Decorates DocumentSentences with information about which HTML tags they are nested in, and removes some redundant data on this rather memory hungry object. Separator information is encoded as a bit set instead of an array of integers.
The change also cleans up the SentenceExtractor class a fair bit. It no longer extracts ngrams, and a significant amount of redundant operations were removed as well. This is still a pretty unpleasant class to work in, but this is the first step in making it a little bit better.
Fix rare bug where the takeWhileZero method would fail to repopulate the underlying buffer. This caused intermittent de-compression errors if takeWhileZero happened at a 64 bit boundary while the underlying buffer was empty.
The change also alters how sequence-lengths are encoded, to more consistently use the getGamma method instead of adding special significance to a zero first byte.
Finally, assertions are added checking the invariants of the gamma and delta coding logic as well as UrlIdCodec to earlier detect issues.
How'd This Ever Work? (tm)
TermFrequencyExporter was using Math.clamp() incorrectly, and SentenceExtractor was synchronizing on its own instance when initializing shared static members, causing rare issues when spinning multiple SE:s up at once.
How'd This Ever Work? (tm)
TermFrequencyExporter was using Math.clamp() incorrectly, and SentenceExtractor was synchronizing on its own instance when initializing shared static members, causing rare issues when spinning multiple SE:s up at once.
It was incorrectly assumed that a "next" value could not be zero or negative, as this is not representable via the Gamam code. This is incorrect in this case, as we're able to provide a negative offset. Changing to using Integer.MIN_VALUE as indicator that a value is absent instead, as this will never be used.
The priority index documents file can be trivially compressed to a large degree.
Compression schema:
```
00b -> diff docord (E gamma)
01b -> diff domainid (E delta) + (1 + docord) (E delta)
10b -> rank (E gamma) + domainid,docord (raw)
11b -> 30 bit size header, followed by 1 raw doc id (61 bits)
```
The implementation was incorrectly using 1 bit more than it should. The change also adds a put method for Elias delta; and cleans up the interface a bit.
This commit introduces a readme.md file to document the functionality and usage of the coded-sequence library. It covers the Elias Gamma code support, how sequences are encoded, and methods the library offers to query sequences, iterate over values, access data, and decode sequences.
The default C++ language standard on macOS is gnu++98, which won't build
this module.
Full error:
```
> Task :code:libraries:array:cpp:compileCpp FAILED
src/main/cpp/cpphelpers.cpp:28:5: error: expected expression
[](const p64x2& fst, const p64x2& snd) {
^
```
It had been previously assumed that re-writing this function in the style of retain() would make it faster, but it had the opposite effect.
The reason why retain is so fast due to properties of the data that hold true when intersecting document lists, where long runs of adjacent documents are expected, but not when looking up the data associated with the already intersected documents, where the data is more sparse.
IntArray gets the YAGNI axe. The array library had two implementations, one for longs which was used, and one for ints, which only ever saw bit rot. Removing the latter, as all it ever did was clutter up the codebase and add technical debt. If we need int arrays, we fork LongArray again (or add int capabilities to it)
Also cleaning up the interfaces, removing layers of redundant abstractions and adding javadocs.
Finally adding sz=2 specializations to the quick- and insertion sort algorithms. It seems the JIT isn't optimizing these particularly well, this is an attempt to help it out a bit.
Retire search functions that weren't used, including the native implementations. Drop confusing suffixes on search function names. Search functions no longer encode search misses as negative values.
Replaced binary search function with a branchless version that is much faster.
Cleaned up benchmark code.
Retire search functions that weren't used, including the native implementations. Drop confusing suffixes on search function names. Search functions no longer encode search misses as negative values.
Replaced binary search function with a branchless version that is much faster.
Cleaned up benchmark code.
Roll back to JDK 21 for now, and make Java version configurable in the root build.gradle
The project has run into no less than three distinct show-stopping bugs in JDK22, across multiple vendors, and gradle still doesn't fully support it, meaning you need multiple JDK versions installed.
The change set cleans up the data model for the term-level data. This used to contain a bunch of fields with document-level metadata. This data-duplication means a larger memory footprint and worse memory locality.
The ranking code is also modified to not accept SearchResultKeywordScores, but rather CompiledQueryLong and CqDataInts containing only the term metadata and the frequency information needed for ranking. This is again an effort to improve memory locality.
The sign of the counter is used to indicate whether a term has appeared as title. Until it's seen in the title, it's provisionally saved as a negative count.
The code would always re-initialize the static ngramLexicon and rdrposTagger fields with new instances even if they were already instantiated, leading to a ton of unnecessary RAM allocation.
The modified behavior checks for nullity before creating a new instance.
Seems to work, tests are green and initial testing finds no errors. Still a bit untested, committing WIP as-is because it would suck to lose weeks of work due to a drive failure or something.
Look, this will make the git history look funny, but trimming unnecessary depth from the source tree is a very necessary sanity-preserving measure when dealing with a super-modularized codebase like this one.
While it makes the project configuration a bit less conventional, it will save you several clicks every time you jump between modules. Which you'll do a lot, because it's *modul*ar. The src/main/java convention makes a lot of sense for a non-modular project though. This ain't that.
Cleaning out a lot of old junk from the code, and one thing lead to another...
* Build is improved, now constructing docker images with 'jib'. Clean build went from 3 minutes to 50 seconds.
* The ProcessService's spawning is smarter. Will now just spawn a java process instead of relying on the application plugin's generated outputs.
