Source code for cherrypy.lib

"""CherryPy Library."""


[docs]def is_iterator(obj): """Detect if the object provided implements the iterator protocol. (i.e. like a generator). This will return False for objects which are iterable, but not iterators themselves. """ from types import GeneratorType if isinstance(obj, GeneratorType): return True elif not hasattr(obj, '__iter__'): return False else: # Types which implement the protocol must return themselves when # invoking 'iter' upon them. return iter(obj) is obj
[docs]def is_closable_iterator(obj): """Detect if the given object is both closable and iterator.""" # Not an iterator. if not is_iterator(obj): return False # A generator - the easiest thing to deal with. import inspect if inspect.isgenerator(obj): return True # A custom iterator. Look for a close method... if not (hasattr(obj, 'close') and callable(obj.close)): return False # ... which doesn't require any arguments. try: inspect.getcallargs(obj.close) except TypeError: return False else: return True
[docs]class file_generator(object): """Yield the given input (a file object) in chunks (default 64k). (Core) """ def __init__(self, input, chunkSize=65536): """Initialize file_generator with file ``input`` for chunked access.""" self.input = input self.chunkSize = chunkSize def __iter__(self): """Return iterator.""" return self def __next__(self): """Return next chunk of file.""" chunk = self.input.read(self.chunkSize) if chunk: return chunk else: if hasattr(self.input, 'close'): self.input.close() raise StopIteration() next = __next__
[docs]def file_generator_limited(fileobj, count, chunk_size=65536): """Yield the given file object in chunks. Stopps after `count` bytes has been emitted. Default chunk size is 64kB. (Core) """ remaining = count while remaining > 0: chunk = fileobj.read(min(chunk_size, remaining)) chunklen = len(chunk) if chunklen == 0: return remaining -= chunklen yield chunk
[docs]def set_vary_header(response, header_name): """Add a Vary header to a response.""" varies = response.headers.get('Vary', '') varies = [x.strip() for x in varies.split(',') if x.strip()] if header_name not in varies: varies.append(header_name) response.headers['Vary'] = ', '.join(varies)