source: main/waeup.sirp/trunk/src/waeup/sirp/datacenter.py @ 4995

"""WAeUP data center.

The waeup data center cares for management of upload data and provides
tools for importing/exporting CSV data.
"""
import logging
import os
import shutil
import grok
from datetime import datetime
from zope.component.interfaces import ObjectEvent
from waeup.sirp.interfaces import (IDataCenter, IDataCenterFile,
                                   IDataCenterStorageMovedEvent)
from waeup.sirp.utils.helpers import copyFileSystemTree

class DataCenter(grok.Container):
    """A data center contains CSV files.
    """
    grok.implements(IDataCenter)
    storage = os.path.join(os.path.dirname(__file__), 'files')

    @property
    def logger(self):
        """Get a logger for datacenter actions.
        """
        # We need a different logger for every site...
        site = grok.getSite()
        sitename = getattr(site, '__name__', 'app')
        loggername = 'waeup.sirp.%s.datacenter' % sitename
        logger = logging.getLogger(loggername)
        if not logger.handlers:
            logger = self._setupLogger(logger)
        return logger

    def __init__(self, *args, **kw):
        super(DataCenter, self).__init__(*args, **kw)
        self._createSubDirs()
        
    def _setupLogger(self, logger):
        """Setup datacenter logger.
        """
        logdir = os.path.join(self.storage, 'logs')
        if not os.path.exists(logdir):
            os.mkdir(logdir)
        filename = os.path.join(logdir, 'datacenter.log')

        # Create a rotating file handler logger for datacenter.
        handler = logging.handlers.RotatingFileHandler(
            filename, maxBytes=5*1024**1, backupCount=5)
        formatter = logging.Formatter(
            '%(asctime)s - %(levelname)s - %(message)s')
        handler.setFormatter(formatter)
        
        # Here we decide, whether our messages will _also_ go to
        # application log.
        logger.propagate = False
        logger.setLevel(logging.DEBUG)
        logger.addHandler(handler)
        return logger

    def _createSubDirs(self):
        """Create standard subdirs.
        """
        for name in ['finished', 'unfinished']:
            path = os.path.join(self.storage, name)
            if os.path.exists(path):
                continue
            os.mkdir(path)
        return
    
    def getFiles(self, sort='name'):
        """Get a list of files stored in `storage`.

        Files are sorted by basename.
        """
        result = []
        if not os.path.exists(self.storage):
            return result
        for filename in sorted(os.listdir(self.storage)):
            fullpath = os.path.join(self.storage, filename)
            if not os.path.isfile(fullpath):
                continue
            result.append(DataCenterFile(fullpath))
        if sort == 'date':
            # sort results in newest-first order...
            result = sorted(result, key=lambda x: x.getTimeStamp(),
                            reverse=True)
        return result

    def getLogFiles(self):
        """Get the files from logs/ subdir. Files are sorted by name.
        """
        result = []
        logdir = os.path.join(self.storage, 'logs')
        if not os.path.exists(logdir):
            os.mkdir(logdir)
        for name in sorted(os.listdir(logdir)):
            if not os.path.isfile(os.path.join(logdir, name)):
                continue
            result.append(
                LogFile(os.path.join(self.storage, 'logs', name)))
        return result
            
    def setStoragePath(self, path, move=False, overwrite=False):
        """Set the path where to store files.
        """
        path = os.path.abspath(path)
        not_copied = []
        if not os.path.exists(path):
            raise ValueError('The path given does not exist: %s' % path)
        if move is True:

            not_copied = copyFileSystemTree(self.storage, path,
                                            overwrite=overwrite)
        self.storage = path
        self._createSubDirs()
        # Adjust logger...
        logger = self.logger
        handlers = logger.handlers
        for handler in handlers:
            logger.removeHandler(handler)
        self._setupLogger(logger)
        grok.notify(DataCenterStorageMovedEvent(self))
        return not_copied

    def _moveFile(self, source, dest):
        """Move file source to dest preserving ctime, mtime, etc.
        """
        if not os.path.exists(source):
            self.logger.warn('No such source path: %s' % source)
            return
        if source == dest:
            return
        shutil.copyfile(source, dest)
        shutil.copystat(source, dest)
        os.unlink(source)
    
    def distProcessedFiles(self, successful, source_path, finished_file,
                           pending_file, move_orig=True):
        """Put processed files into final locations.

        ``successful`` is a boolean that tells, whether processing was
        successful.

        ``source_path``: path to file that was processed.

