This commit adds the infrastructure to plugin building and loading to
allow one plugin to extend another. That is, one plugin may extend
another by the "parent" plugin allowing itself to be extended through
java SPI. When all plugins extending a plugin are finished loading, the
"parent" plugin has a callback (through the ExtensiblePlugin interface)
allowing it to reload SPI.
This commit also adds an example plugin which uses as-yet implemented
extensibility (adding to the painless whitelist).
This allows plugins to plug rescore implementations into
Elasticsearch. While this is a fairly expert thing to do I've
done my best to point folks to the QueryRescorer as one that at
least documents the tradeoffs that it makes. I've attempted to
limit the API surface area by removing `SearchContext` from the
exposed interface, instead exposing just the IndexSearcher and
`QueryShardContext`. I also tried to make some of the class names
more consistent and do some general cleanup while I was there.
I entertained the notion of moving the `QueryRescorer` to module.
After all, it'd be a wonderful test to prove that you can plug
rescore implementation into Elasticsearch if the only built in
rescore implementation is in the module. But I decided against it
because the new module would require a client jar and it'd require
moving some more things around. I think if we really want to do
it, we should do it as a followup.
I did, on the other hand, create an "example" rescore plugin which
should both be a nice example for anyone wanting to plug in their
own rescore implementation and servers as a good integration test
to make sure that you can indeed plug one in.
Closes#26208
Removes the `assemble` task from the `build` task when we have
removed `assemble` from the project. We removed `assemble` from
projects that aren't published so our releases will be faster. But
That broke CI because CI builds with `gradle precommit build` and,
it turns out, that `build` includes `check` and `assemble`. With
this change CI will only run `check` for projects without an
`assemble`.
Removes the `assemble` task from projects that are not published.
This should speed up `gradle assemble` by skipping projects that
don't need to be built. Which is useful because `gradle assemble`
is how we cut releases.
This commit renames the needsScores method so as to make it
automatically generatable, based on the name of the `_score` variable
which is available in search scripts. It also adds documentation to
ScriptContext to explain the naming and signature of such methods.
This commit adds back "id" as the key within a script to specify a
stored script (which with file scripts now gone is no longer ambiguous).
It also adds "source" as a replacement for "code". This is in an attempt
to normalize how scripts are specified across both put stored scripts and script usages, including search template requests. This also deprecates the old inline/stored keys.
ScriptContexts currently understand a FactoryType that can produce
instances of the script InstanceType. However, for search scripts, this
does not work as we have the concept of LeafSearchScript that is created
per lucene segment. This commit effectively renames the existing
SearchScript class into SearchScript.LeafFactory, which is a new,
optional, class that can be defined within a ScriptContext.
LeafSearchScript is effectively renamed back into SearchScript. This
change allows the model of stateless factory -> stateful factory ->
script instance to continue, but in a generic way that any script
context may take advantage of.
relates #20426
This commit renames the concept of the "compiled type" to a "factory
type", along with all implementations of this class to be named Factory.
This brings it inline with the classes purpose.
This commit adds collection of all contexts to the parameters of
getScriptEngine. This will allow script engines like painless to
precache extra information about the contexts.
This is a simple refactoring to move the context definitions into the
type that they use. While we have multiple context names for the same
class at the moment, this will eventually become one ScriptContext per
instance type, so the pattern of a static member on the interface called
CONTEXT can be used. This commit also moves the consolidated list of
contexts provided by core ES into ScriptModule.
This commit changes the compile method of ScriptEngine to be generic in
the same way it is on ScriptService. This moves the shim of handling the
two existing context classes into each script engine, so that each
engine can be worked on independently to convert to real handling of
contexts.
This commit modifies the compile method of ScriptService to be context
aware. The ScriptContext is now a generic class which contains both the
instance type and compiled type for a script. Instance type may be
stateful (for example, pre loading field information for the index a
script will execute on, like in expressions), while the compiled type is
stateless and used to construct instance type instances. This change is
only a first step to cutover ScriptService to the new paradigm. It only
converts callers to the script service, and has a small shim to wrap
compilation from the script engines to support the current two fixed
instance types, SearchScript and ExecutableScript.
Since groovy was removed, we no longer have any ScriptEngines with
resources to release. We may want to keep the option open for a script
engine to close resources, but this would not be common. This commit
adds a default implementation to ScriptEngine for `close()` to reduce
the boiler plate that must be added for a ScriptEngine implementation.
ScriptEngine implementations have an overridable method to indicate they
are safe to use as inline scripts. Since groovy was removed fro 6.0,
there are no longer any implementations which used the default false
value. Furthermore, the value was not actually read anywhere. This
commit removes the method. The ScriptEngineRegistry was also no longer
necessary as it only was used to build a map from language to engine.
This commit renames all rest test files to use the .yml extension
instead of .yaml. This way the extension used within all of
elasticsearch for yaml is consistent.
This commit documents how to write a `ScriptEngine` in order to use
expert internal apis, such as using Lucene directly to find index term
statistics. These documents prepare the way to remove both native
scripts and IndexLookup.
The example java code is actually compiled and tested under a new gradle
subproject for example plugins. This change does not yet breakup
jvm-example into the new examples dir, which should be done separately.
relates #19359
relates #19966
Ryan Ernst
Nik Everett