class HdfsClient:
def __init__(self):
self.client = Config().get_client('dev')
try:
self.client.list('datasets')
except:
self.client.makedirs('datasets')
class PendingWindow(object):
"""docstring for PendingWindow"""
def __init__(self, backup_dir, node):
# TODO: not cut
# each pending window (or node) only has a single downstream cut,
# otherwise inconsistency occurs during truncating
self.backup_dir = backup_dir
self.node = node
self.hdfs_client = Config().get_client('dev')
self.hdfs_client.makedirs(self.backup_dir)
# each backup file is named by the ending version, so the current writing one is named temporarily
self.current_backup_path = os.path.join(self.backup_dir, 'current')
# touch the file for later appending
self.hdfs_client.write(self.current_backup_path, data='')
# the version that last truncation conducted against
self.safe_version_path = os.path.join(self.backup_dir, 'safe_version')
# special case for initial version
self.hdfs_client.write(self.safe_version_path, data=str(0))
# the latest integral version
self.latest_version_path = os.path.join(self.backup_dir,
'latest_version')
# special case for initial version
self.hdfs_client.write(self.latest_version_path, data=str(0))
if self.node.type != 'sink':
self.version_acks = dict()
for n in self.node.downstream_connectors:
self.version_acks[n] = 0
def append(self, tuple_):
"""Make an output tuple persistent, and complete a version if necessary
"""
self.hdfs_client.write(self.current_backup_path,
data=pickle.dumps(tuple_),
append=True)
if isinstance(tuple_, BarrierTuple):
self.hdfs_client.rename(
self.current_backup_path,
os.path.join(self.backup_dir, str(tuple_.version)))
self.hdfs_client.write(self.latest_version_path,
data=str(tuple_.version),
overwrite=True)
self.hdfs_client.write(self.current_backup_path, data='')
def extend(self, tuples):
# TODO: can be improved
with self.hdfs_client.write(self.current_backup_path,
append=True) as f:
for t in tuples:
pickle.dump(t, f)
if isinstance(tuples[-1], BarrierTuple):
self.hdfs_client.rename(
self.current_backup_path,
os.path.join(self.backup_dir, str(tuples[-1].version)))
self.hdfs_client.write(self.latest_version_path,
data=str(tuples[-1].version),
overwrite=True)
self.hdfs_client.write(self.current_backup_path, data='')
def truncate(self, version):
"""Delete files with filename <= version
"""
# with self.hdfs_client.read(self.safe_version_path) as f:
# safe_version = int(f.read())
#
# # only = condition can occur
# if version <= safe_version:
# return
for f in self.hdfs_client.list(self.backup_dir):
if f.isdigit() and int(f) <= version:
self.hdfs_client.delete(os.path.join(self.backup_dir, f))
# self.node.LOGGER.info('truncated version %d' % version)
def handle_version_ack(self, version_ack):
old_safe_version = min(self.version_acks.values())
self.version_acks[version_ack.sent_from] = version_ack.version
new_safe_version = min(self.version_acks.values())
if new_safe_version > old_safe_version:
self.hdfs_client.write(self.safe_version_path,
data=str(new_safe_version),
overwrite=True)
self.truncate(new_safe_version)
def get_latest_version(self):
with self.hdfs_client.read(self.latest_version_path) as f:
latest_version = int(f.read())
return latest_version
def rewind(self, version=None):
"""Delete files with filename > version (including current file)
"""
if version == None:
self.hdfs_client.write(self.current_backup_path,
data='',
overwrite=True)
return
# TODO: underflow
# assert version == 0 or
for f in self.hdfs_client.list(self.backup_dir):
if f.isdigit() and int(f) > version:
self.hdfs_client.delete(os.path.join(self.backup_dir, f))
self.hdfs_client.write(self.current_backup_path,
data='',
overwrite=True)
self.hdfs_client.write(self.latest_version_path,
data=str(version),
overwrite=True)
def replay(self):
"""When both the node and pending window state are ready, replay the pending window before resuming
"""
for v in sorted(
map(
int,
filter(unicode.isdigit,
