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author | Adam Kocoloski <kocolosk@apache.org> | 2009-09-09 20:23:56 +0000 |
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committer | Adam Kocoloski <kocolosk@apache.org> | 2009-09-09 20:23:56 +0000 |
commit | ee29f0bacabd96e72d18a356d28a46cd677ccd3c (patch) | |
tree | e632345d9d841339880c2a562700d57e70d6deb1 /src/couchdb/couch_uuids.erl | |
parent | 9b78e1555d73c888fedaa0b9d256abaeaadbe41a (diff) |
oopsie
git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@813102 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to 'src/couchdb/couch_uuids.erl')
-rw-r--r-- | src/couchdb/couch_uuids.erl | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/src/couchdb/couch_uuids.erl b/src/couchdb/couch_uuids.erl new file mode 100644 index 00000000..24d81aad --- /dev/null +++ b/src/couchdb/couch_uuids.erl @@ -0,0 +1,88 @@ +% 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_uuids). +-include("couch_db.hrl"). + +-behaviour(gen_server). + +-export([start/0, stop/0]). +-export([new/0, random/0, utc_random/0]). + +-export([init/1, terminate/2, code_change/3]). +-export([handle_call/3, handle_cast/2, handle_info/2]). + +start() -> + gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). + +stop() -> + gen_server:cast(?MODULE, stop). + +new() -> + gen_server:call(?MODULE, create). + +random() -> + list_to_binary(couch_util:to_hex(crypto:rand_bytes(16))). + +utc_random() -> + Now = {_, _, Micro} = now(), + Nowish = calendar:now_to_universal_time(Now), + Nowsecs = calendar:datetime_to_gregorian_seconds(Nowish), + Then = calendar:datetime_to_gregorian_seconds({{1970, 1, 1}, {0, 0, 0}}), + Prefix = io_lib:format("~14.16.0b", [(Nowsecs - Then) * 1000000 + Micro]), + list_to_binary(Prefix ++ couch_util:to_hex(crypto:rand_bytes(9))). + +init([]) -> + ok = couch_config:register(fun("uuids", _) -> ?MODULE:stop() end), + AlgoStr = couch_config:get("uuids", "algorithm", "random"), + case couch_util:to_existing_atom(AlgoStr) of + random -> + {ok, random}; + utc_random -> + {ok, utc_random}; + sequential -> + {ok, {sequential, new_prefix(), inc()}}; + Unknown -> + throw({unknown_uuid_algorithm, Unknown}) + end. + +terminate(_Reason, _State) -> + ok. + +handle_call(create, _From, random) -> + {reply, random(), random}; +handle_call(create, _From, utc_random) -> + {reply, utc_random(), utc_random}; +handle_call(create, _From, {sequential, Pref, Seq}) -> + Result = ?l2b(Pref ++ io_lib:format("~6.16.0b", [Seq])), + case Seq >= 16#fff000 of + true -> + {reply, Result, {sequential, new_prefix(), inc()}}; + _ -> + {reply, Result, {sequential, Pref, Seq + inc()}} + end. + +handle_cast(stop, State) -> + {stop, normal, State}; +handle_cast(_Msg, State) -> + {noreply, State}. + +handle_info(_Info, State) -> + {noreply, State}. + +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + +new_prefix() -> + couch_util:to_hex((crypto:rand_bytes(13))). + +inc() -> + crypto:rand_uniform(1, 16#ffe). |