From cd9e9deab379cb5419e9ef972f1055c156f399f4 Mon Sep 17 00:00:00 2001
From: David Bailey <davidbailey.2889@gmail.com>
Date: Thu, 18 May 2023 14:08:28 +0200
Subject: [PATCH] feat: :sparkles: add proper last_used_time updating to
 caching table

---
 lib/timeseries/hoarder/CachingTable.rb | 52 +++++++++++++++++++++-----
 1 file changed, 42 insertions(+), 10 deletions(-)

diff --git a/lib/timeseries/hoarder/CachingTable.rb b/lib/timeseries/hoarder/CachingTable.rb
index 273b96e..c8f967e 100644
--- a/lib/timeseries/hoarder/CachingTable.rb
+++ b/lib/timeseries/hoarder/CachingTable.rb
@@ -7,7 +7,12 @@ require 'json'
 module Timeseries
 	module Hoarder
 		class CachingTable < Table
+			attr_accessor :retention_time
+			attr_reader   :db
+
 			def initialize(db, name, content_name = 'tags', tag_access_update_delay: 60)
+				raise ArgumentError, "DB needs to be a Timeseries::Hoarder::Database!" unless db.is_a? Database
+
 				@content_name = content_name
 				@id_column = content_name + '_id'
 
@@ -18,16 +23,18 @@ module Timeseries
 				@tag_access_updates = {}
 
 				@tag_access_update_delay = tag_access_update_delay
+
+				@retention_time = nil
 			end
 
 			def table_creation
-				@pg.exec("CREATE TABLE ts_hoarder.#{@table_name} ( #{@id_column} SERIAL PRIMARY KEY, #{@content_name} JSONB, created_at TIMESTAMPTZ, last_used TIMESTAMPTZ )")
+				@pg.exec("CREATE TABLE #{@table_id} ( #{@id_column} SERIAL PRIMARY KEY, #{@content_name} JSONB, #{@content_name}_extra JSONB, created_at TIMESTAMPTZ, last_used TIMESTAMPTZ )")
 
-				@pg.exec("CREATE INDEX ON ts_hoarder.#{@table_name} USING GIN ( #{@content_name} )")
+				@pg.exec("CREATE INDEX ON #{@table_id} USING GIN ( #{@content_name} )")
 			end
 
 			def load_cache_content
-				@pg.exec("SELECT * FROM ts_hoarder.#{@table_name}") do |results|
+				@pg.exec("SELECT * FROM #{@table_id} WHERE (NOW() - last_used) < INTERVAL '3h'") do |results|
 					results.each do |tuple|
 
 						tags = JSON.parse(tuple[@content_name])
@@ -46,16 +53,16 @@ module Timeseries
 				returned_id = nil
 
 				@pg.transaction do 
-					@pg.exec("LOCK TABLE ts_hoarder.#{@table_name}")
+					@pg.exec("LOCK TABLE #{@table_id}")
 					
-					res = @pg.exec_params("SELECT * FROM ts_hoarder.#{@table_name} WHERE #{@content_name} = $1::jsonb", [tags.to_json])
+					res = @pg.exec_params("SELECT * FROM #{@table_id} WHERE #{@content_name} = $1::jsonb", [tags.to_json])
 
 					if(res.num_tuples >= 1)
 						returned_id = res[0][@id_column]
 						@known_tags[tags] = returned_id
 						@tag_access_times[tags] = Time.parse(res[0]['last_used'])
 					else
-						res = @pg.exec_params("INSERT INTO ts_hoarder.#{@table_name} (#{@content_name}, created_at, last_used) VALUES ($1::jsonb, NOW(), NOW()) RETURNING #{@id_column}", [tags.to_json])
+						res = @pg.exec_params("INSERT INTO #{@table_id} (#{@content_name}, created_at, last_used) VALUES ($1::jsonb, NOW(), NOW()) RETURNING #{@id_column}", [tags.to_json])
 					
 						returned_id = res[0][@id_column]
 						@known_tags[tags] = returned_id
@@ -66,12 +73,37 @@ module Timeseries
 				returned_id
 			end
 
+			def update_use_times()
+				time_column = []
+				id_column = []
+				
+				@tag_access_updates.each do |tag, value|
+					time_column << @tag_access_times[tag].to_s
+					id_column   << @known_tags[tag]
+				end
+				@tag_access_updates = {}
+
+				time_column = '{'+time_column.join(',')+'}'
+				id_column   = '{'+id_column.join(',')+'}'
+
+				update_query = <<~SQL
+					WITH update_data AS (
+						SELECT unnest($1::timestamptz[]) AS last_used, unnest($2::int[]) AS id
+					)
+					UPDATE #{@table_id} AS o 
+					SET last_used = GREATEST(o.last_used, n.last_used)
+					FROM update_data AS n
+					WHERE #{@id_column} = n.id
+				SQL
+				
+				@pg.exec_params(update_query, [time_column, id_column]);
+			end
+
 			def [](tags)
 				access_time = Time.now()
-				if(((@tag_access_times[tags] || Time.at(0)) - Time.now()) > @tag_access_update_delay)
-					@tag_access_times[tags] = access_time
-					@tag_access_updates[tags] = true
-				end
+				
+				@tag_access_times[tags] = access_time
+				@tag_access_updates[tags] = true
 
 				known_id = @known_tags[tags]
 				return known_id unless known_id.nil?