From 0d2d42c8ac678e505dfd4874b3f463b085457aeb Mon Sep 17 00:00:00 2001
From: Takeshi HASEGAWA <hasegaw@gmail.com>
Date: Tue, 9 Jun 2015 05:05:24 +0000
Subject: [PATCH] plugins/in_mem: no longer flushes empty buffer
 plugins/in_kmsg: no longer flushes empty buffer plugins/in_cpu: no longer
 flushes empty buffer

This changes avoid allocating and flushing unnecessary empty
buffers (size == 0). These also surpress error messages when
no updates in flush interval(typically every 5 seconds).

Signed-off-by: Takeshi HASEGAWA <hasegaw@gmail.com>
---
 plugins/in_cpu/in_cpu.c   | 3 +++
 plugins/in_kmsg/in_kmsg.c | 3 +++
 plugins/in_mem/in_mem.c   | 3 +++
 3 files changed, 9 insertions(+)

diff --git a/plugins/in_cpu/in_cpu.c b/plugins/in_cpu/in_cpu.c
index 4f446341c77..4b783f27052 100644
--- a/plugins/in_cpu/in_cpu.c
+++ b/plugins/in_cpu/in_cpu.c
@@ -158,6 +158,9 @@ void *in_cpu_flush(void *in_context, int *size)
     msgpack_sbuffer *sbuf;
     struct flb_in_cpu_config *ctx = in_context;
 
+    if (ctx->data_idx == 0)
+        return NULL;
+
     sbuf = &ctx->mp_sbuf;
     *size = sbuf->size;
     buf = malloc(sbuf->size);
diff --git a/plugins/in_kmsg/in_kmsg.c b/plugins/in_kmsg/in_kmsg.c
index 152c320f19a..a366067d9ca 100644
--- a/plugins/in_kmsg/in_kmsg.c
+++ b/plugins/in_kmsg/in_kmsg.c
@@ -107,6 +107,9 @@ void *in_kmsg_flush(void *in_context, int *size)
     msgpack_sbuffer *sbuf;
     struct flb_in_kmsg_config *ctx = in_context;
 
+    if (ctx->buffer_id == 0)
+        return NULL;
+
     sbuf = &ctx->mp_sbuf;
     *size = sbuf->size;
     buf = malloc(sbuf->size);
diff --git a/plugins/in_mem/in_mem.c b/plugins/in_mem/in_mem.c
index cc2db0d4f27..72d24eee7c7 100644
--- a/plugins/in_mem/in_mem.c
+++ b/plugins/in_mem/in_mem.c
@@ -99,6 +99,9 @@ void *in_mem_flush(void *in_context, int *size)
     char *buf;
     struct flb_in_mem_config *ctx = in_context;
 
+    if (ctx->idx == 0)
+        return NULL;
+
     buf = malloc(ctx->sbuf.size);
     if (!buf) {
         return NULL;