dosage/dosagelib/util.py
2012-12-08 21:30:23 +01:00

388 lines
12 KiB
Python

# -*- coding: iso-8859-1 -*-
# Copyright (C) 2004-2005 Tristan Seligmann and Jonathan Jacobs
# Copyright (C) 2012 Bastian Kleineidam
from __future__ import division, print_function
import urllib, urllib2, urlparse
import requests
import sys
import os
import cgi
import re
import traceback
import time
from htmlentitydefs import name2codepoint
from .output import out
from .configuration import UserAgent, AppName, App, SupportUrl
from .fileutil import has_module, is_tty
if os.name == 'nt':
from . import colorama
has_curses = has_module("curses")
# Maximum content size for HTML pages
MaxContentBytes = 1024 * 1024 * 2 # 2 MB
# Maximum content size for images
MaxImageBytes = 1024 * 1024 * 20 # 20 MB
# Default connection timeout
ConnectionTimeoutSecs = 60
def tagre(tag, attribute, value, quote='"', before="", after=""):
"""Return a regular expression matching the given HTML tag, attribute
and value. It matches the tag and attribute names case insensitive,
and skips arbitrary whitespace and leading HTML attributes. The "<>" at
the start and end of the HTML tag is also matched.
@param tag: the tag name
@ptype tag: string
@param attribute: the attribute name
@ptype attribute: string
@param value: the attribute value
@ptype value: string
@param quote: the attribute quote (default ")
@ptype quote: string
@param after: match after attribute value but before end
@ptype after: string
@return: the generated regular expression suitable for re.compile()
@rtype: string
"""
if before:
prefix = r"[^>]*%s[^>]*\s+" % before
else:
prefix = r"(?:[^>]*\s+)?"
attrs = dict(
tag=case_insensitive_re(tag),
attribute=case_insensitive_re(attribute),
value=value,
quote=quote,
prefix=prefix,
after=after,
)
return r'<\s*%(tag)s\s+%(prefix)s%(attribute)s\s*=\s*%(quote)s%(value)s%(quote)s[^>]*%(after)s[^>]*>' % attrs
def case_insensitive_re(name):
"""Reformat the given name to a case insensitive regular expression string
without using re.IGNORECASE. This way selective strings can be made case
insensitive.
@param name: the name to make case insensitive
@ptype name: string
@return: the case insenstive regex
@rtype: string
"""
return "".join("[%s%s]" % (c.lower(), c.upper()) for c in name)
baseSearch = re.compile(tagre("base", "href", '([^"]*)'))
def getPageContent(url, max_content_bytes=MaxContentBytes, cookies=None):
# read page data
page = urlopen(url, max_content_bytes=max_content_bytes,
cookies=cookies)
data = page.text
# determine base URL
baseUrl = None
match = baseSearch.search(data)
if match:
baseUrl = match.group(1)
else:
baseUrl = url
return data, baseUrl
def getImageObject(url, referrer, max_content_bytes=MaxImageBytes):
"""Get response object for given image URL."""
return urlopen(url, referrer=referrer, max_content_bytes=max_content_bytes)
def fetchUrl(url, urlSearch, cookies=None):
data, baseUrl = getPageContent(url, cookies=cookies)
match = urlSearch.search(data)
if match:
searchUrl = match.group(1)
if not searchUrl:
raise ValueError("Match empty URL at %s with pattern %s" % (url, urlSearch.pattern))
out.debug('matched URL %r' % searchUrl)
return normaliseURL(urlparse.urljoin(baseUrl, searchUrl))
return None
def fetchUrls(url, imageSearch, prevSearch=None, cookies=None):
data, baseUrl = getPageContent(url, cookies=cookies)
# match images
imageUrls = set()
for match in imageSearch.finditer(data):
imageUrl = match.group(1)
if not imageUrl:
raise ValueError("Match empty image URL at %s with pattern %s" % (url, imageSearch.pattern))
out.debug('matched image URL %r with pattern %s' % (imageUrl, imageSearch.pattern))
imageUrls.add(normaliseURL(urlparse.urljoin(baseUrl, imageUrl)))
if not imageUrls:
out.warn("no images found at %s with pattern %s" % (url, imageSearch.pattern))
if prevSearch is not None:
# match previous URL
match = prevSearch.search(data)
if match:
prevUrl = match.group(1)
if not prevUrl:
raise ValueError("Match empty previous URL at %s with pattern %s" % (url, prevSearch.pattern))
prevUrl = normaliseURL(urlparse.urljoin(baseUrl, prevUrl))
else:
out.debug('no previous URL %s at %s' % (prevSearch.pattern, url))
prevUrl = None
return imageUrls, prevUrl
return imageUrls, None
def unescape(text):
"""
Replace HTML entities and character references.
