1.1.0

Multi-Storage Client (MSC)

This release adds Python 3.14 support to Multi-Storage Client, including Python 3.14 in the tested build matrix and published package metadata.

Breaking Changes

• Removed the msc.zarr and msc.xarray adapters, their multistorageclient.contrib modules, and the corresponding zarr and xarray optional extras. Install multi-storage-client[fsspec] and use the libraries' native fsspec support instead, such as zarr.open("msc://...") or xarray.open_zarr("msc://...").

New Features

• Added Python 3.14 support.
• Add OpenTelemetry metrics for POSIX file descriptor usage: multistorageclient.file_descriptor.open tracks file descriptors held by PosixFile, and multistorageclient.file_descriptor.duration records how long each descriptor remains open.
• Add strict handling for POSIX symlinks that target paths outside the configured base path.

Performance Improvements

• Cache the resolved POSIX base path when evaluating symlinks to avoid repeated realpath system calls.

Bug Fixes

• ObjectFile reads no longer block indefinitely when opening a missing cached object or when a background download fails before creating the local file. Waiting callers now wake and receive the download error.
• PosixFile.readall() no longer emits READ metrics twice (once for itself and once for the instrumented read() it delegated to).
• Sort and de-duplicate source_files in sync_from before merging against the target listing; an unsorted list previously caused up-to-date target files to be deleted and re-copied.
• info("") on a POSIX profile now reports the modification time of the profile's base_path instead of the process working directory.
• OCI listings now strip the bucket from start_after/end_at like every other provider; with a base_path that includes the bucket, end_at previously filtered out every object and start_after was ignored.
• copy.deepcopy of the immutable config dictionary now converts frozen tuples back to lists, so msc config validate no longer emits !!python/tuple tags that yaml.safe_load rejects.
• Azure batch-delete failures now include the response body in the raised error instead of a bound-method repr.
• Declare the record method explicitly on the cross-process Counter/Gauge telemetry proxies (derived from each instrument class's public methods). Proxy generation no longer depends on the installed OpenTelemetry's instrument shape, fixing AttributeError: 'AutoProxy[opentelemetry.metrics.Counter]' object has no attribute 'add' under OpenTelemetry version skew.
• MultiStoragePath.read_text() now honors its errors argument ("ignore", "replace", ...) instead of always decoding strictly.
• RustClient.download_multipart_to_bytes now returns b"" for zero-byte objects and empty ranges instead of failing with an integer underflow / invalid range error.
• ObjectFile.fileno() on in-memory files now returns one stable temporary descriptor instead of allocating a new one on every call (which leaked a descriptor per call until close()), and close() releases tracked descriptors and the append-mode staging file even when the upload fails.
• msc ls now shows the size of files whose provider reports no modification time (for example HuggingFace or AIStore); the size column was previously blanked for every row without a date.
• Percent-encode the container and blob path in Azure presigned (SAS) URLs; blob names containing spaces, #, + or % previously produced URLs that were truncated or rejected.
• Azure downloads of large objects into a StringIO now decode the staged content as UTF-8 regardless of the host locale, matching the small-object path and the upload encoding.
• Rust recursive listing now reports a failed listing task as a regular storage error instead of a Rust panic that bypasses MSC's exception translation.
• Numeric literals in object attribute filters now compare correctly with string-valued metadata for equality and inequality operations.

Multi-Storage File System (MSFS)

MSFS is planned to move to a separate repository and adopt an independent release process.