don't want to return anything from your V8 accessible method: - -```c++ -NAN_METHOD(Foo::Baz) { - ... - - NanReturnUndefined(); -} -``` - - -### NanReturnNull() - -Use `NanReturnNull` when you want to return `Null` from your V8 accessible method: - -```c++ -NAN_METHOD(Foo::Baz) { - ... - - NanReturnNull(); -} -``` - - -### NanReturnEmptyString() - -Use `NanReturnEmptyString` when you want to return an empty `String` from your V8 accessible method: - -```c++ -NAN_METHOD(Foo::Baz) { - ... - - NanReturnEmptyString(); -} -``` - - -### NanReturnThis() - -Use `NanReturnThis` when you want to return `This` from your V8 accessible method: - -```c++ -NAN_METHOD(Foo::Baz) { - ... - - NanReturnThis(); -} -``` - - -### NanReturnHolder() - -Use `NanReturnHolder` when you want to return `Holder` from your V8 accessible method: - -```c++ -NAN_METHOD(Foo::Baz) { - ... - - NanReturnHolder(); -} -``` - - -### NanScope() - -The introduction of `isolate` references for many V8 calls in Node 0.11 makes `NanScope()` necessary, use it in place of `HandleScope scope` when you do not wish to return handles (`Handle` or `Local`) to the surrounding scope (or in functions directly exposed to V8, as they do not return values in the normal sense): - -```c++ -NAN_METHOD(Foo::Bar) { - NanScope(); - - NanReturnValue(NanNew("FooBar!")); -} -``` - -This method is not directly exposed to V8, nor does it return a handle, so it uses an unescapable scope: - -```c++ -bool Foo::Bar() { - NanScope(); - - Local val = NanFalse(); - ... - return val->Value(); -} -``` - - -### NanEscapableScope() - -The separation of handle scopes into escapable and inescapable scopes makes `NanEscapableScope()` necessary, use it in place of `HandleScope scope` when you later wish to return a handle (`Handle` or `Local`) from the scope, this is for internal functions not directly exposed to V8: - -```c++ -Handle Foo::Bar() { - NanEscapableScope(); - - return NanEscapeScope(NanNew("FooBar!")); -} -``` - - -### Local<T> NanEscapeScope(Handle<T> value); -Use together with `NanEscapableScope` to escape the scope. Corresponds to `HandleScope::Close` or `EscapableHandleScope::Escape`. - - -### NanLocker() - -The introduction of `isolate` references for many V8 calls in Node 0.11 makes `NanLocker()` necessary, use it in place of `Locker locker`: - -```c++ -NAN_METHOD(Foo::Bar) { - NanLocker(); - ... - NanUnlocker(); -} -``` - - -### NanUnlocker() - -The introduction of `isolate` references for many V8 calls in Node 0.11 makes `NanUnlocker()` necessary, use it in place of `Unlocker unlocker`: - -```c++ -NAN_METHOD(Foo::Bar) { - NanLocker(); - ... - NanUnlocker(); -} -``` - - -### void * NanGetInternalFieldPointer(Handle<Object>, int) - -Gets a pointer to the internal field with at `index` from a V8 `Object` handle. - -```c++ -Local obj; -... -NanGetInternalFieldPointer(obj, 0); -``` - -### void NanSetInternalFieldPointer(Handle<Object>, int, void *) - -Sets the value of the internal field at `index` on a V8 `Object` handle. - -```c++ -static Persistent dataWrapperCtor; -... -Local wrapper = NanNew(dataWrapperCtor)->NewInstance(); -NanSetInternalFieldPointer(wrapper, 0, this); -``` - - -### Local<Object> NanObjectWrapHandle(const node::ObjectWrap &obj) - -When you want to fetch the V8 object handle from a native object you've wrapped with Node's `ObjectWrap`, you should use `NanObjectWrapHandle`: - -```c++ -NanObjectWrapHandle(iterator)->Get(NanNew("end")) -``` - - -### ~~Local<String> NanSymbol(const char *)~~ - -Deprecated. Use `NanNew` instead. -~~Use to create string symbol objects (i.e. `v8::String::NewSymbol(x)`), for getting and setting object properties, or names of objects.~~ - -```c++ -bool foo = false; -if (obj->Has(NanNew("foo"))) - foo = optionsObj->Get(NanNew("foo"))->BooleanValue() -``` - - -### ~~Type NanGetPointerSafe(Type *[, Type])~~ - -Deprecated. -~~A helper for getting values from optional pointers. If the pointer is `NULL`, the function returns the optional default value, which defaults to `0`. Otherwise, the function returns the value the pointer points to.~~ - -```c++ -char *plugh(uint32_t *optional) { - char res[] = "xyzzy"; - uint32_t param = NanGetPointerSafe(optional, 0x1337); - switch (param) { - ... - } - NanSetPointerSafe(optional, 0xDEADBEEF); -} -``` - - -### ~~bool NanSetPointerSafe(Type *, Type)~~ - -Deprecated. -~~A helper for setting optional argument pointers. If the pointer is `NULL`, the function simply returns `false`. Otherwise, the value is assigned to the variable the pointer points to.~~ - -```c++ -const char *plugh(size_t *outputsize) { - char res[] = "xyzzy"; - if !