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.
As we work towards contexts implying the return type of compilation, we
first need ScriptContext to not be an enum. This commit removes the
Standard enum and Plugin subclass of ScriptContext.
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.
Template script engines (mustache, the only one) currently return a
BytesReference that users must know is utf8 encoded. This commit
modifies all callers and mustache to have the template engine return
String. This is much simpler, and does not require decoding in order to
use (for example, in ingest).
The max concurrent searches logic is complex and we shouldn't duplicate that in multi search template api,
so we should template each individual template search request and then delegate to multi search api.
The max concurrent searches logic is complex and we shouldn't duplicate that in multi search template api,
so we should template each individual template search request and then delegate to multi search api.
This commit renames ScriptEngineService to ScriptEngine. It is often
confusing because we have the ScriptService, and then
ScriptEngineService implementations, but the latter are not services as
we see in other places in elasticsearch.
This adds the `index.mapping.single_type` setting, which enforces that indices
have at most one type when it is true. The default value is true for 6.0+ indices
and false for old indices.
Relates #15613
This commit adds a compileTemplate method to the ScriptService.
Eventually this will be used to easily cutover all consumers to a new
TemplateService.
relates #16314
ScriptService has two executable methods, one which takes a
CompiledScript, which is similar to search, and one that takes a raw
Script and both compiles and returns an ExecutableScript for it. The
latter is not needed, and the call sites which used one or the other
were mixed. This commit removes the extra executable method in favor of
callers first calling compile, then executable.
This change simplifies how the rest test runner finds test files and
removes all leniency. Previously multiple prefixes and suffixes would
be tried, and tests could exist inside or outside of the classpath,
although outside of the classpath never quite worked. Now only classpath
tests are supported, and only one resource prefix is supported,
`/rest-api-spec/tests`.
closes#20240
This commit renames the random ASCII helper methods in ESTestCase. This
is because this method ultimately uses the random ASCII methods from
randomized runner, but these methods actually only produce random
strings generated from [a-zA-Z].
Relates #23886
Gradle's finalizedBy on tasks only ensures one task runs after another,
but not immediately after. This is problematic for our integration tests
since it allows multiple project's integ test clusters to be
simultaneously. While this has not been a problem thus far (gradle 2.13
happened to keep the finalizedBy tasks close enough that no clusters
were running in parallel), with gradle 3.3 the task graph generation has
changed, and numerous clusters may be running simultaneously, causing
memory pressure, and thus generally slower tests, or even failure if the
system has a limited amount of memory (eg in a vagrant host).
This commit reworks how integ tests are configured. It adds an
`integTestCluster` extension to gradle which is equivalent to the current
`integTest.cluster` and moves the rest test runner task to
`integTestRunner`. The `integTest` task is then just a dummy task,
which depends on the cluster runner task, as well as the cluster stop
task. This means running `integTest` in one project will both run the
rest tests, and shut down the cluster, before running `integTest` in
another project.
Now that search templates always get converted to json, we don't need to try and auto-detect their content-type, which anyways didn't work as expected before given that only json was really working.
Elasticsearch accepts multiple content-type formats, hence scripts can be stored/provided in json, yaml, cbor or smile. Yet the format that should be used internally is json. This is a problem mainly around search templates, as they only support json out of the four content-types, so instead of maintaining the content-type of the request we should rather convert the scripts/templates to json.
Binary formats were not previously supported. If you stored a template in yaml format, you'd get back an error "No encoder found for MIME type [application/yaml]" when trying to execute it. With this commit the request content-type is independent from the template, which always gets converted to json internally. That is transparent to users and doesn't affect the content type of the response obtained when executing the template.
This pull request reuses the typed_keys parameter added in #22965, but this time it applies it to suggesters. When set to true, the suggester names in the search response will be prefixed with a prefix that reflects their type.
This pull request adds a new parameter to the REST Search API named `typed_keys`. When set to true, the aggregation names in the search response will be prefixed with a prefix that reflects the internal type of the aggregation.
