| ''' |
| Python3.5+ specific utilities |
| ''' |
| import collections |
|
|
| from ijson import utils, common, compat |
|
|
|
|
| class utf8reader_async(compat.utf8reader): |
| """ |
| Takes a utf8-encoded string asynchronous reader and asynchronously reads |
| bytes out of it |
| """ |
| async def read(self, n): |
| data = await self.str_reader.read(n) |
| return data.encode('utf-8') |
|
|
| async def _get_read(f): |
| """Returns an awaitable read function that reads the requested type""" |
| if type(await f.read(0)) == bytes: |
| return f.read |
| return compat._warn_and_return(utf8reader_async(f).read) |
|
|
| class sendable_deque(collections.deque): |
| '''Like utils.sendable_list, but for deque objects''' |
| send = collections.deque.append |
|
|
| class async_iterable: |
| ''' |
| A utility class that implements an async iterator returning values |
| dispatched by a coroutine pipeline after *it* has received values coming |
| from an async file-like object. |
| ''' |
|
|
| def __init__(self, f, buf_size, *coro_pipeline): |
| self.events = sendable_deque() |
| self.coro = utils.chain(self.events, *coro_pipeline) |
| self.coro_finished = False |
| self.f = f |
| self.buf_size = buf_size |
| self.read = None |
|
|
| def __aiter__(self): |
| return self |
|
|
| async def __anext__(self): |
| if not self.read: |
| self.read = await _get_read(self.f) |
| if self.events: |
| return self.events.popleft() |
| if self.coro_finished: |
| raise StopAsyncIteration |
| while True: |
| data = await self.read(self.buf_size) |
| try: |
| self.coro.send(data) |
| if self.events: |
| return self.events.popleft() |
| except StopIteration: |
| self.coro_finished = True |
| if self.events: |
| return self.events.popleft() |
| raise StopAsyncIteration |
|
|
|
|
| def _make_basic_parse_async(backend): |
| def basic_parse_async(f, buf_size=64*1024, **config): |
| return async_iterable(f, buf_size, |
| *common._basic_parse_pipeline(backend, config) |
| ) |
| return basic_parse_async |
|
|
| def _make_parse_async(backend): |
| def parse_async(f, buf_size=64*1024, **config): |
| return async_iterable(f, buf_size, |
| *common._parse_pipeline(backend, config) |
| ) |
| return parse_async |
|
|
| def _make_items_async(backend): |
| def items_async(f, prefix, map_type=None, buf_size=64*1024, **config): |
| return async_iterable(f, buf_size, |
| *common._items_pipeline(backend, prefix, map_type, config) |
| ) |
| return items_async |
|
|
| def _make_kvitems_async(backend): |
| def kvitems_async(f, prefix, map_type=None, buf_size=64*1024, **config): |
| return async_iterable(f, buf_size, |
| *common._kvitems_pipeline(backend, prefix, map_type, config) |
| ) |
| return kvitems_async |