(NanSetPointerSafe(outputsize, strlen(res) + 1)) { - ... - } - - ... -} -``` - - -### ~~void* NanRawString(Handle<Value>, enum Nan::Encoding, size_t *, void *, size_t, int)~~ - -Deprecated. Use something else. - -~~When you want to convert a V8 `String` to a `char*` buffer, use `NanRawString`. You have to supply an encoding as well as a pointer to a variable that will be assigned the number of bytes in the returned string. It is also possible to supply a buffer and its length to the function in order not to have a new buffer allocated. The final argument allows setting `String::WriteOptions`. -Just remember that you'll end up with an object that you'll need to `delete[]` at some point unless you supply your own buffer:~~ - -```c++ -size_t count; -void* decoded = NanRawString(args[1], Nan::BASE64, &count, NULL, 0, String::HINT_MANY_WRITES_EXPECTED); -... -delete[] reinterpret_cast(decoded); -``` - - -### ~~char* NanCString(Handle<Value>, size_t *[, char *, size_t, int])~~ - -Deprecated. Use `String::Utf8Value` or `NanUtf8String` instead. - -~~When you want to convert a V8 `String` to a null-terminated C `char*` use `NanCString`. The resulting `char*` will be UTF-8-encoded, and you need to supply a pointer to a variable that will be assigned the number of bytes in the returned string. It is also possible to supply a buffer and its length to the function in order not to have a new buffer allocated. The final argument allows optionally setting `String::WriteOptions`, which default to `v8::String::NO_OPTIONS`. -Just remember that you'll end up with an object that you'll need to `delete[]` at some point unless you supply your own buffer:~~ - -```c++ -size_t count; -char* name = NanCString(args[0], &count); -... -delete[] name; -``` - - -### NanAsciiString - -Contrary to the name, this is not actually an ASCII string, it is a one-byte string with no particular encoding. Do not use unless you actually need this incorrect legacy behavior. Consider fixing your broken code instead. If you actually have a proper ASCII-string, use UTF-8, which is a proper superset of ASCII. -Convert a `String` to zero-terminated, sort-of Ascii-encoded `char *`. The underlying buffer is freed when the owner object goes out of scope, so make a copy or heap allocation if you need it to stick around. - -```c++ -NAN_METHOD(foo) { - NanScope(); - NanReturnValue(NanNew(*NanAsciiString(arg[0]))); -} -``` - -####*WRONG*: -the buffer `str` points to has been freed when `baz` was destroyed: -```c++ -static char *str; +Additional to the NAN documentation below, please consult: -NAN_METHOD(bar) { - NanScope(); - NanAsciiString baz(arg[0]); +* [The V8 Getting Started Guide](https://developers.google.com/v8/get_started) +* [The V8 Embedders Guide](https://developers.google.com/v8/embed) +* [V8 API Documentation](http://v8docs.nodesource.com/) - str = *baz; - NanReturnUndefined(); // baz goes out of scope, freeing str -} + -... +### JavaScript-accessible methods -printf(str); // use-after-free error -``` +A _template_ is a blueprint for JavaScript functions and objects in a context. You can use a template to wrap C++ functions and data structures within JavaScript objects so that they can be manipulated from JavaScript. See the V8 Embedders Guide section on [Templates](https://developers.google.com/v8/embed#templates) for further information. + +In order to expose functionality to JavaScript via a template, you must provide it to V8 in a form that it understands. Across the versions of V8 supported by NAN, JavaScript-accessible method signatures vary widely, NAN fully abstracts method declaration and provides you with an interface that is similar to the most recent V8 API but is backward-compatible with older versions that still use the now-deceased `v8::Argument` type. + +* **Method argument types** + - Nan::FunctionCallbackInfo + - Nan::PropertyCallbackInfo + - Nan::ReturnValue +* **Method declarations** + - Method declaration + - Getter declaration + - Setter declaration + - Property getter declaration + - Property setter declaration + - Property enumerator declaration + - Property deleter declaration + - Property query declaration + - Index getter declaration + - Index setter declaration + - Index enumerator declaration + - Index deleter declaration + - Index query declaration +* Method and template helpers + - Nan::SetMethod() + - Nan::SetNamedPropertyHandler() + - Nan::SetIndexedPropertyHandler() + - Nan::SetPrototypeMethod() + - Nan::SetTemplate() + - Nan::SetPrototypeTemplate() + - Nan::SetInstanceTemplate() -####*RIGHT*: -```c++ -static NanAsciiString *str; +### Scopes -NAN_METHOD(bar) { - NanScope(); - str = new NanAsciiString(arg[0]); - NanReturnUndefined(); -} +A _local handle_ is a pointer to an object. All V8 objects are accessed using handles, they are necessary because of the way the V8 garbage collector works. -... +A handle