Here is a simple example:
```
GET /_search?typed_keys
{
"aggs": {
"tweets_per_user": {
"terms": {
"field": "user"
}
}
},
"size": 0
}
```
And the response:
```
{
"aggs": {
"sterms:tweets_per_user": {
...
}
}
}
```
This parameter is intended to make life easier for REST clients that could parse back the prefix and could detect the type of the aggregation to parse. It could also be implemented for suggesters.
We have a bunch of interfaces that have only a single implementation
for 6 years now. These interfaces are pretty useless from a SW development
perspective and only add unnecessary abstractions. They also require
lots of casting in many places where we expect that there is only one
concrete implementation. This change removes the interfaces, makes
all of the classes final and removes the duplicate `foo` `getFoo` accessors
in favor of `getFoo` from these classes.
This commit adds support for the newline delimited JSON Content-Type, which is how
the bulk, multi-search, and multi-search template APIs expect data to be formatted. The
`elasticsearch-js` client has also been using this content type for these types of requests.
Closes#22943
This commit upgrades the checkstyle configuration from version 5.9 to
version 7.5, the latest version as of today. The main enhancement
obtained via this upgrade is better detection of redundant modifiers.
Relates #22960
This change adds a strict mode for xcontent parsing on the rest layer. The strict mode will be off by default for 5.x and in a separate commit will be enabled by default for 6.0. The strict mode, which can be enabled by setting `http.content_type.required: true` in 5.x, will require that all incoming rest requests have a valid and supported content type header before the request is dispatched. In the non-strict mode, the Content-Type header will be inspected and if it is not present or not valid, we will continue with auto detection of content like we have done previously.
The content type header is parsed to the matching XContentType value with the only exception being for plain text requests. This value is then passed on with the content bytes so that we can reduce the number of places where we need to auto-detect the content type.
As part of this, many transport requests and builders were updated to provide methods that
accepted the XContentType along with the bytes and the methods that would rely on auto-detection have been deprecated.
In the non-strict mode, deprecation warnings are issued whenever a request with body doesn't provide the Content-Type header.
See #19388
Currently, stored scripts use a namespace of (lang, id) to be put, get, deleted, and executed. This is not necessary since the lang is stored with the stored script. A user should only have to specify an id to use a stored script. This change makes that possible while keeping backwards compatibility with the previous namespace of (lang, id). Anywhere the previous namespace is used will log deprecation warnings.
The new behavior is the following:
When a user specifies a stored script, that script will be stored under both the new namespace and old namespace.
Take for example script 'A' with lang 'L0' and data 'D0'. If we add script 'A' to the empty set, the scripts map will be ["A" -- D0, "A#L0" -- D0]. If a script 'A' with lang 'L1' and data 'D1' is then added, the scripts map will be ["A" -- D1, "A#L1" -- D1, "A#L0" -- D0].
When a user deletes a stored script, that script will be deleted from both the new namespace (if it exists) and the old namespace.
Take for example a scripts map with {"A" -- D1, "A#L1" -- D1, "A#L0" -- D0}. If a script is removed specified by an id 'A' and lang null then the scripts map will be {"A#L0" -- D0}. To remove the final script, the deprecated namespace must be used, so an id 'A' and lang 'L0' would need to be specified.
When a user gets/executes a stored script, if the new namespace is used then the script will be retrieved/executed using only 'id', and if the old namespace is used then the script will be retrieved/executed using 'id' and 'lang'
This commit adds a SpecialPermission constant and uses that constant
opposed to introducing new instances everywhere.
Additionally, this commit introduces a single static method to check that
the current code has permission. This avoids all the duplicated access
blocks that exist currently.
There are presently 7 ctor args used in any rest handlers:
* `Settings`: Every handler uses it to initialize a logger and
some other strange things.
* `RestController`: Every handler registers itself with it.
