Mike Gerwitz
1a04d99f15
This makes the necessary tweaks to have the entire linker work end-to-end
and produce a compatible xmle file (that is, identical except for
nondeterministic topological ordering). That's good, and finally that can
get off of my plate.
What's disappointing, and what I'll have more information on in future
commits, is how slow it is.
The linking of our largest package goes from ~1s -> ~15s with this
change. The reason is because of tens of millions of `memcpy` calls. Why?
The ParseState abstraction is pure and passes an owned `self` around, and
Parser replaces its own reference using this:
let result;
TransitionResult(Transition(self.state), result) =
take(&mut self.state).parse_token(tok);
Naively, this would store a copy of the old state in `result`, allocate a
new ParseState for `self.state`, pass the original or a copy to
`parse_token`, and then overwrite `self.state` with the new ParseState that
is returned once it is all over.
Of course, that'd be devastating. What we want to happen is for Rust to
realize that it can just pass a reference to `self.state` and perform no
copying at all.
For certain parsers, this is exactly what happens. Great!
But for XIRF, it we have this:
/// Stack of element [`QName`] and [`Span`] pairs,
/// representing the current level of nesting.
///
/// This storage is statically allocated,
/// allowing XIRF's parser to avoid memory allocation entirely.
type ElementStack<const MAX_DEPTH: usize> = ArrayVec<(QName, Span), MAX_DEPTH>;
/// XIRF document parser state.
///
/// This parser is a pushdown automaton that parses a single XML document.
#[derive(Debug, Default, PartialEq, Eq)]
pub enum State<const MAX_DEPTH: usize, SA = AttrParseState>
where
SA: FlatAttrParseState,
{
/// Document parsing has not yet begun.
#[default]
PreRoot,
/// Parsing nodes.
NodeExpected(ElementStack<MAX_DEPTH>),
/// Delegating to attribute parser.
AttrExpected(ElementStack<MAX_DEPTH>, SA),
/// End of document has been reached.
Done,
}
ParseState contains an ArrayVec, and its implementation details are causes
LLVM _not_ to elide the `memcpy`. And there's a lot of them.
Considering that ParseState is supposed to use only statically allocated
memory and be zero-copy, this is rather ironic.
Now, this _could_ be potentially fixed by not using ArrayVec; removing
it (and the corresponding checks for balanced tags) gets us down to
2s (which still needs improvement), but we can't have a core abstraction in
our system resting on a house of cards. What if the optimization changes
between releases and suddenly linking / building becomes shit slow? That's
too much of a risk.
Further, having to limit what abstractions we use just to appease the
compiler to optimize away moves is very restrictive.
The better option seems like to go back to what I used to do: pass around
`&mut self`. I had moved to an owned `self` to force consideration of _all_
state transitions, but I can try to do the same thing in a different type of
way using mutable references, and then we avoid this problem. The
abstraction isn't pure (in the functional sense) anymore, but it's safe and
isn't relying on delicate inlining and optimizer implementation details to
have a performant system.
More information to come.
DEV-10863
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||
|---|---|---|
| bin | ||
| build-aux | ||
| core | ||
| design/tpl | ||
| doc | ||
| progtest | ||
| rater | ||
| src | ||
| tamer | ||
| test | ||
| tools | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| .gitmodules | ||
| .rev-xmle | ||
| .rev-xmlo | ||
| COPYING | ||
| COPYING.FDL | ||
| HACKING | ||
| Makefile.am | ||
| README.md | ||
| RELEASES.md | ||
| VERSION.in | ||
| bootstrap | ||
| c1map.xsd | ||
| configure.ac | ||
| package-lock.json | ||
README.md
TAME
TAME is The Algebraic Metalanguage, a programming language and system of tools designed to aid in the development, understanding, and maintenance of systems performing numerous calculations on a complex graph of dependencies, conditions, and a large number of inputs.
This system was developed at Ryan Specialty Group (formerly LoVullo Associates) to handle the complexity of comparative insurance rating systems. It is a domain-specific language (DSL) that itself encourages, through the use of templates, the creation of sub-DSLs. TAME itself is at heart a calculator—processing only numerical input and output—driven by quantifiers as predicates. Calculations and quantifiers are written declaratively without concern for order of execution.
The system has powerful dependency resolution and data flow capabilities.
TAME consists of a macro processor (implementing a metalanguage), numerous compilers for various targets (JavaScript, HTML documentation and debugging environment, LaTeX, and others), linkers, and supporting tools. The input grammar is XML, and the majority of the project (including the macro processor, compilers, and linkers) is written in a combination of XSLT and Rust.
TAMER
Due to performance requirements, this project is currently being reimplemented in Rust. That project can be found in the tamer/ directory.
Documentation
Compiled documentation for the latest release is available via our GitLab mirror, which uses the same build pipeline as we do on our internal GitLab instance. Available formats are:
Getting Started
To get started, make sure Saxon version 9 or later is available and its path
set as SAXON_CP; that the path to hoxsl is set via HOXSL; and then run
the bootstrap script:
$ export SAXON_CP=/path/to/saxon9he.jar
$ export HOXSL=/path/to/hoxsl/root
$ ./boostrap
Running Test Cases
To run the test cases, invoke make check (or its alias, make test).
Testing Core Features
In order to run tests located at core/test/core/**, a supporting environment
is required. (e.g. mega rater). Inside a supporting rater, either check out a
submodule containing the core tests, or temporarily add them into the
submodule.
Build the core test suite summary page using:
$ make rater/core/test/core/suite.html
Visit the summary page in a web browser and click the Calculate Premium button. If all test cases pass, it will yield a value of $1.
Hacking
Information for TAME developers can be found in the file HACKING.
License
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.