From 23ef0b978775b568391c9b79cd21d6ad3a70b7b1 Mon Sep 17 00:00:00 2001
From: Pavel Kartavyy <kartavyy@yandex-team.ru>
Date: Wed, 4 Mar 2015 19:15:32 +0300
Subject: [PATCH] zkutil: add Increment [#METR-15299]
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███████████: write clicks to cloud [#METR-15299]
---
 libs/libzkutil/include/zkutil/Increment.h | 47 +++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 libs/libzkutil/include/zkutil/Increment.h

diff --git a/libs/libzkutil/include/zkutil/Increment.h b/libs/libzkutil/include/zkutil/Increment.h
new file mode 100644
index 00000000000..bc8925fe4fc
--- /dev/null
+++ b/libs/libzkutil/include/zkutil/Increment.h
@@ -0,0 +1,47 @@
+#pragma once
+
+#include <zkutil/ZooKeeper.h>
+
+namespace zkutil 
+{
+	
+class Increment
+{
+public:
+	Increment(ZooKeeperPtr zk_, const std::string & path_) 
+	: zk(zk_), path(path_)
+	{
+	}
+	
+	size_t get()
+	{
+		LOG_TRACE(log, "Get increment");
+		
+		size_t result = 0;
+		std::string result_str;
+		zkutil::Stat stat;
+		
+		bool success = false;
+		do
+		{
+			if (zk->tryGet(path, result_str, &stat))
+			{
+				result = std::stol(result_str) + 1;
+				success = zk->trySet(path, std::to_string(result), stat.version) == ZOK;
+			}
+			else
+			{
+				success = zk->tryCreate(path, std::to_string(result), zkutil::CreateMode::Persistent) == ZOK;
+			}
+		} 
+		while(!success);
+		
+		return result;
+	}
+private:
+	zkutil::ZooKeeperPtr zk;
+	std::string path;
+	Logger * log = &Logger::get("zkutil::Increment");
+};
+
+}
\ No newline at end of file