Add support for gzip, deflate, and brotli decoding

httpcore/compat.py

@@ -0,0 +1,4 @@
+try:
+    import brotli
+except ImportError:
+    brotli = None

httpcore/datastructures.py

@@ -1,7 +1,7 @@
 import typing
 from urllib.parse import urlsplit
 
-from .decoders import IdentityDecoder
+from .decoders import SUPPORTED_DECODERS, Decoder, IdentityDecoder, MultiDecoder
 from .exceptions import ResponseClosed, StreamConsumed
 
 
@@ -95,10 +95,25 @@ class Response:
         self.on_close = on_close
         self.is_closed = False
         self.is_streamed = False
-        self.decoder = IdentityDecoder()
+
+        decoders = []  # type: typing.List[Decoder]
+        for header, value in self.headers:
+            if header.strip().lower() == b"content-encoding":
+                for part in value.split(b","):
+                    part = part.strip().lower()
+                    decoder_cls = SUPPORTED_DECODERS[part]
+                    decoders.append(decoder_cls())
+
+        if len(decoders) == 0:
+            self.decoder = IdentityDecoder()  # type: Decoder
+        elif len(decoders) == 1:
+            self.decoder = decoders[0]
+        else:
+            self.decoder = MultiDecoder(decoders)
+
         if isinstance(body, bytes):
             self.is_closed = True
-            self.body = body
+            self.body = self.decoder.decode(body) + self.decoder.flush()
         else:
             self.body_aiter = body
 

httpcore/decoders.py

@@ -1,41 +1,118 @@
 """
 Handlers for Content-Encoding.
+
+See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding
 """
+import typing
+import zlib
+
+from .compat import brotli
 
 
-class IdentityDecoder:
-    def decode(self, chunk: bytes) -> bytes:
-        return chunk
+class Decoder:
+    def decode(self, data: bytes) -> bytes:
+        raise NotImplementedError()  # pragma: nocover
+
+    def flush(self) -> bytes:
+        raise NotImplementedError()  # pragma: nocover
+
+
+class IdentityDecoder(Decoder):
+    def decode(self, data: bytes) -> bytes:
+        return data
 
     def flush(self) -> bytes:
         return b""
 
 
-# class DeflateDecoder:
-#     pass
-#
-#
-# class GZipDecoder:
-#     pass
-#
-#
-# class BrotliDecoder:
-#     pass
-#
-#
-# class MultiDecoder:
-#     def __init__(self, children):
-#         self.children = children
-#
-#     def decode(self, chunk: bytes) -> bytes:
-#         data = chunk
-#         for child in children:
-#             data = child.decode(data)
-#         return data
-#
-#     def flush(self) -> bytes:
-#         data = b''
-#         for child in children:
-#             data = child.decode(data)
-#             data = child.flush()
-#         return data
+class DeflateDecoder(Decoder):
+    """
+    Handle 'deflate' decoding.
+
+    See: https://stackoverflow.com/questions/1838699
+    """
+
+    def __init__(self) -> None:
+        self.decompressor = zlib.decompressobj(-zlib.MAX_WBITS)
+
+    def decode(self, data: bytes) -> bytes:
+        return self.decompressor.decompress(data)
+
+    def flush(self) -> bytes:
+        return self.decompressor.flush()
+
+
+class GZipDecoder(Decoder):
+    """
+    Handle 'gzip' decoding.
+
+    See: https://stackoverflow.com/questions/1838699
+    """
+
+    def __init__(self) -> None:
+        self.decompressor = zlib.decompressobj(zlib.MAX_WBITS | 16)
+
+    def decode(self, data: bytes) -> bytes:
+        return self.decompressor.decompress(data)
+
+    def flush(self) -> bytes:
+        return self.decompressor.flush()
+
+
+class BrotliDecoder(Decoder):
+    """
+    Handle 'brotli' decoding.
+
+    Requires `pip install brotlipy`.
+    See: https://brotlipy.readthedocs.io/
+    """
+
+    def __init__(self) -> None:
+        assert (
+            brotli is not None
+        ), "The 'brotlipy' library must be installed to use 'BrotliDecoder'"
+        self.decompressor = brotli.Decompressor()
+
+    def decode(self, data: bytes) -> bytes:
+        return self.decompressor.decompress(data)
+
+    def flush(self) -> bytes:
+        self.decompressor.finish()
+        return b""
+
+
+class MultiDecoder(Decoder):
+    """
+    Handle the case where mutliple encodings have been applied.
+    """
+
+    def __init__(self, children: typing.Sequence[Decoder]) -> None:
+        """
+        children should be a sequence of decoders in the order in which
+        each was applied.
+        """
+        # Note that we reverse the order for decoding.
+        self.children = list(reversed(children))
+
+    def decode(self, data: bytes) -> bytes:
+        for child in self.children:
+            data = child.decode(data)
+        return data
+
+    def flush(self) -> bytes:
+        data = b""
+        for child in self.children:
+            data = child.decode(data) + child.flush()
+        return data
+
+
+SUPPORTED_DECODERS = {
+    b"gzip": GZipDecoder,
+    b"deflate": DeflateDecoder,
+    b"identity": IdentityDecoder,
+    b"br": BrotliDecoder,
+}
+
+
+if brotli is None:
+    SUPPORTED_DECODERS.pop(b"br")  # pragma: nocover

