Source code for v8cffi.platform

# -*- coding: utf-8 -*-

from __future__ import unicode_literals
import os

from _v8 import ffi, lib

from . import exceptions
from . import vm

__all__ = ['platform']

_BLOBS_PATH = os.path.join(os.path.dirname(__file__), 'src', 'v8')
_NATIVES_BLOB_PATH = os.path.join(_BLOBS_PATH, 'natives_blob.bin')
_SNAPSHOT_BLOB_PATH = os.path.join(_BLOBS_PATH, 'snapshot_blob.bin')

def _read_file(path):
    with open(path, 'rb') as fh:

[docs]class _Platform(object): """ V8 platform environment. The underlying\ platform is a singleton that must only\ be initialized once per process. Should be used through :py:data:`platform` :ivar str natives_path: Path to natives_blob.bin :ivar str snapshot_path: Path to snapshot_blob.bin """ def __init__(self): self.natives_path = _NATIVES_BLOB_PATH self.snapshot_path = _SNAPSHOT_BLOB_PATH self._c_platform = None self._is_dead = False # Irreversible state, once it's dead def __enter__(self): """ See :py:func:`set_up` method for docs """ assert not self.is_alive() assert not self._is_dead self._c_platform ='v8cffi_platform_t **') # initialized to NULL ? self._c_platform[0] = ffi.NULL natives_blob = _read_file(self.natives_path) snapshot_blob = _read_file(self.snapshot_path) code = lib.v8cffi_platform_new( self._c_platform, natives_blob, len(natives_blob), snapshot_blob, len(snapshot_blob)) if code != lib.E_V8_OK: raise exceptions.get_exception(code) return self def __exit__(self, *_, **__): """ See :py:func:`tear_down` method for docs """ assert self.is_alive() lib.v8cffi_platform_free(self._c_platform[0]) self._c_platform = None self._is_dead = True
[docs] def is_alive(self): """ Check is initialized and was not exited :return: Whether the platform is alive or not :rtype: bool """ return self._c_platform is not None
[docs] def create_vm(self): """ Create a :py:class:`.VM` for running\ JS scripts within an isolated environment :return: Instance of :py:class:`.VM` :rtype: :py:class:`.VM` """ return vm.VM(self)
[docs] def set_up(self): """ Initialize the V8 platform.\ Remember to call :py:func:`tear_down`\ before exiting the application.\ It's recommended to use a ``with``\ statement instead of this method\ to ensure clean up. This must only be called once\ in an application lifetime :raises V8MemoryError: if there\ is no memory for allocating it,\ the process should die afterwards anyway,\ there is little point in catching this """ return self.__enter__()
[docs] def tear_down(self): """ Destructs the V8 platform """ return self.__exit__()
platform = _Platform()