Make database asynchronous

README.md

@@ -1,7 +1,7 @@
 ColdDB
 ===========
 
-ColdDB is a minetest mod that implements a serverless, NoSQL database engine.<br>
+ColdDB is a minetest mod that implements a serverless, asynchronous, NoSQL database engine.<br>
 It provides a key or key-value storage system using plain Lua tables. It also can iterate through the keys.<br>
 It is not required to add this mod to secure.trusted_mods this mod will still work.
 
@@ -27,16 +27,26 @@ colddb.set_key(coldbase,"MyKey")
 ```lua
 colddb.set(coldbase,"MyKeyAndValue","Hello world")
 ```
-5. retrieve items (get_key will return true, false, or nil)
+5. retrieve items (get_key's callback(arg) will return true, false, or nil)
 ```lua
-local key_and_value = colddb.get(coldbase,"MyKeyAndValue")
+colddb.get(coldbase,"MyKeyAndValue",nil,function(arg)
-local key = colddb.get_key(coldbase,"MyKey")
+	if arg then
+		minetest.log(string.format("value:%s",arg))
+	end
+end)
+colddb.get_key(coldbase,"MyKey",nil,function(arg)
+	if arg then
+		minetest.log("Found key")
+	else
+		minetest.log("Key not found")
+	end
+end)
 ```
 6. delete key(file) this function works on both keys and key-value keys.
 ```lua
 colddb.remove(coldbase,"MyKeyAndValue")
 ```
-7. if add_to_mem_pool is true(true by default). keys are stored in a lua table(memory) for 30 seconds or more depending on its use. This is to prevent the database from constantly loading up the data file.
+7. if add_to_mem_pool is true(true by default). keys are stored in a weak lua table(memory) it will be removed by the gc if its not in-use. Storing data in memory is to prevent the database from constantly loading up data from files.
 ```lua
 coldbase.add_to_mem_pool = true
 ```
@@ -48,9 +58,9 @@ coldbase.indexes = true
 ```lua
 colddb.get_count(coldbase)
 ```
-10. only if coldbase.indexes == true. iterates through the indexing file 50 times per game tick(breaks and ends if it reached the end of the file).
+10. only if coldbase.indexes == true. iterates through the indexing file(breaks and ends if it reached the end of the file).
 ```lua
-colddb.iterate_index_table(coldbase,nil,func_list_keys,nil,50)
+colddb.iterate_index_table(coldbase,nil,func_list_keys,nil)
 ```
 11. adds folders which can be used in other functions that have tag_name arg.
 ```lua
@@ -75,18 +85,14 @@ ip_db = colddb.get_db("watchlist")
 colddb.add_global_tag(ip_db,"ips")
 
 -- return a recorded ip address from the data base.
-function ip_db.find(player)
+function ip_db.find(player,callback)
-	local f = colddb.get(ip_db,player)
+	colddb.get(ip_db,player,nil,callback)
-	if f then
-		return f
-	end
-	return nil
 end
 
 -- Key is the file and file name. Value is the content's within the file.
 -- global tag(ips)--->key(Player name)--->value(ip address)
 function ip_db.record_ip(player,ip)
-	colddb.set(ip_db,player, ip)
+	colddb.set(ip_db,player,ip)
 end
 
 function ip_db.delete(player)
@@ -97,6 +103,23 @@ end
 minetest.register_on_prejoinplayer(function(name, ip)
 	ip_db.record_ip(name,ip)
 end)
+
+minetest.register_chatcommand("ip", {
+	params = "<player>",
+	description = "Get an player's ip address.",
+    func = function(name, param)
+		-- Get the ip record asynchronously.
+		colddb.get(ip_db,param,nil,function(record)
+			-- If record is contains data send it to the player.
+			if record then
+				minetest.chat_send_player(name,string.format("%s:%s",param,record))
+			else
+				-- No record was found.
+				minetest.chat_send_player(name,"Can not find ip record.")
+			end
+		end)
+    end
+})
 ```
 
