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authorIan Bicking <ianb@colorstudy.com>2010-03-31 12:52:33 -0500
committerIan Bicking <ianb@colorstudy.com>2010-03-31 12:52:33 -0500
commitf57891686d88b9754017fe2aaf462e2549323b77 (patch)
tree0bea06e7937aa3d805df7c065354d7cf55d40fef /paste/util
parent40761dc8b9b71ba2788a4caa7a696709748eb2f5 (diff)
downloadpaste-f57891686d88b9754017fe2aaf462e2549323b77.tar.gz
update mimeparse
Diffstat (limited to 'paste/util')
-rw-r--r--paste/util/mimeparse.py136
1 files changed, 39 insertions, 97 deletions
diff --git a/paste/util/mimeparse.py b/paste/util/mimeparse.py
index 2523da1..0fd91e7 100644
--- a/paste/util/mimeparse.py
+++ b/paste/util/mimeparse.py
@@ -2,26 +2,25 @@
This module provides basic functions for handling mime-types. It can handle
matching mime-types against a list of media-ranges. See section 14.1 of
-the HTTP specification [RFC 2616] for a complete explaination.
+the HTTP specification [RFC 2616] for a complete explanation.
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1
Contents:
- - parse_mime_type(): Parses a mime-type into it's component parts.
+ - parse_mime_type(): Parses a mime-type into its component parts.
- parse_media_range(): Media-ranges are mime-types with wild-cards and a 'q' quality parameter.
- quality(): Determines the quality ('q') of a mime-type when compared against a list of media-ranges.
- quality_parsed(): Just like quality() except the second parameter must be pre-parsed.
- best_match(): Choose the mime-type with the highest quality ('q') from a list of candidates.
- - desired_matches(): Provide a list in order of server-desired priorities from a list of candidates.
"""
-__version__ = "0.1.1"
+__version__ = "0.1.2"
__author__ = 'Joe Gregorio'
__email__ = "joe@bitworking.org"
__credits__ = ""
def parse_mime_type(mime_type):
- """Carves up a mime_type and returns a tuple of the
+ """Carves up a mime-type and returns a tuple of the
(type, subtype, params) where 'params' is a dictionary
of all the parameters for the media range.
For example, the media range 'application/xhtml;q=0.5' would
@@ -32,21 +31,21 @@ def parse_mime_type(mime_type):
parts = mime_type.split(";")
params = dict([tuple([s.strip() for s in param.split("=")])\
for param in parts[1:] ])
- try:
- (type, subtype) = parts[0].split("/")
- except ValueError:
- type, subtype = parts[0], '*'
+ full_type = parts[0].strip()
+ # Java URLConnection class sends an Accept header that includes a single "*"
+ # Turn it into a legal wildcard.
+ if full_type == '*': full_type = '*/*'
+ (type, subtype) = full_type.split("/")
return (type.strip(), subtype.strip(), params)
def parse_media_range(range):
"""Carves up a media range and returns a tuple of the
(type, subtype, params) where 'params' is a dictionary
of all the parameters for the media range.
-
- For example, the media range ``application/*;q=0.5`` would
- get parsed into::
+ For example, the media range 'application/*;q=0.5' would
+ get parsed into:
- ('application', '*', {'q', '0.5'})
+ ('application', '*', {'q', '0.5'})
In addition this function also guarantees that there
is a value for 'q' in the params dictionary, filling it
@@ -59,25 +58,24 @@ def parse_media_range(range):
params['q'] = '1'
return (type, subtype, params)
-def quality_parsed(mime_type, parsed_ranges):
- """Find the best match for a given mime_type against
+def fitness_and_quality_parsed(mime_type, parsed_ranges):
+ """Find the best match for a given mime-type against
a list of media_ranges that have already been
- parsed by parse_media_range(). Returns the
- 'q' quality parameter of the best match, 0 if no
- match was found. This function bahaves the same as quality()
- except that 'parsed_ranges' must be a list of
- parsed media ranges. """
+ parsed by parse_media_range(). Returns a tuple of
+ the fitness value and the value of the 'q' quality
+ parameter of the best match, or (-1, 0) if no match
+ was found. Just as for quality_parsed(), 'parsed_ranges'
+ must be a list of parsed media ranges. """
best_fitness = -1
- best_match = ""
best_fit_q = 0
(target_type, target_subtype, target_params) =\
parse_media_range(mime_type)
for (type, subtype, params) in parsed_ranges:
- param_matches = sum([1 for (key, value) in \
- target_params.iteritems() if key != 'q' and \
- params.has_key(key) and value == params[key]])
- if (type == target_type or type == '*') and \
- (subtype == target_subtype or subtype == "*"):
+ if (type == target_type or type == '*' or target_type == '*') and \
+ (subtype == target_subtype or subtype == '*' or target_subtype == '*'):
+ param_matches = reduce(lambda x, y: x+y, [1 for (key, value) in \
+ target_params.iteritems() if key != 'q' and \
+ params.has_key(key) and value == params[key]], 0)
fitness = (type == target_type) and 100 or 0
