import os import logging from io import BytesIO from twisted.internet import defer from twisted.web.client import FileBodyProducer from lbrynet.core.cryptoutils import get_lbry_hash_obj log = logging.getLogger(__name__) class BlobFileCreator(object): """ This class is used to create blobs on the local filesystem when we do not know the blob hash beforehand (i.e, when creating a new stream) """ def __init__(self, blob_dir): self.blob_dir = blob_dir self.buffer = BytesIO() self._is_open = True self._hashsum = get_lbry_hash_obj() self.len_so_far = 0 self.blob_hash = None self.length = None @defer.inlineCallbacks def close(self): self.length = self.len_so_far self.blob_hash = self._hashsum.hexdigest() if self.blob_hash and self._is_open and self.length > 0: # do not save 0 length files (empty tail blob in streams) # or if its been closed already self.buffer.seek(0) out_path = os.path.join(self.blob_dir, self.blob_hash) producer = FileBodyProducer(self.buffer) yield producer.startProducing(open(out_path, 'wb')) self._is_open = False if self.length > 0: defer.returnValue(self.blob_hash) else: # 0 length files (empty tail blob in streams ) # must return None as their blob_hash for # it to be saved properly by EncryptedFileMetadataManagers defer.returnValue(None) def write(self, data): if not self._is_open: raise IOError if not isinstance(data, bytes): data = data.encode() self._hashsum.update(data) self.len_so_far += len(data) self.buffer.write(data)