#============================================================================ 

#Name        : extra.py 

#Part of     : Helium 

#Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

#All rights reserved.

#This component and the accompanying materials are made available

#under the terms of the License "Eclipse Public License v1.0"

#which accompanies this distribution, and is available

#at the URL "http://www.eclipse.org/legal/epl-v10.html".

#

#Initial Contributors:

#Nokia Corporation - initial contribution.

#

#Contributors:

#

#Description:

#===============================================================================

""" Library that contains custom Synergy functionnlities: e.g

        * Snapshotter that can snapshot unfrozen baselines

        * Threaded snapshotter.

"""

import ccm

import os

import threading

import threadpool

import traceback

import logging

from xml.dom.minidom import getDOMImplementation, parse

import StringIO     #pylint throws this up as unused but it is required by delete call in the code 

                    #so do not remove unless removeing the delete (which is required at some point).

# Uncomment this line to enable logging in this module, or configure logging elsewhere

#logging.basicConfig(level=logging.DEBUG)

_logger = logging.getLogger('ccm.extra')

class CCMExtraException(ccm.CCMException):

    """ Exception raised by the methods of this module. """

    def __init__(self, description, subexceptions):

        ccm.CCMException.__init__(self, description)

        self.subexceptions = subexceptions

def Snapshot(project, targetdir, dir=None):

    """ This function can snapshot anything from Synergy, even prep/working projects """

    assert project != None, "a project object must be supplied"

    assert project.type == "project", "project must be of project type"

    if not dir:

        dir = project.root_dir()

    targetdir = os.path.join(targetdir, dir.name)

    os.makedirs(targetdir)

    for object in dir.children(project):

        if object.type == 'dir':

            Snapshot(project, targetdir, object)

        elif object.type == 'project':

            Snapshot(object, targetdir)

        else:

            object.to_file(os.path.join(targetdir, object.name))

class _FastSnapshot:

    """ Snapshot Job executed by the thread pool. """

    def __init__(self, pool, project, targetdir, callback, exc_hld):

        """ Construtor, will store the parameter for the checkout. """

        self.pool = pool

        self.project = project

        self.targetdir = targetdir

        self.callback = callback

        self.exc_hld = exc_hld

    def __call__(self):

        """ Do the checkout, and then walkthrough the project hierarchy to find subproject to snapshot. """

        _logger.info("Snapshotting %s under %s" % (self.project, self.targetdir))

        self.project.snapshot(self.targetdir, False)

        def walk(dir, targetdir):

            """walkthrough the project hierarchy to find subproject to snapshot"""

            for object in dir.children(self.project):

                if isinstance(object, ccm.Dir):

                    walk(object, os.path.join(targetdir, object.name))

                elif isinstance(object, ccm.Project):

                    _logger.info("Adding project %s" % object.objectname)

                    self.pool.addWork(_FastSnapshot(self.pool, object, targetdir, self.callback, self.exc_hld))

        if len(self.project.subprojects) > 0:

            rootdir = self.project.root_dir()

            walk(rootdir, os.path.join(self.targetdir, rootdir.name))

        return ""

def FastSnapshot(project, targetdir, threads=4):

    """ Create snapshot running by running snapshots concurrently.

        Snapshot will be made recursively top-down, and each sub project will

        be snapshotted in parallel. 

    """

    assert threads > 0, "Number of threads must be > 0."

    assert project != None, "a project object must be supplied."

    assert project.type == "project", "project must be of project type."

    # error handling

    exceptions = []

    results = []

    def handle_exception(request, exc_info):

        """ append the exceptions"""

        _logger.error( "Exception occurred in request #%s: %s" % (request.requestID, exc_info[1]))

        exceptions.append(exc_info[1])

    def handle_result(result):

        """ append the result"""

        results.append(result)

    pool = threadpool.ThreadPool(threads)

    pool.addWork(_FastSnapshot(pool, project, targetdir, handle_result, handle_exception))

    pool.wait()

    if len(exceptions):

        raise CCMExtraException("Errors occurred during snapshot.", exceptions)

    return "\n".join(results)

def FastMaintainWorkArea(project, path, pst=None, threads=4, wat=False):

    """ Maintain the workarea of a project in parallel. """

    assert threads > 0, "Number of threads must be > 0."

    assert isinstance(project, ccm.Project), "a valid project object must be supplied."

