pgtoolkit/toolbase.py
author Radek Brich <radek.brich@devl.cz>
Wed, 23 May 2012 11:11:16 +0200
changeset 36 e67101c22e83
parent 34 98c7809af415
child 51 bdc44f96cb0b
permissions -rw-r--r--
pgmanager: Add create_conn_listen() which should be used with wait_for_notify. Update wait_for_notify() to not use put_conn(). Add name to ConnectionInfo. Log queries before they are called. Log exceptions. Add notifyexample.

import argparse
import logging
import re

from pgtoolkit import pgmanager, pgbrowser, config
from pgtoolkit.coloredformatter import ColoredFormatter
from pgtoolkit.highlight import highlight


class ConnectionInfoNotFound(Exception):    
    pass


class BadArgsError(Exception):    
    pass


class ToolBase:
    def __init__(self, name, desc):
        self.parser = argparse.ArgumentParser(description=desc)
        self.parser.add_argument('-d', dest='debug', action='store_true',
            help='Debug mode - print database queries.')
        
        self.config = config.ConfigParser()
        self.config.add_argument('databases', type=dict)
        self.config.add_argument('meta_db')
        self.config.add_argument('meta_query')
        
        self.pgm = pgmanager.get_instance()
        self.target_isolation_level = None
        
    def init(self):
        self.config.load('pgtoolkit.conf')
        self.args = self.parser.parse_args()
        self.init_logging()
    
    def init_logging(self):
        # logging
        handler = logging.StreamHandler()
        format = ColoredFormatter(highlight(1,7,0)+'%(asctime)s %(levelname)-5s'+highlight(0)+' %(message)s', '%H:%M:%S')
        handler.setFormatter(format)
        handler.setLevel(logging.DEBUG)
        self.log = logging.getLogger('main')
        self.log.addHandler(handler)
        self.log.setLevel(logging.DEBUG)
        
        if self.args.debug:
            handler = logging.StreamHandler()
            handler.setFormatter(format)
            handler.setLevel(logging.DEBUG)
            logger = logging.getLogger('pgmanager_sql')
            logger.addHandler(handler)
            logger.setLevel(logging.DEBUG)

    def prepare_conn_from_metadb(self, name, lookup_name):
        '''Create connection in pgmanager using meta DB.
        
        name -- Name for connection in pgmanager.
        lookup_name -- Name of connection in meta DB.
        
        '''
        with self.pgm.cursor('meta') as curs:
            curs.execute(self.config.meta_query, [lookup_name])
            row = curs.fetchone_dict()
            curs.connection.commit()
            if row:
                self.pgm.create_conn(name=name,
                    isolation_level=self.target_isolation_level,
                    **row)
                return True

    def prepare_conn_from_config(self, name, lookup_name):
        '''Create connection in pgmanager using info in config.databases.'''
        if self.config.databases:
            if lookup_name in self.config.databases:
                dsn = self.config.databases[lookup_name]
                self.pgm.create_conn(name=name,
                    isolation_level=self.target_isolation_level,
                    dsn=dsn)
                return True

    def prepare_conns_from_cmdline_args(self, *pgm_names):
        if self.config.meta_db:
            self.pgm.create_conn(name='meta', dsn=self.config.meta_db)
        
        for name in pgm_names:
            lookup_name = self.args.__dict__[name]
            found = self.prepare_conn_from_config(name, lookup_name)
            if not found and self.config.meta_db:
                found = self.prepare_conn_from_metadb(name, lookup_name)
            if not found:
                raise ConnectionInfoNotFound('Connection name "%s" not found in config nor in meta DB.' % lookup_name)
        
        if self.config.meta_db:
            self.pgm.close_conn('meta')


class SimpleTool(ToolBase):
    def __init__(self, name, desc):
        ToolBase.__init__(self, name, desc)        
        self.parser.add_argument('target', metavar='target', type=str, help='Target database')
      
    def init(self):
        ToolBase.init(self)
        self.prepare_conns_from_cmdline_args('target')


class SrcDstTool(ToolBase):
    def __init__(self, name, desc):
        ToolBase.__init__(self, name, desc)        
        self.parser.add_argument('src', metavar='source', type=str, help='Source database')
        self.parser.add_argument('dst', metavar='destination', type=str, help='Destination database')
      
    def init(self):
        ToolBase.init(self)
        self.prepare_conns_from_cmdline_args('src', 'dst')


class SrcDstTablesTool(SrcDstTool):
    def __init__(self, name, desc):
        SrcDstTool.__init__(self, name, desc)
        self.parser.add_argument('-t', '--src-table', metavar='source_table',
            dest='srctable', type=str, default='', help='Source table name.')
        self.parser.add_argument('-s', '--src-schema', metavar='source_schema',
            dest='srcschema', type=str, default='', help='Source schema name (default=public).')
        self.parser.add_argument('--dst-table', metavar='destination_table',
            dest='dsttable', type=str, default='', help='Destination table name (default=source_table).')
        self.parser.add_argument('--dst-schema', metavar='destination_schema',
            dest='dstschema', type=str, default='', help='Destination schema name (default=source_schema).')
        self.parser.add_argument('--regex', action='store_true', help="Use RE in schema or table name.")
    
    def init(self):
        SrcDstTool.init(self)
        
        self.schema1 = self.args.srcschema
        self.table1 = self.args.srctable
        self.schema2 = self.args.dstschema
        self.table2 = self.args.dsttable
        
        # check regex - it applies to source name, dest name must not be specified
        # applies to only one - schema or table name
        if self.args.regex:
            if self.table2 or (self.schema2 and not self.table1):
                raise BadArgsError('Cannot specify both --regex and --dst-schema, --dst-table.')
        # schema defaults to public
        if self.table1 and not self.schema1:
            self.schema1 = 'public'
        # dest defaults to source
        if not self.schema2:
            self.schema2 = self.schema1
        if not self.table2:
            self.table2 = self.table1

    def tables(self):
        '''Generator. Yields schema1, table1, schema2, table2.'''
        srcconn = self.pgm.get_conn('src')
        try:
            srcbrowser = pgbrowser.PgBrowser(srcconn)
            if self.args.regex:
                if not self.table1:
                    # all tables from schemas defined by regex
                    for item in self._iter_schemas_regex(srcbrowser, self.schema1):
                        yield item
                else:
                    # all tables defined by regex
                    for item in self._iter_tables_regex(srcbrowser, self.schema1, self.schema2, self.table1):
                        yield item
            else:
                if not self.table1:
                    if not self.schema1:
                        # all tables from all schemas
                        for item in self._iter_schemas_regex(srcbrowser, self.schema1):
                            yield item
                    else:
                        # all tables from specified schema
                        for item in self._iter_tables_regex(srcbrowser, self.schema1, self.schema2, self.table1):
                            yield item
                else:
                    # one table
                    yield (self.schema1, self.table1, self.schema2, self.table2)
        finally:
            self.pgm.put_conn(srcconn, 'src')
    
    def _iter_schemas_regex(self, browser, regex):
        for schema in browser.list_schemas():
            if schema['system']:
                continue
            schemaname = schema['name']
            if re.match(regex, schemaname):
                for item in self._iter_tables_regex(browser, schemaname, schemaname, ''):
                    yield item
    
    def _iter_tables_regex(self, browser, schema1, schema2, regex):
        for table in browser.list_tables(schema1):
            tablename = table['name']
            if re.match(regex, tablename):
                yield (schema1, tablename, schema2, tablename)