 Quick Look Notes
@@ -126,7 +149,7 @@ API
   
   - **colddb.get_count(db,tag_name)**
   
-  - **colddb.iterate_index_table(db,begin_func,func_on_iterate,end_func,cycles_per_tick,args,tag_name)**
+  - **colddb.iterate_index_table(db,begin_func,func_on_iterate,end_func,args,tag_name)**
   
     - **begin_func(args)**
 	
@@ -138,9 +161,9 @@ API
   
   - **colddb.set_key(db,name,tag_name)**
   
-  - **colddb.get(db,name,tag_name)**
+  - **colddb.get(db,name,tag_name,callback(arg))**
   
-  - **colddb.get_key(db,name,tag_name)**
+  - **colddb.get_key(db,name,tag_name,callback(arg))**
   
   - **colddb.remove(db,name,tag_name)**
   

async.lua

@@ -0,0 +1,209 @@
+if not extended_api then
+	extended_api = {}
+end
+if not extended_api.Async then
+	extended_api.Async = {}
+end
+
+function extended_api.Async.create_async_pool()
+	local pool = {threads = {},globalstep_threads = {},task_queue = {},resting = 200,maxtime = 200,queue_threads = 8,state = "suspended"}
+	return pool
+end
+
+function extended_api.Async.create_worker(pool,func)
+	local thread = coroutine.create(func)
+	table.insert(pool.threads, thread)
+end
+
+function extended_api.Async.create_globalstep_worker(pool,func)
+	local thread = coroutine.create(func)
+	table.insert(pool.globalstep_threads, thread)
+end
+
+function extended_api.Async.run_worker(pool,index)
+	local thread = pool.threads[index]
+	if thread == nil or coroutine.status(thread) == "dead" then
+		table.remove(pool.threads, index)
+		minetest.after(0,extended_api.Async.schedule_worker,pool)
+		return false
+	else
+		coroutine.resume(thread)
+		minetest.after(0,extended_api.Async.schedule_worker,pool)
+		return true
+	end
+end
+
+function extended_api.Async.run_globalstep_worker(pool,index)
+	local thread = pool.globalstep_threads[index]
+	if thread == nil or coroutine.status(thread) == "dead" then
+		table.remove(pool.globalstep_threads, index)
+		minetest.after(0,extended_api.Async.schedule_globalstep_worker,pool)
+		return false
+	else
+		coroutine.resume(thread)
+		minetest.after(0,extended_api.Async.schedule_globalstep_worker,pool)
+		return true
+	end
+end
+
+function extended_api.Async.schedule_worker(pool)
+	pool.state = "running"
+	for index,value in ipairs(pool.threads) do
+		minetest.after(pool.resting / 1000,extended_api.Async.run_worker,pool,index)
+		return true
+	end
+	pool.state = "suspended"
+	return false
+end
+
+function extended_api.Async.schedule_globalstep_worker(pool)
+	for index,value in ipairs(pool.globalstep_threads) do
+		minetest.after(0,extended_api.Async.run_globalstep_worker,pool,index)
+		return true
+	end
+	return false
+end
+
+function extended_api.Async.priority(pool,resting,maxtime)
+	pool.resting = resting
+	pool.maxtime = maxtime
+end
+
+function extended_api.Async.iterate(pool,from,to,func,callback)
+	extended_api.Async.create_worker(pool,function()
+		local last_time = minetest.get_us_time() * 1000
+		local maxtime = pool.maxtime
+		for i = from, to do
+			local b = func(i)
+			if b and b == false then
+				break
+			end
+			if minetest.get_us_time() * 1000 > last_time + maxtime then
+				coroutine.yield()
+				last_time = minetest.get_us_time() * 1000
+			end
+		end
+		if callback then
+			callback()
+		end
+	end)
+	extended_api.Async.schedule_worker(pool)
+end
+
+function extended_api.Async.foreach(pool,array, func, callback)
+	extended_api.Async.create_worker(pool,function()
+		local last_time = minetest.get_us_time() * 1000
+		local maxtime = pool.maxtime
+		for k,v in ipairs(array) do
+			local b = func(k,v)
+			if b and b == false then
+				break
+			end
+			if minetest.get_us_time() * 1000 > last_time + maxtime then
+				coroutine.yield()
+				last_time = minetest.get_us_time() * 1000
+			end
+		end
