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comparison database.rb @ 0:1eef88068f9f tip

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initial commit of maze game source
author ferencd
date Sun, 15 Sep 2019 11:46:47 +0200
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-1:000000000000 0:1eef88068f9f
1 require 'utils'
2 require 'gs_logger'
3
4 #
5 # This class is responsible for handling all database related requests
6 #
7
8 class Database
9
10 private_class_method :new
11
12 def Database.initialize
13
14 @@conn = PG::Connection.new(:dbname => 'mazedb', :user => 'mazedb', :password => 's321851gper')
15
16 @@conn.prepare('ins_prep_stmt', 'insert into games (level_id, level_number,level_type) values ($1,$2,$3)')
17 @@conn.prepare('sel_for_game_id_prep_stmt', 'select * from games where level_id=$1')
18 @@conn.prepare('sel_level_no_prep_stmt', 'select level_number from games where level_id=$1')
19 @@conn.prepare('upd_prep_stmt', 'update games set level_number=$1 where level_id=$2')
20
21 $LOG.info 'Database initialized'
22 rescue => ex
23 $LOG.fatal "Exception caught while preparing the statements: #{ex.class.to_s}\n"
24 exit 1
25 end
26
27 #
28 # Inserts a game ID into the database
29 #
30 def Database.insert_game_id_to_db(game_id, lev_no, gam_type)
31 @@conn.exec_prepared 'ins_prep_stmt', ["#{game_id}", lev_no, gam_type]
32 rescue => ex
33 $LOG.error "Exception caught: #{ex.class.to_s}\n"
34 raise
35 end
36
37 #
38 # Creates a valid game ID by assuring no duplicates in the database
39 #
40 def Database.create_valid_game_id (game_type)
41 game_id = game_type + Utils.random_string(8)
42 # Create a unique ID for the current level
43 loop do
44 begin
45 res = @@conn.exec_prepared 'sel_for_game_id_prep_stmt', ["#{game_id}"]
46 rescue => ex
47 $LOG.error "Exception caught: #{ex.class.to_s}\n"
48 raise
49 end
50
51 break if res.cmd_tuples == 0
52 res.clear
53 game_id = 'S' + Utils.random_string(8)
54
55 end
56 game_id
57 end
58
59 #
60 # Returns the level to which this gid is associated
61 #
62 def Database.get_db_level_for_gid(gid)
63 level_no = 1
64 loop do
65 begin
66 res = @@conn.exec_prepared 'sel_level_no_prep_stmt', ["#{gid}"]
67 rescue => ex
68 $LOG.error "Exception caught: #{ex.class.to_s}\n"
69 raise
70 end
71 return -1 if res.cmd_tuples == 0
72 level_no = res[0]
73 res.clear
74 break
75 end
76 level_no['level_number'].to_i
77 end
78
79 #
80 # Updates the level number for the given game ID to reflect th current state
81 #
82 def Database.update_level_number_for_gid(level_number, gid)
83 loop do
84 begin
85 res = @@conn.exec_prepared 'upd_prep_stmt', [level_number, "#{gid}"]
86 rescue => ex
87 $LOG.error "Exception caught: #{ex.class.to_s}\n"
88 raise
89 end
90 break if res.cmd_tuples == 0
91 res.clear
92 break
93 end
94 end
95
96 end