* `ClusterSettings`: Used by `RestClusterGetSettingsAction` to
render the default values for cluster settings.
* `IndexScopedSettings`: Used by `RestGetSettingsAction` to get
the default values for index settings.
* `SettingsFilter`: Used by a few handlers to filter returned
settings so we don't expose stuff like passwords.
* `IndexNameExpressionResolver`: Used by `_cat/indices` to
filter the list of indices.
* `Supplier<DiscoveryNodes>`: Used to fill enrich the response
by handlers that list tasks.
We probably want to reduce these arguments over time but
switching construction away from guice gives us tighter
control over the list of available arguments.
These parameters are passed to plugins using
`ActionPlugin#initRestHandlers` which is expected to build and
return that handlers immediately. This felt simpler than
returning an reference to the ctors given all the different
possible args.
Breaks java plugins by moving rest handlers off of guice.
This commit tries to simplify the way ElasticsearchException are rendered to xcontent. It adds some documentation and renames and merges some methods. Current behavior is preserved, the goal is to be more readable and centralize everything in the ElasticsearchException class.
Removes `AggregatorParsers`, replacing all of its functionality with
`XContentParser#namedObject`.
This is the third bit of payoff from #22003, one less thing to pass
around the entire application.
* Remove a checked exception, replacing it with `ParsingException`.
* Remove all Parser classes for the yaml sections, replacing them with static methods.
* Remove `ClientYamlTestFragmentParser`. Isn't used any more.
* Remove `ClientYamlTestSuiteParseContext`, replacing it with some static utility methods.
I did not rewrite the parsers using `ObjectParser` because I don't think it is worth it right now.
Introduces `XContentParser#namedObject which works a little like
`StreamInput#readNamedWriteable`: on startup components register
parsers under names and a superclass. At runtime we look up the
parser and call it to parse the object.
Right now the parsers take a context object they use to help with
the parsing but I hope to be able to eliminate the need for this
context as most what it is used for at this point is to move
around parser registries which should be replaced by this method
eventually. I make no effort to do so in this PR because it is
big enough already. This is meant to the a start down a road that
allows us to remove classes like `QueryParseContext`,
`AggregatorParsers`, `IndicesQueriesRegistry`, and
`ParseFieldRegistry`.
The goal here is to reduce the amount of plumbing required to
allow parsing pluggable things. With this you don't have to pass
registries all over the place. Instead you must pass a super
registry to fewer places and use it to wrap the reader. This is
the same tradeoff that we use for NamedWriteable and it allows
much, much simpler binary serialization. We think we want that
same thing for xcontent serialization.
The only parsing actually converted to this method is parsing
`ScoreFunctions` inside of `FunctionScoreQuery`. I chose this
because it is relatively self contained.
We are currenlty checking that no deprecation warnings are emitted in our query tests. That can be moved to ESTestCase (disabled in ESIntegTestCase) as it allows us to easily catch where our tests use deprecated features and assert on the expected warnings.
We return deprecation warnings as response headers, besides logging them. Strict parsing mode stayed around, but was only used in query tests, though we also introduced checks for deprecation warnings there that don't need strict parsing anymore (see #20993).
We can then safely remove support for strict parsing mode. The final goal is to remove the ParseFieldMatcher class, but there are many many users of it. This commit prepares the field for the removal, by deprecating ParseFieldMatcher and making it effectively not needed. Strict parsing is removed from ParseFieldMatcher, and strict parsing is replaced in tests where needed with deprecation warnings checks.
Note that the setting to enable strict parsing was never ported to the new settings infra hance it cannot be set in production. It is really only used in our own tests.
Relates to #19552
Our query DSL supports empty queries (`{}`), which have a different meaning depending on the query that holds it, either ignored, match_all or match_none. We deprecated the support for empty queries in 5.0, where we log a deprecation warning wherever they are used.
