Add query and chart support with multiple fixes to ORM package

netquery/chart_handler.go

@@ -0,0 +1,118 @@
+package netquery
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"strings"
+
+	"github.com/safing/portmaster/netquery/orm"
+)
+
+type ChartHandler struct {
+	Database *Database
+}
+
+func (ch *ChartHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
+	requestPayload, err := ch.parseRequest(req)
+	if err != nil {
+		http.Error(resp, err.Error(), http.StatusBadRequest)
+
+		return
+	}
+
+	query, paramMap, err := requestPayload.generateSQL(req.Context(), ch.Database.Schema)
+	if err != nil {
+		http.Error(resp, err.Error(), http.StatusBadRequest)
+
+		return
+	}
+
+	// actually execute the query against the database and collect the result
+	var result []map[string]interface{}
+	if err := ch.Database.Execute(
+		req.Context(),
+		query,
+		orm.WithNamedArgs(paramMap),
+		orm.WithResult(&result),
+		orm.WithSchema(*ch.Database.Schema),
+	); err != nil {
+		http.Error(resp, "Failed to execute query: "+err.Error(), http.StatusInternalServerError)
+
+		return
+	}
+
+	// send the HTTP status code
+	resp.WriteHeader(http.StatusOK)
+
+	// prepare the result encoder.
+	enc := json.NewEncoder(resp)
+	enc.SetEscapeHTML(false)
+	enc.SetIndent("", "  ")
+
+	enc.Encode(map[string]interface{}{
+		"results": result,
+		"query":   query,
+		"params":  paramMap,
+	})
+}
+
+func (ch *ChartHandler) parseRequest(req *http.Request) (*QueryActiveConnectionChartPayload, error) {
+	var body io.Reader
+
+	switch req.Method {
+	case http.MethodPost, http.MethodPut:
+		body = req.Body
+	case http.MethodGet:
+		body = strings.NewReader(req.URL.Query().Get("q"))
+	default:
+		return nil, fmt.Errorf("invalid HTTP method")
+	}
+
+	var requestPayload QueryActiveConnectionChartPayload
+	blob, err := ioutil.ReadAll(body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read body" + err.Error())
+	}
+
+	body = bytes.NewReader(blob)
+
+	dec := json.NewDecoder(body)
+	dec.DisallowUnknownFields()
+
+	if err := json.Unmarshal(blob, &requestPayload); err != nil && !errors.Is(err, io.EOF) {
+		return nil, fmt.Errorf("invalid query: %w", err)
+	}
+
+	return &requestPayload, nil
+}
+
+func (req *QueryActiveConnectionChartPayload) generateSQL(ctx context.Context, schema *orm.TableSchema) (string, map[string]interface{}, error) {
+	template := `
+WITH RECURSIVE epoch(x) AS (
+	SELECT strftime('%%s')-600
+	UNION ALL
+		SELECT x+1 FROM epoch WHERE x+1 < strftime('%%s')+0
+)
+SELECT x as timestamp, COUNT(*) AS value FROM epoch
+	JOIN connections
+	ON strftime('%%s', connections.started)+0 <= timestamp+0 AND (connections.ended IS NULL OR strftime('%%s', connections.ended)+0 > timestamp+0)
+		%s
+	GROUP BY round(timestamp/10, 0)*10;`
+
+	clause, params, err := req.Query.toSQLWhereClause(ctx, "", schema, orm.DefaultEncodeConfig)
+	if err != nil {
+		return "", nil, err
+	}
+
+	if clause == "" {
+		return fmt.Sprintf(template, ""), map[string]interface{}{}, nil
+	}
+
+	return fmt.Sprintf(template, "WHERE ( "+clause+")"), params, nil
+}