scope can be thought of as a container for any number of handles. When you've finished with your handles, instead of deleting each one individually you can simply delete their scope. + +The creation of `HandleScope` objects is different across the supported versions of V8. Therefore, NAN provides its own implementations that can be used safely across these. + + - Nan::HandleScope + - Nan::EscapableHandleScope + +Also see the V8 Embedders Guide section on [Handles and Garbage Collection](https://developers.google.com/v8/embed#handles). + +### Persistent references + +An object reference that is independent of any `HandleScope` is a _persistent_ reference. Where a `Local` handle only lives as long as the `HandleScope` in which it was allocated, a `Persistent` handle remains valid until it is explicitly disposed. + +Due to the evolution of the V8 API, it is necessary for NAN to provide a wrapper implementation of the `Persistent` classes to supply compatibility across the V8 versions supported. + + - Nan::PersistentBase & v8::PersistentBase + - Nan::NonCopyablePersistentTraits & v8::NonCopyablePersistentTraits + - Nan::CopyablePersistentTraits & v8::CopyablePersistentTraits + - Nan::Persistent + - Nan::Global + - Nan::WeakCallbackInfo + - Nan::WeakCallbackType -printf(**str); -``` +### New - -### NanUtf8String +NAN provides a `Nan::New()` helper for the creation of new JavaScript objects in a way that's compatible across the supported versions of V8. -Equivalent to `String::Utf8Value`, it only exists for the sake of completeness. -Convert a `String` to zero-terminated, Utf8-encoded `char *`. The underlying buffer is freed when the owner object goes out of scope, so make a copy or heap allocation if you need it to stick around. + - Nan::New() + - Nan::Undefined() + - Nan::Null() + - Nan::True() + - Nan::False() + - Nan::EmptyString() -```c++ -NAN_METHOD(foo) { - NanScope(); - NanReturnValue(NanNew(*NanUtf8String(arg[0]))); -} -``` -####*WRONG*: -the buffer `str` points to has been freed when `baz` was destroyed: -```c++ -static char *str; +### Converters -NAN_METHOD(bar) { - NanScope(); - NanUtf8String baz(arg[0]); +NAN contains functions that convert `v8::Value`s to other `v8::Value` types and native types. Since type conversion is not guaranteed to succeed, they return `Nan::Maybe` types. These converters can be used in place of `value->ToX()` and `value->XValue()` (where `X` is one of the types, e.g. `Boolean`) in a way that provides a consistent interface across V8 versions. Newer versions of V8 use the new `v8::Maybe` and `v8::MaybeLocal` types for these conversions, older versions don't have this functionality so it is provided by NAN. - str = *baz; - NanReturnUndefined(); // baz goes out of scope, freeing str -} + - Nan::To -... +### Maybe Types -printf(str); // use-after-free error -``` +The `Nan::MaybeLocal` and `Nan::Maybe` types are monads that encapsulate `v8::Local` handles that _may be empty_. -####*RIGHT*: -```c++ -static NanUtf8String *str; +* **Maybe Types** + - Nan::MaybeLocal + - Nan::Maybe + - Nan::Nothing + - Nan::Just +* **Maybe Helpers** + - Nan::ToDetailString() + - Nan::ToDetailString() + - Nan::ToArrayIndex() + - Nan::Equals() + - Nan::NewInstance() + - Nan::GetFunction() + - Nan::Set() + - Nan::ForceSet() + - Nan::Get() + - Nan::GetPropertyAttributes() + - Nan::Has() + - Nan::Delete() + - Nan::GetPropertyNames() + - Nan::GetOwnPropertyNames() + - Nan::SetPrototype() + - Nan::ObjectProtoToString() + - Nan::HasOwnProperty() + - Nan::HasRealNamedProperty() + - Nan::HasRealIndexedProperty() + - Nan::HasRealNamedCallbackProperty() + - Nan::GetRealNamedPropertyInPrototypeChain() + - Nan::GetRealNamedProperty() + - Nan::CallAsFunction() + - Nan::CallAsConstructor() + - Nan::GetSourceLine() + - Nan::GetLineNumber() + - Nan::GetStartColumn() + - Nan::GetEndColumn() + - Nan::CloneElementAt() -NAN_METHOD(bar) { - NanScope(); - str = new NanUtf8String(arg[0]); - NanReturnUndefined(); -} +### Script -... +NAN provides a `v8::Script` helpers as the API has changed over the supported versions of V8. -printf(**str); -``` + - Nan::CompileScript() + - Nan::RunScript() - -### NanUcs2String +### Errors -Equivalent to `String::Value`, it only exists for the sake of completeness. -Convert a `String` to zero-terminated, Ucs2-encoded `uint16_t *`. The underlying buffer is freed when the owner object goes out of scope, so make a copy or heap allocation if you need it to stick around. +NAN includes helpers for creating, throwing and catching Errors as much of this functionality varies across the supported versions of V8 and must be abstracted. -```c++ -NAN_METHOD(foo) { - NanScope(); - NanReturnValue(NanNew(*NanUcs2String(arg[0]))); -} -``` +Note that an Error object is