+		if callback then
+			callback()
+		end
+	end)
+	extended_api.Async.schedule_worker(pool)
+end
+
+function extended_api.Async.do_while(pool,condition_func, func, callback)
+	extended_api.Async.create_worker(pool,function()
+		local last_time = minetest.get_us_time() * 1000
+		local maxtime = pool.maxtime
+		while(condition_func()) do
+			local c = func()
+			if c and c ~= condition_func() then
+				break
+			end
+			if minetest.get_us_time() * 1000 > last_time + maxtime then
+				coroutine.yield()
+				last_time = minetest.get_us_time() * 1000
+			end
+		end
+		if callback then
+			callback()
+		end
+	end)
+	extended_api.Async.schedule_worker(pool)
+end
+
+function extended_api.Async.register_globalstep(pool,func)
+	extended_api.Async.create_globalstep_worker(pool,function()
+		local last_time = minetest.get_us_time() * 1000
+		local dtime = last_time
+		while(true) do
+			local c = func(dtime)
+			if c and c == false then
+				break
+			end
+			dtime = minetest.get_us_time() * 1000
+			-- 0.05 seconds
+			if minetest.get_us_time() * 1000 > last_time + 50 then
+				coroutine.yield()
+				local last_time = minetest.get_us_time() * 1000
+			end
+		end
+	end)
+	extended_api.Async.schedule_globalstep_worker(pool)
+end
+
+function extended_api.Async.chain_task(pool,tasks,callback)
+	extended_api.Async.create_worker(pool,function()
+		local pass_arg = nil
+		local last_time = minetest.get_us_time() * 1000
+		local maxtime = pool.maxtime
+		for index, task_func in pairs(tasks) do
+			local p = task_func(pass_arg)
+			if p then
+				pass_arg = p
+			end
+			if minetest.get_us_time() * 1000 > last_time + maxtime then
+				coroutine.yield()
+				last_time = minetest.get_us_time() * 1000
+			end
+		end
+		if callback then
+			callback(pass_arg)
+		end
+	end)
+	extended_api.Async.schedule_worker(pool)
+end
+
+function extended_api.Async.queue_task(pool,func,callback)
+	table.insert(pool.task_queue,{func = func,callback = callback})
+	if pool.queue_threads > 0 then
+		pool.queue_threads = pool.queue_threads - 1
+		extended_api.Async.create_worker(pool,function()
+			local pass_arg = nil
+			local last_time = minetest.get_us_time() * 1000
+			local maxtime = pool.maxtime
+			while(true) do
+				local task_func = pool.task_queue[1]
+				table.remove(pool.task_queue,1)
+				if task_func and task_func.func then
+					pass_arg = nil
+					local p = task_func.func(pass_arg)
+					if p then
+						pass_arg = p
+					end
+					if task_func.callback then
+						task_func.callback(pass_arg)
+					end
+					if minetest.get_us_time() * 1000 > last_time + maxtime then
+						coroutine.yield()
+						last_time = minetest.get_us_time() * 1000
+					end
+				else
+					pool.queue_threads = pool.queue_threads + 1
+					break
+				end
+			end
+		end)
+		extended_api.Async.schedule_worker(pool)
+	end
+end

colddb.lua

@@ -33,7 +33,9 @@ function colddb.get_db(directory)
 		iterate_queue = {},
 		indexes = false,
 		add_to_mem_pool = true,
+		async_pool = extended_api.Async.create_async_pool(),
 	}
+	extended_api.Async.priority(db.async_pool,150,250)
 	-- make tables weak so the garbage-collector will remove unused data
 	setmetatable(db.tags, {__mode = "kv"})
 	setmetatable(db.mem_pool, {__mode = "kv"})
@@ -250,7 +252,7 @@ function colddb.delete_lines(db,_lines,tag_name)
 		local copyfile = string.format("%s%sæIndex_table.cold.replacer",db.directory,t)
 		local args = {db=db,cs=cs,oldfile=oldfile,copyfile=copyfile,do_not_skip_removed_items=true}
 		db.indexes_pool[cs] = f
-		colddb.iterate_index_table(db,delete_lines_func_begin,delete_lines_func_i,delete_lines_func_end,150,args,tag_name)
+		colddb.iterate_index_table(db,delete_lines_func_begin,delete_lines_func_i,delete_lines_func_end,args,tag_name)
 	end
 end
 