self.hdfs_client.list(self.backup_dir)))):
# filter out the faster nodes
tuples = []
with self.hdfs_client.read(os.path.join(self.backup_dir,
str(v))) as f:
while True:
try:
t = pickle.load(f)
tuples.append(t)
except EOFError:
self.node.LOGGER.debug(
'reached EOF, send this version')
break
# Spout needs version too, so that data source can resend from a version
# except pickle.UnpickleableError:
# self.node.LOGGER.debug('spout reached partial dump location, send this incomplete version')
# break
self.node.multicast(self.node.downstream_nodes, tuples)
class HadoopWebExplorer:
def __init__(self, debug=False):
path = os.path.join(os.path.dirname(os.path.abspath(__file__)),
'.hdfscli.cfg')
self.client = Config(path).get_client()
self.debug = debug
def print(self, *args):
if self.debug:
print(*args)
def path_exists(self, path):
"""
Checks whether such path already exists
:param path: path to check
:type path: unicode
:return: boolean flag indicating whether path already exists or not
:rtype: bool
"""
return self.client.status(path, strict=False) is not None
@catch_hdfs_error
def create_folder(self, folder_name):
"""
Creates folder with the given name if it does not exist
:param folder_name: the name of the folder we want to add
:type folder_name: unicode
:return: returns true if created folder or it already exists, otherwise false
:rtype: bool
"""
if self.path_exists(folder_name):
print(f'Folder already exists: {folder_name}')
return True
self.print(f'Folder does not exist: {folder_name}')
self.client.makedirs(folder_name)
self.print(f'Folder created: {folder_name}')
@catch_hdfs_error
def write_to_file(self,
folder_name,
file_name,
data,
overwrite=False,
append=False):
"""
Writes provided data into file in the specified folder
:param folder_name: name of the folder where file is located
:type folder_name: unicode
:param file_name: name of the file where data should be written to
:type file_name: unicode
:param data: data to be written
:type data: unicode
:param overwrite: overwrite any existing file or directory
:type overwrite: bool
:param append: append to a file rather than create a new one.
:type append: bool
:return: returns true if it successfully wrote the data, otherwise false
:rtype: bool
"""
path = os.path.join(folder_name, file_name)
if append and not self.path_exists(path):
self.client.write(path,
data,
encoding='utf-8',
overwrite=overwrite)
else:
self.client.write(path,
data,
encoding='utf-8',
overwrite=overwrite,
append=append)
self.print("Written data to HDFS file")
@catch_hdfs_error
def read_from_file(self, folder_name, file_name):
"""
Reads from file in the specified folder
:param folder_name: name of the folder where file is located
:type folder_name: unicode
:param file_name: name of the file where data should be read from
:type file_name: unicode
"""
path = os.path.join(folder_name, file_name)
if not self.path_exists(path):
self.print(f'File does not exists: {path}')
return None
return self.client.read(path)
@catch_hdfs_error
def delete_file(self, folder_name, file_name):
"""
Deletes file in the specified folder
:param folder_name: name of the folder where file is located
:type folder_name: unicode
:param file_name: name of the file to be deleted
:type file_name: unicode
:return: returns true if it successfully deleted the file, otherwise false
:rtype: bool
"""
path = os.path.join(folder_name, file_name)
return self.client.delete(path)
@catch_hdfs_error
def delete_folder(self, folder_name):
"""
Deletes the specified folder
:param folder_name: name of the folder where file is located
:type folder_name: unicode
:return: returns true if it successfully deleted the folder, otherwise false
:rtype: bool
"""
return self.client.delete(folder_name, recursive=True)
@catch_hdfs_error
def explore_folder(self, folder_name):
"""
Explores the specified folder
:param folder_name: name of the folder to be observed
:type folder_name: unicode
"""
if not self.path_exists(folder_name):