    # error handling

    exceptions = []

    results = []

    def handle_exception(request, exc_info):

        """append the exception"""

        _logger.error( "Exception occured in request #%s: %s\n%s" % (request.requestID, exc_info[1], traceback.format_exception(exc_info[0], exc_info[1], exc_info[2])))

        exceptions.append(exc_info[1])

    def handle_result(result):

        """append  the result"""

        results.append(result)

    class __MaintainProject:

        """_Maintain Project"""

        def __init__(self, subproject, toplevel, wat=False):

            self.subproject = subproject

            self.toplevel = toplevel

            self.wat = wat

        def __call__(self):

            output = ""

            _logger.info("Maintaining project %s" % self.subproject)

            for tuple in self.subproject.finduse():

                if tuple['project'] == self.toplevel:

                    self.subproject['wa_path'] = os.path.join(self.toplevel['wa_path'], tuple['path'])

                    self.subproject["project_subdir_template"] = ""

                    _logger.info("Maintaining project %s under %s" % (self.subproject, self.subproject['wa_path']))

                    output = self.subproject.work_area(True, True, True, wat=self.wat)

            _logger.info("Project %s maintained" % self.subproject)

            return output

    pool = threadpool.ThreadPool(threads)

    project.work_area(True, False, True, path, pst, wat=wat)

    for subproject in project.get_members(type="project"):

        _logger.info("Adding project %s" % subproject)

        pool.addWork(__MaintainProject(subproject, project, wat), callback=handle_result, exc_callback=handle_exception)

    pool.wait()

    if len(exceptions) > 0:

        raise CCMExtraException("Errors occured during work area maintenance.", exceptions)

    return "\n".join(results)

def get_toplevel_project(session, path):

    """get the top level project from CCM or return None"""

    try:

        wainfo = session.get_workarea_info(path)

        project = get_toplevel_project(session, os.path.dirname(wainfo['path']))

        if project == None:

            project = wainfo['project']

        return project

    except ccm.CCMException:

        return None

class SessionProvider:

    """ A class which provides an open user session """

    def __init__(self, opener=None):

        """initialisation"""

        self._opener = opener

        if self._opener is None:

            self._opener = ccm.open_session

    def get(self, username=None, password=None, engine=None, dbpath=None, database=None, reuse=True):

        """return the paramaters required to open a synergy session"""

        _logger.debug("SessionProvider: Creating a new session.")

        return self._opener(username, password, engine, dbpath, database, reuse)

    def __del__(self):

        """delete the CCM session"""

        _logger.info("Deleting the session provider.")

        self.close()

    def close(self):

        """close the session which actually does nothing"""

        pass

class CachedSessionProvider(SessionProvider):

    """

<sessions>

    <session database="foobar" ccmaddr="xxxx"/>

    <session database="foobarx" ccmaddr="xxxx"/>

</sessions>

    """

    def __init__(self, opener=None, cache=None):

        """ Creates CachedSessionProvider, with a specific 

            opener and cache file.

        """

        SessionProvider.__init__(self, opener=opener)

        _logger.info("Using CachedSessionProvider.")

        self.__closed = False

        self._lock = threading.Lock()

        self.cacheXml = cache

        self.cacheFree = {}

        self.cacheUsed = []

        self.load()

    def close(self):

        """ Closing the SessionProvider. """

        _logger.info("Closing the CachedSessionProvider.")

        self.save()

        if self.cacheXml == None:

            _logger.info("Cleaning up opened sessions.")

            self._lock.acquire()

            for dbname in self.cacheFree.keys():

                while len(self.cacheFree[dbname]) > 0:

                    session = self.cacheFree[dbname].pop()

                    session.close_on_exit = True

                    session.close()

            while len(self.cacheUsed) > 0:

                session = self.cacheUsed.pop()

                session.close_on_exit = True

            self._lock.release()

        self.__closed = True

    def save(self):

        """ save the sessionProvider"""

        if self.cacheXml is not None and not self.__closed:

