# -*- coding: utf-8 -*-
#
# Copyright (C) 2016 Dr. Robert C. Green II.
#
# This file is part of Combox.
#
# Combox is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Combox is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Combox (see COPYING). If not, see
# <http://www.gnu.org/licenses/>.
import pickledb
from os import path
from threading import Lock
from combox.file import hash_file
class ComboxSilo(object):
"""Helps keep track of files in combox directory.
:param dict config:
A dictionary that contains configuration information about
combox.
:param threading.Lock lock:
Lock used by :class:`.ComboxDirMonitor` and
:class:`.NodeDirMonitor` to access this object.
"""
def __init__(self, config, lock):
"""Initialize ComboxSilo.
"""
self.config = config
self.silo_path = path.join(config['silo_dir'], 'silo.db')
self.db = pickledb.load(self.silo_path, True)
## things we need for housekeep the node directories
self.node_dicts = ['file_created', 'file_modified', 'file_moved',
'file_deleted', 'file_moved_info']
"""List of names of dictionaries stored in DB to housekeep the node
directories.
Initialized to::
['file_created', 'file_modified', 'file_moved',
'file_deleted', 'file_moved_info']
when :class:`ComboxSilo` object is created.
"""
# created the dicts if not already created.
for ndict in self.node_dicts:
if not self.db.get(ndict):
self.db.dcreate(ndict)
self.lock = lock
def reload(self):
"""Re-loads the DB from disk.
"""
with self.lock:
self.db = pickledb.load(self.silo_path, True)
def update(self, filep):
"""Update filep's info in DB.
Path of `filep` and the hash of its content is written to the
DB.
:param str filep:
Path to the file under the combox directory.
:returns: `True`
:rtype: bool
"""
self.reload()
with self.lock:
fhash = hash_file(filep)
return self.db.set(filep, fhash)
def keys(self):
"""Returns list of file' paths tracked by combox.
:returns:
List of file paths of files tracked by combox.
:rtype:
`True`
"""
# this is why Redis or some other key-value DB should be used
# instead of PickleDB
self.reload()
with self.lock:
return self.db.db.keys()
def remove(self, filep):
"""Removes `filep` from DB.
:param str filep:
Path to a file under combox directory whose information
has to be removed from the DB.
:returns:
Returns `False` if `filep` is not present in the DB; `True`
otherwise.
:rtype: bool
"""
try:
self.reload()
with self.lock:
return self.db.rem(filep)
except KeyError, e:
# means `filep' not present in db.
return False
def exists(self, filep):
"""Checks if filep's info is stored in DB.
:param str filep:
Path to a file under the combox directory.
:returns:
Returns `True` if filep's info is in DB; `False` otherwise.
:rtype: bool
"""
self.reload()
with self.lock:
if self.db.get(filep) is None:
return False
else:
return True
def stale(self, filep, fhash=None):
"""Checks if filep's info in the DB is outdated.
:param str filep:
Path to a file under the combox directory.
:param bool fhash:
If not `None`, it is assumed to be filep's hash.
:returns:
Returns `True`, if filep's hash is outdated; `False` if
filep's hash is correct; `None` if filep's info is not yet
stored in DB.
:rtype: bool
"""
if not fhash:
fhash = hash_file(filep)
self.reload()
with self.lock:
fhash_in_db = self.db.get(filep)
if fhash_in_db is None:
return None
elif fhash == fhash_in_db:
return False
else:
return True
def nodedicts(self):
"""Returns :attr:`node_dicts`
"""
return self.node_dicts
def node_set(self, type_, file_, num=-1):
"""Update information about the shard of `file_` in dictionary `type_` in the DB.
:param str type_:
The name of the dictinary in DB. It must be one of the
following values: `file_created`, `file_modified`,
`file_moved`, `file_deleted`.
:param str file_:
Path of the file under the combox directory.
:param int num:
Integer associated with the `file_`.
"""
self.reload()
with self.lock:
if num != -1:
self.db.dadd(type_, (file_, num))
return
try:
num = self.db.dget(type_, file_)
num += 1
except KeyError, e:
# I don't think this is the right way to do this. :|
#
# If we are here it means file_ is not already there,
# so:
num = 1
self.db.dadd(type_, (file_, num))
def node_store_moved_info(self, src_path, dest_path):
"""
Make note of a file/directory moved from `src_path` to `dest_path`.
:param str src_path:
The source path of the file being moved.
:param str dest_path:
The destination path of the file being moved.
"""
self.reload()
with self.lock:
self.db.dadd('file_moved_info', (src_path, dest_path))
def node_get(self, type_, file_):
"""Returns a number denoting the number of node directories in which the `file_`'s shards was created/modified/moved/deleted.
:param str type_:
The name of the dictinary in DB. It must be one of the
following values: `file_created`, `file_modified`,
`file_moved`, `file_deleted`.
:param str file_:
Path of the file under the combox directory.
:returns:
Number denoting the number of node directories in which
the `file_`' shards were created/modified/moved/deleted.
:rtype: int
"""
self.reload()
with self.lock:
try:
return self.db.dget(type_, file_)
except KeyError, e:
# file_ info not there under type_ dict.
return None
def node_rem(self, type_, file_):
"""Removes information about the shards of `file_` in the `type_` dictionary in DB.
:param str type_:
The name of the dictinary in DB. It must be one of the
following values: `file_created`, `file_modified`,
`file_moved`, `file_deleted`.
:param str file_:
Path of the file under the combox directory.
"""
self.reload()
with self.lock:
try:
return self.db.dpop(type_, file_)
except KeyError, e:
# means file_'s info was already removed.
# do nothing
pass
