SynergySession.py

#!/usr/bin/env python
# encoding: utf-8
"""
SynergySession.py

Copyright (c) 2011, Nokia
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Neither the name of the Nokia nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.    IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""

import os
import re
import time
import random
from subprocess import Popen, PIPE

class SynergySession(object):
    """This class is a wrapper around the Synergy command line client"""

    def __init__(self, database, engine=None, command_name='ccm', ccm_ui_path='/dev/null', ccm_eng_path='/dev/null', ccm_addr=None):
        self.command_name = command_name
        self.database = database
        self.engine = engine
        self.sessionID = -1 # set to -1 for singular sessions; for multiple sessions populate from zero and up after creating the individual sessions
        self.keep_session_alive = False  # Keep session alive when deleting the object

        # This dictionary will contain the status of the next command and will be emptied by self.run()
        self.command = ''
        self.status = {}

        # Store the warnings and errors that might be found along the preparation or execution of a command
        self.warnings = []
        self.errors = []

        # Open the session
        args = [self.command_name]
        args.append('start')
        args.append('-nogui')
        args.append('-d')
        args.append(self.database) # database
        args.append('-m') # permit multiple sessions
        args.append('-q') #quiet
        if self.engine:
            args.append('-d')
            args.append(self.engine) # engine

        env = os.environ
        self.environment = env.copy()

        self.environment['CCM_UILOG'] = ccm_ui_path
        self.environment['CCM_ENGLOG'] = ccm_eng_path

        #Check if an existing session should be used
        if not ccm_addr:
            # Open the session
            p = Popen(args, stdout=PIPE, stderr=PIPE, env=self.environment)
            # Store the session data
            #p.wait()
            stdout, stderr = p.communicate()
            if stderr:
                raise SynergyException('Error while starting a synergy Session: ' + stderr)

            # Set the environment variable for the Synergy session
            self.environment['CCM_ADDR'] = stdout
        else:
            self.environment['CCM_ADDR'] = ccm_addr

        # Get the delimiter and store it
        self.delimiter = self.delim()

    def setSessionID(self, sessionID):
        self.sessionID = sessionID

    def getSessionID(self):
        return self.sessionID

    def getCCM_ADDR(self):
        return self.environment['CCM_ADDR'].strip()

    def get_database_name(self):
        splitted = os.path.split(self.database)
        if splitted[-1] == '':
            return os.path.split(splitted)[1]
        return splitted[-1]

    def __del__(self):
        # Close the session
        if not self.keep_session_alive:
            self.stop()
            print "Stopping %s" % self.getCCM_ADDR()

    def _reset_status(self):
        """Reset the status of the object"""
        self.command = ''
        self.status = {}
        self.warnings = []
        self.errors = []

    def _run(self, command):
        """Execute a Synergy command"""
        if not command[0] == self.command_name:
            command.insert(0, self.command_name)

        # retry all commands 3 times to patch over ccm concurrency issues
        for retrycount in range(3):
            # stagger parallel commands to patch over ccm concurrency issues
            if (self.sessionID >= 0):
                time.sleep(0.2 * random.random())

            if (retrycount > 0): # more sleep on retry operations
                time.sleep(0.2 * random.random())

            p = Popen(command, stdout=PIPE, stderr=PIPE, env=self.environment)

            # Store the result as a single string. It will be splitted later
            stdout, stderr = p.communicate()

            if not stderr:
                break

        if stderr:
            raise SynergyException('Error while running the Synergy command: %s \nError message: %s' % (command, stderr))

        return stdout

    def delim(self):
        """Returns the delimiter defined in the Synergy DB"""
        self._reset_status()
        return self._run(['delim']).strip()

    def stop(self):
        """Stops the current Synergy session"""
        if 'CCM_ADDR' in self.environment:
            self._run(['stop'])

    def query(self, query_string):
        """Set a query that will be executed"""
        self.command = 'query'
        self.status['arguments'] = [query_string]
        self.status['formattable'] = True
        if 'format' not in self.status:
            self.status['format'] = ['%objectname']
        return self

    def cat(self, object_name):
        """Cat an object"""
        self.command = 'cat'
        self.status['arguments'] = [object_name]
        self.status['formattable'] = False
        if 'format' in self.status:
            self.status['format'] = []
        return self

    def finduse(self, object_name):
        """Finduse of an object"""
        self.command = 'finduse'
        self.status['arguments'] = [object_name]
        self.status['option'] = []
        self.status['formattable'] = False
        if 'format' in self.status:
            self.status['format'] = []
        return self

