/
_multipart.py
205 lines (165 loc) · 6.48 KB
/
_multipart.py
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import binascii
import os
import typing
from pathlib import Path
from ._transports.base import AsyncByteStream, SyncByteStream
from ._types import FileContent, FileTypes, RequestFiles
from ._utils import (
format_form_param,
guess_content_type,
peek_filelike_length,
primitive_value_to_str,
to_bytes,
)
class DataField:
"""
A single form field item, within a multipart form field.
"""
def __init__(
self, name: str, value: typing.Union[str, bytes, int, float, None]
) -> None:
if not isinstance(name, str):
raise TypeError(
f"Invalid type for name. Expected str, got {type(name)}: {name!r}"
)
if value is not None and not isinstance(value, (str, bytes, int, float)):
raise TypeError(
f"Invalid type for value. Expected primitive type, got {type(value)}: {value!r}"
)
self.name = name
self.value: typing.Union[str, bytes] = (
value if isinstance(value, bytes) else primitive_value_to_str(value)
)
def render_headers(self) -> bytes:
if not hasattr(self, "_headers"):
name = format_form_param("name", self.name)
self._headers = b"".join(
[b"Content-Disposition: form-data; ", name, b"\r\n\r\n"]
)
return self._headers
def render_data(self) -> bytes:
if not hasattr(self, "_data"):
self._data = to_bytes(self.value)
return self._data
def get_length(self) -> int:
headers = self.render_headers()
data = self.render_data()
return len(headers) + len(data)
def render(self) -> typing.Iterator[bytes]:
yield self.render_headers()
yield self.render_data()
class FileField:
"""
A single file field item, within a multipart form field.
"""
def __init__(self, name: str, value: FileTypes) -> None:
self.name = name
fileobj: FileContent
if isinstance(value, tuple):
try:
filename, fileobj, content_type = value # type: ignore
except ValueError:
filename, fileobj = value # type: ignore
content_type = guess_content_type(filename)
else:
filename = Path(str(getattr(value, "name", "upload"))).name
fileobj = value
content_type = guess_content_type(filename)
self.filename = filename
self.file = fileobj
self.content_type = content_type
self._consumed = False
def get_length(self) -> int:
headers = self.render_headers()
if isinstance(self.file, (str, bytes)):
return len(headers) + len(to_bytes(self.file))
# Let's do our best not to read `file` into memory.
file_length = peek_filelike_length(self.file)
if file_length is None:
# As a last resort, read file and cache contents for later.
assert not hasattr(self, "_data")
self._data = to_bytes(self.file.read())
file_length = len(self._data)
return len(headers) + file_length
def render_headers(self) -> bytes:
if not hasattr(self, "_headers"):
parts = [
b"Content-Disposition: form-data; ",
format_form_param("name", self.name),
]
if self.filename:
filename = format_form_param("filename", self.filename)
parts.extend([b"; ", filename])
if self.content_type is not None:
content_type = self.content_type.encode()
parts.extend([b"\r\nContent-Type: ", content_type])
parts.append(b"\r\n\r\n")
self._headers = b"".join(parts)
return self._headers
def render_data(self) -> typing.Iterator[bytes]:
if isinstance(self.file, (str, bytes)):
yield to_bytes(self.file)
return
if hasattr(self, "_data"):
# Already rendered.
yield self._data
return
if self._consumed: # pragma: nocover
self.file.seek(0)
self._consumed = True
for chunk in self.file:
yield to_bytes(chunk)
def render(self) -> typing.Iterator[bytes]:
yield self.render_headers()
yield from self.render_data()
class MultipartStream(SyncByteStream, AsyncByteStream):
"""
Request content as streaming multipart encoded form data.
"""
def __init__(self, data: dict, files: RequestFiles, boundary: bytes = None) -> None:
if boundary is None:
boundary = binascii.hexlify(os.urandom(16))
self.boundary = boundary
self.content_type = "multipart/form-data; boundary=%s" % boundary.decode(
"ascii"
)
self.fields = list(self._iter_fields(data, files))
def _iter_fields(
self, data: dict, files: RequestFiles
) -> typing.Iterator[typing.Union[FileField, DataField]]:
for name, value in data.items():
if isinstance(value, list):
for item in value:
yield DataField(name=name, value=item)
else:
yield DataField(name=name, value=value)
file_items = files.items() if isinstance(files, typing.Mapping) else files
for name, value in file_items:
yield FileField(name=name, value=value)
def iter_chunks(self) -> typing.Iterator[bytes]:
for field in self.fields:
yield b"--%s\r\n" % self.boundary
yield from field.render()
yield b"\r\n"
yield b"--%s--\r\n" % self.boundary
def iter_chunks_lengths(self) -> typing.Iterator[int]:
boundary_length = len(self.boundary)
# Follow closely what `.iter_chunks()` does.
for field in self.fields:
yield 2 + boundary_length + 2
yield field.get_length()
yield 2
yield 2 + boundary_length + 4
def get_content_length(self) -> int:
return sum(self.iter_chunks_lengths())
# Content stream interface.
def get_headers(self) -> typing.Dict[str, str]:
content_length = str(self.get_content_length())
content_type = self.content_type
return {"Content-Length": content_length, "Content-Type": content_type}
def __iter__(self) -> typing.Iterator[bytes]:
for chunk in self.iter_chunks():
yield chunk
async def __aiter__(self) -> typing.AsyncIterator[bytes]:
for chunk in self.iter_chunks():
yield chunk