Issue #13464: Add a readinto() method to http.client.HTTPResponse.
Patch by Jon Kuhn.
diff --git a/Lib/http/client.py b/Lib/http/client.py
index 88da550..7062569 100644
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -485,11 +485,17 @@
self.close()
return b""
- if self.chunked:
- return self._read_chunked(amt)
+ if amt is not None:
+ # Amount is given, so call base class version
+ # (which is implemented in terms of self.readinto)
+ return super(HTTPResponse, self).read(amt)
+ else:
+ # Amount is not given (unbounded read) so we must check self.length
+ # and self.chunked
- if amt is None:
- # unbounded read
+ if self.chunked:
+ return self._readall_chunked()
+
if self.length is None:
s = self.fp.read()
else:
@@ -498,61 +504,49 @@
self.close() # we read everything
return s
+ def readinto(self, b):
+ if self.fp is None:
+ return 0
+
+ if self._method == "HEAD":
+ self.close()
+ return 0
+
+ if self.chunked:
+ return self._readinto_chunked(b)
+
if self.length is not None:
- if amt > self.length:
+ if len(b) > self.length:
# clip the read to the "end of response"
- amt = self.length
+ b = memoryview(b)[0:self.length]
# we do not use _safe_read() here because this may be a .will_close
# connection, and the user is reading more bytes than will be provided
# (for example, reading in 1k chunks)
- s = self.fp.read(amt)
+ n = self.fp.readinto(b)
if self.length is not None:
- self.length -= len(s)
+ self.length -= n
if not self.length:
self.close()
- return s
+ return n
- def _read_chunked(self, amt):
- assert self.chunked != _UNKNOWN
- chunk_left = self.chunk_left
- value = []
- while True:
- if chunk_left is None:
- line = self.fp.readline(_MAXLINE + 1)
- if len(line) > _MAXLINE:
- raise LineTooLong("chunk size")
- i = line.find(b";")
- if i >= 0:
- line = line[:i] # strip chunk-extensions
- try:
- chunk_left = int(line, 16)
- except ValueError:
- # close the connection as protocol synchronisation is
- # probably lost
- self.close()
- raise IncompleteRead(b''.join(value))
- if chunk_left == 0:
- break
- if amt is None:
- value.append(self._safe_read(chunk_left))
- elif amt < chunk_left:
- value.append(self._safe_read(amt))
- self.chunk_left = chunk_left - amt
- return b''.join(value)
- elif amt == chunk_left:
- value.append(self._safe_read(amt))
- self._safe_read(2) # toss the CRLF at the end of the chunk
- self.chunk_left = None
- return b''.join(value)
- else:
- value.append(self._safe_read(chunk_left))
- amt -= chunk_left
+ def _read_next_chunk_size(self):
+ # Read the next chunk size from the file
+ line = self.fp.readline(_MAXLINE + 1)
+ if len(line) > _MAXLINE:
+ raise LineTooLong("chunk size")
+ i = line.find(b";")
+ if i >= 0:
+ line = line[:i] # strip chunk-extensions
+ try:
+ return int(line, 16)
+ except ValueError:
+ # close the connection as protocol synchronisation is
+ # probably lost
+ self.close()
+ raise
- # we read the whole chunk, get another
- self._safe_read(2) # toss the CRLF at the end of the chunk
- chunk_left = None
-
+ def _read_and_discard_trailer(self):
# read and discard trailer up to the CRLF terminator
### note: we shouldn't have any trailers!
while True:
@@ -566,11 +560,72 @@
if line == b"\r\n":
break
+ def _readall_chunked(self):
+ assert self.chunked != _UNKNOWN
+ chunk_left = self.chunk_left
+ value = []
+ while True:
+ if chunk_left is None:
+ try:
+ chunk_left = self._read_next_chunk_size()
+ if chunk_left == 0:
+ break
+ except ValueError:
+ raise IncompleteRead(b''.join(value))
+ value.append(self._safe_read(chunk_left))
+
+ # we read the whole chunk, get another
+ self._safe_read(2) # toss the CRLF at the end of the chunk
+ chunk_left = None
+
+ self._read_and_discard_trailer()
+
# we read everything; close the "file"
self.close()
return b''.join(value)
+ def _readinto_chunked(self, b):
+ assert self.chunked != _UNKNOWN
+ chunk_left = self.chunk_left
+
+ total_bytes = 0
+ mvb = memoryview(b)
+ while True:
+ if chunk_left is None:
+ try:
+ chunk_left = self._read_next_chunk_size()
+ if chunk_left == 0:
+ break
+ except ValueError:
+ raise IncompleteRead(bytes(b[0:total_bytes]))
+
+ if len(mvb) < chunk_left:
+ n = self._safe_readinto(mvb)
+ self.chunk_left = chunk_left - n
+ return n
+ elif len(mvb) == chunk_left:
+ n = self._safe_readinto(mvb)
+ self._safe_read(2) # toss the CRLF at the end of the chunk
+ self.chunk_left = None
+ return n
+ else:
+ temp_mvb = mvb[0:chunk_left]
+ n = self._safe_readinto(temp_mvb)
+ mvb = mvb[n:]
+ total_bytes += n
+
+ # we read the whole chunk, get another
+ self._safe_read(2) # toss the CRLF at the end of the chunk
+ chunk_left = None
+
+ self._read_and_discard_trailer()
+
+ # we read everything; close the "file"
+ self.close()
+
+ return total_bytes
+
def _safe_read(self, amt):
"""Read the number of bytes requested, compensating for partial reads.
@@ -594,6 +649,22 @@
amt -= len(chunk)
return b"".join(s)
+ def _safe_readinto(self, b):
+ """Same as _safe_read, but for reading into a buffer."""
+ total_bytes = 0
+ mvb = memoryview(b)
+ while total_bytes < len(b):
+ if MAXAMOUNT < len(mvb):
+ temp_mvb = mvb[0:MAXAMOUNT]
+ n = self.fp.readinto(temp_mvb)
+ else:
+ n = self.fp.readinto(mvb)
+ if not n:
+ raise IncompleteRead(bytes(mvb[0:total_bytes]), len(b))
+ mvb = mvb[n:]
+ total_bytes += n
+ return total_bytes
+
def fileno(self):
return self.fp.fileno()