From ee09a0de9f8356abe24a0ac0f26cdff35f8fa704 Mon Sep 17 00:00:00 2001 From: John Christopher Anderson Date: Fri, 29 Jan 2010 22:43:33 +0000 Subject: Allow storing attachments in compressed form. Closes COUCHDB-583. Thanks Filipe Manana git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@904650 13f79535-47bb-0310-9956-ffa450edef68 --- src/mochiweb/mochiweb_request.erl | 41 ++++++ src/mochiweb/mochiweb_util.erl | 282 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 323 insertions(+) (limited to 'src/mochiweb') diff --git a/src/mochiweb/mochiweb_request.erl b/src/mochiweb/mochiweb_request.erl index fc296f40..5d7af26b 100644 --- a/src/mochiweb/mochiweb_request.erl +++ b/src/mochiweb/mochiweb_request.erl @@ -20,6 +20,7 @@ -export([should_close/0, cleanup/0]). -export([parse_cookie/0, get_cookie_value/1]). -export([serve_file/2, serve_file/3]). +-export([accepted_encodings/1]). -export([test/0]). -define(SAVE_QS, mochiweb_request_qs). @@ -730,6 +731,46 @@ parse_range_request(RawRange) when is_list(RawRange) -> fail end. +%% @spec accepted_encodings([encoding()]) -> [encoding()] | error() +%% @type encoding() -> string() +%% @type error() -> bad_accept_encoding_value +%% +%% @doc Returns a list of encodings accepted by a request. Encodings that are +%% not supported by the server will not be included in the return list. +%% This list is computed from the "Accept-Encoding" header and +%% its elements are ordered, descendingly, according to their Q values. +%% +%% Section 14.3 of the RFC 2616 (HTTP 1.1) describes the "Accept-Encoding" +%% header and the process of determining which server supported encodings +%% can be used for encoding the body for the request's response. +%% +%% Examples +%% +%% 1) For a missing "Accept-Encoding" header: +%% accepted_encodings(["gzip", "identity"]) -> ["identity"] +%% +%% 2) For an "Accept-Encoding" header with value "gzip, deflate": +%% accepted_encodings(["gzip", "identity"]) -> ["gzip", "identity"] +%% +%% 3) For an "Accept-Encoding" header with value "gzip;q=0.5, deflate": +%% accepted_encodings(["gzip", "deflate", "identity"]) -> +%% ["deflate", "gzip", "identity"] +%% +accepted_encodings(SupportedEncodings) -> + AcceptEncodingHeader = case get_header_value("Accept-Encoding") of + undefined -> + ""; + Value -> + Value + end, + case mochiweb_util:parse_qvalues(AcceptEncodingHeader) of + invalid_qvalue_string -> + bad_accept_encoding_value; + QList -> + mochiweb_util:pick_accepted_encodings( + QList, SupportedEncodings, "identity" + ) + end. test() -> ok = test_range(), diff --git a/src/mochiweb/mochiweb_util.erl b/src/mochiweb/mochiweb_util.erl index 73cacea4..d8fc89d5 100644 --- a/src/mochiweb/mochiweb_util.erl +++ b/src/mochiweb/mochiweb_util.erl @@ -12,6 +12,7 @@ -export([shell_quote/1, cmd/1, cmd_string/1, cmd_port/2]). -export([record_to_proplist/2, record_to_proplist/3]). -export([safe_relative_path/1, partition/2]). +-export([parse_qvalues/1, pick_accepted_encodings/3]). -export([test/0]). -define(PERCENT, 37). % $\% @@ -435,6 +436,136 @@ shell_quote([C | Rest], Acc) when C =:= $\" orelse C =:= $\` orelse shell_quote([C | Rest], Acc) -> shell_quote(Rest, [C | Acc]). +%% @spec parse_qvalues(string()) -> [qvalue()] | error() +%% @type qvalue() -> {element(), q()} +%% @type element() -> string() +%% @type q() -> 0.0 .. 1.0 +%% @type error() -> invalid_qvalue_string +%% +%% @doc Parses a list (given as a string) of elements with Q values associated +%% to them. Elements are separated by commas and each element is separated +%% from its Q value by a semicolon. Q values are optional but when missing +%% the value of an element is considered as 1.0. A Q value is always in the +%% range [0.0, 1.0]. A Q value list is used for example as the value of the +%% HTTP "Accept-Encoding" header. +%% +%% Q values are described in section 2.9 of the RFC 2616 (HTTP 1.1). +%% +%% Example: +%% +%% parse_qvalues("gzip; q=0.5, deflate, identity;q=0.0") -> +%% [{"gzip", 0.5}, {"deflate", 1.0}, {"identity", 0.0}] +%% +parse_qvalues(QValuesStr) -> + try + {ok, Re} = re:compile("^\\s*q\\s*=\\s*((?:0|1)(?:\\.