Module: BlackStack::PostgreSQL

Defined in:
lib/blackstack-db/postgresql.rb

Constant Summary collapse

@@db_url =

database connection parameters

nil
@@db_port = 
nil
@@db_name = 
nil
@@db_user = 
nil
@@db_password = 
nil
@@db_max_connections = 
nil

Class Method Summary collapse

Class Method Details

.connect ⇒ Object

create database connection



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# File 'lib/blackstack-db/postgresql.rb', line 95

def self.connect
    BlackStack::set_db_type(BlackStack::TYPE_POSTGRESQL)
    s = BlackStack::PostgreSQL.connection_string
    opts = {}
    opts[:max_connections] = @@db_max_connections if @@db_max_connections
    Sequel.connect(s, **opts)
end

.connection_string ⇒ Object

return the connection string for a postgresql database



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# File 'lib/blackstack-db/postgresql.rb', line 12

def self.connection_string
    "postgresql://#{@@db_user}:#{@@db_password}@#{@@db_url}:#{@@db_port}/#{@@db_name}"
end

.db_max_connections ⇒ Object 



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# File 'lib/blackstack-db/postgresql.rb', line 32

def self.db_max_connections
    @@db_max_connections
end

.db_name ⇒ Object 



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# File 'lib/blackstack-db/postgresql.rb', line 23

def self.db_name
    @@db_name
end

.db_password ⇒ Object 



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# File 'lib/blackstack-db/postgresql.rb', line 29

def self.db_password
    @@db_password
end

.db_port ⇒ Object 



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# File 'lib/blackstack-db/postgresql.rb', line 20

def self.db_port
    @@db_port
end

.db_url ⇒ Object

database connection getters



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# File 'lib/blackstack-db/postgresql.rb', line 17

def self.db_url
    @@db_url
end

.db_user ⇒ Object 



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# File 'lib/blackstack-db/postgresql.rb', line 26

def self.db_user
    @@db_user
end

.guid ⇒ Object

return a postgresql uuid



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# File 'lib/blackstack-db/postgresql.rb', line 104

def self.guid()
    DB['SELECT uuid_generate_v4() AS id'].first[:id]
end

.now ⇒ Object

return current datetime with format ‘%Y-%m-%d %H:%M:%S %Z`, using the timezone of the database (`select current_setting(’TIMEZONE’)‘) TODO: I am hardcoding the value of tz because for any reason `SELECT current_setting(’TIMEZONE’)‘ returns UTC instead of America/Argentina/Buenos_Aires when I run it from Ruby. Be sure your database is ALWAYS configured with the correct timezone.



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# File 'lib/blackstack-db/postgresql.rb', line 111

def self.now()
    tz = 'America/Argentina/Buenos_Aires' #DB["SELECT current_setting('TIMEZONE') AS tz"].first[:tz]
    DB["SELECT current_timestamp at TIME ZONE '#{tz}' AS now"].first[:now]
end

.seconds_ago(n) ⇒ Object 



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# File 'lib/blackstack-db/postgresql.rb', line 116

def self.seconds_ago(n)
    tz = 'America/Argentina/Buenos_Aires' #DB["SELECT current_setting('TIMEZONE') AS tz"].first[:tz]
    DB["SELECT (current_timestamp - interval '#{n} seconds') at TIME ZONE '#{tz}' AS now"].first[:now]
end

.set_db_params(h) ⇒ Object 



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# File 'lib/blackstack-db/postgresql.rb', line 36

def self.set_db_params(h)
    # validate: the parameter h is requred
    raise "The parameter h is required." if h.nil?

    # validate: the parameter h must be a hash
    raise "The parameter h must be a hash" unless h.is_a?(Hash)

    # validate: the :db_url key is required
    raise 'The key :db_url is required' unless h.has_key?(:db_url)

    # validate: the :db_port key is required
    raise 'The key :db_port is required' unless h.has_key?(:db_port)

    # validate: the db_name key is required
    raise 'The key :db_name is required' unless h.has_key?(:db_name)

    # validate: the db_user key is required
    raise 'The key :db_user is required' unless h.has_key?(:db_user)

    # validate: the db_password key is required
    raise 'The key :db_password is required' unless h.has_key?(:db_password)

                # validate: optional :max_connections key
                if h.has_key?(:max_connections)
                    value = h[:max_connections]
                    unless value.is_a?(Integer) || (value.is_a?(String) && value.to_i.to_s == value)
                        raise 'The key :max_connections must be an integer'
                    end
                    raise 'The key :max_connections must be greater than zero' unless value.to_i > 0
                end

    # validate: the :db_url key must be a string
    raise 'The key :db_url must be a string' unless h[:db_url].is_a?(String)

    # validate: the :db_port key must be an integer, or a string that can be converted to an integer
    raise 'The key :db_port must be an integer' unless h[:db_port].is_a?(Integer) || (h[:db_port].is_a?(String) && h[:db_port].to_i.to_s == h[:db_port])

    # validate: the :db_name key must be a string
    raise 'The key :db_name must be a string' unless h[:db_name].is_a?(String)

    # validate: the :db_user key must be a string
    raise 'The key :db_user must be a string' unless h[:db_user].is_a?(String)

    # validate: the :db_password key must be a string
    raise 'The key :db_password must be a string' unless h[:db_password].is_a?(String)

    # set type
    BlackStack::set_db_type(BlackStack::TYPE_POSTGRESQL)

    # map values
    @@db_url = h[:db_url]
    @@db_port = h[:db_port].to_i
    @@db_name = h[:db_name]
    @@db_user = h[:db_user]
    @@db_password = h[:db_password]
    @@db_max_connections = h[:max_connections] ? h[:max_connections].to_i : nil
end

.test(l = nil) ⇒ Object

test the connection to the database. raise an exception if the connection fails, or if any incongruence is found.



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# File 'lib/blackstack-db/postgresql.rb', line 123

def self.test(l=nil)
    l = BlackStack::DummyLogger.new if l.nil?
    @db = nil

    #l.log "Connection String:"
    #l.log BlackStack::PostgreSQL::connection_string
    
    l.logs "Testing connection... "
    begin
        @db = BlackStack::PostgreSQL::connect
        l.logf "success".green
    rescue => e
        l.logf "failed".red
        l.log e.message
    end
    
    # if the name of databsase in `config.rb` is wrong, the connection is made to the defaultdb.
    # This validation checks the connection to the correct database.
    begin
        l.logs "Verify database name... "
        s = @db["SELECT datname FROM pg_database WHERE datname='#{BlackStack::PostgreSQL::db_name}'"].first
        raise 'Wrong database name' if s.nil?
        l.logf "success".green
    rescue => e
        l.logf "failed".red
        l.log e.message
    end
end