From ddc4e717df1da722682b6ccdbf152a6b7e15f378 Mon Sep 17 00:00:00 2001 From: beaver Date: Wed, 25 Mar 2015 18:03:26 +0300 Subject: stdlib: Add gb_trees:iterator_from --- lib/stdlib/doc/src/gb_trees.xml | 13 +++++++++- lib/stdlib/src/gb_trees.erl | 31 ++++++++++++++++++++++-- lib/stdlib/test/dict_SUITE.erl | 50 +++++++++++++++++++++++++++++++++++---- lib/stdlib/test/dict_test_lib.erl | 5 +++- 4 files changed, 91 insertions(+), 8 deletions(-) (limited to 'lib') diff --git a/lib/stdlib/doc/src/gb_trees.xml b/lib/stdlib/doc/src/gb_trees.xml index b2f237e1d7..82167e1083 100644 --- a/lib/stdlib/doc/src/gb_trees.xml +++ b/lib/stdlib/doc/src/gb_trees.xml @@ -4,7 +4,7 @@
- 20012014 + 20012015 Ericsson AB. All Rights Reserved. @@ -182,6 +182,17 @@ memory at one time.

+ + + Return an iterator for a tree starting from specified key + +

Returns an iterator that can be used for traversing the + entries of Tree; see next/1. + The difference as compared to the iterator returned by + iterator/1 is that the first key greater than + or equal to Key is returned.

+ + Return a list of the keys in a tree diff --git a/lib/stdlib/src/gb_trees.erl b/lib/stdlib/src/gb_trees.erl index 7069b61873..259e8f718b 100644 --- a/lib/stdlib/src/gb_trees.erl +++ b/lib/stdlib/src/gb_trees.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2001-2014. All Rights Reserved. +%% Copyright Ericsson AB 2001-2015. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -102,6 +102,10 @@ %% approach is that it does not require the complete list of all %% elements to be built in memory at one time. %% +%% - iterator_from(K, T): returns an iterator that can be used for +%% traversing the entries of tree T with key greater than or +%% equal to K; see `next'. +%% %% - next(S): returns {X, V, S1} where X is the smallest key referred to %% by the iterator S, and S1 is the new iterator to be used for %% traversing the remaining entries, or the atom `none' if no entries @@ -117,7 +121,7 @@ update/3, enter/3, delete/2, delete_any/2, balance/1, is_defined/2, keys/1, values/1, to_list/1, from_orddict/1, smallest/1, largest/1, take_smallest/1, take_largest/1, - iterator/1, next/1, map/2]). + iterator/1, iterator_from/2, next/1, map/2]). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% @@ -529,6 +533,29 @@ iterator({_, _, L, _} = T, As) -> iterator(nil, As) -> As. +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +-spec iterator_from(Key, Tree) -> Iter when + Tree :: tree(Key, Value), + Iter :: iter(Key, Value). + +iterator_from(S, {_, T}) -> + iterator_1_from(S, T). + +iterator_1_from(S, T) -> + iterator_from(S, T, []). + +iterator_from(S, {K, _, _, T}, As) when K < S -> + iterator_from(S, T, As); +iterator_from(_, {_, _, nil, _} = T, As) -> + [T | As]; +iterator_from(S, {_, _, L, _} = T, As) -> + iterator_from(S, L, [T | As]); +iterator_from(_, nil, As) -> + As. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + -spec next(Iter1) -> 'none' | {Key, Value, Iter2} when Iter1 :: iter(Key, Value), Iter2 :: iter(Key, Value). diff --git a/lib/stdlib/test/dict_SUITE.erl b/lib/stdlib/test/dict_SUITE.erl index 69814e12ce..ab624e8dd2 100644 --- a/lib/stdlib/test/dict_SUITE.erl +++ b/lib/stdlib/test/dict_SUITE.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2008-2013. All Rights Reserved. +%% Copyright Ericsson AB 2008-2015. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -25,16 +25,16 @@ -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, init_per_group/2,end_per_group/2, init_per_testcase/2,end_per_testcase/2, - create/1,store/1]). + create/1,store/1,iterate/1]). -include_lib("test_server/include/test_server.hrl"). --import(lists, [foldl/3,reverse/1]). +-import(lists, [foldl/3]). suite() -> [{ct_hooks,[ts_install_cth]}]. all() -> - [create, store]. + [create, store, iterate]. groups() -> []. @@ -92,6 +92,48 @@ store_1(List, M) -> end, D0. +%%% +%%% Test specifics for gb_trees. +%%% + +iterate(Config) when is_list(Config) -> + test_all(fun iterate_1/1). + +iterate_1(M) -> + case M(module, []) of + gb_trees -> iterate_2(M); + _ -> ok + end, + M(empty, []). + +iterate_2(M) -> + random:seed(1, 2, 42), + iter_tree(M, 1000). + +iter_tree(_M, 0) -> + ok; +iter_tree(M, N) -> + L = [{I, I} || I <- lists:seq(1, N)], + T = M(from_list, L), + L = lists:reverse(iterate_tree(M, T)), + R = random:uniform(N), + KV = lists:reverse(iterate_tree_from(M, R, T)), + KV = [P || P={K,_} <- L, K >= R], + iter_tree(M, N-1). + +iterate_tree(M, Tree) -> + I = M(iterator, Tree), + iterate_tree_1(M, M(next, I), []). + +iterate_tree_from(M, Start, Tree) -> + I = M(iterator_from, {Start, Tree}), + iterate_tree_1(M, M(next, I), []). + +iterate_tree_1(_, none, R) -> + R; +iterate_tree_1(M, {K, V, I}, R) -> + iterate_tree_1(M, M(next, I), [{K, V} | R]). + %%% %%% Helper functions. %%% diff --git a/lib/stdlib/test/dict_test_lib.erl b/lib/stdlib/test/dict_test_lib.erl index 4fdb4fa0bd..81d26ce5f8 100644 --- a/lib/stdlib/test/dict_test_lib.erl +++ b/lib/stdlib/test/dict_test_lib.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2008-2013. All Rights Reserved. +%% Copyright Ericsson AB 2008-2015. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -29,6 +29,9 @@ new(Mod, Eq) -> (module, []) -> Mod; (size, D) -> Mod:size(D); (is_empty, D) -> Mod:is_empty(D); + (iterator, S) -> Mod:iterator(S); + (iterator_from, {Start, S}) -> Mod:iterator_from(Start, S); + (next, I) -> Mod:next(I); (to_list, D) -> to_list(Mod, D) end. -- cgit v1.2.3