Added API struct; moved query logic to API

api.go

@@ -0,0 +1,101 @@
+// Copyright 2017 Pilosa Corp.
+//
+// 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.
+
+package pilosa
+
+import (
+	"context"
+	"strings"
+
+	"github.com/pilosa/pilosa/pql"
+)
+
+type QueryOptions struct {
+	Remote       bool
+	ExcludeAttrs bool
+	ExcludeBits  bool
+	ColumnAttrs  bool
+}
+
+type API struct {
+	holder *Holder
+	// The execution engine for running queries.
+	executor interface {
+		Execute(context context.Context, index string, query *pql.Query, slices []uint64, opt *ExecOptions) ([]interface{}, error)
+	}
+}
+
+func (a *API) ExecuteQuery(ctx context.Context, req *QueryRequest) (QueryResponse, error) {
+	resp := QueryResponse{}
+
+	q, err := pql.NewParser(strings.NewReader(req.Query)).Parse()
+	if err != nil {
+		// TODO: Wrap
+		return resp, err
+	}
+	execOpts := &ExecOptions{
+		Remote:       req.Remote,
+		ExcludeAttrs: req.ExcludeAttrs,
+		ExcludeBits:  req.ExcludeBits,
+	}
+	results, err := a.executor.Execute(ctx, req.Index, q, req.Slices, execOpts)
+	if err != nil {
+		return resp, err
+	}
+	resp.Results = results
+
+	// Fill column attributes if requested.
+	if req.ColumnAttrs && !req.ExcludeBits {
+		// Consolidate all column ids across all calls.
+		var columnIDs []uint64
+		for _, result := range results {
+			bm, ok := result.(*Bitmap)
+			if !ok {
+				continue
+			}
+			columnIDs = uint64Slice(columnIDs).merge(bm.Bits())
+		}
+
+		// Retrieve column attributes across all calls.
+		columnAttrSets, err := a.readColumnAttrSets(a.holder.Index(req.Index), columnIDs)
+		if err != nil {
+			return resp, err
+		}
+		resp.ColumnAttrSets = columnAttrSets
+	}
+	return resp, nil
+}
+
+// readColumnAttrSets returns a list of column attribute objects by id.
+func (api *API) readColumnAttrSets(index *Index, ids []uint64) ([]*ColumnAttrSet, error) {
+	if index == nil {
+		return nil, nil
+	}
+
+	ax := make([]*ColumnAttrSet, 0, len(ids))
+	for _, id := range ids {
+		// Read attributes for column. Skip column if empty.
+		attrs, err := index.ColumnAttrStore().Attrs(id)
+		if err != nil {
+			return nil, err
+		} else if len(attrs) == 0 {
+			continue
+		}
+
+		// Append column with attributes.
+		ax = append(ax, &ColumnAttrSet{ID: id, Attrs: attrs})
+	}
+
+	return ax, nil
+}

handler.go

@@ -69,6 +69,8 @@ type Handler struct {
 
 	// Keeps the query argument validators for each handler
 	validators map[string]*queryValidationSpec
+
+	api *API
 }
 
 // externalPrefixFlag denotes endpoints that are intended to be exposed to clients.
@@ -328,8 +330,6 @@ type getStatusResponse struct {
 
 // handlePostQuery handles /query requests.
 func (h *Handler) handlePostQuery(w http.ResponseWriter, r *http.Request) {
-	indexName := mux.Vars(r)["index"]
-
 	// Parse incoming request.
 	req, err := h.readQueryRequest(r)
 	if err != nil {
@@ -337,46 +337,13 @@ func (h *Handler) handlePostQuery(w http.ResponseWriter, r *http.Request) {
 		h.writeQueryResponse(w, r, &QueryResponse{Err: err})
 		return
 	}
+	// TODO: Remove
+	req.Index = mux.Vars(r)["index"]
 
-	// Build execution options.
-	opt := &ExecOptions{
-		Remote:       req.Remote,
-		ExcludeAttrs: req.ExcludeAttrs,
-		ExcludeBits:  req.ExcludeBits,
-	}
-
-	// Parse query string.
-	q, err := pql.NewParser(strings.NewReader(req.Query)).Parse()
+	resp, err := h.api.ExecuteQuery(r.Context(), req)
 	if err != nil {
 		w.WriteHeader(http.StatusBadRequest)
-		h.writeQueryResponse(w, r, &QueryResponse{Err: err})
-		return
-	}
-
-	// Execute the query.
-	results, err := h.Executor.Execute(r.Context(), indexName, q, req.Slices, opt)
-	resp := &QueryResponse{Results: results, Err: err}
-
-	// Fill column attributes if requested.
-	if req.ColumnAttrs && !req.ExcludeBits {
-		// Consolidate all column ids across all calls.
-		var columnIDs []uint64
-		for _, result := range results {
-			bm, ok := result.(*Bitmap)
-			if !ok {
-				continue
-			}
-			columnIDs = uint64Slice(columnIDs).merge(bm.Bits())
-		}
-
-		// Retrieve column attributes across all calls.
-		columnAttrSets, err := h.readColumnAttrSets(h.Holder.Index(indexName), columnIDs)
-		if err != nil {
-			w.WriteHeader(http.StatusInternalServerError)
-			h.writeQueryResponse(w, r, &QueryResponse{Err: err})
-			return
-		}
-		resp.ColumnAttrSets = columnAttrSets
+		h.writeQueryResponse(w, r, &resp)
 	}
 
 	// Set appropriate status code, if there is an error.
@@ -390,7 +357,7 @@ func (h *Handler) handlePostQuery(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Write response back to client.
-	if err := h.writeQueryResponse(w, r, resp); err != nil {
+	if err := h.writeQueryResponse(w, r, &resp); err != nil {
 		h.Logger.Printf("write query response error: %s", err)
 	}
 }

server.go

@@ -117,6 +117,10 @@ func NewServer() *Server {
 
 	s.Handler.Holder = s.Holder
 	s.diagnostics.server = s
+	s.Handler.api = &API{
+		holder: s.Holder,
+	}
+
 	return s
 }
 
@@ -172,6 +176,7 @@ func (s *Server) Open() error {
 	s.Handler.Executor = e
 
 	s.Cluster.prefect = s.Handler
+	s.Handler.api.executor = e
 
 	// Initialize Holder.
 	s.Holder.Broadcaster = s.Broadcaster