Only collect keys if using rnd read mode

Signed-off-by: Adam Baxter <[email protected]>

cmd/bbolt/main.go

@@ -1107,20 +1107,29 @@ func (cmd *benchCommand) Run(args ...string) error {
 
 	// Write to the database.
 	var writeResults BenchResults
-	keys := make([]nestedKey, 0, options.Iterations)
+	var keys []nestedKey
+
+	if options.ReadMode == "rnd" {
+		keys = make([]nestedKey, 0, options.Iterations)
+	} else {
+		keys = nil
+	}
+
 	fmt.Fprintf(cmd.Stderr, "starting write benchmark.\n")
 	if err := cmd.runWrites(db, options, &writeResults, r, &keys); err != nil {
 		return fmt.Errorf("write: %v", err)
 	}
 
-	r.Shuffle(len(keys), func(i, j int) {
-		keys[i], keys[j] = keys[j], keys[i]
-	})
+	if keys != nil {
+		r.Shuffle(len(keys), func(i, j int) {
+			keys[i], keys[j] = keys[j], keys[i]
+		})
+	}
 
 	var readResults BenchResults
 	fmt.Fprintf(cmd.Stderr, "starting read benchmark.\n")
 	// Read from the database.
-	if err := cmd.runReads(db, options, &readResults, r, keys); err != nil {
+	if err := cmd.runReads(db, options, &readResults, keys); err != nil {
 		return fmt.Errorf("bench: read: %s", err)
 	}
 
@@ -1252,7 +1261,9 @@ func (cmd *benchCommand) runWritesWithSource(db *bolt.DB, options *BenchOptions,
 				if err := b.Put(key, value); err != nil {
 					return err
 				}
-				*keys = append(*keys, nestedKey{nil, key})
+				if *keys != nil {
+					*keys = append(*keys, nestedKey{nil, key})
+				}
 				results.AddCompletedOps(1)
 			}
 			fmt.Fprintf(cmd.Stderr, "Finished write iteration %d\n", i)
@@ -1297,7 +1308,9 @@ func (cmd *benchCommand) runWritesNestedWithSource(db *bolt.DB, options *BenchOp
 				if err := b.Put(key, value); err != nil {
 					return err
 				}
-				*keys = append(*keys, nestedKey{name, key})
+				if *keys != nil {
+					*keys = append(*keys, nestedKey{nil, key})
+				}
 				results.AddCompletedOps(1)
 			}
 			fmt.Fprintf(cmd.Stderr, "Finished write iteration %d\n", i)
@@ -1311,7 +1324,7 @@ func (cmd *benchCommand) runWritesNestedWithSource(db *bolt.DB, options *BenchOp
 }
 
 // Reads from the database.
-func (cmd *benchCommand) runReads(db *bolt.DB, options *BenchOptions, results *BenchResults, r *rand.Rand, keys []nestedKey) error {
+func (cmd *benchCommand) runReads(db *bolt.DB, options *BenchOptions, results *BenchResults, keys []nestedKey) error {
 	// Start profiling for reads.
 	if options.ProfileMode == "r" {
 		cmd.startProfiling(options)