From 6af72ef686ecc1c29c18bd0cbfbdd91e4ade9b26 Mon Sep 17 00:00:00 2001 From: Guido Günther Date: Tue, 29 Oct 2013 14:32:43 +0100 Subject: Initial commit --- .gitignore | 3 + COPYING | 165 +++++++++++++++++++++++++++++++++++++++++++++++++++++ README | 24 ++++++++ rebar | Bin 0 -> 119212 bytes rebar.config | 3 + src/guid.app.src | 9 +++ src/guid.erl | 55 ++++++++++++++++++ test/guid_test.erl | 29 ++++++++++ 8 files changed, 288 insertions(+) create mode 100644 .gitignore create mode 100644 COPYING create mode 100644 README create mode 100755 rebar create mode 100644 rebar.config create mode 100644 src/guid.app.src create mode 100644 src/guid.erl create mode 100644 test/guid_test.erl diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..4e57610 --- /dev/null +++ b/.gitignore @@ -0,0 +1,3 @@ +.eunit/ +ebin/ +*~ diff --git a/COPYING b/COPYING new file mode 100644 index 0000000..65c5ca8 --- /dev/null +++ b/COPYING @@ -0,0 +1,165 @@ + GNU LESSER GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + + This version of the GNU Lesser General Public License incorporates +the terms and conditions of version 3 of the GNU General Public +License, supplemented by the additional permissions listed below. + + 0. Additional Definitions. + + As used herein, "this License" refers to version 3 of the GNU Lesser +General Public License, and the "GNU GPL" refers to version 3 of the GNU +General Public License. + + "The Library" refers to a covered work governed by this License, +other than an Application or a Combined Work as defined below. + + An "Application" is any work that makes use of an interface provided +by the Library, but which is not otherwise based on the Library. +Defining a subclass of a class defined by the Library is deemed a mode +of using an interface provided by the Library. + + A "Combined Work" is a work produced by combining or linking an +Application with the Library. The particular version of the Library +with which the Combined Work was made is also called the "Linked +Version". + + The "Minimal Corresponding Source" for a Combined Work means the +Corresponding Source for the Combined Work, excluding any source code +for portions of the Combined Work that, considered in isolation, are +based on the Application, and not on the Linked Version. + + The "Corresponding Application Code" for a Combined Work means the +object code and/or source code for the Application, including any data +and utility programs needed for reproducing the Combined Work from the +Application, but excluding the System Libraries of the Combined Work. + + 1. Exception to Section 3 of the GNU GPL. + + You may convey a covered work under sections 3 and 4 of this License +without being bound by section 3 of the GNU GPL. + + 2. Conveying Modified Versions. + + If you modify a copy of the Library, and, in your modifications, a +facility refers to a function or data to be supplied by an Application +that uses the facility (other than as an argument passed when the +facility is invoked), then you may convey a copy of the modified +version: + + a) under this License, provided that you make a good faith effort to + ensure that, in the event an Application does not supply the + function or data, the facility still operates, and performs + whatever part of its purpose remains meaningful, or + + b) under the GNU GPL, with none of the additional permissions of + this License applicable to that copy. + + 3. Object Code Incorporating Material from Library Header Files. + + The object code form of an Application may incorporate material from +a header file that is part of the Library. You may convey such object +code under terms of your choice, provided that, if the incorporated +material is not limited to numerical parameters, data structure +layouts and accessors, or small macros, inline functions and templates +(ten or fewer lines in length), you do both of the following: + + a) Give prominent notice with each copy of the object code that the + Library is used in it and that the Library and its use are + covered by this License. + + b) Accompany the object code with a copy of the GNU GPL and this license + document. + + 4. Combined Works. + + You may convey a Combined Work under terms of your choice that, +taken together, effectively do not restrict modification of the +portions of the Library contained in the Combined Work and reverse +engineering for debugging such modifications, if you also do each of +the following: + + a) Give prominent notice with each copy of the Combined Work that + the Library is used in it and that the Library and its use are + covered by this License. + + b) Accompany the Combined Work with a copy of the GNU GPL and this license + document. + + c) For a Combined Work that displays copyright notices during + execution, include the copyright notice for the Library among + these notices, as well as a reference directing the user to the + copies of the GNU GPL and this license document. + + d) Do one of the following: + + 0) Convey the Minimal Corresponding Source under the terms of this + License, and the Corresponding Application Code in a form + suitable for, and under terms that permit, the user to + recombine or relink the Application with a modified version of + the Linked Version to produce a modified Combined Work, in the + manner specified by section 6 of the GNU GPL for conveying + Corresponding Source. + + 1) Use a suitable shared library mechanism for linking with the + Library. A suitable mechanism is one that (a) uses at run time + a copy of the Library already present on the user's computer + system, and (b) will operate properly with a modified version + of the Library that is interface-compatible with the Linked + Version. + + e) Provide Installation Information, but only if you would otherwise + be required to provide such information under section 6 of the + GNU GPL, and only to the extent that such information is + necessary to install and execute a modified version of the + Combined Work