    def attr(self, object_name):
        """Attributes of an object"""
        self.command = 'attr'
        self.status['arguments'] = [object_name]
        self.status['option'] = []
        self.status['formattable'] = False
        if 'format' in self.status:
            self.status['format'] = []
        return self

    def task(self, task, formattable=False):
        """Task command"""
        self.command = 'task'
        self.status['arguments'] = [task]
        self.status['option'] = []
        self.status['formattable'] = formattable
        if 'format' not in self.status:
            self.status['format'] = ['%objectname']
        return self

    def rp(self, project):
        """Reconfigure properties command"""
        self.command = 'rp'
        self.status['arguments'] = [project]
        self.status['option'] = []
        self.status['formattable'] = True
        if 'format' not in self.status:
            self.status['format'] = ['%objectname']
        return self

    def diff(self, new, old):
        """Difference between to files"""
        self.command = 'diff'
        self.status['arguments'] = [old, new]
        self.status['option'] = []
        self.status['formattable'] = False
        if 'format' in self.status:
            self.status['format'] = []
        return self

    def hist(self, obj):
        """history command"""
        self.command = 'hist'
        self.status['arguments'] = [obj]
        self.status['options'] = []
        self.status['formattable'] = True
        if 'format' not in self.status:
            self.status['format'] = ['%objectname']
        return self


    def format(self, format):
        """Sets the output format for the command, if it supports formatting.

        The input can be an iterable or a string"""

        if isinstance(format, str):
            if 'format' not in self.status:
                self.status['format'] = []
            self.status['format'].append(format)
            return self

        if not hasattr(format, '__iter__'):
            self.warnings.append('The argument of format(format) must be something iterable or a string')
            return self

        if not self.status['format']:
            for element in format:
                self.status['format'].append(element)

        return self

    def option(self, option):
        """Sets the options for the command, if it supports options.

        The input can be an iterable or a string"""
        if isinstance(option, str):
            if 'option' not in self.status:
                self.status['option'] = []
            self.status['option'].append(option)
            return self

        if not hasattr(option, '__iter__'):
            self.warnings.append('The argument of option(option) must be something iterable or a string')
            return self

        if not self.status['option']:
            for element in option:
                self.status['option'].append(element)

        return self

    def run(self):
        """
        Run the Synergy command.

        At this point the command must be already set by i.e. query()
        """
        if not self.status:
            self.errors.append('before run() the status of the command must be already set')

        command = [self.command_name]

        command.append(self.command)

        if 'formattable' in self.status and self.status['formattable']:
            if 'format' not in self.status:
                raise SynergyException("status['format'] undefined")
            if 'hist' not in command:
                command.append('-u')
            if 'task' not in command and 'rp' not in command and 'hist' not in command:
                command.append('-nf')
            command.append('-f')
            if 'hist' not in command:
                command.append('|SEPARATOR|'.join(self.status['format']) + '|ITEM_SEPARATOR|')
            else:
                command.append('|SEPARATOR|'.join(self.status['format']))

        if 'arguments' not in self.status:
            raise SynergyException("status['arguments'] undefined")

        if 'option' in self.status:
            for element in self.status['option']:
                command.append(element)

        command.extend(self.status['arguments'])

        result = self._run(command)
        # Parse the result and return it
        if 'formattable' in self.status and self.status['formattable']:
            if not result:
                # Clean up
                self._reset_status()
                return []

            final_result = []
            items = []
            if 'hist' in command:
                items = result.split('*****************************************************************************')[
                        :-1]
            else:
                items = result.split('|ITEM_SEPARATOR|')[:-1]

            for item in items:
                splitted_item = item.split('|SEPARATOR|')
                if len(splitted_item) != len(self.status['format']):
                    raise SynergyException("the length of status['format'] and the splitted result is not the same")
                line = {}
                for k, v in zip(self.status['format'], splitted_item):
                    line[k[1:]] = v.strip()
                if 'hist' in command:
                    # History command is special ;)
                    p = re.compile("(?s)(.*?)Predecessors:\s*(.*)Successors:\s*(.*?)$")
                    m = p.match(splitted_item[len(splitted_item) - 1])
                    if m:
                        line[self.status['format'][-1]] = m.group(1).split()
                        line['predecessors'] = m.group(2).split()
                        line['successors'] = m.group(3).split()
                    else:
                        line['predecessors'] = []
                        line['successors'] = []

                final_result.append(line)
                # Clean up
            self._reset_status()
            return final_result
        else:
            # Clean up
            self._reset_status()
            return result


class SynergyException(Exception):
    """User defined exception raised by SynergySession"""
    def __init__(self, value):
        self.value = value

    def __str__(self):
        return repr(self.value)



def main():
    pass

if __name__ == '__main__':
    main()