From 5ba6fe50c70095e2d25077a9c77b765aba785381 Mon Sep 17 00:00:00 2001
From: Oran Agra <oran@redislabs.com>
Date: Thu, 24 Oct 2019 14:24:55 +0300
Subject: [PATCH] Module API for LatencyAddSample

---
 src/latency.c     | 2 +-
 src/latency.h     | 2 +-
 src/module.c      | 9 +++++++++
 src/redismodule.h | 2 ++
 4 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/latency.c b/src/latency.c
index b834da5c7..74ced72a5 100644
--- a/src/latency.c
+++ b/src/latency.c
@@ -95,7 +95,7 @@ void latencyMonitorInit(void) {
  * This function is usually called via latencyAddSampleIfNeeded(), that
  * is a macro that only adds the sample if the latency is higher than
  * server.latency_monitor_threshold. */
-void latencyAddSample(char *event, mstime_t latency) {
+void latencyAddSample(const char *event, mstime_t latency) {
     struct latencyTimeSeries *ts = dictFetchValue(server.latency_events,event);
     time_t now = time(NULL);
     int prev;
diff --git a/src/latency.h b/src/latency.h
index 0fe26e0e4..76640cfce 100644
--- a/src/latency.h
+++ b/src/latency.h
@@ -62,7 +62,7 @@ struct latencyStats {
 };
 
 void latencyMonitorInit(void);
-void latencyAddSample(char *event, mstime_t latency);
+void latencyAddSample(const char *event, mstime_t latency);
 int THPIsEnabled(void);
 
 /* Latency monitoring macros. */
diff --git a/src/module.c b/src/module.c
index ff5eba787..1fccaabce 100644
--- a/src/module.c
+++ b/src/module.c
@@ -3793,6 +3793,14 @@ void RM__Assert(const char *estr, const char *file, int line) {
     _serverAssert(estr, file, line);
 }
 
+/* Allows adding event to the latency monitor to be observed by the LATENCY
+ * command. The call is skipped if the latency is smaller than the configured
+ * latency-monitor-threshold. */
+void RM_LatencyAddSample(const char *event, mstime_t latency) {
+    if (latency >= server.latency_monitor_threshold)
+        latencyAddSample(event, latency);
+}
+
 /* --------------------------------------------------------------------------
  * Blocking clients from modules
  * -------------------------------------------------------------------------- */
@@ -6024,6 +6032,7 @@ void moduleRegisterCoreAPI(void) {
     REGISTER_API(Log);
     REGISTER_API(LogIOError);
     REGISTER_API(_Assert);
+    REGISTER_API(LatencyAddSample);
     REGISTER_API(StringAppendBuffer);
     REGISTER_API(RetainString);
     REGISTER_API(StringCompare);
diff --git a/src/redismodule.h b/src/redismodule.h
index 19a9cd897..5dc3cb61b 100644
--- a/src/redismodule.h
+++ b/src/redismodule.h
@@ -319,6 +319,7 @@ float REDISMODULE_API_FUNC(RedisModule_LoadFloat)(RedisModuleIO *io);
 void REDISMODULE_API_FUNC(RedisModule_Log)(RedisModuleCtx *ctx, const char *level, const char *fmt, ...);
 void REDISMODULE_API_FUNC(RedisModule_LogIOError)(RedisModuleIO *io, const char *levelstr, const char *fmt, ...);
 void REDISMODULE_API_FUNC(RedisModule__Assert)(const char *estr, const char *file, int line);
+void REDISMODULE_API_FUNC(RedisModule_LatencyAddSample)(const char *event, mstime_t latency);
 int REDISMODULE_API_FUNC(RedisModule_StringAppendBuffer)(RedisModuleCtx *ctx, RedisModuleString *str, const char *buf, size_t len);
 void REDISMODULE_API_FUNC(RedisModule_RetainString)(RedisModuleCtx *ctx, RedisModuleString *str);
 int REDISMODULE_API_FUNC(RedisModule_StringCompare)(RedisModuleString *a, RedisModuleString *b);
@@ -509,6 +510,7 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
     REDISMODULE_GET_API(Log);
     REDISMODULE_GET_API(LogIOError);
     REDISMODULE_GET_API(_Assert);
+    REDISMODULE_GET_API(LatencyAddSample);
     REDISMODULE_GET_API(StringAppendBuffer);
     REDISMODULE_GET_API(RetainString);
     REDISMODULE_GET_API(StringCompare);