            _logger.info("Writing %s" % self.cacheXml)

            impl = getDOMImplementation()

            sessions = impl.createDocument(None, "sessions", None)

            top_element = sessions.documentElement

            self._lock.acquire()

            def add_session(dbname, session):

                """add session"""

                sessionNode = sessions.createElement("session")

                sessionNode.setAttribute("database", dbname)

                sessionNode.setAttribute("ccmaddr", session.addr())

                top_element.appendChild(sessionNode)

            for dbname in self.cacheFree.keys():

                for session in self.cacheFree[dbname]:

                    add_session(dbname, session)

            for session in self.cacheUsed:

                add_session(session.database(), session)

            self._lock.release()

            open_f = open(self.cacheXml, "w+")

            open_f.write(sessions.toprettyxml())

            open_f.close()

            _logger.debug(sessions.toprettyxml())

    def load(self):

        """load the command"""

        if self.cacheXml is not None and os.path.exists(self.cacheXml):

            _logger.info("Loading %s" % self.cacheXml)

            doc = parse(open(self.cacheXml, 'r')) 

            sessions = doc.documentElement

            self._lock.acquire()

            try:

                for child in sessions.childNodes:

                    if child.nodeType == child.ELEMENT_NODE and child.tagName == "session" and child.hasAttribute('database') and child.hasAttribute('ccmaddr'):

                        if child.getAttribute('database') not in self.cacheFree:

                            self.cacheFree[child.getAttribute('database')] = []

                        if ccm.session_exists(child.getAttribute('ccmaddr'), child.getAttribute('database')):

                            _logger.info(" + Session: database=%s, ccmaddr=%s" % (child.getAttribute('database'), child.getAttribute('ccmaddr')))

                            self.cacheFree[child.getAttribute('database')].append(ccm.Session(None, None, None, ccm_addr=child.getAttribute('ccmaddr'), close_on_exit=False))

                        else:

                            _logger.info(" - Session database=%s, ccmaddr=%s doesn't seem to be valid anymore." % (child.getAttribute('database'), child.getAttribute('ccmaddr')))

            finally:

                self._lock.release()

    def get(self, username=None, password=None, engine=None, dbpath=None, database=None, reuse=True):

        """create a CCM session"""

        if self.__closed:

            raise Exception("Could not create further session the provider is closed.")

        _logger.debug("CachedSessionProvider: Getting a session.")

        if database is not None and database in self.cacheFree and len(self.cacheFree[database]) > 0:

            _logger.info("CachedSessionProvider: Reusing session.")

            self._lock.acquire()

            session_free = self.cacheFree[database].pop()

            self.cacheUsed.append(session_free)

            self._lock.release()

            return CachedProxySession(self, session_free) 

        else:

            _logger.debug("CachedSessionProvider: Creating new session.")

            session = SessionProvider.get(self, username, password, engine, dbpath, database, False)

            session.close_on_exit = False

            proxy_session = CachedProxySession(self, session)

            data_base = proxy_session.database()

            self._lock.acquire()

            if data_base not in self.cacheFree:

                self.cacheFree[data_base] = []

            self.cacheUsed.append(session)

            self._lock.release()

            return proxy_session

    def free(self, session):

        """freeup a CCM session"""

        _logger.debug("CachedSessionProvider: Freeing session: %s" % session)

        data_base = session.database()

        if session in self.cacheUsed:

            _logger.debug("CachedSessionProvider: Removing session from used list.")

            self._lock.acquire()

            self.cacheUsed.remove(session)

            self.cacheFree[data_base].append(session)

            self._lock.release()

class CachedProxySession:

    """ Proxy session which will cleanup the session and free it from the provider """

    def __init__(self, provider, session):

        """ Constructor. """

        self.__session = session 

        self.__provider = provider

    def __getattr__(self, attrib):

        """ Delegate attributes to the session object. """

        _logger.debug("CachedProxySession.__getattr__(%s)" % attrib)

        if attrib == "close":

            return self.__close

        return getattr(self.__session, attrib)

    def __close(self):

        """ Overriding the session closing. """

        _logger.debug("CachedProxySession.__close")

        self.__provider.free(self.__session)

        self.__session.close()

    def __del__(self):

        """ Free the session on destruction. """

        _logger.debug("CachedProxySession.__del__")

        self.__close()