Introduces native Erlang query servers. Closes COUCHDB-377

Thanks Mark Hammond and Paul Davis for doing most of the work, and Michael McDaniel for the inspiration.

There is still room for improvement on the APIs exposed to the Erlang views, as well as likely a whole lot of work to be done to increase parallelism. But the important part now is that we have native Erlang views.


git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@803685 13f79535-47bb-0310-9956-ffa450edef68

5 files changed, 126 insertions, 27 deletions

diff --git a/share/www/script/couch.js b/share/www/script/couch.js
index af3bb8fb..eba60ad5 100644
--- a/share/www/script/couch.js
+++ b/share/www/script/couch.js
@@ -127,8 +127,8 @@ function CouchDB(name, httpHeaders) {
   }
 
   // Applies the map function to the contents of database and returns the results.
-  this.query = function(mapFun, reduceFun, options, keys) {
-    var body = {language: "javascript"};
+  this.query = function(mapFun, reduceFun, options, keys, language) {
+    var body = {language: language || "javascript"};
     if(keys) {
       body.keys = keys ;
     }
diff --git a/share/www/script/couch_tests.js b/share/www/script/couch_tests.js
index 3d415952..7ddfa312 100644
--- a/share/www/script/couch_tests.js
+++ b/share/www/script/couch_tests.js
@@ -81,6 +81,7 @@ loadScript("script/oauth.js");
 loadTest("oauth.js");
 loadTest("stats.js");
 loadTest("rev_stemming.js");
+loadTest("erlang_views.js");
 
 function makeDocs(start, end, templateDoc) {
   var templateDocSrc = templateDoc ? JSON.stringify(templateDoc) : "{}"
diff --git a/share/www/script/futon.browse.js b/share/www/script/futon.browse.js
index 29c0d86a..7fa880fd 100644
--- a/share/www/script/futon.browse.js
+++ b/share/www/script/futon.browse.js
@@ -206,32 +206,48 @@
 
