• Language: en

Source code for django.core.files.base

from __future__ import unicode_literals

import os
from io import BytesIO, StringIO, UnsupportedOperation

from django.core.files.utils import FileProxyMixin
from django.utils import six
from django.utils.encoding import (
    force_bytes, force_str, force_text, python_2_unicode_compatible,

[docs]class File(FileProxyMixin): DEFAULT_CHUNK_SIZE = 64 * 2 ** 10 def __init__(self, file, name=None): self.file = file if name is None: name = getattr(file, 'name', None) self.name = name if hasattr(file, 'mode'): self.mode = file.mode def __str__(self): return force_text(self.name or '') def __repr__(self): return force_str("<%s: %s>" % (self.__class__.__name__, self or "None")) def __bool__(self): return bool(self.name) def __nonzero__(self): # Python 2 compatibility return type(self).__bool__(self) def __len__(self): return self.size def _get_size_from_underlying_file(self): if hasattr(self.file, 'size'): return self.file.size if hasattr(self.file, 'name'): try: return os.path.getsize(self.file.name) except (OSError, TypeError): pass if hasattr(self.file, 'tell') and hasattr(self.file, 'seek'): pos = self.file.tell() self.file.seek(0, os.SEEK_END) size = self.file.tell() self.file.seek(pos) return size raise AttributeError("Unable to determine the file's size.") def _get_size(self): if hasattr(self, '_size'): return self._size self._size = self._get_size_from_underlying_file() return self._size def _set_size(self, size): self._size = size size = property(_get_size, _set_size)
[docs] def chunks(self, chunk_size=None): """ Read the file and yield chunks of ``chunk_size`` bytes (defaults to ``UploadedFile.DEFAULT_CHUNK_SIZE``). """ if not chunk_size: chunk_size = self.DEFAULT_CHUNK_SIZE try: self.seek(0) except (AttributeError, UnsupportedOperation): pass while True: data = self.read(chunk_size) if not data: break yield data
[docs] def multiple_chunks(self, chunk_size=None): """ Returns ``True`` if you can expect multiple chunks. NB: If a particular file representation is in memory, subclasses should always return ``False`` -- there's no good reason to read from memory in chunks. """ if not chunk_size: chunk_size = self.DEFAULT_CHUNK_SIZE return self.size > chunk_size
[docs] def __iter__(self): # Iterate over this file-like object by newlines buffer_ = None for chunk in self.chunks(): for line in chunk.splitlines(True): if buffer_: if endswith_cr(buffer_) and not equals_lf(line): # Line split after a \r newline; yield buffer_. yield buffer_ # Continue with line. else: # Line either split without a newline (line # continues after buffer_) or with \r\n # newline (line == b'\n'). line = buffer_ + line # buffer_ handled, clear it. buffer_ = None # If this is the end of a \n or \r\n line, yield. if endswith_lf(line): yield line else: buffer_ = line if buffer_ is not None: yield buffer_
def __enter__(self): return self def __exit__(self, exc_type, exc_value, tb): self.close()
[docs] def open(self, mode=None): if not self.closed: self.seek(0) elif self.name and os.path.exists(self.name): self.file = open(self.name, mode or self.mode) else: raise ValueError("The file cannot be reopened.")
[docs] def close(self): self.file.close()
[docs]class ContentFile(File): """ A File-like object that takes just raw content, rather than an actual file. """ def __init__(self, content, name=None): if six.PY3: stream_class = StringIO if isinstance(content, six.text_type) else BytesIO else: stream_class = BytesIO content = force_bytes(content) super(ContentFile, self).__init__(stream_class(content), name=name) self.size = len(content) def __str__(self): return 'Raw content' def __bool__(self): return True def __nonzero__(self): # Python 2 compatibility return type(self).__bool__(self) def open(self, mode=None): self.seek(0) def close(self): pass
def endswith_cr(line): """ Return True if line (a text or byte string) ends with '\r'. """ return line.endswith('\r' if isinstance(line, six.text_type) else b'\r') def endswith_lf(line): """ Return True if line (a text or byte string) ends with '\n'. """ return line.endswith('\n' if isinstance(line, six.text_type) else b'\n') def equals_lf(line): """ Return True if line (a text or byte string) equals '\n'. """ return line == ('\n' if isinstance(line, six.text_type) else b'\n')
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