Renamed lib.encodings to lib.encoding to avoid shadowing the builtin.

1 files changed, 220 insertions, 0 deletions

diff --git a/cherrypy/lib/encoding.py b/cherrypy/lib/encoding.py
new file mode 100644
index 00000000..5496936d
--- /dev/null
+++ b/cherrypy/lib/encoding.py
@@ -0,0 +1,220 @@
+import struct
+import time
+
+import cherrypy
+
+
+def decode(encoding=None, default_encoding='utf-8'):
+    """Decode cherrypy.request.params ."""
+    if not encoding:
+        ct = cherrypy.request.headers.elements("Content-Type")
+        if ct:
+            ct = ct[0]
+            encoding = ct.params.get("charset", None)
+            if (not encoding) and ct.value.lower().startswith("text/"):
+                # http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1
+                # When no explicit charset parameter is provided by the
+                # sender, media subtypes of the "text" type are defined
+                # to have a default charset value of "ISO-8859-1" when
+                # received via HTTP.
+                encoding = "ISO-8859-1"
+        
+        if not encoding:
+            encoding = default_encoding
+    
+    try:
+        decode_params(encoding)
+    except UnicodeDecodeError:
+        # IE and Firefox don't supply a charset when submitting form
+        # params with a CT of application/x-www-form-urlencoded.
+        # So after all our guessing, it could *still* be wrong.
+        # Start over with ISO-8859-1, since that seems to be preferred.
+        decode_params("ISO-8859-1")
+
+def decode_params(encoding):
+    decodedParams = {}
+    for key, value in cherrypy.request.params.items():
+        if hasattr(value, 'file'):
+            # This is a file being uploaded: skip it
+            decodedParams[key] = value
+        elif isinstance(value, list):
+            # value is a list: decode each element
+            decodedParams[key] = [v.decode(encoding) for v in value]
+        else:
+            # value is a regular string: decode it
+            decodedParams[key] = value.decode(encoding)
+    
+    # Decode all or nothing, so we can try again on error.
+    cherrypy.request.params = decodedParams
+
+
+# Encoding
+
+def encode(encoding=None, errors='strict'):
+    ct = cherrypy.response.headers.elements("Content-Type")
+    if ct:
+        ct = ct[0]
+        if ct.value.lower().startswith("text/"):
+            # Set "charset=..." param on response Content-Type header
+            ct.params['charset'] = find_acceptable_charset(encoding, errors=errors)
+            cherrypy.response.headers["Content-Type"] = str(ct)
+
+def encode_stream(encoding, errors='strict'):
+    """Encode a streaming response body.
+    
+    Use a generator wrapper, and just pray it works as the stream is
+    being written out.
+    """
+    def encoder(body):
+        for line in body:
+            yield line.encode(encoding, errors)
+    cherrypy.response.body = encoder(cherrypy.response.body)
+    return True
+
+def encode_string(encoding, errors='strict'):
+    """Encode a buffered response body."""
+    try:
+        body = []
+        for chunk in cherrypy.response.body:
+            body.append(chunk.encode(encoding, errors))
+        cherrypy.response.body = body
+    except UnicodeError:
+        return False
+    else:
+        return True
+
+def find_acceptable_charset(encoding=None, default_encoding='utf-8', errors='strict'):
+    response = cherrypy.response
+    
+    attempted_charsets = []
+    
+    stream = cherrypy.config.get("stream_response", False)
+    if stream:
+        encoder = encode_stream
+    else:
+        response.collapse_body()
+        encoder = encode_string
+    
+    failmsg = "The response could not be encoded with %s"
+    
+    if encoding is not None:
+        # If specified, force this encoding to be used, or fail.
+        if encoder(encoding, errors):
+            return encoding
+        else:
+            raise cherrypy.HTTPError(500, failmsg % encoding)
+    
+    # Parse the Accept_Charset request header, and try to provide one
+    # of the requested charsets (in order of user preference).
+    encs = cherrypy.request.headers.elements('Accept-Charset')
+    if not encs:
+        # Any character-set is acceptable.