       // Populate the languages dropdown, and listen to selection changes
       this.populateLanguagesMenu = function() {
+        var all_langs = {};
+        fill_language = function() {
+          var select = $("#language");
+          for (var language in all_langs) {
+            var option = $(document.createElement("option"))
+              .attr("value", language).text(language)
+              .appendTo(select);
+          }
+          if (select[0].options.length == 1) {
+            select[0].disabled = true;
+          } else {
+            select[0].disabled = false;
+            select.val(page.viewLanguage);
+            select.change(function() {
+              var language = $("#language").val();
+              if (language != page.viewLanguage) {
+                var mapFun = $("#viewcode_map").val();
+                if (mapFun == "" || mapFun == templates[page.viewLanguage]) {
+                  // no edits made, so change to the new default
+                  $("#viewcode_map").val(templates[language]);
+                }
+                page.viewLanguage = language;
+                $("#viewcode_map")[0].focus();
+              }
+              return false;
+            });
+          }
+        }
         $.couch.config({
           success: function(resp) {
-            var select = $("#language");
             for (var language in resp) {
-              var option = $(document.createElement("option"))
-                .attr("value", language).text(language)
-                .appendTo(select);
+              all_langs[language] = resp[language];
             }
-            if (select[0].options.length == 1) {
-              select[0].disabled = true;
-            } else {
-              select.val(page.viewLanguage);
-              select.change(function() {
-                var language = $("#language").val();
-                if (language != page.viewLanguage) {
-                  var mapFun = $("#viewcode_map").val();
-                  if (mapFun == "" || mapFun == templates[page.viewLanguage]) {
-                    // no edits made, so change to the new default
-                    $("#viewcode_map").val(templates[language]);
-                  }
-                  page.viewLanguage = language;
-                  $("#viewcode_map")[0].focus();
+
+            $.couch.config({
+              success: function(resp) {
+                for (var language in resp) {
+                  all_langs[language] = resp[language];
                 }
-                return false;
-              });
-            }
+                fill_language();
+              }
+            }, "native_query_servers");
           }
         }, "query_servers");
       }
diff --git a/share/www/script/test/changes.js b/share/www/script/test/changes.js
index d8abcc71..393ff034 100644
--- a/share/www/script/test/changes.js
+++ b/share/www/script/test/changes.js
@@ -161,13 +161,13 @@ couchTests.changes = function(debug) {
   var ddoc = {
     _id : "_design/changes_filter",
     "filters" : {
-      "bop" : "function(doc, req, userCtx) { return (doc.bop);}",
-      "dynamic" : stringFun(function(doc, req, userCtx) { 
+      "bop" : "function(doc, req) { return (doc.bop);}",
+      "dynamic" : stringFun(function(doc, req) { 
         var field = req.query.field;
         return doc[field];
       }),
-      "userCtx" : stringFun(function(doc, req, userCtx) {
-        return doc.user && (doc.user == userCtx.name);
+      "userCtx" : stringFun(function(doc, req) {
+        return doc.user && (doc.user == req.userCtx.name);
       })
     }
   }
diff --git a/share/www/script/test/erlang_views.js b/share/www/script/test/erlang_views.js
new file mode 100644
index 00000000..6a378690
--- /dev/null
+++ b/share/www/script/test/erlang_views.js
@@ -0,0 +1,82 @@
+// 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.erlang_views = function(debug) {
+  var db = new CouchDB("test_suite_db");
+  db.deleteDb();
+  db.createDb();
+  if (debug) debugger;
+
+
+
+  run_on_modified_server(
+    [{section: "native_query_servers",
+      key: "erlang",
+      value: "{couch_native_process, start_link, []}"}],
+    function() {
+      // Note we just do some basic 'smoke tests' here - the
+      // test/query_server_spec.rb tests have more comprehensive tests
+      var doc = {integer: 1, string: "str1", array: [1, 2, 3]};
+      T(db.save(doc).ok);
+
+      var mfun = 'fun({Doc}) -> ' +
+                 ' K = proplists:get_value(<<"integer">>, Doc, null), ' +
+                 ' V = proplists:get_value(<<"string">>, Doc, null), ' +
+                 ' Emit(K, V) ' +
+                 'end.';
+
+      // emitting a key value that is undefined should result in that row not
+      // being included in the view results
+      var results = db.query(mfun, null, null, null, "erlang");
+      T(results.total_rows == 1);
+      T(results.rows[0].key == 1);
+      T(results.rows[0].value == "str1");
+      // check simple reduction - another doc with same key.
+      var doc = {integer: 1, string: "str2"};
+      T(db.save(doc).ok);
+      rfun = "fun(Keys, Values, ReReduce) -> length(Values) end."
+      results = db.query(mfun, rfun, null, null, "erlang");
+      T(results.rows[0].value == 2);
+
+      // simple 'list' tests
+      var designDoc = {
+        _id:"_design/erlview",
+        language: "erlang",
+        lists: {
+          simple_list :
+            'fun(Head, {Req}) -> ' +
+            '  Send(<<"head">>), ' +
+            '  Fun = fun({Row}, _) -> ' +
+            '    Send(proplists:get_value(<<"value">>, Row, null)), ' +
+            '    {ok, nil} ' +
+            '  end, ' +
+            '  {ok, _} = FoldRows(Fun, nil), ' +
+            '  <<"tail">> ' +
+            'end. '
+        },
+        views: {
+          simple_view : {
+            map: mfun,
+            reduce: rfun
+          }
+        }
+      };
+      T(db.save(designDoc).ok);
+
+      // *sob* - show functions have problems :(
+      /***
+      var xhr = CouchDB.request("GET", "/test_suite_db/_design/erlview/_list/simple_list/simple_view");
+      T(xhr.status == 200, "standard get should be 200");
+      T(xhr.responseText == "head2tail");
+      ***/
+    });
+};