feat(query/influxql): expose default database and retention policy for transpiler

The influxql transpiler can now be configured with a default database
and retention policy.

http/transpiler_handler.go

@@ -50,11 +50,12 @@ func (h *TranspilerQueryHandler) handlePostQuery(w http.ResponseWriter, r *http.
 		return
 	}
 
-	//TODO(nathanielc): Get database and rp information if needed.
-
+	// Create a new transpiler from the http request.
 	ce := influxqlCE
+	transpiler := ce.transpiler(r)
 
-	results, err := query.QueryWithTranspile(ctx, h.OrgID, queryStr, h.QueryService, ce.transpiler)
+	// Run the transpiler against the query service.
+	results, err := query.QueryWithTranspile(ctx, h.OrgID, queryStr, h.QueryService, transpiler)
 	if err != nil {
 		kerrors.EncodeHTTP(ctx, err, w)
 		return
@@ -68,15 +69,21 @@ func (h *TranspilerQueryHandler) handlePostQuery(w http.ResponseWriter, r *http.
 	}
 }
 
-// crossExecute contains the components needed to execute a transpiled query and encode results
+// crossExecute contains the components needed to execute a transpiled query and encode results.
 type crossExecute struct {
-	transpiler  query.Transpiler
+	transpiler  func(req *http.Request) query.Transpiler
 	encoder     query.MultiResultEncoder
 	contentType string
 }
 
 var influxqlCE = crossExecute{
-	transpiler:  influxql.NewTranspiler(),
+	transpiler: func(req *http.Request) query.Transpiler {
+		config := influxql.Config{
+			DefaultDatabase:        req.FormValue("db"),
+			DefaultRetentionPolicy: req.FormValue("rp"),
+		}
+		return influxql.NewTranspilerWithConfig(config)
+	},
 	encoder:     influxql.NewMultiResultEncoder(),
 	contentType: "application/json",
 }

query/influxql/config.go

@@ -0,0 +1,7 @@
+package influxql
+
+// Config modifies the behavior of the Transpiler.
+type Config struct {
+	DefaultDatabase        string
+	DefaultRetentionPolicy string
+}

query/influxql/transpiler.go

@@ -13,12 +13,20 @@ import (
 )
 
 // Transpiler converts InfluxQL queries into a query spec.
-type Transpiler struct{}
+type Transpiler struct {
+	Config *Config
+}
 
 func NewTranspiler() *Transpiler {
 	return new(Transpiler)
 }
 
+func NewTranspilerWithConfig(cfg Config) *Transpiler {
+	return &Transpiler{
+		Config: &cfg,
+	}
+}
+
 func (t *Transpiler) Transpile(ctx context.Context, txt string) (*query.Spec, error) {
 	// Parse the text of the query.
 	q, err := influxql.ParseQuery(txt)
@@ -26,7 +34,7 @@ func (t *Transpiler) Transpile(ctx context.Context, txt string) (*query.Spec, er
 		return nil, err
 	}
 
-	transpiler := newTranspilerState()
+	transpiler := newTranspilerState(t.Config)
 	for i, s := range q.Statements {
 		stmt, ok := s.(*influxql.SelectStatement)
 		if !ok {
@@ -42,17 +50,21 @@ func (t *Transpiler) Transpile(ctx context.Context, txt string) (*query.Spec, er
 type transpilerState struct {
 	id     int
 	stmt   *influxql.SelectStatement
+	config Config
 	spec   *query.Spec
 	nextID map[string]int
 	now    time.Time
 }
 
-func newTranspilerState() *transpilerState {
+func newTranspilerState(config *Config) *transpilerState {
 	state := &transpilerState{
 		spec:   &query.Spec{},
 		nextID: make(map[string]int),
 		now:    time.Now(),
 	}
+	if config != nil {
+		state.config = *config
+	}
 	return state
 }
 
@@ -101,11 +113,18 @@ func (t *transpilerState) mapType(ref *influxql.VarRef) influxql.DataType {
 func (t *transpilerState) from(m *influxql.Measurement) (query.OperationID, error) {
 	db, rp := m.Database, m.RetentionPolicy
 	if db == "" {
+		if t.config.DefaultDatabase == "" {
 			return "", errors.New("database is required")
 		}
+		db = t.config.DefaultDatabase
+	}
 	if rp == "" {
+		if t.config.DefaultRetentionPolicy != "" {
+			rp = t.config.DefaultRetentionPolicy
+		} else {
 			rp = "autogen"
 		}
+	}
 
 	spec := &functions.FromOpSpec{
 		Bucket: fmt.Sprintf("%s/%s", db, rp),

query/transpiler.go

@@ -8,6 +8,7 @@ import (
 
 // Transpiler can convert a query from a source lanague into a query spec.
 type Transpiler interface {
+	// Transpile will perform the transpilation.
 	Transpile(ctx context.Context, txt string) (*Spec, error)
 }