"""
def _fixup(m):
text = m.group(0)
if text[:2] == "&#":
# character reference
try:
if text[:3] == "&#x":
text = unichr(int(text[3:-1], 16))
else:
text = unichr(int(text[2:-1]))
except ValueError:
pass
else:
# named entity
try:
text = unichr(name2codepoint[text[1:-1]])
except KeyError:
pass
if isinstance(text, unicode):
text = text.encode('utf-8')
text = urllib2.quote(text, safe=';/?:@&=+$,')
return text
return re.sub(r"&#?\w+;", _fixup, text)
def normaliseURL(url):
"""
Removes any leading empty segments to avoid breaking urllib2; also replaces
HTML entities and character references.
"""
# XXX: brutal hack
url = unescape(url)
pu = list(urlparse.urlparse(url))
segments = pu[2].split('/')
while segments and segments[0] in ('', '..'):
del segments[0]
pu[2] = '/' + '/'.join(segments).replace(' ', '%20')
# remove leading '&' from query
if pu[4].startswith('&'):
pu[4] = pu[4][1:]
# remove anchor
pu[5] = ""
return urlparse.urlunparse(pu)
def urlopen(url, referrer=None, retries=3, retry_wait_seconds=5, max_content_bytes=None,
timeout=ConnectionTimeoutSecs, cookies=None):
out.debug('Open URL %s' % url)
assert retries >= 0, 'invalid retry value %r' % retries
assert retry_wait_seconds > 0, 'invalid retry seconds value %r' % retry_wait_seconds
headers = {'User-Agent': UserAgent}
config = {"max_retries": retries}
if referrer:
headers['Referer'] = referrer
if not cookies:
cookies = {}
try:
req = requests.get(url, headers=headers, config=config,
prefetch=False, timeout=timeout, cookies=cookies)
check_content_size(url, req.headers, max_content_bytes)
req.raise_for_status()
return req
except requests.exceptions.RequestException as err:
msg = 'URL retrieval of %s failed: %s' % (url, err)
raise IOError(msg)
def check_content_size(url, headers, max_content_bytes):
if not max_content_bytes:
return
if 'content-length' in headers:
size = int(headers['content-length'])
if size > max_content_bytes:
msg = 'URL content of %s with %d Bytes exceeds %d Bytes.' % (url, size, max_content_bytes)
raise IOError(msg)
def get_columns (fp):
"""Return number of columns for given file."""
if not is_tty(fp):
return 80
if os.name == 'nt':
return colorama.get_console_size().X
if has_curses:
import curses
try:
curses.setupterm(os.environ.get("TERM"), fp.fileno())
return curses.tigetnum("cols")
except curses.error:
pass
return 80
def splitpath(path):
c = []
head, tail = os.path.split(path)
while tail:
c.insert(0, tail)
head, tail = os.path.split(head)
return c
def getRelativePath(basepath, path):
basepath = splitpath(os.path.abspath(basepath))
path = splitpath(os.path.abspath(path))
afterCommon = False
for c in basepath:
if afterCommon or path[0] != c:
path.insert(0, os.path.pardir)
afterCommon = True
else:
del path[0]
return os.path.join(*path)
def getQueryParams(url):
query = urlparse.urlsplit(url)[3]
out.debug('Extracting query parameters from %r (%r)...' % (url, query))
return cgi.parse_qs(query)
def internal_error(out=sys.stderr, etype=None, evalue=None, tb=None):
"""Print internal error message (output defaults to stderr)."""
