Initial checkin of _changes filters. The prime weak-spot for this approach is that it maintains an OS-process per connected filtered _changes consumer. I'm pretty sure we'll be able to work around this without changing the API, but it'll involve a lot of OS-process bookkeeping. Those enhancements should generally improve show & list performance as well. Punting on them for now, first wanted to get _changes filters implemented so people could give feedback.

git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@795687 13f79535-47bb-0310-9956-ffa450edef68

4 files changed, 90 insertions, 1 deletions

diff --git a/share/Makefile.am b/share/Makefile.am
index 99a05426..d1cdb457 100644
--- a/share/Makefile.am
+++ b/share/Makefile.am
@@ -13,6 +13,7 @@
 JS_FILE = server/main.js
 
 JS_FILE_COMPONENTS = \
+    server/filter.js \
     server/render.js \
     server/state.js \
     server/util.js \
diff --git a/share/server/filter.js b/share/server/filter.js
new file mode 100644
index 00000000..23536db0
--- /dev/null
+++ b/share/server/filter.js
@@ -0,0 +1,25 @@
+// 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.
+
+var Filter = {
+  filter : function(docs, req, userCtx) {
+    var results = [];
+    try {
+      for (var i=0; i < docs.length; i++) {
+        results.push((funs[0](docs[i], req, userCtx) && true) || false);
+      };
+      respond([true, results]);
+    } catch (error) {
+      respond(error);
+    }
+  }
+};
diff --git a/share/server/loop.js b/share/server/loop.js
index d65ff02b..af656121 100644
--- a/share/server/loop.js
+++ b/share/server/loop.js
@@ -41,7 +41,8 @@ var dispatch = {
   "rereduce" : Views.rereduce,
   "validate" : Validate.validate,
   "show"     : Render.show,
-  "list"     : Render.list
+  "list"     : Render.list,
+  "filter"   : Filter.filter
 };
 
 while (line = eval(readline())) {
diff --git a/share/www/script/test/changes.js b/share/www/script/test/changes.js
index f2d33c17..f5a3e149 100644
--- a/share/www/script/test/changes.js
+++ b/share/www/script/test/changes.js
@@ -110,4 +110,66 @@ couchTests.changes = function(debug) {
     T(str.charAt(str.length - 1) == "\n")
     T(str.charAt(str.length - 2) == "\n")
   }
+  
+  // test the filtered changes
+  var ddoc = {
+    _id : "_design/changes_filter",
+    "filters" : {
+      "bop" : "function(doc, req, userCtx) { return (doc.bop);}",
+      "dynamic" : stringFun(function(doc, req, userCtx) { 
+        var field = req.query.field;
+        return doc[field];
+      }),
+      "userCtx" : stringFun(function(doc, req, userCtx) {
+        return doc.user && (doc.user == userCtx.name);
+      })
+    }
+  }
+
+  db.save(ddoc);
+
+  var req = CouchDB.request("GET", "/test_suite_db/_changes?filter=changes_filter/bop");
+  var resp = JSON.parse(req.responseText);
+  T(resp.results.length == 0); 
+
+  db.save({"bop" : "foom"});
+  
+  var req = CouchDB.request("GET", "/test_suite_db/_changes?filter=changes_filter/bop");
+  var resp = JSON.parse(req.responseText);
+  T(resp.results.length == 1);
+    
+  req = CouchDB.request("GET", "/test_suite_db/_changes?filter=changes_filter/dynamic&field=woox");
+  resp = JSON.parse(req.responseText);
+  T(resp.results.length == 0);
+  
+  req = CouchDB.request("GET", "/test_suite_db/_changes?filter=changes_filter/dynamic&field=bop");
+  resp = JSON.parse(req.responseText);
+  T(resp.results.length == 1);
+  
+  // test for userCtx
+  run_on_modified_server(
+    [{section: "httpd",
+      key: "authentication_handler",
+      value: "{couch_httpd, special_test_authentication_handler}"},
+     {section:"httpd",
+      key: "WWW-Authenticate",
+      value:  "X-Couch-Test-Auth"}],
+
+    function() {
+      var authOpts = {"headers":{"WWW-Authenticate": "X-Couch-Test-Auth Chris Anderson:mp3"}};
+      
+      T(db.save({"user" : "Noah Slater"}).ok);
+      var req = CouchDB.request("GET", "/test_suite_db/_changes?filter=changes_filter/userCtx", authOpts);
+      var resp = JSON.parse(req.responseText);
+      T(resp.results.length == 0);
+
+      var docResp = db.save({"user" : "Chris Anderson"});
+      T(docResp.ok);
+      req = CouchDB.request("GET", "/test_suite_db/_changes?filter=changes_filter/userCtx", authOpts);
+      resp = JSON.parse(req.responseText);
+      T(resp.results.length == 1);
+      T(resp.results[0].id == docResp.id);
+    });
+  
+  // todo implement adhoc filters...
 };