From c596db1079f5a062a89c4c70dbb1e2929f7b0d84 Mon Sep 17 00:00:00 2001 From: John Christopher Anderson Date: Tue, 12 May 2009 21:38:43 +0000 Subject: You can now specify either "_sum" or "_count" as the source code for 2 built-in Erlang reduce functions. The framework is ready for YOU to add more built in reductions. The short list includes: _avg, _stddev, _min, and _max. We could also have one function that does all that in a single function, but it might not be as fun to use. git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@774101 13f79535-47bb-0310-9956-ffa450edef68 --- share/www/script/couch_tests.js | 1 + share/www/script/test/reduce_builtin.js | 119 ++++++++++++++++++++++++++++++++ src/couchdb/couch_query_servers.erl | 52 ++++++++++++-- 3 files changed, 167 insertions(+), 5 deletions(-) create mode 100644 share/www/script/test/reduce_builtin.js diff --git a/share/www/script/couch_tests.js b/share/www/script/couch_tests.js index 62e877d8..6528835d 100644 --- a/share/www/script/couch_tests.js +++ b/share/www/script/couch_tests.js @@ -37,6 +37,7 @@ loadTest("bulk_docs.js"); loadTest("lots_of_docs.js"); loadTest("reduce.js"); loadTest("reduce_false.js"); +loadTest("reduce_builtin.js"); loadTest("design_options.js"); loadTest("multiple_rows.js"); loadTest("large_docs.js"); diff --git a/share/www/script/test/reduce_builtin.js b/share/www/script/test/reduce_builtin.js new file mode 100644 index 00000000..c3d00339 --- /dev/null +++ b/share/www/script/test/reduce_builtin.js @@ -0,0 +1,119 @@ +// 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. + +couchTests.reduce_builtin = function(debug) { + var db = new CouchDB("test_suite_db"); + db.deleteDb(); + db.createDb(); + if (debug) debugger; + + var numDocs = 500 + var docs = makeDocs(1,numDocs + 1); + db.bulkSave(docs); + + var summate = function(N) {return (N+1)*N/2;}; + + // this is the same test as the reduce.js test + // only we'll let CouchDB run reduce in Erlang + var map = function (doc) { + emit(doc.integer, doc.integer); + emit(doc.integer, doc.integer)}; + + var result = db.query(map, "_sum"); + T(result.rows[0].value == 2*summate(numDocs)); + result = db.query(map, "_count"); + T(result.rows[0].value == 1000); + + result = db.query(map, "_sum", {startkey: 4, endkey: 4}); + T(result.rows[0].value == 8); + result = db.query(map, "_count", {startkey: 4, endkey: 4}); + T(result.rows[0].value == 2); + + result = db.query(map, "_sum", {startkey: 4, endkey: 5}); + T(result.rows[0].value == 18); + result = db.query(map, "_count", {startkey: 4, endkey: 5}); + T(result.rows[0].value == 4); + + result = db.query(map, "_sum", {startkey: 4, endkey: 6}); + T(result.rows[0].value == 30); + result = db.query(map, "_count", {startkey: 4, endkey: 6}); + T(result.rows[0].value == 6); + + result = db.query(map, "_sum", {group:true, limit:3}); + T(result.rows[0].value == 2); + T(result.rows[1].value == 4); + T(result.rows[2].value == 6); + + for(var i=1; i Pid = get_os_process(Lang), Grouped = group_reductions_results(ReducedValues), Results = try lists:zipwith( - fun(FunSrc, Values) -> + fun + (<<"_", _/binary>> = FunSrc, Values) -> + {ok, [Result]} = builtin_reduce(rereduce, [FunSrc], [[[], V] || V <- Values], []), + Result; + (FunSrc, Values) -> [true, [Result]] = couch_os_process:prompt(Pid, [<<"rereduce">>, [FunSrc], Values]), Result @@ -99,15 +103,53 @@ rereduce(Lang, RedSrcs, ReducedValues) -> reduce(_Lang, [], _KVs) -> {ok, []}; reduce(Lang, RedSrcs, KVs) -> + {OsRedSrcs, BuiltinReds} = lists:partition(fun + (<<"_", _/binary>>) -> false; + (_OsFun) -> true + end, RedSrcs), + {ok, OsResults} = os_reduce(Lang, OsRedSrcs, KVs), + {ok, BuiltinResults} = builtin_reduce(reduce, BuiltinReds, KVs, []), + recombine_reduce_results(RedSrcs, OsResults, BuiltinResults, []). + +recombine_reduce_results([], [], [], Acc) -> + {ok, lists:reverse(Acc)}; +recombine_reduce_results([<<"_", _/binary>>|RedSrcs], OsResults, [BRes|BuiltinResults], Acc) -> + recombine_reduce_results(RedSrcs, OsResults, BuiltinResults, [BRes|Acc]); +recombine_reduce_results([_OsFun|RedSrcs], [OsR|OsResults], BuiltinResults, Acc) -> + recombine_reduce_results(RedSrcs, OsResults, BuiltinResults, [OsR|Acc]). + +os_reduce(Lang, [], KVs) -> + {ok, []}; +os_reduce(Lang, OsRedSrcs, KVs) -> Pid = get_os_process(Lang), - Results = try couch_os_process:prompt(Pid, - [<<"reduce">>, RedSrcs, KVs]) of + OsResults = try couch_os_process:prompt(Pid, + [<<"reduce">>, OsRedSrcs, KVs]) of [true, Reductions] -> Reductions after ok = ret_os_process(Lang, Pid) end, - {ok, Results}. - + {ok, OsResults}. + +builtin_reduce(_Re, [], KVs, Acc) -> + {ok, lists:reverse(Acc)}; +builtin_reduce(Re, [<<"_sum">>|BuiltinReds], KVs, Acc) -> + Sum = builtin_sum_rows(KVs), + builtin_reduce(Re, BuiltinReds, KVs, [Sum|Acc]); +builtin_reduce(reduce, [<<"_count">>|BuiltinReds], KVs, Acc) -> + Count = length(KVs), + builtin_reduce(reduce, BuiltinReds, KVs, [Count|Acc]); +builtin_reduce(rereduce, [<<"_count">>|BuiltinReds], KVs, Acc) -> + Count = builtin_sum_rows(KVs), + builtin_reduce(rereduce, BuiltinReds, KVs, [Count|Acc]). + +builtin_sum_rows(KVs) -> + lists:foldl(fun + ([_Key, Value], Acc) when is_number(Value) -> + Acc + Value; + (_Else, _Acc) -> + throw({invalid_value, <<"builtin _sum function requires map values to be numbers">>}) + end, 0, KVs). + validate_doc_update(Lang, FunSrc, EditDoc, DiskDoc, Ctx) -> Pid = get_os_process(Lang), JsonEditDoc = couch_doc:to_json_obj(EditDoc, [revs]), -- cgit v1.2.3