simply a specialized form of `v8::Value`. -####*WRONG*: -the buffer `str` points to has been freed when `baz` was destroyed: -```c++ -static char *str; +Also consult the V8 Embedders Guide section on [Exceptions](https://developers.google.com/v8/embed#exceptions) for more information. -NAN_METHOD(bar) { - NanScope(); - NanUcs2String baz(arg[0]); + - Nan::Error() + - Nan::RangeError() + - Nan::ReferenceError() + - Nan::SyntaxError() + - Nan::TypeError() + - Nan::ThrowError() + - Nan::ThrowRangeError() + - Nan::ThrowReferenceError() + - Nan::ThrowSyntaxError() + - Nan::ThrowTypeError() + - Nan::FatalException() + - Nan::ErrnoException() + - Nan::TryCatch - str = *baz; - NanReturnUndefined(); // baz goes out of scope, freeing str -} -... +### Buffers -printf(str); // use-after-free error -``` +NAN's `node::Buffer` helpers exist as the API has changed across supported Node versions. Use these methods to ensure compatibility. -####*RIGHT*: -```c++ -static NanUcs2String *str; + - Nan::NewBuffer() + - Nan::CopyBuffer() -NAN_METHOD(bar) { - NanScope(); - str = new NanUcs2String(arg[0]); - NanReturnUndefined(); -} -... +### Nan::Callback -printf(**str); -``` +`Nan::Callback` makes it easier to use `v8::Function` handles as callbacks. A class that wraps a `v8::Function` handle, protecting it from garbage collection and making it particularly useful for storage and use across asynchronous execution. - -### ~~bool NanBooleanOptionValue(Handle<Value>, Handle<String>[, bool])~~ + - Nan::Callback -Deprecated. -~~When you have an "options" object that you need to fetch properties from, boolean options can be fetched with this pair. They check first if the object exists (`IsEmpty`), then if the object has the given property (`Has`) then they get and convert/coerce the property to a `bool`.~~ +### Asynchronous work helpers -~~The optional last parameter is the *default* value, which is `false` if left off:~~ +`Nan::AsyncWorker` and `Nan::AsyncProgressWorker` are helper classes that make working with asynchronous code easier. -```c++ -// `foo` is false unless the user supplies a truthy value for it -bool foo = NanBooleanOptionValue(optionsObj, NanNew("foo")); -// `bar` is true unless the user supplies a falsy value for it -bool bar = NanBooleanOptionValueDefTrue(optionsObj, NanNew("bar"), true); -``` + - Nan::AsyncWorker + - Nan::AsyncProgressWorker + - Nan::AsyncQueueWorker - -### ~~uint32_t NanUInt32OptionValue(Handle<Value>, Handle<String>, uint32_t)~~ +### Strings & Bytes -Deprecated. -~~Similar to `NanBooleanOptionValue`, use `NanUInt32OptionValue` to fetch an integer option from your options object. Can be any kind of JavaScript `Number` and it will be coerced to an unsigned 32-bit integer.~~ +Miscellaneous string & byte encoding and decoding functionality provided for compatibility across supported versions of V8 and Node. Implemented by NAN to ensure that all encoding types are supported, even for older versions of Node where they are missing. -~~Requires all 3 arguments as a default is not optional:~~ + - Nan::Encoding + - Nan::Encode() + - Nan::DecodeBytes() + - Nan::DecodeWrite() -```c++ -uint32_t count = NanUInt32OptionValue(optionsObj, NanNew("count"), 1024); -``` - -### NanError(message), NanRangeError(message), NanReferenceError(message), NanSyntaxError(message), NanTypeError(message) +### V8 internals -For making `Error`, `RangeError`, `ReferenceError`, `SyntaxError` and `TypeError` objects. +The hooks to access V8 internals—including GC and statistics—are different across the supported versions of V8, therefore NAN provides its own hooks that call the appropriate V8 methods. -```c++ -Local res = NanError("you must supply a callback argument"); -``` + - NAN_GC_CALLBACK() + - Nan::AddGCEpilogueCallback()Nan::RemoveGCEpilogueCallback()Nan::AddGCPrologueCallback()Nan::RemoveGCPrologueCallback()Nan::GetHeapStatistics()Nan::GetHeapStatistics() + - Nan::SetCounterFunction() + - Nan::SetCreateHistogramFunction() + - Nan::SetAddHistogramSampleFunction() + - Nan::IdleNotification() + - Nan::LowMemoryNotification() + - Nan::ContextDisposedNotification() + - Nan::GetInternalFieldPointer() + - Nan::SetInternalFieldPointer() + - Nan::AdjustExternalMemory() - -### NanThrowError(message), NanThrowRangeError(message), NanThrowReferenceError(message), NanThrowSyntaxError(message), NanThrowTypeError(message), NanThrowError(Local<Value>), NanThrowError(Local<Value>, int) -For throwing `Error`, `RangeError`, `ReferenceError`, `SyntaxError` and `TypeError` objects. - -```c++ -NanThrowError("you must supply a callback argument"); -``` - -Can also handle any custom object you may want to throw. If used with the error code argument, it will add the supplied error code to the error object as a