\\d{1,3})?)\\s*$"), + lists:map( + fun(Pair) -> + case string:tokens(Pair, ";") of + [Enc] -> + {string:strip(Enc), 1.0}; + [Enc, QStr] -> + case re:run(QStr, Re, [{capture, [1], list}]) of + {match, [Q]} -> + QVal = case Q of + "0" -> + 0.0; + "1" -> + 1.0; + Else -> + list_to_float(Else) + end, + case QVal < 0.0 orelse QVal > 1.0 of + false -> + {string:strip(Enc), QVal} + end + end + end + end, + string:tokens(string:to_lower(QValuesStr), ",") + ) + catch + _Type:_Error -> + invalid_qvalue_string + end. + +%% @spec pick_accepted_encodings(qvalues(), [encoding()], encoding()) -> +%% [encoding()] +%% @type qvalues() -> [ {encoding(), q()} ] +%% @type encoding() -> string() +%% @type q() -> 0.0 .. 1.0 +%% +%% @doc Determines which encodings specified in the given Q values list are +%% valid according to a list of supported encodings and a default encoding. +%% +%% The returned list of encodings is sorted, descendingly, according to the +%% Q values of the given list. The last element of this list is the given +%% default encoding unless this encoding is explicitily or implicitily +%% marked with a Q value of 0.0 in the given Q values list. +%% Note: encodings with the same Q value are kept in the same order as +%% found in the input Q values list. +%% +%% This encoding picking process is described in section 14.3 of the +%% RFC 2616 (HTTP 1.1). +%% +%% Example: +%% +%% pick_accepted_encodings( +%% [{"gzip", 0.5}, {"deflate", 1.0}], +%% ["gzip", "identity"], +%% "identity" +%% ) -> +%% ["gzip", "identity"] +%% +pick_accepted_encodings(AcceptedEncs, SupportedEncs, DefaultEnc) -> + SortedQList = lists:reverse( + lists:sort(fun({_, Q1}, {_, Q2}) -> Q1 < Q2 end, AcceptedEncs) + ), + {Accepted, Refused} = lists:foldr( + fun({E, Q}, {A, R}) -> + case Q > 0.0 of + true -> + {[E | A], R}; + false -> + {A, [E | R]} + end + end, + {[], []}, + SortedQList + ), + Refused1 = lists:foldr( + fun(Enc, Acc) -> + case Enc of + "*" -> + lists:subtract(SupportedEncs, Accepted) ++ Acc; + _ -> + [Enc | Acc] + end + end, + [], + Refused + ), + Accepted1 = lists:foldr( + fun(Enc, Acc) -> + case Enc of + "*" -> + lists:subtract(SupportedEncs, Accepted ++ Refused1) ++ Acc; + _ -> + [Enc | Acc] + end + end, + [], + Accepted + ), + Accepted2 = case lists:member(DefaultEnc, Accepted1) of + true -> + Accepted1; + false -> + Accepted1 ++ [DefaultEnc] + end, + [E || E <- Accepted2, lists:member(E, SupportedEncs), + not lists:member(E, Refused1)]. + test() -> test_join(), test_quote_plus(), @@ -453,6 +584,8 @@ test() -> test_cmd_string(), test_partition(), test_safe_relative_path(), + test_parse_qvalues(), + test_pick_accepted_encodings(), ok. test_shell_quote() -> @@ -575,3 +708,152 @@ test_safe_relative_path() -> undefined = safe_relative_path("foo/../.."), undefined = safe_relative_path("foo//"), ok. + +test_parse_qvalues() -> + [] = parse_qvalues(""), + [{"identity", 0.0}] = parse_qvalues("identity;q=0"), + [{"identity", 0.0}] = parse_qvalues("identity ;q=0"), + [{"identity", 0.0}] = parse_qvalues(" identity; q =0 "), + [{"identity", 0.0}] = parse_qvalues("identity ; q = 0"), + [{"identity", 0.0}] = parse_qvalues("identity ; q= 0.0"), + [{"gzip", 1.0}, {"deflate", 1.0}, {"identity", 0.0}] = parse_qvalues( + "gzip,deflate,identity;q=0.0" + ), + [{"deflate", 1.0}, {"gzip", 1.0}, {"identity", 0.0}] = parse_qvalues( + "deflate,gzip,identity;q=0.0" + ), + [{"gzip", 1.0}, {"deflate", 1.0}, {"gzip", 1.0}, {"identity", 0.0}] = + parse_qvalues("gzip,deflate,gzip,identity;q=0"), + [{"gzip", 1.0}, {"deflate", 1.0}, {"identity", 0.0}] = parse_qvalues( + "gzip, deflate , identity; q=0.0" + ), + [{"gzip", 1.0}, {"deflate", 1.0}, {"identity", 0.0}] = parse_qvalues( + "gzip; q=1, deflate;q=1.0, identity;q=0.0" + ), + [{"gzip", 0.5}, {"deflate", 1.0}, {"identity", 0.0}] = parse_qvalues( + "gzip; q=0.5, deflate;q=1.0, identity;q=0" + ), + [{"gzip", 0.5}, {"deflate", 1.0}, {"identity", 0.0}] = parse_qvalues( + "gzip; q=0.5, deflate , identity;q=0.0" + ), + [{"gzip", 0.5}, {"deflate", 0.8}, {"identity", 0.0}] = parse_qvalues( + "gzip; q=0.5, deflate;q=0.8, identity;q=0.0" + ), + [{"gzip", 0.5}, {"deflate", 1.0}, {"identity", 1.0}] = parse_qvalues( + "gzip; q=0.5,deflate,identity" + ), + [{"gzip", 0.5}, {"deflate", 1.0}, {"identity", 1.0}, {"identity", 1.0}] = + parse_qvalues("gzip; q=0.5,deflate,identity, identity "), + invalid_qvalue_string = parse_qvalues("gzip; q=1.1, deflate"), + invalid_qvalue_string = parse_qvalues("gzip; q=0.5, deflate;q=2"), + invalid_qvalue_string = parse_qvalues("gzip, deflate;q=AB"), + invalid_qvalue_string = parse_qvalues("gzip; q=2.1, deflate"), + ok. + +test_pick_accepted_encodings() -> + ["identity"] = pick_accepted_encodings( + [], + ["gzip", "identity"], + "identity" + ), + ["gzip", "identity"] = pick_accepted_encodings( + [{"gzip", 1.0}], + ["gzip", "identity"], + "identity" + ), + ["identity"] = pick_accepted_encodings( + [{"gzip", 0.0}], + ["gzip", "identity"], + "identity" + ), + ["gzip", "identity"] = pick_accepted_encodings( + [{"gzip", 1.0}, {"deflate", 1.0}], + ["gzip", "identity"], + "identity" + ), + ["gzip", "identity"] = pick_accepted_encodings( + [{"gzip", 0.5}, {"deflate", 1.0}], + ["gzip", "identity"], + "identity" + ), + ["identity"] = pick_accepted_encodings( + [{"gzip", 0.0}, {"deflate", 0.0}], + ["gzip", "identity"], + "identity" + ), + ["gzip"] = pick_accepted_encodings( + [{"gzip", 1.0}, {"deflate", 1.0}, {"identity", 0.0}], + ["gzip", "identity"], + "identity" + ), + ["gzip", "deflate", "identity"] = pick_accepted_encodings( + [{"gzip", 1.0}, {"deflate", 1.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["gzip", "deflate"] = pick_accepted_encodings( + [{"gzip", 1.0}, {"deflate", 1.0}, {"identity", 0.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["deflate", "gzip", "identity"] = pick_accepted_encodings( + [{"gzip", 0.2}, {"deflate", 1.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["deflate", "deflate", "gzip", "identity"] = pick_accepted_encodings( + [{"gzip", 0.2}, {"deflate", 1.0}, {"deflate", 1.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["deflate", "gzip", "gzip", "identity"] = pick_accepted_encodings( + [{"gzip", 0.2}, {"deflate", 1.0}, {"gzip", 1.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["gzip", "deflate", "gzip", "identity"] = pick_accepted_encodings( + [{"gzip", 0.2}, {"deflate", 0.9}, {"gzip", 1.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + [] = pick_accepted_encodings( + [{"*", 0.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["gzip", "deflate", "identity"] = pick_accepted_encodings( + [{"*", 1.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["gzip", "deflate", "identity"] = pick_accepted_encodings( + [{"*", 0.6}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["gzip"] = pick_accepted_encodings( + [{"gzip", 1.0}, {"*", 0.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["gzip", "deflate"] = pick_accepted_encodings( + [{"gzip", 1.0}, {"deflate", 0.6}, {"*", 0.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["deflate", "gzip"] = pick_accepted_encodings( + [{"gzip", 0.5}, {"deflate", 1.0}, {"*", 0.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["gzip", "identity"] = pick_accepted_encodings( + [{"deflate", 0.0}, {"*", 1.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ["gzip", "identity"] = pick_accepted_encodings( + [{"*", 1.0}, {"deflate", 0.0}], + ["gzip", "deflate", "identity"], + "identity" + ), + ok. -- cgit v1.2.3