self.print(f'Folder does not exists: {folder_name}')
self.print(f'Exploring folder: {folder_name}')
for path, dirs, files in self.client.walk(folder_name, status=True):
for file in files:
block_size = file[1]['blockSize']
size = file[1]['length']
owner = file[1]['owner']
self.print(
f'\tFile: {file[0]}, blockSize: {block_size}, size: {size}, owner: {owner}'
)
class HomuraFS():
def __init__(self):
self.client = Config().get_client('dev')
self.prompt = 'homura_fs $ '
self.name = None
self.local_xml = None
self.hdfs_xml = '.last_sync.xml'
self.hdfs_loc_xml = None
self.mount_root = None #os.getcwd() + '/test'
self.hdfs_root = '/cs219'
self.meta = HomuraMeta()
self.monitor = None
if sys.platform.startswith('darwin'):
logging.basicConfig(filename='mylog.log', level=logging.INFO)
self.monitor = Monitor_Start()
def shell_loop(self):
while True:
cmd = raw_input(self.prompt)
if cmd == 'sync':
print "Current devices attached:"
id_mapping = dict()
count = 1
if len(self.monitor.devs) == 0:
print "No device attached"
continue
for dev in self.monitor.devs:
#print dev
devname = dev['Dname']
manufacture = dev['Man']
hname = dev['Hname']
id_mapping[count] = dev
print "{}) Dname: {}, Hname: {}, Manufacture: {}.\n".format(
count, devname, hname, manufacture)
count += 1
dev_id = int(raw_input("Which device to sync:\n"))
if dev_id == 0:
continue
if dev_id in id_mapping:
#self.name = id_mapping[dev_id]['UID']
self.name = ''
self.mount_root = id_mapping[dev_id]['Path']
self.local_xml = self.mount_root + '/.last_sync.xml'
self.hdfs_loc_xml = self.mount_root + '/.cur_hdfs.xml'
self.meta.myRootpath = self.mount_root
log('Mount root is ' + self.mount_root)
log('Device xml file is ' + self.local_xml)
log('HDFS xml file is ' + self.hdfs_xml)
log('Copy of HDFS xml stored at ' + self.hdfs_loc_xml)
log('Syncing files for device ' +
id_mapping[dev_id]['Dname'])
self.sync_files()
else:
pass
elif cmd == 'test':
pass
#log('Setting up test directory with default config')
#self.__test()
elif cmd == 'download':
pass
elif cmd == 'quit':
if self.monitor:
Monitor_Stop(self.monitor)
return
def download_all(self):
log('Downloading all files from HDFS to local device')
try:
self.create_file(self.mount_root, self.hdfs_root, 1)
for dir_or_file in os.listdir(self.mount_root + self.hdfs_root):
if not dir_or_file.startswith('.'):
shutil.move(
self.mount_root + self.hdfs_root + '/' + dir_or_file,
self.mount_root)
shutil.rmtree(self.mount_root + self.hdfs_root)
except:
log('Something went wrog while downloading files')
try:
shutil.rmtree(self.mount_root + self.hdfs_root)
except:
pass
self.meta.path2Xml(self.mount_root)
self.meta.saveXml(self.local_xml, Xml='temp')
def upload_all(self):
log('Uploading all files from local device to HDFS')
for dir_or_file in os.listdir(self.mount_root):
if not dir_or_file.startswith('.'):
try:
log('Uploading to ' + self.hdfs_root + '/' + dir_or_file)
self.client.upload(self.hdfs_root + '/' + dir_or_file,
self.mount_root + '/' + dir_or_file,
n_threads=0)
except:
log('Warning: could not upload')
def load_HDFS_XML(self):
log("Attempting to fetch HDFS xml")
self.update_file(self.hdfs_loc_xml, self.hdfs_xml, 1)
log("Loading HDFS xml")
self.meta.loadHDFSXml(self.hdfs_loc_xml)
os.remove(self.hdfs_loc_xml)
def sync_files(self):
# check if we have an old snapshot xml
if not os.path.isfile(
self.local_xml
): # snapshot doesn't exist, so download everything
log("No local snapshot file was found at " + self.local_xml)
self.meta.Snapshotdoc = self.meta.emptyXml() # use empty
try:
# fetch HDFS xml and store locally
self.load_HDFS_XML()
except:
self.meta.HDFSdoc = self.meta.emptyXml()
else:
log("Fetching local snapshot xml from " + self.local_xml)
self.meta.loadSnapshotXml(self.local_xml)
try:
# fetch HDFS xml and store locally
self.load_HDFS_XML()
except:
self.meta.HDFSdoc = self.meta.emptyXml()
self.meta.path2Xml(self.mount_root)
self.meta.mydoc = self.meta.tempdoc
#print 'HDFS XML:'