print(os.linesep, file=out)
print("""********** Oops, I did it again. *************
You have found an internal error in %(app)s. Please write a bug report
at %(url)s and include at least the information below:
Not disclosing some of the information below due to privacy reasons is ok.
I will try to help you nonetheless, but you have to give me something
I can work with ;) .
""" % dict(app=AppName, url=SupportUrl), file=out)
if etype is None:
etype = sys.exc_info()[0]
if evalue is None:
evalue = sys.exc_info()[1]
print(etype, evalue, file=out)
if tb is None:
tb = sys.exc_info()[2]
traceback.print_exception(etype, evalue, tb, None, out)
print_app_info(out=out)
print_proxy_info(out=out)
print_locale_info(out=out)
print(os.linesep,
"******** %s internal error, over and out ********" % AppName, file=out)
def print_env_info(key, out=sys.stderr):
"""If given environment key is defined, print it out."""
value = os.getenv(key)
if value is not None:
print(key, "=", repr(value), file=out)
def print_proxy_info(out=sys.stderr):
"""Print proxy info."""
print_env_info("http_proxy", out=out)
def print_locale_info(out=sys.stderr):
"""Print locale info."""
for key in ("LANGUAGE", "LC_ALL", "LC_CTYPE", "LANG"):
print_env_info(key, out=out)
def print_app_info(out=sys.stderr):
"""Print system and application info (output defaults to stderr)."""
print("System info:", file=out)
print(App, file=out)
print("Python %(version)s on %(platform)s" %
{"version": sys.version, "platform": sys.platform}, file=out)
stime = strtime(time.time())
print("Local time:", stime, file=out)
print("sys.argv", sys.argv, file=out)
def strtime(t):
"""Return ISO 8601 formatted time."""
return time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(t)) + \
strtimezone()
def strtimezone():
"""Return timezone info, %z on some platforms, but not supported on all.
"""
if time.daylight:
zone = time.altzone
else:
zone = time.timezone
return "%+04d" % (-zone//3600)
def asciify(name):
"""Remove non-ascii characters from string."""
return re.sub("[^0-9a-zA-Z_]", "", name)
def unquote(text):
while '%' in text:
newtext = urllib.unquote(text)
if newtext == text:
break
text = newtext
return text
def quote(text):
return urllib.quote(text)
def strsize (b):
"""Return human representation of bytes b. A negative number of bytes
raises a value error."""
if b < 0:
raise ValueError("Invalid negative byte number")
if b < 1024:
return "%dB" % b
if b < 1024 * 10:
return "%dKB" % (b // 1024)
if b < 1024 * 1024:
return "%.2fKB" % (float(b) / 1024)
if b < 1024 * 1024 * 10:
return "%.2fMB" % (float(b) / (1024*1024))
if b < 1024 * 1024 * 1024:
return "%.1fMB" % (float(b) / (1024*1024))
if b < 1024 * 1024 * 1024 * 10:
return "%.2fGB" % (float(b) / (1024*1024*1024))
return "%.1fGB" % (float(b) / (1024*1024*1024))
def getDirname(name):
"""Replace slashes with path separator of name."""
return name.replace('/', os.sep)
def getFilename(name):
# first replace all illegal chars
name = re.sub(r"[^0-9a-zA-Z_\-\.]", "_", name)
# then remove double dots and underscores
while ".." in name:
name = name.replace('..', '.')
while "__" in name:
name = name.replace('__', '_')
# remove a leading dot or minus
if name.startswith((".", "-")):
name = name[1:]
return name