Merge 57a2c8e into 6af24a3

levelgraph · Dec 8, 2013 · 5f339e9 · 5f339e9
2 parents 6af24a3 + 57a2c8e
commit 5f339e9
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Showing 6 changed files with 126 additions and 86 deletions.
diff --git a/lib/joinstream.js b/lib/joinstream.js
@@ -4,8 +4,8 @@ var Transform = require('./streamwrapper').Transform
   , utilities = require('./utilities')
   , queryMask = utilities.queryMask
   , variablesMask = utilities.variablesMask
-  , maskUpdater
-  , matcher;
+  , maskUpdater = utilities.maskUpdater
+  , matcher = utilities.matcher;
 
 function JoinStream(options) {
   if (!(this instanceof JoinStream)) {
@@ -59,38 +59,3 @@ JoinStream.prototype._transform = function(solution, encoding, done) {
 };
 
 module.exports = JoinStream;
-
-matcher = function(pattern) {
-  var variables = variablesMask(pattern);
-  return function(solution, triple) {
-    var bindable = Object.keys(variables).every(function(key) {
-      var variable = variables[key];
-      return variable.isBindable(solution, triple[key]);
-    });
-
-    if (!bindable) {
-      return false;
-    }
-
-    return Object.keys(variables).reduce(function(newsolution, key) {
-      var variable = variables[key];
-      return variable.bind(newsolution, triple[key]);
-    }, solution);
-  };
-};
-
-maskUpdater = function(pattern) {
-  var variables = variablesMask(pattern);
-  return function(solution, mask) {
-    return Object.keys(variables).reduce(function(newMask, key) {
-      var variable = variables[key];
-      if (variable.isBound(solution)) {
-        newMask[key] = solution[variable.name];
-      }
-      return newMask;
-    }, Object.keys(mask).reduce(function(acc, key) {
-      acc[key] = mask[key];
-      return acc;
-    }, {}));
-  };
-};
diff --git a/lib/keyfilterstream.js b/lib/keyfilterstream.js
@@ -18,6 +18,8 @@ function KeyFilterStream(options) {
     that.source = source;
   });
 
+  this.filter = options.filter;
+
   this._destroyed = false;
 }
 
@@ -28,10 +30,12 @@ KeyFilterStream.prototype = Object.create(
 
 KeyFilterStream.prototype._transform = function(data, encoding, done) {
 
+  data.value = JSON.parse(data.value);
+
   if (this._destroyed || data.key.indexOf(this.start) < 0) {
     this.source.destroy();
-  } else {
-    this.push(JSON.parse(data.value));
+  } else if (!this.filter || this.filter(data.value)) {
+    this.push(data.value);
   }
 
   done();

diff --git a/lib/sortjoinstream.js b/lib/sortjoinstream.js
@@ -1,14 +1,14 @@
 
 var Transform = require('./streamwrapper').Transform
   , Variable = require('./variable')
-  , queryMask = require('./utilities').queryMask
-  , variablesMask = require('./utilities').variablesMask
-  , maskUpdater
-  , matcher
-  , materializer = require('./utilities').materializer
-  , createQuery = require('./utilities').createQuery
-  , genKey = require('./utilities').genKey
-  , genKeys = require('./utilities').genKeys;
+  , utilities = require('./utilities')
+  , queryMask = utilities.queryMask
+  , variablesMask = utilities.variablesMask
+  , matcher = utilities.matcher
+  , materializer = utilities.materializer
+  , createQuery = utilities.createQuery
+  , genKey = utilities.genKey
+  , genKeys = utilities.genKeys;
 
 var counter = 0;
 
@@ -33,6 +33,7 @@ function SortJoinStream(options) {
   });
 
   this._queryMask = queryMask(options.triple);
+  this._queryMask.filter = options.triple.filter;
 
   this.index = options.index;
 
@@ -159,38 +160,3 @@ SortJoinStream.prototype._transform = function(solution, encoding, done) {
 };
 
 module.exports = SortJoinStream;
-
-matcher = function(pattern) {
-  var variables = variablesMask(pattern);
-  return function(solution, triple) {
-    var bindable = Object.keys(variables).every(function(key) {
-      var variable = variables[key];
-      return variable.isBindable(solution, triple[key]);
-    });
-
-    if (!bindable) {
-      return false;
-    }
-
-    return Object.keys(variables).reduce(function(newsolution, key) {
-      var variable = variables[key];
-      return variable.bind(newsolution, triple[key]);
-    }, solution);
-  };
-};
-
-maskUpdater = function(pattern) {
-  var variables = variablesMask(pattern);
-  return function(solution, mask) {
-    return Object.keys(variables).reduce(function(newMask, key) {
-      var variable = variables[key];
-      if (variable.isBound(solution)) {
-        newMask[key] = solution[variable.name];
-      }
-      return newMask;
-    }, Object.keys(mask).reduce(function(acc, key) {
-      acc[key] = mask[key];
-      return acc;
-    }, {}));
-  };
-};
diff --git a/lib/utilities.js b/lib/utilities.js
@@ -103,15 +103,29 @@ function findIndex(types, preferiteIndex) {
 
 module.exports.findIndex = findIndex;
 