#self.meta.showHDFSXml()
#print '---\nSnapshot Xml'
#self.meta.showSnapshotXml()
#print '---\nLocal Xml'
#self.meta.showMyXml()
# find operations since last sync
(my_creates, my_deletes, my_modifies, hdfs_creates, hdfs_deletes,
hdfs_modifies) = self.meta.getOperations()
root = self.mount_root
name = self.hdfs_root
# apply operations on current device
for path in my_creates:
if path.endswith('/'): # path is a folder we want to create
os.makedirs(root + path)
else:
self.create_file(root + path, name + path, 1)
for path in my_modifies:
self.update_file(root + path, name + path, 1)
for path in my_deletes:
self.delete_file(root + path, 1)
# apply operations on HDFS
for path in hdfs_creates:
if path.endswith('/'): # path is a folder we want to create
self.client.makedirs(name + path)
else:
self.create_file(root + path, name + path, 0)
for path in hdfs_modifies:
self.update_file(root + path, name + path, 0)
for path in hdfs_deletes:
self.delete_file(name + path, 0)
# update last sync for both HDFS and current device
self.meta.path2Xml(self.mount_root)
self.meta.saveXml(self.local_xml, Xml='temp')
self.update_file(self.local_xml, self.hdfs_xml, 0)
return
# in this set of functions, when kyuubey = 0, the operation goes
# from loc to hdfs (i.e. local becomes the "master")
# when kyuubey = 1, the operation goes from hdfs to loc
# (i.e. hdfs becomes the "master")
def create_file(self, loc_path, hdfs_path, kyuubey):
if kyuubey == 0:
log('Creating ' + hdfs_path + ' on HDFS')
self.client.upload(hdfs_path, loc_path, n_threads=0)
elif kyuubey == 1:
log('Creating ' + loc_path + ' locally')
self.client.download(hdfs_path, loc_path, n_threads=0)
def update_file(self, loc_path, hdfs_path, kyuubey):
if kyuubey == 0: # updating file on HDFS
log('Updating file ' + hdfs_path + ' on HDFS')
with open(loc_path) as reader:
with self.client.write(hdfs_path, overwrite=True) as writer:
for line in reader:
writer.write(line)
elif kyuubey == 1:
log('Updating file ' + loc_path + ' locally')
with open(loc_path, 'w') as writer:
with self.client.read(hdfs_path) as reader:
data = reader.read()
writer.write(data)
def delete_file(self, path, kyuubey):
if kyuubey == 0: # delete file on HDFS
log('Deleting file ' + path + ' from HDFS')
self.client.delete(path, recursive=True)
elif kyuubey == 1: # delete file locally
log('Deleting file ' + path + ' locally')
os.remove(path)
def move_file(self, src_path, dst_path, kyuubey):
if kyuubey == 0: # move file on HDFS
log('Moving file from ' + src_path + ' to ' + dst_path +
' on HDFS')
self.client.rename(src_path, dst_path)
elif kyuubey == 1: # move file locally
os.rename(src_path, dst_path)
log('Moving file from ' + src_path + ' to ' + dst_path +
' locally')
def __test(self, test_no=1):
self.__reset_test()
if test_no == 1:
self.__config_basic()
elif test_no == 2:
self.__config_outer_empty()
def __reset_test(self):
root = self.mount_root
log('Resetting mount directory')
if os.path.exists(root):
shutil.rmtree(root)
os.makedirs(root)
def __config_basic(self):
root = self.mount_root
log('Config 1: default')
with open(root + '/test1.txt', 'w') as writer:
writer.write('hi\nthere\n!\n')
with open(root + '/test2.txt', 'w') as writer:
writer.write('one-liner')
with open(root + '/test3.txt', 'w') as writer:
writer.write('')
os.makedirs(root + '/subdir')
with open(root + '/subdir/test1.txt', 'w') as writer:
writer.write('a different\ntest1.txt\nfile!\n')
os.makedirs(root + '/subdir/subsubdir')
with open(root + '/subdir/subsubdir/test1.txt', 'w') as writer:
writer.write('yet another different\ntest1.txt\nfile!\n')
def __config_outer_empty(self):
root = self.mount_root
log('Config 2: outer directory empty')
os.makedirs(root + '/subdir')
with open(root + '/subdir/test1.txt', 'w') as writer:
writer.write('a different\ntest1.txt\nfile!\n')
os.makedirs(root + '/subdir/subsubdir')
with open(root + '/subdir/subsubdir/test1.txt', 'w') as writer:
writer.write('yet another different\ntest1.txt\nfile!\n')