property called `code`. - - -### Local<Object> NanNewBufferHandle(char *, uint32_t), Local<Object> NanNewBufferHandle(uint32_t) - -The `Buffer` API has changed a little in Node 0.11, this helper provides consistent access to `Buffer` creation: - -```c++ -NanNewBufferHandle((char*)value.data(), value.size()); -``` - -Can also be used to initialize a `Buffer` with just a `size` argument. - -Can also be supplied with a `NanFreeCallback` and a hint for the garbage collector. - - -### Local<Object> NanBufferUse(char*, uint32_t) - -`Buffer::New(char*, uint32_t)` prior to 0.11 would make a copy of the data. -While it was possible to get around this, it required a shim by passing a -callback. So the new API `Buffer::Use(char*, uint32_t)` was introduced to remove -needing to use this shim. - -`NanBufferUse` uses the `char*` passed as the backing data, and will free the -memory automatically when the weak callback is called. Keep this in mind, as -careless use can lead to "double free or corruption" and other cryptic failures. - - -### bool NanHasInstance(Persistent<FunctionTemplate>&, Handle<Value>) - -Can be used to check the type of an object to determine it is of a particular class you have already defined and have a `Persistent` handle for. - - -### ~~Local<Context> NanNewContextHandle([ExtensionConfiguration*, Handle<ObjectTemplate>, Handle<Value>])~~ - -Deprecated. Use `NanNew` instead. - -~~Creates a new `Local` handle.~~ - -```c++ -Local ftmpl = NanNew(); -Local otmpl = ftmpl->InstanceTemplate(); -Local ctx = NanNewContextHandle(NULL, otmpl); -``` - - -### Local<Context> NanGetCurrentContext() - -Gets the current context. - -```c++ -Local ctx = NanGetCurrentContext(); -``` - - -### void NanDisposePersistent(Persistent<T> &) - -Use `NanDisposePersistent` to dispose a `Persistent` handle. - -```c++ -NanDisposePersistent(persistentHandle); -``` - - -### NanAssignPersistent(handle, object) - -Use `NanAssignPersistent` to assign a non-`Persistent` handle to a `Persistent` one. You can no longer just declare a `Persistent` handle and assign directly to it later, you have to `Reset` it in Node 0.11, so this makes it easier. - -In general it is now better to place anything you want to protect from V8's garbage collector as properties of a generic `Object` and then assign that to a `Persistent`. This works in older versions of Node also if you use `NanAssignPersistent`: - -```c++ -Persistent persistentHandle; - -... - -Local obj = NanNew(); -obj->Set(NanNew("key"), keyHandle); // where keyHandle might be a Local -NanAssignPersistent(persistentHandle, obj) -``` - - -### _NanWeakCallbackInfo<T, P>* NanMakeWeakPersistent(Handle<T>, P*, _NanWeakCallbackInfo<T, P>::Callback) - -Creates a weak persistent handle with the supplied parameter and `NAN_WEAK_CALLBACK`. - -```c++ -NAN_WEAK_CALLBACK(weakCallback) { - -... - -} - -Local func; - -... - -int *parameter = new int(0); -NanMakeWeakPersistent(func, parameter, &weakCallback); -``` +### Miscellaneous V8 Helpers - -### NanSetTemplate(templ, name, value [, attributes]) + - Nan::Utf8String + - Nan::GetCurrentContext() + - Nan::SetIsolateData() + - Nan::GetIsolateData() -Use to add properties on object and function templates. - -### NanSetPrototypeTemplate(templ, name, value [, attributes]) +### Miscellaneous Node Helpers -Use to add prototype properties on function templates. + - Nan::MakeCallback() + - Nan::ObjectWrap + - NAN_MODULE_INIT() + - Nan::Export() - -### NanSetInstanceTemplate(templ, name, value [, attributes]) + -Use to add instance properties on function templates. - -### NanMakeCallback(target, func, argc, argv) - -Use instead of `node::MakeCallback` to call javascript functions. This (or `NanCallback`) is the only proper way of calling functions. You must _*never, ever*_ directly use `Function::Call`, it will lead to run-time failures. - - -### NanFatalException(const v8::TryCatch &) - -Replaces `node::FatalException`. - - -### NanErrnoException(int errorno, const char *syscall = NULL, const char *message = NULL, const char *path = NULL) - -Replaces `node::ErrnoException`. - - -### NanGetIsolateData(v8::Isolate *) - -Replaces `v8::Isolate::GetData`. - - -### NanSetIsolateData(v8::Isolate *, T*) - -Replaces `v8::Isolate::SetData`. - - -### NanEncode(const void*, size_t[, enum Nan::Encoding]) - -Replaces `node::Encode`. - - -### NanDecodeBytes(v8::Handle<v8::Value>[, enum Nan::Encoding]) - -Replaces `node::DecodeBytes`. - - -### NanDecodeWrite(char *, size_t, v8::Handle<v8::Value>[, enum Nan::Encoding]) - -Replaces `node::DecodeWrite`. - - -### NanCompileScript(Handle s [, const ScriptOrigin& origin]) - -Use to create new scripts bound to the current context. - - -### NanRunScript(script) - -Use to run both bound and unbound