DDlog is a programming language for incremental computation. It is well suited for writing programs that continuously update their output in response to input changes. A DDlog programmer does not write incremental algorithms; instead they specify the desired input-output mapping in a declarative manner.
AnyDeserialize impl. The DDlog compiler generates an
implementation of the AnyDeserialize trait, which allows clients to
deserialize instances of ddlog_std::Any provided they know relation id of
the value being deserialized. This feature is not used by most applications,
but can cause significant code bloat and slow down compilation. We
feature-gate this impl, so that only users who require this functionality
have to pay the price.The self-profiler remains a useful tool for troubleshooting DDlog performance issues. It runs with low overhead, allows enabling/disabling CPU and change profiling at runtime to only instrument parts of the program, and because it is integrated into the DDlog runtime it can precisely match each DD operator to the corresponding DDlog operator. DDshow does not currently have these features.
In this release we revamp the self profiler to improve its ergonomics. The new self-profiler has the following features:
Produces profiles in the form of interactive HTML tables. Each row in the table represents a DD operator and contains operator description, e.g., "Arrange relation 'Rel1' by 'x,y,z'" along with links to one or more source code location that this operator corresponds to (e.g., all locations where this specific arrangement of 'Rel1' is used).
The new dump_profile API dumps the profile into an HTML file
on the disk instead of returning it as a string. All profiles
generated by the same process are generated in the same folder, even
if the process creates multiple instances of DDlog. This folder
also contains a complete snapshot of all DDlog code in the
program, so that the profiler can show program sources even when
the program does not run on the same system where it was compiled.
Internally, the self-profiler represents profiles using a well-defined JSON format. New APIs were added to extract each of the four profiles currently supported by DDlog (arrangement size profile, peak arrangement size profile, change profile, and CPU profile) in the JSON format, for automatic processing by third-party tools.
This release includes a revamped self-profiler as a feature preview for testing and evaluation only.
internment.dl: optimized the implementation of Intern::default() to avoid
excessive heap allocations and contention.ddlog_clone(): C and Java API to clone a ddlog_record.index could be interpreted
as part of an index declaration or as a regular identifier.Rust compilation option checked_weights for the code generated by
DDlog, which will crash DDlog programs at runtime if they overflow the
weights attached to data values. This may be preferable to generating
incorrect results.
Add queryIndex Java API (#1093)