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|
% Licensed under the Apache License, Version 2.0 (the "License"); you may not
% use this file except in compliance with the License. You may obtain a copy of
% the License at
%
% http://www.apache.org/licenses/LICENSE-2.0
%
% Unless required by applicable law or agreed to in writing, software
% distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
% WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
% License for the specific language governing permissions and limitations under
% the License.
-module(couch_util).
-export([priv_dir/0, start_driver/1,terminate_linked/1]).
-export([should_flush/0, should_flush/1, to_existing_atom/1]).
-export([rand32/0, implode/2, collate/2, collate/3]).
-export([abs_pathname/1,abs_pathname/2, trim/1, ascii_lower/1]).
-export([encodeBase64Url/1, decodeBase64Url/1]).
-export([to_hex/1, parse_term/1, dict_find/3]).
-export([file_read_size/1, get_nested_json_value/2, json_user_ctx/1]).
-export([to_binary/1, to_integer/1, to_list/1, url_encode/1]).
-export([json_encode/1, json_decode/1]).
-export([verify/2]).
-export([compressible_att_type/1]).
-include("couch_db.hrl").
-include_lib("kernel/include/file.hrl").
% arbitrarily chosen amount of memory to use before flushing to disk
-define(FLUSH_MAX_MEM, 10000000).
priv_dir() ->
case code:priv_dir(couch) of
{error, bad_name} ->
% small hack, in dev mode "app" is couchdb. Fixing requires
% renaming src/couch to src/couch. Not really worth the hassle.
% -Damien
code:priv_dir(couchdb);
Dir -> Dir
end.
start_driver(LibDir) ->
case erl_ddll:load_driver(LibDir, "couch_icu_driver") of
ok ->
ok;
{error, already_loaded} ->
ok = erl_ddll:reload_driver(LibDir, "couch_icu_driver");
{error, Error} ->
exit(erl_ddll:format_error(Error))
end.
% works like list_to_existing_atom, except can be list or binary and it
% gives you the original value instead of an error if no existing atom.
to_existing_atom(V) when is_list(V) ->
try list_to_existing_atom(V) catch _ -> V end;
to_existing_atom(V) when is_binary(V) ->
try list_to_existing_atom(?b2l(V)) catch _ -> V end;
to_existing_atom(V) when is_atom(V) ->
V.
terminate_linked(normal) ->
terminate_linked(shutdown);
terminate_linked(Reason) ->
{links, Links} = process_info(self(), links),
[catch exit(Pid, Reason) || Pid <- Links],
ok.
to_hex([]) ->
[];
to_hex(Bin) when is_binary(Bin) ->
to_hex(binary_to_list(Bin));
to_hex([H|T]) ->
[to_digit(H div 16), to_digit(H rem 16) | to_hex(T)].
to_digit(N) when N < 10 -> $0 + N;
to_digit(N) -> $a + N-10.
parse_term(Bin) when is_binary(Bin) ->
parse_term(binary_to_list(Bin));
parse_term(List) ->
{ok, Tokens, _} = erl_scan:string(List ++ "."),
erl_parse:parse_term(Tokens).
get_nested_json_value({Props}, [Key|Keys]) ->
case proplists:get_value(Key, Props, nil) of
nil -> throw({not_found, <<"missing json key: ", Key/binary>>});
Value -> get_nested_json_value(Value, Keys)
end;
get_nested_json_value(Value, []) ->
Value;
get_nested_json_value(_NotJSONObj, _) ->
throw({not_found, json_mismatch}).
json_user_ctx(#db{name=DbName, user_ctx=Ctx}) ->
{[{<<"db">>, DbName},
{<<"name">>,Ctx#user_ctx.name},
{<<"roles">>,Ctx#user_ctx.roles}]}.
% returns a random integer
rand32() ->
crypto:rand_uniform(0, 16#100000000).
% given a pathname "../foo/bar/" it gives back the fully qualified
% absolute pathname.
abs_pathname(" " ++ Filename) ->
% strip leading whitspace
abs_pathname(Filename);
abs_pathname([$/ |_]=Filename) ->
Filename;
abs_pathname(Filename) ->
{ok, Cwd} = file:get_cwd(),
{Filename2, Args} = separate_cmd_args(Filename, ""),
abs_pathname(Filename2, Cwd) ++ Args.
abs_pathname(Filename, Dir) ->
Name = filename:absname(Filename, Dir ++ "/"),
OutFilename = filename:join(fix_path_list(filename:split(Name), [])),
% If the filename is a dir (last char slash, put back end slash
case string:right(Filename,1) of
"/" ->
OutFilename ++ "/";
"\\" ->
OutFilename ++ "/";
_Else->
OutFilename
end.