scripts. - - -### NanAdjustExternalMemory(int change_in_bytes) - -Simply does `AdjustAmountOfExternalAllocatedMemory`, note that the argument and returned value have type `int`. - - -### NanAddGCEpilogueCallback(GCEpilogueCallback callback, GCType gc_type_filter=kGCTypeAll) - -Simply does `AddGCEpilogueCallback` - - -### NanAddGCPrologueCallback(GCPrologueCallback callback, GCType gc_type_filter=kGCTypeAll) - -Simply does `AddGCPrologueCallback` - - -### NanRemoveGCEpilogueCallback(GCEpilogueCallback callback) - -Simply does `RemoveGCEpilogueCallback` - - -### NanRemoveGCPrologueCallback(GCPrologueCallback callback) - -Simply does `RemoveGCPrologueCallback` - - -### NanGetHeapStatistics(HeapStatistics *heap_statistics) - -Simply does `GetHeapStatistics` - - -### NanSetCounterFunction(CounterLookupCallback cb) - -Simply does `SetCounterFunction` - - -### NanSetCreateHistogramFunction(CreateHistogramCallback cb) - -Simply does `SetCreateHistogramFunction` - - -### NanSetAddHistogramSampleFunction(AddHistogramSampleCallback cb) - -Simply does `SetAddHistogramSampleFunction` - - -### NanIdleNotification(int idle_time_in_ms) - -Simply does `IdleNotification` - - -### NanLowMemoryNotification() - -Simply does `LowMemoryNotification` - - -### NanContextDisposedNotification() - -Simply does `ContextDisposedNotification` - - -### NanCallback - -Because of the difficulties imposed by the changes to `Persistent` handles in V8 in Node 0.11, creating `Persistent` versions of your `Handle` is annoyingly tricky. `NanCallback` makes it easier by taking your handle, making it persistent until the `NanCallback` is deleted and even providing a handy `Call()` method to fetch and execute the callback `Function`. - -```c++ -Local callbackHandle = args[0].As(); -NanCallback *callback = new NanCallback(callbackHandle); -// pass `callback` around and it's safe from GC until you: -delete callback; -``` - -You can execute the callback like so: - -```c++ -// no arguments: -callback->Call(0, NULL); - -// an error argument: -Handle argv[] = { - NanError(NanNew("fail!")) -}; -callback->Call(1, argv); - -// a success argument: -Handle argv[] = { - NanNull(), - NanNew("w00t!") -}; -callback->Call(2, argv); -``` - -`NanCallback` also has a `Local GetFunction()` method that you can use -to fetch a local handle to the underlying callback function, as well as a -`void SetFunction(Handle)` for setting the callback on the -`NanCallback`. You can check if a `NanCallback` is empty with the `bool IsEmpty()` method. Additionally a generic constructor is available for using -`NanCallback` without performing heap allocations. - - -### NanAsyncWorker - -`NanAsyncWorker` is an abstract class that you can subclass to have much of the annoying async queuing and handling taken care of for you. It can even store arbitrary V8 objects for you and have them persist while the async work is in progress. - -See a rough outline of the implementation: - -```c++ -class NanAsyncWorker { -public: - NanAsyncWorker (NanCallback *callback); - - // Clean up persistent handles and delete the *callback - virtual ~NanAsyncWorker (); - - // Check the `ErrorMessage()` and call HandleOKCallback() - // or HandleErrorCallback depending on whether it has been set or not - virtual void WorkComplete (); - - // You must implement this to do some async work. If there is an - // error then use `SetErrorMessage()` to set an error message and the callback will - // be passed that string in an Error object - virtual void Execute (); - - // Save a V8 object in a Persistent handle to protect it from GC - void SaveToPersistent(const char *key, Local &obj); - - // Fetch a stored V8 object (don't call from within `Execute()`) - Local GetFromPersistent(const char *key); - - // Get the error message (or NULL) - const char *ErrorMessage(); - - // Set an error message - void SetErrorMessage(const char *msg); - -protected: - // Default implementation calls the callback function with no arguments. - // Override this to return meaningful data - virtual void HandleOKCallback (); - - // Default implementation calls the callback function with an Error object - // wrapping the `errmsg` string - virtual void HandleErrorCallback (); -}; -``` - - -### NanAsyncQueueWorker(NanAsyncWorker *) - -`NanAsyncQueueWorker` will run a `NanAsyncWorker` asynchronously via libuv. Both the *execute* and *after_work* steps are taken care of for you—most of the logic for this is embedded in `NanAsyncWorker`. - - + ### Tests To run the NAN tests do: @@ -1324,52 +306,7 @@ npm install make test ``` -## Porting - -Follows is a guide to porting your C++ node to NAN. - - - - - - - - - - - - - - - - - -
AspectWithout NANWith NAN
Function declaration
class MyClass : public ObjectWrap {
-    ....