requirements.txt

@@ -1,6 +1,10 @@
 certifi
 h11
 
+# Optional
+brotlipy
+
+
 # Testing
 autoflake
 black

tests/test_decoding.py

@@ -0,0 +1,79 @@
+import zlib
+
+import brotli
+import pytest
+
+import httpcore
+
+
+def test_deflate():
+    body = b"test 123"
+    compressor = zlib.compressobj(9, zlib.DEFLATED, -zlib.MAX_WBITS)
+    compressed_body = compressor.compress(body) + compressor.flush()
+
+    headers = [(b"Content-Encoding", b"deflate")]
+    response = httpcore.Response(200, headers=headers, body=compressed_body)
+    assert response.body == body
+
+
+def test_gzip():
+    body = b"test 123"
+    compressor = zlib.compressobj(9, zlib.DEFLATED, zlib.MAX_WBITS | 16)
+    compressed_body = compressor.compress(body) + compressor.flush()
+
+    headers = [(b"Content-Encoding", b"gzip")]
+    response = httpcore.Response(200, headers=headers, body=compressed_body)
+    assert response.body == body
+
+
+def test_brotli():
+    body = b"test 123"
+    compressed_body = brotli.compress(body)
+
+    headers = [(b"Content-Encoding", b"br")]
+    response = httpcore.Response(200, headers=headers, body=compressed_body)
+    assert response.body == body
+
+
+def test_multi():
+    body = b"test 123"
+
+    deflate_compressor = zlib.compressobj(9, zlib.DEFLATED, -zlib.MAX_WBITS)
+    compressed_body = deflate_compressor.compress(body) + deflate_compressor.flush()
+
+    gzip_compressor = zlib.compressobj(9, zlib.DEFLATED, zlib.MAX_WBITS | 16)
+    compressed_body = (
+        gzip_compressor.compress(compressed_body) + gzip_compressor.flush()
+    )
+
+    headers = [(b"Content-Encoding", b"deflate, gzip")]
+    response = httpcore.Response(200, headers=headers, body=compressed_body)
+    assert response.body == body
+
+
+def test_multi_with_identity():
+    body = b"test 123"
+    compressed_body = brotli.compress(body)
+
+    headers = [(b"Content-Encoding", b"br, identity")]
+    response = httpcore.Response(200, headers=headers, body=compressed_body)
+    assert response.body == body
+
+    headers = [(b"Content-Encoding", b"identity, br")]
+    response = httpcore.Response(200, headers=headers, body=compressed_body)
+    assert response.body == body
+
+
+@pytest.mark.asyncio
+async def test_streaming():
+    body = b"test 123"
+    compressor = zlib.compressobj(9, zlib.DEFLATED, zlib.MAX_WBITS | 16)
+
+    async def compress(body):
+        yield compressor.compress(body)
+        yield compressor.flush()
+
+    headers = [(b"Content-Encoding", b"gzip")]
+    response = httpcore.Response(200, headers=headers, body=compress(body))
+    assert not hasattr(response, "body")
+    assert await response.read() == body