From 52e0ca954149321fe6d976e4d3a116ba627880ba Mon Sep 17 00:00:00 2001
From: Mu-Woong Lee <muwoong.lee@samsung.com>
Date: Tue, 17 Jan 2017 13:13:30 +0900
Subject: [PATCH] Add a cache for application display types

Change-Id: I4e49ae6e9161ac4d4db6f539499de249bb998243
Signed-off-by: Mu-Woong Lee <muwoong.lee@samsung.com>
---
 src/app-stats/ActiveWindowMonitor.cpp | 65 +++++++++++++++++++++++++--
 1 file changed, 61 insertions(+), 4 deletions(-)

diff --git a/src/app-stats/ActiveWindowMonitor.cpp b/src/app-stats/ActiveWindowMonitor.cpp
index 107d598..97a5b48 100644
--- a/src/app-stats/ActiveWindowMonitor.cpp
+++ b/src/app-stats/ActiveWindowMonitor.cpp
@@ -16,6 +16,8 @@
 
 #include <sys/types.h>
 #include <time.h>
+#include <list>
+#include <utility>
 #include <app_manager.h>
 
 #include <Json.h>
@@ -27,6 +29,51 @@
 /* Active window changes frequently.
  * We thus consider the apps being foregrounded at least 3 secs */
 #define ONE_DAY_IN_SEC 86400
+#define DEFAULT_CACHE_SIZE 10
+#define TOP_TIER_LIMIT 2
+
+class AppDisplayTypeCache {
+private:
+	unsigned int __size;
+	std::list<std::pair<std::string, bool>> __cache;
+
+public:
+	AppDisplayTypeCache(unsigned int size) :
+		__size(size)
+	{
+	}
+
+	void put(const std::string& appId, bool noDisp)
+	{
+		__cache.push_front(std::make_pair(appId, noDisp));
+
+		if (__cache.size() > __size)
+			__cache.pop_back();
+	}
+
+	bool get(const std::string& appId, bool* noDisp)
+	{
+		int index = 0;
+
+		for (auto it = __cache.begin(); it != __cache.end(); ++it) {
+			if ((*it).first != appId) {
+				++index;
+				continue;
+			}
+
+			*noDisp = (*it).second;
+
+			if (index > TOP_TIER_LIMIT) {
+				__cache.erase(it);
+				__cache.push_front(std::make_pair(appId, *noDisp));
+			}
+
+			return true;
+		}
+
+		return false;
+	}
+};
 
 ctx::AppUseMonitor::AppUseMonitor() :
 	__signalId(-1),
@@ -117,13 +164,20 @@ void ctx::AppUseMonitor::__finishRecord(std::string appId)
 
 bool ctx::AppUseMonitor::__isSkippable(std::string appId)
 {
-	/* TODO: circular cache */
+	static AppDisplayTypeCache __cache(DEFAULT_CACHE_SIZE);
+
+	bool noDisp = false;
+
+	if (__cache.get(appId, &noDisp))
+		return noDisp;
+
+	_D("No cache for '%s'", appId.c_str());
+
 	app_info_h appInfo = NULL;
 	int err = app_manager_get_app_info(appId.c_str(), &appInfo);
 	IF_FAIL_RETURN_TAG(err == APP_MANAGER_ERROR_NONE && appInfo, true, _E, "app_manager_get_app_info() failed");
 
-	bool nodisp = false;
-	err = app_info_is_nodisplay(appInfo, &nodisp);
+	err = app_info_is_nodisplay(appInfo, &noDisp);
 	if (err != APP_MANAGER_ERROR_NONE) {
 		app_info_destroy(appInfo);
 		_E("app_info_is_nodisplay() failed");
@@ -131,7 +185,10 @@ bool ctx::AppUseMonitor::__isSkippable(std::string appId)
 	}
 
 	app_info_destroy(appInfo);
-	return nodisp;
+
+	__cache.put(appId, noDisp);
+
+	return noDisp;
 }
 
 void ctx::AppUseMonitor::__removeExpired()
-- 
2.34.1