% if this as an executable with arguments, seperate out the arguments
% ""./foo\ bar.sh -baz=blah" -> {"./foo\ bar.sh", " -baz=blah"}
separate_cmd_args("", CmdAcc) ->
{lists:reverse(CmdAcc), ""};
separate_cmd_args("\\ " ++ Rest, CmdAcc) -> % handle skipped value
separate_cmd_args(Rest, " \\" ++ CmdAcc);
separate_cmd_args(" " ++ Rest, CmdAcc) ->
{lists:reverse(CmdAcc), " " ++ Rest};
separate_cmd_args([Char|Rest], CmdAcc) ->
separate_cmd_args(Rest, [Char | CmdAcc]).
% lowercases string bytes that are the ascii characters A-Z.
% All other characters/bytes are ignored.
ascii_lower(String) ->
ascii_lower(String, []).
ascii_lower([], Acc) ->
lists:reverse(Acc);
ascii_lower([Char | RestString], Acc) when Char >= $A, Char =< $B ->
ascii_lower(RestString, [Char + ($a-$A) | Acc]);
ascii_lower([Char | RestString], Acc) ->
ascii_lower(RestString, [Char | Acc]).
% Is a character whitespace?
is_whitespace($\s) -> true;
is_whitespace($\t) -> true;
is_whitespace($\n) -> true;
is_whitespace($\r) -> true;
is_whitespace(_Else) -> false.
% removes leading and trailing whitespace from a string
trim(String) ->
String2 = lists:dropwhile(fun is_whitespace/1, String),
lists:reverse(lists:dropwhile(fun is_whitespace/1, lists:reverse(String2))).
% takes a heirarchical list of dirs and removes the dots ".", double dots
% ".." and the corresponding parent dirs.
fix_path_list([], Acc) ->
lists:reverse(Acc);
fix_path_list([".."|Rest], [_PrevAcc|RestAcc]) ->
fix_path_list(Rest, RestAcc);
fix_path_list(["."|Rest], Acc) ->
fix_path_list(Rest, Acc);
fix_path_list([Dir | Rest], Acc) ->
fix_path_list(Rest, [Dir | Acc]).
implode(List, Sep) ->
implode(List, Sep, []).
implode([], _Sep, Acc) ->
lists:flatten(lists:reverse(Acc));
implode([H], Sep, Acc) ->
implode([], Sep, [H|Acc]);
implode([H|T], Sep, Acc) ->
implode(T, Sep, [Sep,H|Acc]).
drv_port() ->
case get(couch_drv_port) of
undefined ->
Port = open_port({spawn, "couch_icu_driver"}, []),
put(couch_drv_port, Port),
Port;
Port ->
Port
end.
collate(A, B) ->
collate(A, B, []).
collate(A, B, Options) when is_binary(A), is_binary(B) ->
Operation =
case lists:member(nocase, Options) of
true -> 1; % Case insensitive
false -> 0 % Case sensitive
end,
SizeA = byte_size(A),
SizeB = byte_size(B),
Bin = <<SizeA:32/native, A/binary, SizeB:32/native, B/binary>>,
[Result] = erlang:port_control(drv_port(), Operation, Bin),
% Result is 0 for lt, 1 for eq and 2 for gt. Subtract 1 to return the
% expected typical -1, 0, 1
Result - 1.
should_flush() ->
should_flush(?FLUSH_MAX_MEM).
should_flush(MemThreshHold) ->
{memory, ProcMem} = process_info(self(), memory),
BinMem = lists:foldl(fun({_Id, Size, _NRefs}, Acc) -> Size+Acc end,
0, element(2,process_info(self(), binary))),
if ProcMem+BinMem > 2*MemThreshHold ->
garbage_collect(),
{memory, ProcMem2} = process_info(self(), memory),
BinMem2 = lists:foldl(fun({_Id, Size, _NRefs}, Acc) -> Size+Acc end,
0, element(2,process_info(self(), binary))),
ProcMem2+BinMem2 > MemThreshHold;
true -> false end.