* Project is migrated to GraalVM
* gRPC clients are re-written with a neat fluent/functional style. e.g.
```channelPool.call(grpcStub::method)
.async(executor) // <-- optional
.run(argument);
```
This change is primarily to allow handling ManagedChannel errors, but it turned out to be a pretty clean API overall.
* For now the project is all in on zookeeper
* Service discovery is now based on APIs and not services. Theoretically means we could ship the same code either a monolith or a service mesh.
* To this end, began modularizing a few of the APIs so that they aren't strongly "living" in a service. WIP!
Missing is documentation and testing, and some more breaking apart of code.
To avoid having to either hard-code or manually configure service addresses (possibly several dozen), and to reduce the project's dependency on docker to deal with routing and discovery, the option to use [Zookeeper](https://zookeeper.apache.org/) to manage services and discovery has been added.
A service registry interface was added, with a Zookeeper implementation and a basic implementation that only works on docker and hard-codes everything.
The last remaining REST service, the assistant-service, has been migrated to gRPC.
This also proved a good time to clear out primordial technical debt from the root of the codebase. The 'service-client' library has been taken behind the barn and given a last farewell. It's replaced by a small library for managing gRPC channels.
Since it's no longer used by anything, RxJava has been removed as a dependency from the project.
Although the current state seems reasonably stable, this is a work-in-progress commit.
The readme for the array library was extremely out of date. Updating it with accurate information about how the library works, and a demo that should compile.
Also added a system property for disabling the use of sun.misc.Unsafe.
The RandomFileAssembler implementations, introduced in commit 53c575db3f were all acting subtly differently. The RWF implementation wrote BigEndian longs instead of the native endianness used by the other implementations (and expected by the index construction code), further the mmap implementation exposed a bug in LongArray.write() that caused it to create a larger file than necessary.
A test was built to ensure the output of these implementations is equivalent.
To cope with writing large files out of order, the system needs some form of strategy to avoid writing them directly to disk, as this causes insane amounts of disk thrashing. By default, the data is just buffered in RAM. This works well on a large server, but smaller systems struggle.
To help systems with small RAM process large amounts of data, the old RandomWriteFunnel is brought back if the system property 'system.conserve-memory' is set to true. RandomWriteFunnel is buffering the construction by creating a series of small files that pigeonhole the writes into rough neighborhoods, and then it goes over the files one by one to construct one area of the file at a time. This is relatively slow and uses more than twice the disk size.
A new interface RandomFileAssembler is introduced as an abstraction for this operation. A third strategy, direct mmaps, is also introduced if the file is very small (less than 1 GB). In this domain, disk thrashing is unlikely since it will comfortably fit in RAM.
The flag is `system.languageDetectionModelVersion`.
* If negative, no model is used.
* If 0, both models are used.
* If 1, the old crappy model is used.
* If 2, the new fasttext model is used.
The flag is `system.languageDetectionModelVersion`.
* If negative, no model is used.
* If 0, both models are used.
* If 1, the old crappy model is used.
* If 2, the new fasttext model is used.
The production configuration assumes all content of interest is 7 bit ASCII, and makes a series of optimizations based on this. This assumption holds poorly in the wild.
Adding an **experimental** system property 'system.noFlattenUnicode', that when set to TRUE, will disable this behavior.
IMPORTANT!! The index needs to be re-constructed when this flag is changed, as different hash functions are selected for the keyword->identifier mappings.
java.lang.Error:s were not handled properly, leading to mismatch in the bookkeeping of the FSMs. These are now caught, acted on, and re-thrown.
MqSynchronousInbox also no longer assumes all exceptions are InterruptedException.
The change adds a new column to the MESSAGE_QUEUE table called AUDIT_RELATED_ID. This field is populated transparently, using a dictionary mapping Thread IDs to Message IDs, populated by the inbox handlers.
The existing RELATED_ID field has too many semantics associated with them,
among other things the FSM code uses them this field in tracking state changes.
The change set also improves the consistency of inbox names. The IndexClient was buggy and populated its outbox with a UUID. This is fixed. All Service2Service outboxes are now prefixed with 'pp:' to make them even easier to differentiate.
Use a system.properties file to configure the system. This is loaded statically by MainClass or ProcessMainClass. Update the property names to be more consistent, and update the documentations to reflect the changes.
Several tests were manually running migrations in a large copy-paste blob of code. This makes the test less useful as it's possible to break the code while keeping the tests green by introducing a new migration that never gets run in the tests, and it's also difficult to reason about what the tests are doing.
A new test helper library is introduced with a TestMigrationLoader that can both run Flyway migrations, or load specific migrations in the cases a specific set of migrations need to be loaded. Existing tests are migrated to use the new code.
Added a new constant, MAX_TEXT_LENGTH, to the SentenceExtractor class. If the length of the text input exceeds this limit, the text is truncated to fit within the limit. This modification is designed to prevent excessive resource usage for unusually long text inputs.
Added a new constant, MAX_TEXT_LENGTH, to the SentenceExtractor class. If the length of the text input exceeds this limit, the text is truncated to fit within the limit. This modification is designed to prevent excessive resource usage for unusually long text inputs.
Modify processingiterator to be constructed via a factory, to enable re-use of its backing executor service.
This reduces thread churn in the converter sideloader style processing of regular crawl data.
Updated ProcessingIterator's queue polling from one second to 50 milliseconds for improved performance. This facilitates faster document processing across more cores, reducing bottlenecks and slow single-threaded processing.