+        charsets = []
+        if encoder(default_encoding, errors):
+            return default_encoding
+        else:
+            raise cherrypy.HTTPError(500, failmsg % default_encoding)
+    else:
+        charsets = [enc.value.lower() for enc in encs]
+        if "*" not in charsets:
+            # If no "*" is present in an Accept-Charset field, then all
+            # character sets not explicitly mentioned get a quality
+            # value of 0, except for ISO-8859-1, which gets a quality
+            # value of 1 if not explicitly mentioned.
+            iso = 'iso-8859-1'
+            if iso not in charsets:
+                attempted_charsets.append(iso)
+                if encoder(iso, errors):
+                    return iso
+        
+        for element in encs:
+            if element.qvalue > 0:
+                if element.value == "*":
+                    # Matches any charset. Try our default.
+                    if default_encoding not in attempted_charsets:
+                        attempted_charsets.append(default_encoding)
+                        if encoder(default_encoding, errors):
+                            return default_encoding
+                else:
+                    encoding = element.value
+                    if encoding not in attempted_charsets:
+                        attempted_charsets.append(encoding)
+                        if encoder(encoding, errors):
+                            return encoding
+    
+    # No suitable encoding found.
+    ac = cherrypy.request.headers.get('Accept-Charset')
+    if ac is None:
+        msg = "Your client did not send an Accept-Charset header."
+    else:
+        msg = "Your client sent this Accept-Charset header: %s." % ac
+    msg += " We tried these charsets: %s." % ", ".join(attempted_charsets)
+    raise cherrypy.HTTPError(406, msg)
+
+
+# GZIP
+
+def compress(body, compress_level):
+    """Compress 'body' at the given compress_level."""
+    import zlib
+    
+    yield '\037\213'      # magic header
+    yield '\010'         # compression method
+    yield '\0'
+    yield struct.pack("<L", long(time.time()))
+    yield '\002'
+    yield '\377'
+    
+    crc = zlib.crc32("")
+    size = 0
+    zobj = zlib.compressobj(compress_level,
+                            zlib.DEFLATED, -zlib.MAX_WBITS,
+                            zlib.DEF_MEM_LEVEL, 0)
+    for line in body:
+        size += len(line)
+        crc = zlib.crc32(line, crc)
+        yield zobj.compress(line)
+    yield zobj.flush()
+    yield struct.pack("<l", crc)
+    yield struct.pack("<L", size & 0xFFFFFFFFL)
+
+def gzip(compress_level=9, mime_types=['text/html', 'text/plain']):
+    response = cherrypy.response
+    if not response.body:
+        # Response body is empty (might be a 304 for instance)
+        return
+    
+    def zipit():
+        # Return a generator that compresses the page
+        varies = response.headers.get("Vary", "")
+        varies = [x.strip() for x in varies.split(",") if x.strip()]
+        if "Accept-Encoding" not in varies:
+            varies.append("Accept-Encoding")
+        response.headers['Vary'] = ", ".join(varies)
+        
+        response.headers['Content-Encoding'] = 'gzip'
+        response.body = compress(response.body, compress_level)
+    
+    acceptable = cherrypy.request.headers.elements('Accept-Encoding')
+    if not acceptable:
+        # If no Accept-Encoding field is present in a request,
+        # the server MAY assume that the client will accept any
+        # content coding. In this case, if "identity" is one of
+        # the available content-codings, then the server SHOULD use
+        # the "identity" content-coding, unless it has additional
+        # information that a different content-coding is meaningful
+        # to the client.
+        return
+    
+    ct = response.headers.get('Content-Type').split(';')[0]
+    for coding in acceptable:
+        if coding.value == 'identity' and coding.qvalue != 0:
+            return
+        if coding.value in ('gzip', 'x-gzip'):
+            if coding.qvalue == 0:
+                return
+            if ct in mime_types:
+                zipit()
+            return
+    cherrypy.HTTPError(406, "identity, gzip").set_response()
+