The way we supported it once we moved query parsing to the coordinating node was having an Optional<QueryBuilder> return type in all of our parse methods (called fromXContent). See #17624. The central place for this was QueryParseContext#parseInnerQueryBuilder. We can now remove all the optional return types and simply throw an exception whenever an empty query is found.
To get #22003 in cleanly we need to centralize as much `XContentParser` creation as possible into `RestRequest`. That'll mean we have to plumb the `NamedXContentRegistry` into fewer places.
This removes `RestAction.hasBody`, `RestAction.guessBodyContentType`, and `RestActions.getRestContent`, moving callers over to `RestRequest.hasContentOrSourceParam`, `RestRequest.contentOrSourceParam`, and `RestRequest.contentOrSourceParamParser` and `RestRequest.withContentOrSourceParamParserOrNull`. The idea is to use `withContentOrSourceParamParserOrNull` if you need to handle requests without any sort of body content and to use `contentOrSourceParamParser` otherwise.
I believe the vast majority of this PR to be purely mechanical but I know I've made the following behavioral change (I'll add more if I think of more):
* If you make a request to an endpoint that requires a request body and has cut over to the new APIs instead of getting `Failed to derive xcontent` you'll get `Body required`.
* Template parsing is now non-strict by default. This is important because we need to be able to deprecate things without requests failing.
SearchTemplateRequest to implement CompositeIndicesRequest
Given that SearchTemplateRequest effectively delegates to search when a search is being executed, it should implement the CompositeIndicesRequest interface. The subrequests method should return a single search request. When a search is not going to be executed, because we are in simulate mode, there are no inner requests, and there are no corresponding indices to that request either.
Closes#21747
At one point in the past when moving out the rest tests from core to
their own subproject, we had multiple test classes which evenly split up
the tests to run. However, we simplified this and went back to a single
test runner to have better reproduceability in tests. This change
removes the remnants of that multiplexing support.
This adds checks for expected warning headers to the query builder test
infrastructure. Tests that are adding deprecation warnings to the response
headers need to check those, otherwise the abstract base class for the test
class will complain at teardown.
Refactored ScriptType to clean up some of the variable and method names. Added more documentation. Deprecated the 'in' ParseField in favor of 'stored' to match the indexed scripts being replaced by stored scripts.
Today SearchContext expose the current context as a thread local which makes any kind of sane interface design very very hard. This PR removes the thread local entirely and instead passes the relevant context anywhere needed. This simplifies state management dramatically and will allow for a much leaner SearchContext interface down the road.
Today when parsing a request, Elasticsearch silently ignores incorrect
(including parameters with typos) or unused parameters. This is bad as
it leads to requests having unintended behavior (e.g., if a user hits
the _analyze API and misspell the "tokenizer" then Elasticsearch will
just use the standard analyzer, completely against intentions).
This commit removes lenient URL parameter parsing. The strategy is
simple: when a request is handled and a parameter is touched, we mark it
as such. Before the request is actually executed, we check to ensure
that all parameters have been consumed. If there are remaining
parameters yet to be consumed, we fail the request with a list of the
unconsumed parameters. An exception has to be made for parameters that
format the response (as opposed to controlling the request); for this
case, handlers are able to provide a list of parameters that should be
excluded from tripping the unconsumed parameters check because those
parameters will be used in formatting the response.
Additionally, some inconsistencies between the parameters in the code
and in the docs are corrected.
Relates #20722
We can now run templates using `explain` and/or `profile` parameters.
Which is interesting when you have defined a complicated profile but want to debug it in an easier way than running the full query again.
You can use `explain` parameter when running a template:
```js
GET /_search/template
{
"file": "my_template",
"params": {
"status": [ "pending", "published" ]
},
"explain": true
}
```
You can use `profile` parameter when running a template:
```js
GET /_search/template
{
"file": "my_template",
"params": {
"status": [ "pending", "published" ]
},
"profile": true
}
```
This commit modifies the call sites that allocate a parameterized
message to use a supplier so that allocations are avoided unless the log
level is fine enough to emit the corresponding log message.