produced by recombining or relinking the + Application with a modified version of the Linked Version. (If + you use option 4d0, the Installation Information must accompany + the Minimal Corresponding Source and Corresponding Application + Code. If you use option 4d1, you must provide the Installation + Information in the manner specified by section 6 of the GNU GPL + for conveying Corresponding Source.) + + 5. Combined Libraries. + + You may place library facilities that are a work based on the +Library side by side in a single library together with other library +facilities that are not Applications and are not covered by this +License, and convey such a combined library under terms of your +choice, if you do both of the following: + + a) Accompany the combined library with a copy of the same work based + on the Library, uncombined with any other library facilities, + conveyed under the terms of this License. + + b) Give prominent notice with the combined library that part of it + is a work based on the Library, and explaining where to find the + accompanying uncombined form of the same work. + + 6. Revised Versions of the GNU Lesser General Public License. + + The Free Software Foundation may publish revised and/or new versions +of the GNU Lesser General Public License from time to time. Such new +versions will be similar in spirit to the present version, but may +differ in detail to address new problems or concerns. + + Each version is given a distinguishing version number. If the +Library as you received it specifies that a certain numbered version +of the GNU Lesser General Public License "or any later version" +applies to it, you have the option of following the terms and +conditions either of that published version or of any later version +published by the Free Software Foundation. If the Library as you +received it does not specify a version number of the GNU Lesser +General Public License, you may choose any version of the GNU Lesser +General Public License ever published by the Free Software Foundation. + + If the Library as you received it specifies that a proxy can decide +whether future versions of the GNU Lesser General Public License shall +apply, that proxy's public statement of acceptance of any version is +permanent authorization for you to choose that version for the +Library. diff --git a/README b/README new file mode 100644 index 0000000..1dbe3f6 --- /dev/null +++ b/README @@ -0,0 +1,24 @@ +Some function to generate v4 uuids +================================== + +Generate a random uuid: + + 1> UUID = guid:v4(). + <<254,194,254,188,1,12,79,173,84,118,109,153,143,115,228,127>> + +Convert to text representation: + + 2> guid:unparse(UUID). + "0ee31c01-26cc-43f1-a0f9-b52c6de7fcf7" + +Check it's version: + + 3> guid:version(UUID). + 4 + +Generate text representation drectly: + + 4> guid:v4string(). + "68718f41-06ff-49a8-8283-00582b2d5269" + + diff --git a/rebar b/rebar new file mode 100755 index 0000000..7bdb274 Binary files /dev/null and b/rebar differ diff --git a/rebar.config b/rebar.config new file mode 100644 index 0000000..21412f8 --- /dev/null +++ b/rebar.config @@ -0,0 +1,3 @@ +%%-*- mode: erlang -*- + +{deps, []}. diff --git a/src/guid.app.src b/src/guid.app.src new file mode 100644 index 0000000..afb6108 --- /dev/null +++ b/src/guid.app.src @@ -0,0 +1,9 @@ +%%-*- mode: erlang -*- +{application, guid, + [ + {description, "Simple v4 uuid generator"}, + {vsn, git}, + {registered, []}, + {applications, []}, + {env, []} + ]}. diff --git a/src/guid.erl b/src/guid.erl new file mode 100644 index 0000000..4c3fc15 --- /dev/null +++ b/src/guid.erl @@ -0,0 +1,55 @@ +%% @author Guido Günther +%% @copyright 2013 godiug.net +%% +%% This library is free software; you can redistribute it and/or +%% modify it under the terms of the GNU Lesser General Public +%% License as published by the Free Software Foundation; either +%% version 3 of the License, or (at your option) any later version. +%% +%% This library is distributed in the hope that it will be useful, +%% but WITHOUT ANY WARRANTY; without even the implied warranty of +%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +%% Lesser General Public License for more details. +%% +%% You should have received a copy of the GNU Lesser General Public +%% License along with this library. If not, see +%% . +%% +%% @doc Simple v4 uuid generator + +-module(guid). +-export([v4/0, + v4string/0, + unparse/1, + version/1]). + +%% @doc generate a version 4 uuid as bin +v4() -> + << D1:32, D2:16, D3:16, D4:64 >> = crypto:rand_bytes(16), + << D1:32, D2:16, 4:4, D3:12, D4:64 >>. + +%% @doc generate a version 4 uuid as string +v4string() -> + unparse(v4()). + +%% @doc convert a uuid from bin to string +unparse(UUID) -> + lists:flatten( + io_lib:format("~8.16.0b-" + "~4.16.0b-" + "~4.16.0b-" + "~2.16.0b~2.16.0b-" + "~12.16.0b", parts(UUID))). + +%% @doc get a uuid's version number +version(<< _:48, Version:4, _:76 >>) -> + Version. + +%% @private +% Return the parts of the uuid as per rfc4122: +% time_low (32), time_mid (16), time_hi_and_version (16) +% clock_seq_hi_and_reseved (8), clock_seq_low(8), node (48) +parts(<< TL:32, TM:16, THV:16, CSHR:8, CSL:8, N:48 >>) -> + [TL, TM, THV, CSHR, CSL, N]. + + diff --git a/test/guid_test.erl b/test/guid_test.erl new file mode 100644 index 0000000..d98c853 --- /dev/null +++ b/test/guid_test.erl @@ -0,0 +1,29 @@ +-module(guid_test). +-include_lib("eunit/include/eunit.hrl"). + +% Test descriptions +v4_test_() -> + [{"A v4 uuid must have version 4", + check_v4_version()}, + {"A uuid must be 16 bytes", + check_v4_length()} + ]. + +text_test_() -> + [{"The text representation must be 38 characters long", + check_v4_string_length()} + ]. + +% Tests +check_v4_version() -> + Uuid = guid:v4(), + [?_assertEqual(guid:version(Uuid), 4)]. + + +check_v4_length() -> + Uuid = guid:v4(), + [?_assertEqual(byte_size(Uuid), 16)]. + +check_v4_string_length() -> + String = guid:v4string(), + [?_assertEqual(length(String), 36)]. -- cgit v1.2.3