+function typesFromPattern(pattern) {
+  return Object.keys(pattern).filter(function(key) {
+    switch(key) {
+      case 'subject':
+      case 'predicate':
+      case 'object':
+        return true;
+      default:
+        return false;
+    }
+  });
+}
+
 function createQuery(pattern, options) {
-  var types = Object.keys(pattern)
+  var types = typesFromPattern(pattern)
     , preferiteIndex = (options || {}).index
     , index = findIndex(types, preferiteIndex)
     , key = genKey(index, pattern)
     , query = {
-        start: key,
-        end: key + '\xff',
-        fillCache: true
+          start: key
+        , end: key + '\xff'
+        , fillCache: true
+        , filter: pattern.filter
       };
 
   return query;
@@ -180,3 +194,45 @@ module.exports.materializer = materializer;
     return objectMask(c, object);
   };
 })();
+
+var variablesMask = module.exports.variablesMask;
+
+function maskUpdater(pattern) {
+  var variables = variablesMask(pattern);
+  return function(solution, mask) {
+    return Object.keys(variables).reduce(function(newMask, key) {
+      var variable = variables[key];
+      if (variable.isBound(solution)) {
+        newMask[key] = solution[variable.name];
+      }
+      newMask.filter = pattern.filter;
+      return newMask;
+    }, Object.keys(mask).reduce(function(acc, key) {
+      acc[key] = mask[key];
+      return acc;
+    }, {}));
+  };
+}
+
+module.exports.maskUpdater = maskUpdater;
+
+function matcher(pattern) {
+  var variables = variablesMask(pattern);
+  return function(solution, triple) {
+    var bindable = Object.keys(variables).every(function(key) {
+      var variable = variables[key];
+      return variable.isBindable(solution, triple[key]);
+    });
+
+    if (!bindable) {
+      return false;
+    }
+
+    return Object.keys(variables).reduce(function(newsolution, key) {
+      var variable = variables[key];
+      return variable.bind(newsolution, triple[key]);
+    }, solution);
+  };
+}
+
+module.exports.matcher = matcher;
diff --git a/test/abstract_join_algorithm.js b/test/abstract_join_algorithm.js
@@ -240,4 +240,37 @@ module.exports = function(joinAlgorithm) {
       done();
     });
   });
+
+  it('should support filtering inside a condition', function(done) {
+    db.search([{
+      subject: db.v('x'),
+      predicate: 'friend',
+      object: 'daniele',
+      filter: function(triple) { return triple.subject !== 'matteo'; }
+    }], function(err, results) {
+      expect(results).to.have.length(0);
+      done();
+    });
+  });
+
+  it('should support filtering inside a second-level condition', function(done) {
+    db.search([{
+      subject: 'matteo',
+      predicate: 'friend',
+      object: db.v('y'),
+    }, {
+      subject: db.v('y'),
+      predicate: 'friend',
+      object: db.v('x'),
+      filter: function(triple) { 
+        return triple.object !== 'matteo';
+      }
+    }], function(err, results) {
+      expect(results).to.eql([{
+        'y': 'daniele',
+        'x': 'marco'
+      }]);
+      done();
+    });
+  });
 };
diff --git a/test/triple_store_spec.js b/test/triple_store_spec.js
@@ -222,4 +222,20 @@ describe('a basic triple store', function() {
   it('should alias search to join', function() {
     expect(db.join).to.eql(db.search);
   });
+
+  it('should support filtering', function(done) {
+    var triple1 = { subject: 'a', predicate: 'b', object: 'd' }
+      , triple2 = { subject: 'a', predicate: 'b', object: 'c' };
+
+    db.put([triple1, triple2], function() {
+      function filter(triple) {
+        return triple.object === 'd';
+      }
+
+      db.get({ subject: 'a', predicate: 'b', filter: filter }, function(err, results) {
+        expect(results).to.eql([triple1]);
+        done();
+      });
+    });
+  });
 });