@@ -374,21 +376,15 @@ function colddb.get_count(db,tag_name)
 	return nil
 end
 
-local function iterate(db,func_on_iterate,end_func,cycles_per_tick,count,cs,args)
+local function iterate(db,func_on_iterate,end_func,count,cs,args)
 	local f = db.indexes_pool[cs]
 	local fl = f.file
-	for i=1,cycles_per_tick do
+	extended_api.Async.iterate(db.async_pool,1,count,function(i)
-		if count < 1 then
-			break
-		end
 		local line = fl:read("*l")
 		if args.do_not_skip_removed_items or not db.indexes_pool[cs].deleted_items[line] then
 			func_on_iterate(line,i,args)
 		end
-		count = count - 1
+	end,function() 
-	end
-	db.indexes_pool[cs] = f
-	if count < 1 then
 		if end_func then
 			end_func(args)
 		end
@@ -405,19 +401,18 @@ local function iterate(db,func_on_iterate,end_func,cycles_per_tick,count,cs,args
 					copy.args = a
 				end
 			end
-			minetest.after(0,iterate,copy.db,copy.func_on_iterate,copy.end_func,copy.cycles_per_tick,copy.count,copy.cs,copy.args)
+			minetest.after(0,iterate,copy.db,copy.func_on_iterate,copy.end_func,copy.count,copy.cs,copy.args)
 			table.remove(db.iterate_queue[cs],1)
-			return true
+			return false
 		else
 			db.iterate_queue[cs] = nil
 		end
 			db.indexes_pool[cs].iterating = false
-		return true
+		return false
-	end
+	end)
-	minetest.after(0,iterate,db,func_on_iterate,end_func,cycles_per_tick,count,cs,args)
 end
 
-function colddb.iterate_index_table(db,begin_func,func_on_iterate,end_func,cycles_per_tick,args,tag_name)
+function colddb.iterate_index_table(db,begin_func,func_on_iterate,end_func,args,tag_name)
 	local t = ""
 	local name = "æIndex_table"
 	if tag_name then
@@ -455,7 +450,7 @@ function colddb.iterate_index_table(db,begin_func,func_on_iterate,end_func,cycle
 			end
 		end
 		-- Start iterating the index table
-		iterate(db,func_on_iterate,end_func,cycles_per_tick,c,cs,args)
+		iterate(db,func_on_iterate,end_func,c,cs,args)
 	elseif f and f.file then
 		-- If its iterating some other function then add this one to the queue list
 		fl:seek("set")
@@ -467,7 +462,7 @@ function colddb.iterate_index_table(db,begin_func,func_on_iterate,end_func,cycle
 		if not db.iterate_queue[cs] then
 			db.iterate_queue[cs] = {}
 		end
-		local _table = {db=db,begin_func=begin_func,func_on_iterate=func_on_iterate,end_func=end_func,cycles_per_tick=cycles_per_tick,count=c,cs=cs,tag_name=tag_name,args=args}
+		local _table = {db=db,begin_func=begin_func,func_on_iterate=func_on_iterate,end_func=end_func,count=c,cs=cs,tag_name=tag_name,args=args}
 		table.insert(db.iterate_queue[cs],_table)
 	end
 end
@@ -494,14 +489,18 @@ function colddb.set(db,name,_table,tag_name)
 		t = colddb.get_tag(db,tag_name)
 	end
 	if db.indexes and not colddb.file_Exists(db,name,tag_name) then
+		extended_api.Async.queue_task(db.async_pool,function() 
 			local cs2 = string.format("%s%s",t,"æIndex_table")
 			local om = db.indexes_pool[cs2]
 			if not colddb.file_Exists(db,"æIndex_table",tag_name) or not (om and om.file) then
 				colddb.open_index_table(db,tag_name)
 			end
-		minetest.after(0,function(db,name,tag_name)colddb.append_index_table(db,name,tag_name)end,db,name,tag_name)
+			colddb.append_index_table(db,name,tag_name)
+		end)
 	end
-	minetest.after(1,function(db,name, _table,tag_name)colddb.save_table(db,name, _table,tag_name)end,db,name, _table,tag_name)
+	extended_api.Async.queue_task(db.async_pool,function() 
+		colddb.save_table(db,name, _table,tag_name)
+	end)
 	if db.add_to_mem_pool then
 		load_into_mem(db,name,_table,tag_name)
 	end
@@ -513,20 +512,25 @@ function colddb.set_key(db,name,tag_name)
 		t = colddb.get_tag(db,tag_name)
 	end
 	if db.indexes and not colddb.file_Exists(db,name,tag_name) then
+		extended_api.Async.queue_task(db.async_pool,function() 
 			local cs2 = string.format("%s%s",t,"æIndex_table")
 			local om = db.indexes_pool[cs2]
 			if not colddb.file_Exists(db,"æIndex_table",tag_name) or not (om and om.file) then
 				colddb.open_index_table(db,tag_name)
 			end
-		minetest.after(0,function(db,name,tag_name)colddb.append_index_table(db,name,tag_name)end,db,name,tag_name)
+			colddb.append_index_table(db,name,tag_name)
+		end)
 	end
-	minetest.after(1,function(db,name, tag_name)colddb.save_key(db,name, tag_name)end,db,name, tag_name)
+	extended_api.Async.queue_task(db.async_pool,function() 
+		colddb.save_key(db,name, tag_name)
+	end)
 	if db.add_to_mem_pool then
 		load_into_mem(db,name,"",tag_name)
 	end
 end
 