-    static Handle ToString(const Arguments& args);
-    ....
-}
class MyClass : public ObjectWrap {
-    ....
-    static NAN_METHOD(ToString);
-    ....
-}
Function definition
Handle
-MyClass::ToString(const Arguments& args)
-{
-	HandleScope scope;
-	....
-}
-NAN_METHOD(MyClass::ToString)
-{
-  NanScope();
-  ....
-}
Return a value
return scope.Close(result);
NanReturnValue(result);
Return undefined
return Undefined();
NanReturnUndefined();
Throw an error
return ThrowException(
-  Exception::Error(
-    String::New("Error text...")));
return NanThrowError("Error text...");
New v8 string literal
String::NewSymbol("my text")
NanNew("my text")
- -## Contributors - - ## Governance & Contributing NAN is governed by the [io.js](https://iojs.org/) Addon API Working Group diff --git a/doc/.build.sh b/doc/.build.sh new file mode 100755 index 00000000..75a975af --- /dev/null +++ b/doc/.build.sh @@ -0,0 +1,38 @@ +#!/usr/bin/env bash + +files=" \ + methods.md \ + scopes.md \ + persistent.md \ + new.md \ + converters.md \ + maybe_types.md \ + script.md \ + errors.md \ + buffers.md \ + callback.md \ + asyncworker.md \ + string_bytes.md \ + v8_internals.md \ + v8_misc.md \ + node_misc.md \ +" + +__dirname=$(dirname "${BASH_SOURCE[0]}") +head=$(perl -e 'while (<>) { if (!$en){print;} if ($_=~/ NanNew("foo").ToLocalChecked() */ + if (arguments[groups[3][0]] === 'NanNew') { + return [arguments[0], '.ToLocalChecked()'].join(''); + } + + /* insert warning for removed functions as comment on new line above */ + switch (arguments[groups[4][0]]) { + case 'GetIndexedPropertiesExternalArrayData': + case 'GetIndexedPropertiesExternalArrayDataLength': + case 'GetIndexedPropertiesExternalArrayDataType': + case 'GetIndexedPropertiesPixelData': + case 'GetIndexedPropertiesPixelDataLength': + case 'HasIndexedPropertiesInExternalArrayData': + case 'HasIndexedPropertiesInPixelData': + case 'SetIndexedPropertiesToExternalArrayData': + case 'SetIndexedPropertiesToPixelData': + return arguments[groups[4][0] - 1] ? arguments[0] : [warning1, arguments[0]].join(''); + default: + } + + /* remove unnecessary NanScope() */ + switch (arguments[groups[5][0]]) { + case 'NAN_GETTER': + case 'NAN_METHOD': + case 'NAN_SETTER': + case 'NAN_INDEX_DELETER': + case 'NAN_INDEX_ENUMERATOR': + case 'NAN_INDEX_GETTER': + case 'NAN_INDEX_QUERY': + case 'NAN_INDEX_SETTER': + case 'NAN_PROPERTY_DELETER': + case 'NAN_PROPERTY_ENUMERATOR': + case 'NAN_PROPERTY_GETTER': + case 'NAN_PROPERTY_QUERY': + case 'NAN_PROPERTY_SETTER': + return arguments[groups[5][0] - 1]; + default: + } + + /* Value converstion */ + switch (arguments[groups[6][0]]) { + case 'Boolean': + case 'Int32': + case 'Integer': + case 'Number': + case 'Object': + case 'String': + case 'Uint32': + return [arguments[groups[6][0] - 2], 'NanTo(', arguments[groups[6][0] - 1]].join(''); + default: + } + + /* other value conversion */ + switch (arguments[groups[7][0]]) { + case 'BooleanValue': + return [arguments[groups[7][0] - 2], 'NanTo(', arguments[groups[7][0] - 1]].join(''); + case 'Int32Value': + return [arguments[groups[7][0] - 2], 'NanTo(', arguments[groups[7][0] - 1]].join(''); + case 'IntegerValue': + return [arguments[groups[7][0] - 2], 'NanTo(', arguments[groups[7][0] - 1]].join(''); + case 'Uint32Value': + return [arguments[groups[7][0] - 2], 'NanTo(', arguments[groups[7][0] - 1]].join(''); + default: + } + + /* NAN_WEAK_CALLBACK */ + if (arguments[groups[8][0]] === 'NAN_WEAK_CALLBACK') { + return ['template\nvoid ', + arguments[groups[8][0] + 1], '(const NanWeakCallbackInfo &data)'].join(''); + } + + /* use methods on NAN classes instead */ + switch (arguments[groups[9][0]]) { + case 'NanDisposePersistent': + return [arguments[groups[9][0] + 1], '.Reset('].join(''); + case 'NanObjectWrapHandle': + return [arguments[groups[9][0] + 1], '->handle('].join(''); + default: + } + + /* use method on NanPersistent instead */ + if (arguments[groups[10][0]] === 'NanMakeWeakPersistent') { + return arguments[groups[10][0] + 1] + '.SetWeak('; + } + + /* These return Maybes, the upper ones take no arguments */ + switch (arguments[groups[11][0]]) { + case 'GetEndColumn': + case 