diff options
Diffstat (limited to '.venv/lib/python3.12/site-packages/fsspec/transaction.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/fsspec/transaction.py | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/fsspec/transaction.py b/.venv/lib/python3.12/site-packages/fsspec/transaction.py new file mode 100644 index 00000000..77293f63 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/fsspec/transaction.py @@ -0,0 +1,90 @@ +from collections import deque + + +class Transaction: + """Filesystem transaction write context + + Gathers files for deferred commit or discard, so that several write + operations can be finalized semi-atomically. This works by having this + instance as the ``.transaction`` attribute of the given filesystem + """ + + def __init__(self, fs, **kwargs): + """ + Parameters + ---------- + fs: FileSystem instance + """ + self.fs = fs + self.files = deque() + + def __enter__(self): + self.start() + return self + + def __exit__(self, exc_type, exc_val, exc_tb): + """End transaction and commit, if exit is not due to exception""" + # only commit if there was no exception + self.complete(commit=exc_type is None) + if self.fs: + self.fs._intrans = False + self.fs._transaction = None + self.fs = None + + def start(self): + """Start a transaction on this FileSystem""" + self.files = deque() # clean up after previous failed completions + self.fs._intrans = True + + def complete(self, commit=True): + """Finish transaction: commit or discard all deferred files""" + while self.files: + f = self.files.popleft() + if commit: + f.commit() + else: + f.discard() + self.fs._intrans = False + self.fs._transaction = None + self.fs = None + + +class FileActor: + def __init__(self): + self.files = [] + + def commit(self): + for f in self.files: + f.commit() + self.files.clear() + + def discard(self): + for f in self.files: + f.discard() + self.files.clear() + + def append(self, f): + self.files.append(f) + + +class DaskTransaction(Transaction): + def __init__(self, fs): + """ + Parameters + ---------- + fs: FileSystem instance + """ + import distributed + + super().__init__(fs) + client = distributed.default_client() + self.files = client.submit(FileActor, actor=True).result() + + def complete(self, commit=True): + """Finish transaction: commit or discard all deferred files""" + if commit: + self.files.commit().result() + else: + self.files.discard().result() + self.fs._intrans = False + self.fs = None |