From 8f1178c329bc6f8a59c792fd9f599c58c781db2c Mon Sep 17 00:00:00 2001
From: Pavel Berezhnoy <p.berezhnoy@corp.mail.ru>
Date: Thu, 24 Sep 2015 20:19:30 +0300
Subject: [PATCH] Rima.lua: fast tasks statistics added

---
 rima.lua | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)

diff --git a/rima.lua b/rima.lua
index 7431fa5..66d00f1 100644
--- a/rima.lua
+++ b/rima.lua
@@ -30,8 +30,13 @@
 --   Index 0: TREE { task_id }
 --   Index 1: TREE { key }
 --
+-- Space 4: Fast tasks monitoring
+--   Tuple: { key (NUM), added_tasks_count (NUM), deleted_tasks_count (NUM) }
+--   Index 0: TREE { key }
+--
 
 local EXPIRATION_TIME = 30 * 60 -- seconds
+local FAST_TASKS_STAT_EXP_TIME = 60 * 60 * 24 * 365 -- seconds (1 year)
 
 --
 -- Put task to the queue.
@@ -72,11 +77,120 @@ function rima_put_sync(key, data, prio)
 	return rima_put_impl(key, data, prio, box.time())
 end
 
+--
+-- Get a key for fast tasks monitoring
+--
+local function rima_get_monitoring_key(t)
+	if t == nil or t == 0 then
+		t = box.time()
+	end
+	return t - (t % 60)
+end
+
+--
+-- Increment fast tasks count
+--
+local function rima_inc_fast_tasks_count()
+	local key = rima_get_monitoring_key()
+	local update_result = box.update(4, key, '+p', 1, 1)
+
+	if update_result == nil then
+		-- no stat for current key
+		box.insert(4, key, 1, 0)
+	end
+
+	-- increment total number of fast tasks in queue
+	update_result = box.update(4, 0, '+p', 1, 1)
+	if update_result == nil then
+		box.insert(4, 0, 1)
+	end
+end
+
+--
+-- Decrement fast tasks count
+--
+local function rima_dec_fast_tasks_count()
+	local key = rima_get_monitoring_key()
+	local update_result = box.update(4, key, '+p', 2, 1)
+
+	if update_result == nil then
+		-- no stat for current key
+		box.insert(4, key, 0, 1)
+	end
+
+	-- decrement total number of fast tasks
+	box.update(4, 0, '-p', 1, 1) -- ignore case when no tasks was in queue
+end
+
+--
+-- Remove old records from tarantool
+--
+local function rima_clear_expired_stat()
+	local cur_key = rima_get_monitoring_key(box.time())
+	local expired_key = cur_key - FAST_TASKS_STAT_EXP_TIME
+	local iter = box.space[4].index[0]:iterator(box.index.LE, expired_key)
+
+	for tuple in iter do
+		box.delete(4, tuple[0])
+	end
+end
+
+--
+-- Get statistic from monitoring for given time interval
+--
+function rima_get_monitoring_statistics(start_time, end_time)
+	if start_time ~= nil then
+		start_time = box.unpack('i', start_time)
+	end
+	if end_time ~= nil then
+		end_time = box.unpack('i', end_time)
+	end
+
+	rima_clear_expired_stat()
+
+	if start_time == nil or start_time == 0 then
+		-- request all statistics, but 0 is global tasks counter
+		start_time = 1
+	else
+		start_time = rima_get_monitoring_key(start_time)
+	end
+
+	end_time = rima_get_monitoring_key(end_time)
+	if end_time < start_time then
+		end_time, start_time = start_time, end_time
+	end
+
+	local tuple = box.select(4, 0, 0)
+	local currently_in_queue = 0
+	if tuple ~= nil then
+		currently_in_queue = box.unpack('i', tuple[1])
+	end
+
+	local total_added, total_deleted = 0, 0
+	local iter = box.space[4].index[0]:iterator(box.index.GE, start_time)
+	for tuple in iter do
+		if box.unpack('i', tuple[0]) > end_time then
+			break
+		end
+
+		total_added = total_added + box.unpack('i', tuple[1])
+		total_deleted = total_deleted + box.unpack('i', tuple[2])
+	end
+
+	-- string will be returned
+	return box.cjson.encode({
+		fast_tasks_in_queue = currently_in_queue,
+		fast_tasks_added = total_added,
+		fast_tasks_deleted = total_deleted,
+	})
+end
+
 --
 -- Put fetch single mail task to the queue.
 --
 function rima_put_fetchmail(key, data)
 	box.auto_increment(3, key, data, box.time())
+	rima_inc_fast_tasks_count()
 end
 
 local function get_prio_key(prio, source)
@@ -132,6 +246,7 @@ function rima_get_fetchmail()
 	local tuples = { box.select_limit(3, 1, 0, 1000, key) }
 	for _, tuple in pairs(tuples) do
 		tuple = box.delete(3, box.unpack('l', tuple[0]))
+		rima_dec_fast_tasks_count()
 		if tuple ~= nil then
 			table.insert(result, { box.unpack('i', tuple[3]), tuple[2] })
 			n = 1