-function colddb.get(db,name,tag_name)
+function colddb.get(db,name,tag_name,callback)
+	extended_api.Async.queue_task(db.async_pool,function() 
 		local t = ""
 		if tag_name then
 			t = colddb.get_tag(db,tag_name)
@@ -543,9 +547,11 @@ function colddb.get(db,name,tag_name)
 			end
 		end
 		return nil
+	end,callback)
 end
 
-function colddb.get_key(db,name,tag_name)
+function colddb.get_key(db,name,tag_name,callback)
+	extended_api.Async.queue_task(db.async_pool,function() 
 		local t = ""
 		if tag_name then
 			t = colddb.get_tag(db,tag_name)
@@ -562,6 +568,7 @@ function colddb.get_key(db,name,tag_name)
 			end
 		end
 		return nil
+	end,callback)
 end
 
 function colddb.remove(db,name,tag_name)
@@ -574,11 +581,15 @@ function colddb.remove(db,name,tag_name)
 		db.mem_pool[cs] = nil
 	end
 	if db.indexes and colddb.file_Exists(db,"æIndex_table",tag_name) then
+		extended_api.Async.queue_task(db.async_pool,function()
 			local cs2 = string.format("%s%s",t,"æIndex_table")
 			if not (db.indexes_pool[cs2] and db.indexes_pool[cs2].file) then
 				colddb.open_index_table(db,tag_name)
 			end
 			colddb.delete_lines(db,name,tag_name)
+		end)
 	end
-	minetest.after(0,function(db,name,tag_name)colddb.delete_file(db,name,tag_name)end,db,name,tag_name)
+	extended_api.Async.queue_task(db.async_pool,function()
+		colddb.delete_file(db,name,tag_name)
+	end)
 end

depends.txt

@@ -0,0 +1 @@
+extended_api?

description.txt

@@ -1 +1 @@
-pure lua No-sql database mod.
+pure lua No-sql Asynchronous database mod.

init.lua

@@ -1,2 +1,4 @@
 modpath = minetest.get_modpath("colddb")
-dofile(modpath .. "/colddb.lua")
+
+dofile(string.format("%s/async.lua",modpath))
+dofile(string.format("%s/colddb.lua",modpath))