Changelog

Unreleased

Added

• Add opt-in thread-pool dispatch of pad callbacks via Pipeline.run(threaded=...) for elements that set thread_safe = True. This composes with subprocess parallelization: threaded is now forwarded through the automatic Parallelize path, so thread_safe elements still dispatch onto the thread pool in the main process while Parallelize* elements run in workers.

Changed

• Pad callbacks (new/pull/internal) are now invoked positionally rather than by keyword (e.g. call(pad) instead of call(pad=...)), required for thread-pool dispatch. Subclasses that renamed the first new/pull parameter away from pad/frame are unaffected as long as they accept it positionally.

0.8.0 - 2026-04-17

Added

• Add on_startup() hook on elements for setup that runs after the pipeline is fully constructed but before the first frame, called in graph order
• Support name in pipeline membership tests for elements and pads
• Support building reusable composed elements by subclassing ComposedSourceElement, ComposedTransformElement, and ComposedSinkElement, as an alternative to the Compose builder

Fixed

• Pipelines using parallel elements no longer hang on Ctrl-C
• Pipeline visualization renders correctly when element or pad names contain HTML special characters

0.7.0 - 2026-03-09

Changed

• Lower per-loop execution log from INFO to DEBUG

0.6.0 - 2026-02-23

Added

• Expose extra internal source pads in composed transforms
• Handle duplicate pad names in Compose

Changed

• Make ParallelizeBase part of the public API
• Make Bottle HTTP control use a random port by default
• Put tag in registry file full path

0.5.0 - 2026-01-15

Added

• Add Compose class for composing multiple elements into reusable units
• Support for ComposedSourceElement, ComposedTransformElement, ComposedSinkElement via .as_source(), .as_transform(), .as_sink()
• Add class-level fixed/extra pad configuration for elements via static_sink_pads, static_source_pads, allow_dynamic_sink_pads, allow_dynamic_source_pads
• Add validation decorators for element reuse
• Add CollectSink flag to keep frames where data is None

Changed

• Use short pad names as keys in CollectSink and IterSource
• Expose pad_name (short name) from pads, specify full name within base PadLike class
• Switch to native types for type hints where applicable
• Make buffer logging level DEBUG instead of INFO

Fixed

• Fix CollectSink for TSFrame buffers attribute
• Fix pickling issues on Mac OS for parallelize elements

0.4.0 - 2025-11-03

Added

• Add pipeline.connect() for implicit pipeline linking with automatic pad matching
• Add select() and group() for element grouping and pad selection
• select_by_source() / select_by_sink() for iterating over pads
• Add partial match strategy for connect() with overlapping pad names
• Add StatsSource for system/process statistics via psutil
• Add WorkerContext for consistent subprocess/parallelize API
• Add error propagation from worker processes in parallelize elements
• Add element entry point registration

Changed

• Bump minimum Python version to 3.10
• Simplify parallelize and subprocess API
• Define abstract base classes for elements and PadLike
• Allow generic frame-like objects for elements
• Migrate logging functionality to separate logger module

Fixed

• Fix memory profiling when logger is set to NOTSET
• Provide pad context for runtime exceptions

0.3.0 - 2025-05-14

Added

• Add threading mode for parallelize elements (_use_threading_override)
• Add DataSpec for frame data specification and validation
• Add sub_process_shutdown() for graceful worker shutdown

Changed

• Flatten pad class hierarchy

Fixed

• Reset received signals in SignalEOS on context manager exit
• Make sure input queue is actually empty when cleaning up subprocess
• Improve exception handling in subprocess

0.2.0 - 2025-04-17

Added

• Add HTTPControl for REST endpoint monitoring and control
• GET/POST routes with wildcard key support
• exchange_state() for bidirectional state updates
• Configurable tag prefix for routes
• Registry file location control
• Add CallableTransform.from_callable() and from_combinations() class methods
• Add subprocess/parallelize elements for multiprocessing
• ParallelizeTransformElement, ParallelizeSinkElement, ParallelizeSourceElement
• Shared memory support via Parallelize.to_shm()
• Add SignalEOS for graceful SIGINT/SIGTERM handling
• Add memory profiling via SGNLOGLEVEL=pipeline:MEMPROF
• Add pipeline visualization via pipeline.visualize()
• Add Jupyter notebook support (auto-detects running event loop)
• Add InternalPad to all elements
• Add element logging support
• Add NullSink verbose option
• Add pipeline.check() for validating pad connections

Changed

• Rename TransformElement.transform() to .new()
• Use abbreviated "snk" instead of "sink" in internal pad names

Fixed

• Fix CallableTransform.from_combinations pad uniqueness
• Fix NullSink EOS handling based on frame.EOS

0.1.0 - 2024-12-13

• Initial release
• Core framework: SourceElement, TransformElement, SinkElement
• Frame with data, EOS, is_gap, spec, metadata attributes
• SourcePad, SinkPad with linking and graph execution
• Pipeline with async event loop and TopologicalSorter-based DAG execution
• NullSource, IterSource, DequeSource built-in sources
• NullSink, CollectSink, DequeSink built-in sinks
• CallableTransform for wrapping callables as transforms