Parsing a search request is currently split up among a number of
classes, using multiple public static methods, which take multiple
regstries of elements that may appear in the search request like query
parsers and aggregations. This change begins consolidating all this code
by collapsing the registries normally used for parsing search requests
into a single SearchRequestParsers class. It is also made available to
plugin services to enable templating of search requests. Eventually all
of the actual parsing logic should move to the class, and the registries
should be hidden, but for now they are at least co-located to reduce the
number of objects that must be passed around.
Squashes all the subpackages of `org.elasticsearch.rest.action` down to
the following:
* `o.e.rest.action.admin` - Administrative actions
* `o.e.rest.action.cat` - Actions that make tables for `grep`ing
* `o.e.rest.action.document` - Actions that act on documents
* `o.e.rest.action.ingest` - Actions that act on ingest pipelines
* `o.e.rest.action.search` - Actions that search
I'm tempted to merge `search` into `document` but the `document`
package feels fairly complete as is and `Suggest` isn't actually always
about documents either....
I'm also tempted to merge `ingest` into `admin.cluster` because the
latter contains the actions for dealing with stored scripts.
I've moved the `o.e.rest.action.support` into `o.e.rest.action`.
I've also added `package-info.java`s to all packges in `o.e.rest`. I
figure if the package is too small to deserve a `package-info.java` file
then it is too small to deserve to be a package....
Also fixes checkstyle in all moved classes.
When compiling many dynamically changing scripts, parameterized
scripts (<https://www.elastic.co/guide/en/elasticsearch/reference/master/modules-scripting-using.html#prefer-params>)
should be preferred. This enforces a limit to the number of scripts that
can be compiled within a minute. A new dynamic setting is added -
`script.max_compilations_per_minute`, which defaults to 15.
If more dynamic scripts are sent, a user will get the following
exception:
```json
{
"error" : {
"root_cause" : [
{
"type" : "circuit_breaking_exception",
"reason" : "[script] Too many dynamic script compilations within one minute, max: [15/min]; please use on-disk, indexed, or scripts with parameters instead",
"bytes_wanted" : 0,
"bytes_limit" : 0
}
],
"type" : "search_phase_execution_exception",
"reason" : "all shards failed",
"phase" : "query",
"grouped" : true,
"failed_shards" : [
{
"shard" : 0,
"index" : "i",
"node" : "a5V1eXcZRYiIk8lecjZ4Jw",
"reason" : {
"type" : "general_script_exception",
"reason" : "Failed to compile inline script [\"aaaaaaaaaaaaaaaa\"] using lang [painless]",
"caused_by" : {
"type" : "circuit_breaking_exception",
"reason" : "[script] Too many dynamic script compilations within one minute, max: [15/min]; please use on-disk, indexed, or scripts with parameters instead",
"bytes_wanted" : 0,
"bytes_limit" : 0
}
}
}
],
"caused_by" : {
"type" : "general_script_exception",
"reason" : "Failed to compile inline script [\"aaaaaaaaaaaaaaaa\"] using lang [painless]",
"caused_by" : {
"type" : "circuit_breaking_exception",
"reason" : "[script] Too many dynamic script compilations within one minute, max: [15/min]; please use on-disk, indexed, or scripts with parameters instead",
"bytes_wanted" : 0,
"bytes_limit" : 0
}
}
},
"status" : 500
}
```
This also fixes a bug in `ScriptService` where requests being executed
concurrently on a single node could cause a script to be compiled
multiple times (many in the case of a powerful node with many shards)
due to no synchronization between checking the cache and compiling the
script. There is now synchronization so that a script being compiled
will only be compiled once regardless of the number of concurrent
searches on a node.
Relates to #19396
This commit updates Jackson to the 2.8.1 version, which is more strict when it comes to build objects. It also adds the snakeyaml dependency that was previously shaded in jackson libs.