'GetFunction': + case 'GetLineNumber': + case 'GetOwnPropertyNames': + case 'GetPropertyNames': + case 'GetSourceLine': + case 'GetStartColumn': + case 'NewInstance': + case 'ObjectProtoToString': + case 'ToArrayIndex': + case 'ToDetailString': + return [arguments[groups[11][0] - 2], 'Nan', arguments[groups[11][0]], '(', arguments[groups[11][0] - 1]].join(''); + case 'CallAsConstructor': + case 'CallAsFunction': + case 'CloneElementAt': + case 'Delete': + case 'ForceSet': + case 'Get': + case 'GetPropertyAttributes': + case 'GetRealNamedProperty': + case 'GetRealNamedPropertyInPrototypeChain': + case 'Has': + case 'HasOwnProperty': + case 'HasRealIndexedProperty': + case 'HasRealNamedCallbackProperty': + case 'HasRealNamedProperty': + case 'Set': + case 'SetAccessor': + case 'SetIndexedPropertyHandler': + case 'SetNamedPropertyHandler': + case 'SetPrototype': + return [arguments[groups[11][0] - 2], 'Nan', arguments[groups[11][0]], '(', arguments[groups[11][0] - 1], ', '].join(''); + default: + } + + /* Automatic ToLocalChecked(), take it or leave it */ + switch (arguments[groups[12][0]]) { + case 'Date': + case 'String': + case 'RegExp': + return ['NanNew', arguments[groups[12][0] - 1], arguments[groups[12][0] + 1], '.ToLocalChecked()'].join(''); + default: + } + + /* NanEquals is now required for uniformity */ + if (arguments[groups[13][0]] === 'Equals') { + return [arguments[groups[13][0] - 1], 'NanEquals(', arguments[groups[13][0] - 1], ', ', arguments[groups[13][0] + 1]].join(''); + } + + /* use method on replacement class instead */ + if (arguments[groups[14][0]] === 'NanAssignPersistent') { + return [arguments[groups[14][0] + 1], '.Reset('].join(''); + } + + /* args --> info */ + if (arguments[groups[15][0]] === 'args') { + return [arguments[groups[15][0] - 1], 'info', arguments[groups[15][0] + 1]].join(''); + } + + /* ObjectWrap --> NanObjectWrap */ + if (arguments[groups[16][0]] === 'ObjectWrap') { + return [arguments[groups[16][0] - 1], 'NanObjectWrap', arguments[groups[16][0] + 1]].join(''); + } + + /* Persistent --> NanPersistent */ + if (arguments[groups[17][0]] === 'Persistent') { + return [arguments[groups[17][0] - 1], 'NanPersistent', arguments[groups[17][0] + 1]].join(''); + } + + /* This should not happen. A switch is probably missing a case if it does. */ + throw 'Unhandled match: ' + arguments[0]; +} + +/* reads a file, runs replacement and writes it back */ +function processFile(file) { + fs.readFile(file, {encoding: 'utf8'}, function (err, data) { + if (err) { + throw err; + } + + /* run replacement twice, might need more runs */ + fs.writeFile(file, data.replace(master, replace).replace(master, replace), function (err) { + if (err) { + throw err; + } + }); + }); +} + +/* process file names from command line and process the identified files */ +for (i = 2, length = process.argv.length; i < length; i++) { + glob(process.argv[i], function (err, matches) { + if (err) { + throw err; + } + matches.forEach(processFile); + }); +} diff --git a/tools/README.md b/tools/README.md new file mode 100644 index 00000000..7f07e4b8 --- /dev/null +++ b/tools/README.md @@ -0,0 +1,14 @@ +1to2 naively converts source code files from NAN 1 to NAN 2. There will be erroneous conversions, +false positives and missed opportunities. The input files are rewritten in place. Make sure that +you have backups. You will have to manually review the changes afterwards and do some touchups. + +```sh +$ tools/1to2.js + + Usage: 1to2 [options] + + Options: + + -h, --help output usage information + -V, --version output the version number +``` diff --git a/tools/package.json b/tools/package.json new file mode 100644 index 00000000..2dcdd789 --- /dev/null +++ b/tools/package.json @@ -0,0 +1,19 @@ +{ + "name": "1to2", + "version": "1.0.0", + "description": "NAN 1 -> 2 Migration Script", + "main": "1to2.js", + "repository": { + "type": "git", + "url": "git://github.com/nodejs/nan.git" + }, + "contributors": [ + "Benjamin Byholm (https://github.com/kkoopa/)", + "Mathias Küsel (https://github.com/mathiask88/)" + ], + "dependencies": { + "glob": "~5.0.10", + "commander": "~2.8.1" + }, + "license": "MIT" +}