1 files changed, 42 insertions, 0 deletions
diff --git a/src/mongo/gotools/src/github.com/mongodb/mongo-tools/mongostat/stat_consumer/formatter.go b/src/mongo/gotools/src/github.com/mongodb/mongo-tools/mongostat/stat_consumer/formatter.go
new file mode 100644
index 00000000000..eda62b0dda6
--- /dev/null
+++ b/src/mongo/gotools/src/github.com/mongodb/mongo-tools/mongostat/stat_consumer/formatter.go
@@ -0,0 +1,42 @@
+// Copyright (C) MongoDB, Inc. 2014-present.
+//
+// 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
+
+package stat_consumer
+
+import (
+	"sync/atomic"
+
+	"github.com/mongodb/mongo-tools/mongostat/stat_consumer/line"
+)
+
+// A LineFormatter formats StatLines for printing.
+type LineFormatter interface {
+	// FormatLines returns the string representation of the StatLines that are passed in.
+	FormatLines(lines []*line.StatLine, headerKeys []string, keyNames map[string]string) string
+
+	// IsFinished returns true iff the formatter cannot print any more data
+	IsFinished() bool
+	// Finish() is called whem mongostat is shutting down so that the fomatter can clean up
+	Finish()
+}
+
+type limitableFormatter struct {
+	// atomic operations are performed on rowCount, so these two variables
+	// should stay at the beginning for the sake of variable alignment
+	maxRows, rowCount int64
+}
+
+func (lf *limitableFormatter) increment() {
+	atomic.AddInt64(&lf.rowCount, 1)
+}
+
+func (lf *limitableFormatter) IsFinished() bool {
+	return lf.maxRows > 0 && atomic.LoadInt64(&lf.rowCount) >= lf.maxRows
+}
+
+type FormatterConstructor func(maxRows int64, includeHeader bool) LineFormatter
+
+var FormatterConstructors = map[string]FormatterConstructor{}