encodeBase64Url(Url) ->
Url1 = iolist_to_binary(re:replace(base64:encode(Url), "=+$", "")),
Url2 = iolist_to_binary(re:replace(Url1, "/", "_", [global])),
iolist_to_binary(re:replace(Url2, "\\+", "-", [global])).
decodeBase64Url(Url64) ->
Url1 = re:replace(iolist_to_binary(Url64), "-", "+", [global]),
Url2 = iolist_to_binary(
re:replace(iolist_to_binary(Url1), "_", "/", [global])
),
Padding = ?l2b(lists:duplicate((4 - size(Url2) rem 4) rem 4, $=)),
base64:decode(<<Url2/binary, Padding/binary>>).
dict_find(Key, Dict, DefaultValue) ->
case dict:find(Key, Dict) of
{ok, Value} ->
Value;
error ->
DefaultValue
end.
file_read_size(FileName) ->
case file:read_file_info(FileName) of
{ok, FileInfo} ->
FileInfo#file_info.size;
Error -> Error
end.
to_binary(V) when is_binary(V) ->
V;
to_binary(V) when is_list(V) ->
try
list_to_binary(V)
catch
_ ->
list_to_binary(io_lib:format("~p", [V]))
end;
to_binary(V) when is_atom(V) ->
list_to_binary(atom_to_list(V));
to_binary(V) ->
list_to_binary(io_lib:format("~p", [V])).
to_integer(V) when is_integer(V) ->
V;
to_integer(V) when is_list(V) ->
erlang:list_to_integer(V);
to_integer(V) when is_binary(V) ->
erlang:list_to_integer(binary_to_list(V)).
to_list(V) when is_list(V) ->
V;
to_list(V) when is_binary(V) ->
binary_to_list(V);
to_list(V) when is_atom(V) ->
atom_to_list(V);
to_list(V) ->
lists:flatten(io_lib:format("~p", [V])).
url_encode(Bin) when is_binary(Bin) ->
url_encode(binary_to_list(Bin));
url_encode([H|T]) ->
if
H >= $a, $z >= H ->
[H|url_encode(T)];
H >= $A, $Z >= H ->
[H|url_encode(T)];
H >= $0, $9 >= H ->
[H|url_encode(T)];
H == $_; H == $.; H == $-; H == $: ->
[H|url_encode(T)];
true ->
case lists:flatten(io_lib:format("~.16.0B", [H])) of
[X, Y] ->
[$%, X, Y | url_encode(T)];
[X] ->
[$%, $0, X | url_encode(T)]
end
end;
url_encode([]) ->
[].
json_encode(V) ->
Handler =
fun({L}) when is_list(L) ->
{struct,L};
(Bad) ->
exit({json_encode, {bad_term, Bad}})
end,
(mochijson2:encoder([{handler, Handler}]))(V).
json_decode(V) ->
try (mochijson2:decoder([{object_hook, fun({struct,L}) -> {L} end}]))(V)
catch
_Type:_Error ->
throw({invalid_json,V})
end.
verify([X|RestX], [Y|RestY], Result) ->
verify(RestX, RestY, (X bxor Y) bor Result);
verify([], [], Result) ->
Result == 0.
verify(<<X/binary>>, <<Y/binary>>) ->
verify(?b2l(X), ?b2l(Y));
verify(X, Y) when is_list(X) and is_list(Y) ->
case length(X) == length(Y) of
true ->
verify(X, Y, 0);
false ->
false
end;
verify(_X, _Y) -> false.
compressible_att_type(MimeType) when is_binary(MimeType) ->
compressible_att_type(?b2l(MimeType));
compressible_att_type(MimeType) ->
TypeExpList = re:split(
couch_config:get("attachments", "compressible_types", ""),
"\\s+",
[{return, list}]
),
lists:any(
fun(TypeExp) ->
Regexp = "^\\s*" ++
re:replace(TypeExp, "\\*", ".*", [{return, list}]) ++ "\\s*$",
case re:run(MimeType, Regexp, [caseless]) of
{match, _} ->
true;
_ ->
false
end
end,
[T || T <- TypeExpList, T /= []]
).
|