Add query timeout functionality

cli/start.go

@@ -82,6 +82,8 @@ func init() {
 	startCmd.PersistentFlags().IntVar(&opts.Port, "port", 8000, "The port on which to serve the web server")
 	startCmd.PersistentFlags().StringVarP(&opts.Bind, "bind", "b", "0.0.0.0", "The hostname or ip address to listen for connections on")
 
+	startCmd.PersistentFlags().DurationVar(&opts.Query.Timeout, "timeout", 0, "")
+
 	startCmd.PersistentFlags().StringVarP(&opts.DB.Code, "key", "k", "", "Encryption key to use for on-disk encryption")
 
 	startCmd.PersistentFlags().DurationVar(&opts.DB.Proc.Flush, "db-flush", 0, "A time duration to use when syncing data to persistent storage")

cnf/cnf.go

@@ -59,6 +59,10 @@ type Options struct {
 		Nets []*net.IPNet // Allowed cidr ranges for authentication
 	}
 
+	Query struct {
+		Timeout time.Duration // Fixed query timeout
+	}
+
 	Logging struct {
 		Level  string // Stores the configured logging level
 		Output string // Stores the configured logging output

db/executor.go

@@ -22,6 +22,7 @@ import (
 
 	"runtime/debug"
 
+	"github.com/abcum/surreal/cnf"
 	"github.com/abcum/surreal/kvs"
 	"github.com/abcum/surreal/log"
 	"github.com/abcum/surreal/sql"
@@ -267,6 +268,22 @@ func (e *executor) operate(ctx context.Context, stm sql.Statement) (res []interf
 	// can monitor the running time, and ensure
 	// it runs no longer than specified.
 
+	if cnf.Settings.Query.Timeout > 0 {
+		if perm(ctx) != cnf.AuthKV {
+			ctx, canc = context.WithTimeout(ctx, cnf.Settings.Query.Timeout)
+			defer func() {
+				if tim := ctx.Err(); err == nil && tim != nil {
+					res, err = nil, &TimerError{timer: cnf.Settings.Query.Timeout}
+				}
+				canc()
+			}()
+		}
+	}
+
+	// Mark the beginning of this statement so we
+	// can monitor the running time, and ensure
+	// it runs no longer than specified.
+
 	if stm, ok := stm.(sql.KillableStatement); ok {
 		if dur := stm.Duration(); dur > 0 {
 			ctx, canc = context.WithTimeout(ctx, dur)