##// END OF EJS Templates
util: compression APIs to support revlog compression...
util: compression APIs to support revlog compression As part of "zstd all of the things," we need to teach revlogs to use non-zlib compression formats. Because we're routing all compression via the "compression manager" and "compression engine" APIs, we need to introduction functionality there for performing revlog operations. Ideally, revlog compression and decompression operations would be implemented in terms of simple "compress" and "decompress" primitives. However, there are a few considerations that make us want to have a specialized primitive for handling revlogs: 1) Performance. Revlogs tend to do compression and especially decompression operations in batches. Any overhead for e.g. instantiating a "context" for performing an operation can be noticed. For this reason, our "revlog compressor" primitive is reusable. For zstd, we reuse the same compression "context" for multiple operations. I've measured this to have a performance impact versus constructing new contexts for each operation. 2) Specialization. By having a primitive dedicated to revlog use, we can make revlog-specific choices and leave the door open for more functionality in the future. For example, the zstd revlog compressor may one day make use of dictionary compression. A future patch will introduce a decompress() on the compressor object. The code for the zlib compressor is basically copied from revlog.compress(). Although it doesn't handle the empty input case, the null first byte case, and the 'u' prefix case. These cases will continue to be handled in revlog.py once that code is ported to use this API.

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wsgicgi.py
90 lines | 2.8 KiB | text/x-python | PythonLexer
# hgweb/wsgicgi.py - CGI->WSGI translator
#
# Copyright 2006 Eric Hopper <hopper@omnifarious.org>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
#
# This was originally copied from the public domain code at
# http://www.python.org/dev/peps/pep-0333/#the-server-gateway-side
from __future__ import absolute_import
from .. import (
encoding,
util,
)
from . import (
common,
)
def launch(application):
util.setbinary(util.stdin)
util.setbinary(util.stdout)
environ = dict(encoding.environ.iteritems())
environ.setdefault('PATH_INFO', '')
if environ.get('SERVER_SOFTWARE', '').startswith('Microsoft-IIS'):
# IIS includes script_name in PATH_INFO
scriptname = environ['SCRIPT_NAME']
if environ['PATH_INFO'].startswith(scriptname):
environ['PATH_INFO'] = environ['PATH_INFO'][len(scriptname):]
stdin = util.stdin
if environ.get('HTTP_EXPECT', '').lower() == '100-continue':
stdin = common.continuereader(stdin, util.stdout.write)
environ['wsgi.input'] = stdin
environ['wsgi.errors'] = util.stderr
environ['wsgi.version'] = (1, 0)
environ['wsgi.multithread'] = False
environ['wsgi.multiprocess'] = True
environ['wsgi.run_once'] = True
if environ.get('HTTPS', 'off').lower() in ('on', '1', 'yes'):
environ['wsgi.url_scheme'] = 'https'
else:
environ['wsgi.url_scheme'] = 'http'
headers_set = []
headers_sent = []
out = util.stdout
def write(data):
if not headers_set:
raise AssertionError("write() before start_response()")
elif not headers_sent:
# Before the first output, send the stored headers
status, response_headers = headers_sent[:] = headers_set
out.write('Status: %s\r\n' % status)
for header in response_headers:
out.write('%s: %s\r\n' % header)
out.write('\r\n')
out.write(data)
out.flush()
def start_response(status, response_headers, exc_info=None):
if exc_info:
try:
if headers_sent:
# Re-raise original exception if headers sent
raise exc_info[0](exc_info[1], exc_info[2])
finally:
exc_info = None # avoid dangling circular ref
elif headers_set:
raise AssertionError("Headers already set!")
headers_set[:] = [status, response_headers]
return write
content = application(environ, start_response)
try:
for chunk in content:
write(chunk)
if not headers_sent:
write('') # send headers now if body was empty
finally:
getattr(content, 'close', lambda : None)()