Class: PgSync::DataSource

Inherits:
Object
  • Object
show all
Defined in:
lib/pgsync/data_source.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(source, timeout: 3) ⇒ DataSource

Returns a new instance of DataSource.



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# File 'lib/pgsync/data_source.rb', line 5

def initialize(source, timeout: 3)
  @url = resolve_url(source)
  @timeout = timeout
end

Instance Attribute Details

#url ⇒ Object (readonly)

Returns the value of attribute url.



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# File 'lib/pgsync/data_source.rb', line 3

def url
  @url
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 104

def close
  if @conn
    @conn.close
    @conn = nil
  end
end

#columns(table) ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 42

def columns(table)
  query = "SELECT column_name FROM information_schema.columns WHERE table_schema = $1 AND table_name = $2"
  execute(query, table.split(".", 2)).map { |row| row["column_name"] }
end

#conn ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 88

def conn
  @conn ||= begin
    begin
      ENV["PGCONNECT_TIMEOUT"] ||= @timeout.to_s
      if @url =~ /\Apostgres(ql)?:\/\//
        config = @url
      else
        config = {dbname: @url}
      end
      PG::Connection.new(config)
    rescue URI::InvalidURIError
      raise Error, "Invalid connection string"
    end
  end
end

#dbname ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 26

def dbname
  @dbname ||= conninfo[:dbname]
end

#dump_command(tables) ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 111

def dump_command(tables)
  tables = tables ? tables.keys.map { |t| "-t #{Shellwords.escape(quote_ident_full(t))}" }.join(" ") : ""
  "pg_dump -Fc --verbose --schema-only --no-owner --no-acl #{tables} -d #{@url}"
end

#exists? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pgsync/data_source.rb', line 10

def exists?
  @url && @url.size > 0
end

#fully_resolve_tables(tables) ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 121

def fully_resolve_tables(tables)
  no_schema_tables = {}
  search_path_index = Hash[search_path.map.with_index.to_a]
  self.tables.group_by { |t| t.split(".", 2)[-1] }.each do |group, t2|
    no_schema_tables[group] = t2.sort_by { |t| [search_path_index[t.split(".", 2)[0]] || 1000000, t] }[0]
  end

  Hash[tables.map { |k, v| [no_schema_tables[k] || k, v] }]
end

#host ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 18

def host
  @host ||= conninfo[:host]
end

#last_value(seq) ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 59

def last_value(seq)
  execute("select last_value from #{seq}")[0]["last_value"]
end

#local? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pgsync/data_source.rb', line 14

def local?
  !host || %w(localhost 127.0.0.1).include?(host)
end

#max_id(table, primary_key, sql_clause = nil) ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 51

def max_id(table, primary_key, sql_clause = nil)
  execute("SELECT MAX(#{quote_ident(primary_key)}) FROM #{quote_ident_full(table)}#{sql_clause}")[0]["max"].to_i
end

#min_id(table, primary_key, sql_clause = nil) ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 55

def min_id(table, primary_key, sql_clause = nil)
  execute("SELECT MIN(#{quote_ident(primary_key)}) FROM #{quote_ident_full(table)}#{sql_clause}")[0]["min"].to_i
end

#port ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 22

def port
  @port ||= conninfo[:port]
end

#primary_key(table) ⇒ Object

stackoverflow.com/a/20537829



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# File 'lib/pgsync/data_source.rb', line 68

def primary_key(table)
  query = "    SELECT\n      pg_attribute.attname,\n      format_type(pg_attribute.atttypid, pg_attribute.atttypmod)\n    FROM\n      pg_index, pg_class, pg_attribute, pg_namespace\n    WHERE\n      pg_class.oid = $2::regclass AND\n      indrelid = pg_class.oid AND\n      nspname = $1 AND\n      pg_class.relnamespace = pg_namespace.oid AND\n      pg_attribute.attrelid = pg_class.oid AND\n      pg_attribute.attnum = any(pg_index.indkey) AND\n      indisprimary\n  SQL\n  row = execute(query, [table.split(\".\", 2)[0], quote_ident_full(table)])[0]\n  row && row[\"attname\"]\nend\n"

#restore_command ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 116

def restore_command
  if_exists = Gem::Version.new(pg_restore_version) >= Gem::Version.new("9.4.0")
  "pg_restore --verbose --no-owner --no-acl --clean #{if_exists ? "--if-exists" : nil} -d #{@url}"
end

#search_path ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 131

def search_path
  @search_path ||= execute("SELECT current_schemas(true)")[0]["current_schemas"][1..-2].split(",")
end

#sequences(table, columns) ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 47

def sequences(table, columns)
  execute("SELECT #{columns.map { |f| "pg_get_serial_sequence(#{escape("#{quote_ident_full(table)}")}, #{escape(f)}) AS #{quote_ident(f)}" }.join(", ")}")[0].values.compact
end

#table_exists?(table) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pgsync/data_source.rb', line 38

def table_exists?(table)
  table_set.include?(table)
end

#tables ⇒ Object

gets visible tables



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# File 'lib/pgsync/data_source.rb', line 31

def tables
  @tables ||= begin
    query = "SELECT table_schema, table_name FROM information_schema.tables WHERE table_type = 'BASE TABLE' AND table_schema NOT IN ('information_schema', 'pg_catalog') ORDER BY 1, 2"
    execute(query).map { |row| "#{row["table_schema"]}.#{row["table_name"]}" }
  end
end

#truncate(table) ⇒ Object 



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# File 'lib/pgsync/data_source.rb', line 63

def truncate(table)
  execute("TRUNCATE #{quote_ident_full(table)} CASCADE")
end