fitness += (subtype == target_subtype) and 10 or 0
fitness += param_matches
@@ -85,10 +83,20 @@ def quality_parsed(mime_type, parsed_ranges):
best_fitness = fitness
best_fit_q = params['q']
- return float(best_fit_q)
-
+ return best_fitness, float(best_fit_q)
+
+def quality_parsed(mime_type, parsed_ranges):
+ """Find the best match for a given mime-type against
+ a list of media_ranges that have already been
+ parsed by parse_media_range(). Returns the
+ 'q' quality parameter of the best match, 0 if no
+ match was found. This function bahaves the same as quality()
+ except that 'parsed_ranges' must be a list of
+ parsed media ranges. """
+ return fitness_and_quality_parsed(mime_type, parsed_ranges)[1]
+
def quality(mime_type, ranges):
- """Returns the quality 'q' of a mime_type when compared
+ """Returns the quality 'q' of a mime-type when compared
against the media-ranges in ranges. For example:
>>> quality('text/html','text/*;q=0.3, text/html;q=0.7, text/html;level=1, text/html;level=2;q=0.4, */*;q=0.5')
@@ -109,73 +117,7 @@ def best_match(supported, header):
'text/xml'
"""
parsed_header = [parse_media_range(r) for r in header.split(",")]
- weighted_matches = [(quality_parsed(mime_type, parsed_header), mime_type)\
+ weighted_matches = [(fitness_and_quality_parsed(mime_type, parsed_header), mime_type)\
for mime_type in supported]
weighted_matches.sort()
- return weighted_matches[-1][0] and weighted_matches[-1][1] or ''
-
-def desired_matches(desired, header):
- """Takes a list of desired mime-types in the order the server prefers to
- send them regardless of the browsers preference.
-
- Browsers (such as Firefox) technically want XML over HTML depending on how
- one reads the specification. This function is provided for a server to
- declare a set of desired mime-types it supports, and returns a subset of
- the desired list in the same order should each one be Accepted by the
- browser.
-
- >>> sorted_match(['text/html', 'application/xml'], \
- ... 'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png')
- ['text/html', 'application/xml']
- >>> sorted_match(['text/html', 'application/xml'], 'application/xml,application/json')
- ['application/xml']
- """
- matches = []
- parsed_ranges = [parse_media_range(r) for r in header.split(",")]
- for mimetype in desired:
- if quality_parsed(mimetype, parsed_ranges):
- matches.append(mimetype)
- return matches
-
-if __name__ == "__main__":
- import unittest
-
- class TestMimeParsing(unittest.TestCase):
-
- def test_parse_media_range(self):
- self.assert_(('application', 'xml', {'q': '1'}) == parse_media_range('application/xml;q=1'))
- self.assertEqual(('application', 'xml', {'q': '1'}), parse_media_range('application/xml'))
- self.assertEqual(('application', 'xml', {'q': '1'}), parse_media_range('application/xml;q='))
- self.assertEqual(('application', 'xml', {'q': '1'}), parse_media_range('application/xml ; q='))
- self.assertEqual(('application', 'xml', {'q': '1', 'b': 'other'}), parse_media_range('application/xml ; q=1;b=other'))
- self.assertEqual(('application', 'xml', {'q': '1', 'b': 'other'}), parse_media_range('application/xml ; q=2;b=other'))
-
- def test_rfc_2616_example(self):
- accept = "text/*;q=0.3, text/html;q=0.7, text/html;level=1, text/html;level=2;q=0.4, */*;q=0.5"
- self.assertEqual(1, quality("text/html;level=1", accept))
- self.assertEqual(0.7, quality("text/html", accept))
- self.assertEqual(0.3, quality("text/plain", accept))
- self.assertEqual(0.5, quality("image/jpeg", accept))
- self.assertEqual(0.4, quality("text/html;level=2", accept))
- self.assertEqual(0.7, quality("text/html;level=3", accept))
-
- def test_best_match(self):
- mime_types_supported = ['application/xbel+xml', 'application/xml']
- # direct match
- self.assertEqual(best_match(mime_types_supported, 'application/xbel+xml'), 'application/xbel+xml')
- # direct match with a q parameter
- self.assertEqual(best_match(mime_types_supported, 'application/xbel+xml; q=1'), 'application/xbel+xml')
- # direct match of our second choice with a q parameter
- self.assertEqual(best_match(mime_types_supported, 'application/xml; q=1'), 'application/xml')
- # match using a subtype wildcard
- self.assertEqual(best_match(mime_types_supported, 'application/*; q=1'), 'application/xml')
- # match using a type wildcard
- self.assertEqual(best_match(mime_types_supported, '*/*'), 'application/xml')
-
- mime_types_supported = ['application/xbel+xml', 'text/xml']
- # match using a type versus a lower weighted subtype
- self.assertEqual(best_match(mime_types_supported, 'text/*;q=0.5,*/*; q=0.1'), 'text/xml')
- # fail to match anything
- self.assertEqual(best_match(mime_types_supported, 'text/html,application/atom+xml; q=0.9'), '')
-
- unittest.main()
+ return weighted_matches[-1][0][1] and weighted_matches[-1][1] or ''