fix #102. Support expressions in where condition

CHANGELOG.md

@@ -149,6 +149,7 @@
 - [Issue #88](https://github.com/influxdb/influxdb/issues/88). Support datetime strings
 - [Issue #64](https://github.com/influxdb/influxdb/issues/64). Shard writes and queries across cluster with replay for briefly downed nodes (< 24 hrs)
 - [Issue #78](https://github.com/influxdb/influxdb/issues/78). Sequence numbers persist across restarts so they're not reused
+- [Issue #102](https://github.com/influxdb/influxdb/issues/102). Support expressions in where condition
 
 ## Bugfixes
 

src/datastore/arithemtic.go

@@ -1,4 +1,4 @@
-package engine
+package datastore
 
 import (
 	"common"
@@ -20,7 +20,7 @@ func init() {
 	registeredArithmeticOperator["/"] = DivideOperator
 }
 
-func getValue(value *parser.Value, fields []string, point *protocol.Point) (*protocol.FieldValue, error) {
+func GetValue(value *parser.Value, fields []string, point *protocol.Point) (*protocol.FieldValue, error) {
 	switch value.Type {
 	case parser.ValueSimpleName:
 		for idx, f := range fields {
@@ -44,11 +44,11 @@ func getValue(value *parser.Value, fields []string, point *protocol.Point) (*pro
 }
 
 func PlusOperator(elems []*parser.Value, fields []string, point *protocol.Point) (*protocol.FieldValue, error) {
-	leftValue, err := getValue(elems[0], fields, point)
+	leftValue, err := GetValue(elems[0], fields, point)
 	if err != nil {
 		return nil, err
 	}
-	rightValues, err := getValue(elems[1], fields, point)
+	rightValues, err := GetValue(elems[1], fields, point)
 	if err != nil {
 		return nil, err
 	}
@@ -65,11 +65,11 @@ func PlusOperator(elems []*parser.Value, fields []string, point *protocol.Point)
 }
 
 func MinusOperator(elems []*parser.Value, fields []string, point *protocol.Point) (*protocol.FieldValue, error) {
-	leftValue, err := getValue(elems[0], fields, point)
+	leftValue, err := GetValue(elems[0], fields, point)
 	if err != nil {
 		return nil, err
 	}
-	rightValues, err := getValue(elems[1], fields, point)
+	rightValues, err := GetValue(elems[1], fields, point)
 	if err != nil {
 		return nil, err
 	}
@@ -86,11 +86,11 @@ func MinusOperator(elems []*parser.Value, fields []string, point *protocol.Point
 }
 
 func MultiplyOperator(elems []*parser.Value, fields []string, point *protocol.Point) (*protocol.FieldValue, error) {
-	leftValue, err := getValue(elems[0], fields, point)
+	leftValue, err := GetValue(elems[0], fields, point)
 	if err != nil {
 		return nil, err
 	}
-	rightValues, err := getValue(elems[1], fields, point)
+	rightValues, err := GetValue(elems[1], fields, point)
 	if err != nil {
 		return nil, err
 	}
@@ -107,11 +107,11 @@ func MultiplyOperator(elems []*parser.Value, fields []string, point *protocol.Po
 }
 
 func DivideOperator(elems []*parser.Value, fields []string, point *protocol.Point) (*protocol.FieldValue, error) {
-	leftValue, err := getValue(elems[0], fields, point)
+	leftValue, err := GetValue(elems[0], fields, point)
 	if err != nil {
 		return nil, err
 	}
-	rightValues, err := getValue(elems[1], fields, point)
+	rightValues, err := GetValue(elems[1], fields, point)
 	if err != nil {
 		return nil, err
 	}

src/datastore/filtering.go

@@ -38,6 +38,12 @@ func getExpressionValue(values []*parser.Value, fields []string, point *protocol
 			}
 
 			fieldValues = append(fieldValues, point.Values[fieldIdx])
+		case parser.ValueExpression:
+			v, err := GetValue(value, fields, point)
+			if err != nil {
+				return nil, err
+			}
+			fieldValues = append(fieldValues, v)
 		default:
 			return nil, fmt.Errorf("Cannot evaluate expression")
 		}

src/engine/engine.go

@@ -3,6 +3,7 @@ package engine
 import (
 	"common"
 	"coordinator"
+	"datastore"
 	"fmt"
 	"os"
 	"parser"
@@ -438,7 +439,7 @@ func (self *QueryEngine) executeArithmeticQuery(user common.User, database strin
 			}
 			for _, field := range newSeries.Fields {
 				value := names[field]
-				v, err := getValue(value, series.Fields, point)
+				v, err := datastore.GetValue(value, series.Fields, point)
 				if err != nil {
 					return err
 				}

src/integration/benchmark_test.go

@@ -637,6 +637,29 @@ func (self *IntegrationSuite) TestIssue105(c *C) {
 	c.Assert(data[0].Points[0][3], Equals, 1.0)
 }
 
+func (self *IntegrationSuite) TestWhereConditionWithExpression(c *C) {
+	err := self.server.WriteData(`
+[
+  {
+    "name": "test_issue_105",
+    "columns": ["time", "a", "b"],
+    "points":[
+		  [1386262529794, 2, 1],
+		  [1386262529794, 2, 0]
+	  ]
+  }
+]`, "time_precision=m")
+	c.Assert(err, IsNil)
+	bs, err := self.server.RunQuery("select a, b from test_issue_105 where a + b >= 3")
+	c.Assert(err, IsNil)
+	data := []*h.SerializedSeries{}
+	err = json.Unmarshal(bs, &data)
+	c.Assert(data, HasLen, 1)
+	c.Assert(data[0].Columns, HasLen, 4)
+	c.Assert(data[0].Points, HasLen, 1)
+	c.Assert(data[0].Points[0][3], Equals, 1.0)
+}
+
 // test for issue #41
 func (self *IntegrationSuite) TestDbDelete(c *C) {
 	err := self.server.WriteData(`