diff --git a/content/post/mini-racer-v0.12.2.md b/content/post/mini-racer-v0.12.2.md index cf4ce0f..f67d54b 100644 --- a/content/post/mini-racer-v0.12.2.md +++ b/content/post/mini-racer-v0.12.2.md @@ -177,77 +177,86 @@ such calls are ignored. Here's roughly what the system looks like: +
+ ```goat +----------------------------------------+ | | -| (Python) MiniRacer user code | +| MiniRacer user code | | | | +----------------------+ | | | | | | | my_callback_func | | | | | | -| +------------+---------+ | -| 3 | ^ | -+----------------------------|---|-------+ - 1 | | | - v | | -+----------------------------|---|-------+ -| | | | -| (Python) MiniRacer | | | -| | | | -| +--------------------------|---|-----+ | -| | | | | | -| | (Python) _Context | | | | -| | v | 10 | | +| +----------+-----------+ | +| 3 | ^ | ++--------------------------|-----|-------+ + 1 | | | + v | | ++--------------------------|-----|-------+ +| | | | +| MiniRacer | | | +| | | | +| +------------------------|-----|-----+ | +| | | | | | +| | _Context | | | | +| | v | 10 | | | | +----------------------------+---+ | | | | | | | | | | | _CallbackRegistry | | | | | | | | | -| | +------------------------+-------+ | | -| | 4 | ^ | | -| +---------------+----------|---|-----+ | -| 2 | | | | -+-----------------|----------|---|-------+ - | | | - v | | -+----------------------------|---|-----------------------------------------+ -| (C++) MiniRacer::Context | | | -| | | | -| v | | -| +------------------------------|---+ +-------------------------------+ | -| | | | | 5 | | -| | (C++) MiniRacer | +-------+ (C++) v8::Isolate | | -| | ::JSCallbackMaker 9 | | | v | | -| | +----------------------------+-+ | | +---------------------------+ | | -| | | | | | | | | | -| | | (C++) | | | | v8::Function | | | -| | | MiniRacer::CallbackCaller | | | | | | | -| | | | | | | | | | -| | +------------------------------+ | | | | | | -| | ^ | | | | | | -| +------------------------------|---+ | | +----------------------+ | | | -| | 8 | | | | | | | -| +-----------------------+---+ | | | (data) | | | | -| | | | | | v8::Array | | | | -| | (C++) |<----+ | [callback_id, | | | | -| | MiniRacer | 7 | | | callback_caller_id] | | | | -| | ::JSCallbackMaker | | | | | | | | -| | ::OnCalledStatic | | | +----------------------+ | | | -| | | | | | | | -| +---------------------------+ | +---------------------------+ | | -| | ^ | | -| | | 6 | | -| | +------------+--------------+ | | -| | | | | | -| | | JavaScript code | | | -| | | | | | -| | +---------------------------+ | | -| | | | -| +-------------------------------+ | -| | -+--------------------------------------------------------------------------+ +| | +----------------------+---------+ | | +| | 4 | ^ | | +| +---------------+--------|-----|-----+ | +| 2 | | | | ++-----------------|--------|-----|-------+ + | | | + Python space | | | +··················|········|·····|································ + C++ space | | | + v | | ++--------------------------|-----|-----+ +| MiniRacer::Context | | | +| | | | +| v | | +| +------------------------------|---+ | +| | | | | +---------------------+ +| | MiniRacer::JSCallbackMaker | | | | | +| | 9 | | | | (C++) | +| | +----------------------------+-+ | | | MiniRacer | +| | | | | | | ::JSCallbackMaker | +| | | MiniRacer::CallbackCaller |<------+ ::OnCalledStatic | +| | | | | | 8 | | +| | +------------------------------+ | | +---------------------+ +| | | | ^ +| +------------------------+---------+ +--------------|----------+ +| 5 | | | +| +------------------------|--------------------------|--------+ | +| | | | | | +| | v8::Isolate | 7 | | | +| | | | | | +| | | +-----------------------+------+ | | +| | | | | | | +| | `->| v8::Function | | | +| | | | | | +| | | data: | | | +| | | +--------------------------+ | | | +| | +-----------------+ | | | | | | +| | | | 6 | | v8::Array | | | | +| | | JavaScript code |------>| | [callback_id, | | | | +| | | | | | callback_caller_id] | | | | +| | +-----------------+ | | | | | | +| | | +--------------------------+ | | | +| | | | | | +| | +------------------------------+ | | +| | | | +| +------------------------------------------------------------+ | +| | ++----------------------------------------------------------------+ ``` +
+ 1. MiniRacer Python user code instantiates a `py_mini_racer.MiniRacer` object which contains a `py_mini_racer._Context` object. @@ -259,9 +268,9 @@ Here's roughly what the system looks like: 3. MiniRacer Python user code passes Python function `my_callback_func` into `MiniRacer.wrap_py_function`. `MiniRacer` stores a wrapper of - `my_callback_func` in its `_CallbackRegistry`, thus generating a callback ID. + `my_callback_func` in its `_CallbackRegistry`, thus generating a `callback_id`. -4. `MiniRacer.wrap_py_function` passes this callback ID down to the C++ side of +4. `MiniRacer.wrap_py_function` passes this `callback_id` down to the C++ side of the house to generate a V8 callback function. 5. `MiniRacer::JSCallbackMaker` creates a `v8::Function` within the @@ -279,14 +288,14 @@ Here's roughly what the system looks like: 8. `MiniRacer::JSCallbackMaker::OnCalledStatic` digs out the `[callback_id, callback_caller_id]` array to find the - `MiniRacer::CallbackCaller`, and the context-specific callback ID to pass + `MiniRacer::CallbackCaller`, and the `callback_id` to pass back to it. 9. `MiniRacer::CallbackCaller` converts the returned V8 value to a `MiniRacer::BinaryValue`, and calls back to the Python C function pointer - with that and the callback ID. + with that and the `callback_id`. -10. The `MiniRacer._ContextRegistry` converts the callback ID to the destination +10. The `MiniRacer._ContextRegistry` converts the `callback_id` to the destination Python function object (`my_callback_func`), and finally passes the function parameters back to it. @@ -348,12 +357,12 @@ This rule seems obvious in restrospect! But it's hard to implement. I: ### Breaking up the Python code -As of `v0.7.0` PyMiniRacer was basically a single file, 519 lines of code. +As of `v0.7.0` PyMiniRacer was basically a single Python file, 519 lines of code. -As of `v0.11.1` that file was up to 1,355 lines of code. This was quickly +As of `v0.11.1` that Python file was up to 1,355 lines of code. This was quickly growing beyond manageability! -So I split it up. The largest file is now 473 LoC. +So I split it up. The largest Python file is now 473 LoC. Splitting up code is always an exercise in breaking the code down into component parts, drawing out a DAG (hopefully acyclic!), and lumping things back together