From 0c038b477ffce97c03664361663a68fd97b8a05a Mon Sep 17 00:00:00 2001 From: Josh Bleecher Snyder Date: Tue, 17 Aug 2021 12:29:58 -0700 Subject: [PATCH] logtail: add a re-usable buffer for uploads This avoids a per-upload alloc (which in practice often means per-log-line), up to 4k. Signed-off-by: Josh Bleecher Snyder --- logtail/logtail.go | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/logtail/logtail.go b/logtail/logtail.go index 71d449079..9763452bb 100644 --- a/logtail/logtail.go +++ b/logtail/logtail.go @@ -200,9 +200,10 @@ func (l *Logger) drainBlock() (shuttingDown bool) { } // drainPending drains and encodes a batch of logs from the buffer for upload. +// It uses scratch as its initial buffer. // If no logs are available, drainPending blocks until logs are available. -func (l *Logger) drainPending() (res []byte) { - buf := new(bytes.Buffer) +func (l *Logger) drainPending(scratch []byte) (res []byte) { + buf := bytes.NewBuffer(scratch[:0]) buf.WriteByte('[') entries := 0 @@ -261,8 +262,9 @@ func (l *Logger) drainPending() (res []byte) { func (l *Logger) uploading(ctx context.Context) { defer close(l.shutdownDone) + scratch := make([]byte, 4096) // reusable buffer to write into for { - body := l.drainPending() + body := l.drainPending(scratch) origlen := -1 // sentinel value: uncompressed // Don't attempt to compress tiny bodies; not worth the CPU cycles. if l.zstdEncoder != nil && len(body) > 256 {