def decompress(self, body):
buf = IO()
for chunk in body:
buf.write(chunk)
buf.seek(0)
gzfile = GzipFile(mode='rb', fileobj=buf)
data = gzfile.read()
gzfile.close()
del buf
del gzfile
return data
def __call__(self, request, status, headers, body):
"""Compress, if able, the response.
This has the side effect that if your application does not declare a content-length, this filter will.
"""
# TODO: Remove some of this debug logging; it'll slow things down and isn't really needed.
if request.get('wsgi.compression', True) is False:
log.debug("Bypassing compression at application's request.")
return status, headers, body
if request.get('wsgi.async') and hasattr(body, '__call__'):
log.debug("Can not compress async responses, returning original response.")
return status, headers, body
if b'gzip' not in request.get('HTTP_ACCEPT_ENCODING', b''):
log.debug("Browser support for GZip encoding not found, returning original response.")
return status, headers, body
def find(header):
"""Determine the value and index into headers for the given header, or None if not found."""
for i, (name, value) in enumerate(headers):
if name.lower() == header:
return value, i
return None, None
if find(b'content-encoding')[0]:
log.debug("Content encoding already defined, returning original response.")
return status, headers, body
ctype, ctypeidx = find(b'content-type')
if not ctype or not ctype.startswith((b'text/', b'application/')) or b'zip' in ctype:
log.debug("Encountered uncompressable Content-Type (%s), returning original response.", ctype)
return status, headers, body
clength, clengthidx = find(b'content-length')
headers.append((b"Content-Encoding", b'gzip'))
# We have to read the entire body into a buffer before we can compress it.
# This is because we need to determine the final Content-Length.
# TODO: If the Content-Length is > 4MiB, we should use a tmpfile on-disk instead!
buf = IO()
compressed = GzipFile(mode='wb', compresslevel=self.level, fileobj=buf)
for chunk in body:
compressed.write(chunk)
compressed.close()
del compressed
length = buf.tell()
buf.seek(0)
if clength:
clength = int(clength)
log.debug("Content-Length: %d - Compressed: %d - Savings: %d (%d%%)", clength, length, clength - length, length * 100 // clength)
if length > int(clength):
log.warn("Compression increased size of response!")
length = (b'Content-Length', unicode(length).encode('ascii'))
if clength: headers[clengthidx] = length
else: headers.append(length)
return status, headers, iter(partial(buf.read, 4096), b'')
def render(self, encoding='ascii'):
indentation = 0
text = False
stack = []
buf = IO()
for k, t in self:
if k == 'enter':
indent = getattr(t, 'indent', True)
stack.append(t)
if t.strip: continue
if text and indent:
buf.write('\n')
if indent:
buf.write(' ' * indentation)
for element in t.enter():
buf.write(element.encode(encoding))
if indent:
buf.write('\n')
indentation += 1
text = False
continue
if k == 'exit':
indent = getattr(t, 'indent', True)
stack.pop()
if t.strip: continue
if indent:
indentation -= 1
if not t.simple:
if text and indent: buf.write('\n')
if indent: buf.write(' ' * indentation)
for element in t.exit():
buf.write(element.encode(encoding))
if not t.simple or t.children: buf.write('\n')
text = False
continue
if k == 'text':
indent = getattr(stack[-1], 'indent', True)
if not text and indent:
buf.write(' ' * indentation)
t = t.encode(encoding)
buf.write(t.replace('\n', '\n' + ' ' * indentation) if indent else t)
text = True
if k == 'flush':
yield buf.getvalue()
del buf
buf = IO()
yield buf.getvalue()