        ``finished_file``, ``pending_file``: paths to the respective
        generated .pending and .finished file. The .pending file path
        may be ``None``.

        If finished file is placed in a location outside the local
        storage dir, the complete directory is removed
        afterwards. Regular importers should put their stuff in
        dedicated temporary dirs.
        
        See datacenter.txt for more info about how this works.
        """
        basename = os.path.basename(source_path)
        pending_name = basename
        pending = False
        finished_dir = os.path.join(self.storage, 'finished')
        unfinished_dir = os.path.join(self.storage, 'unfinished')

        if basename.endswith('.pending.csv'):
            maybe_basename = "%s.csv" % basename.rsplit('.', 2)[0]
            maybe_src = os.path.join(unfinished_dir, maybe_basename)
            if os.path.isfile(maybe_src):
                basename = maybe_basename
                pending = True
                
        base, ext = os.path.splitext(basename)
        finished_name = "%s.finished%s" % (base, ext)
        if not pending:
            pending_name = "%s.pending%s" % (base, ext)

        # Put .pending and .finished file into respective places...
        pending_dest = os.path.join(self.storage, pending_name)
        finished_dest = os.path.join(finished_dir, finished_name)
        self._moveFile(finished_file, finished_dest)
        if pending_file is not None:
            self._moveFile(pending_file, pending_dest)

        # Put source file into final location...
        finished_dest = os.path.join(finished_dir, basename)
        unfinished_dest = os.path.join(unfinished_dir, basename)
        if successful and not pending:
            self._moveFile(source_path, finished_dest)
        elif successful and pending:
            self._moveFile(unfinished_dest, finished_dest)
            os.unlink(source_path)
        elif not successful and not pending:
            self._moveFile(source_path, unfinished_dest)

        # If finished and pending-file were created in a location
        # outside datacenter storage, we remove it.
        maybe_temp_dir = os.path.dirname(finished_file)
        if os.path.commonprefix(
            [self.storage, maybe_temp_dir]) != self.storage:
            shutil.rmtree(maybe_temp_dir)
        return

    
class DataCenterFile(object):
    """A description of a file stored in data center.
    """
    grok.implements(IDataCenterFile)
    
    def __init__(self, context):
        self.context = context
        self.name = os.path.basename(self.context)
        self.size = self.getSize()
        self.uploaddate = self.getDate()
        self.lines = self.getLinesNumber()

    def getDate(self):
        """Get a human readable datetime representation.
        """
        date = datetime.fromtimestamp(os.path.getctime(self.context))
        return date.strftime('%c')

    def getTimeStamp(self):
        """Get a (machine readable) timestamp.
        """
        return os.path.getctime(self.context)
    
    def getSize(self):
        """Get a human readable file size.
        """
        bytesize = os.path.getsize(self.context)
        size = "%s bytes" % bytesize
        units = ['kb', 'MB', 'GB']
        for power, unit in reversed(list(enumerate(units))):
            power += 1
            if bytesize >= 1024 ** power:
                size = "%.2f %s" % (bytesize/(1024.0**power), unit)
                break
        return size

    def getLinesNumber(self):
        """Get number of lines.
        """
        num = 0
        for line in open(self.context, 'rb'):
            num += 1
        return num
    
class LogFile(DataCenterFile):
    """A description of a log file.
    """
    def __init__(self, context):
        super(LogFile, self).__init__(context)
        self._markers = dict()
        self._parsed = False
        self.userid = self.getUserId()
        self.mode = self.getMode()
        self.stats = self.getStats()
        self.source = self.getSourcePath()

    def _parseFile(self, maxline=10):
        """Find markers in a file.
        """
        if self._parsed:
            return
        for line in open(self.context, 'rb'):
            line = line.strip()
            if not ':' in line:
                continue
            name, text = line.split(':', 1)
            self._markers[name.lower()] = text
        self._parsed = True
        return

    def _getMarker(self, marker):
        marker = marker.lower()
        if not self._parsed:
            self._parseFile()
        if marker in self._markers.keys():
            return self._markers[marker]
    
    def getUserId(self):
        return self._getMarker('user') or '<UNKNOWN>'

    def getMode(self):
        return self._getMarker('mode') or '<NOT SET>'

    def getStats(self):
        return self._getMarker('processed') or '<Info not avail.>'

    def getSourcePath(self):
        return self._getMarker('source') or None


class DataCenterStorageMovedEvent(ObjectEvent):
    """An event fired, when datacenter storage moves.
    """
    grok.implements(IDataCenterStorageMovedEvent)