It also closes#18076
Adds `warnings` syntax to the yaml test that allows you to expect
a `Warning` header that looks like:
```
- do:
warnings:
- '[index] is deprecated'
- quotes are not required because yaml
- but this argument is always a list, never a single string
- no matter how many warnings you expect
get:
index: test
type: test
id: 1
```
These are accessible from the docs with:
```
// TEST[warning:some warning]
```
This should help to force you to update the docs if you deprecate
something. You *must* add the warnings marker to the docs or the build
will fail. While you are there you *should* update the docs to add
deprecation warnings visible in the rendered results.
After #13834 many tests that used Groovy scripts (for good or bad reason) in their tests have been moved in the lang-groovy module and the issue #13837 has been created to track these messy tests in order to clean them up.
The work started with #19280, #19302 and #19336 and this PR moves the remaining messy tests back in core, removes the dependency on Groovy, changes the scripts in order to use the mocked script engine, and change the tests to integration tests.
It also moves IndexLookupIT test back (even if it has good chance to be removed soon) and fixes its tests.
It also changes AbstractQueryTestCase to use custom script plugins in tests.
closes#13837
In an effort to reduce the number of tiny packages we have in the
code base this moves all the files that were in subdirectories of
`org.elasticsearch.rest.action.admin.cluster` into
`org.elasticsearch.rest.action.admin.cluster`.
Also fixes line length in these packages.
This makes it obvious that these tests are for running the client yaml
suites. Now that there are other ways of running tests using the REST
client against a running cluster we can't go on calling the shared
client yaml tests "REST tests". They are rest tests, but they aren't
**the** rest tests.
This adds a header that looks like `Location: /test/test/1` to the
response for the index/create/update API. The requirement for the header
comes from https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.htmlhttps://tools.ietf.org/html/rfc7231#section-7.1.2 claims that relative
URIs are OK. So we use an absolute path which should resolve to the
appropriate location.
Closes#19079
This makes large changes to our rest test infrastructure, allowing us
to write junit tests that test a running cluster via the rest client.
It does this by splitting ESRestTestCase into two classes:
* ESRestTestCase is the superclass of all tests that use the rest client
to interact with a running cluster.
* ESClientYamlSuiteTestCase is the superclass of all tests that use the
rest client to run the yaml tests. These tests are shared across all
official clients, thus the `ClientYamlSuite` part of the name.
Messy tests with mustache were either moved to core, moved to a rest test or remained untouched if they actually tested mustache.
Also removed tests that were redundant.
Remove `ParseField` constants used for names where there are no deprecated
names and just use the `String` version of the registration method instead.
This is step 2 in cleaning up the plugin interface for extending
search time actions. Aggregations are next.
This is breaking for plugins because those that register a new query should
now implement `SearchPlugin` rather than `onModule(SearchModule)`.
* Removed `Template` class and unified script & template parsing logic. Templates are scripts, so they should be defined as a script. Unless there will be separate template infrastructure, templates should share as much code as possible with scripts.
* Removed ScriptParseException in favour for ElasticsearchParseException
* Moved TemplateQueryBuilder to lang-mustache module because this query is hard coded to work with mustache only
Switches most search behavior extensions from push (`onModule(SearchModule)`)
to pull (`implements SearchPlugin`). This effort in general gives plugin
authors a much cleaner view of how to extend Elasticsearch and starts to
set up portions of Elasticsearch as "the plugin API". This commit in
particular does that for search-time behavior like customized suggesters,
highlighters, score functions, and significance heuristics.
It also switches most such customization to being done at search module
construction time which is much, much easier to reason about from a testing
perspective. It also helps significantly in the process of de-guice-ing
Elasticsearch's startup.
There are at least two major search time extensions that aren't covered in
this commit that will simply have to wait for the next commit on the topic
because this one has already grown large: custom aggregations and custom
queries. These will likely live in the same SearchPlugin interface as well.
This commit renames writeThrowable to writeException. The situation here
stems from the fact that the StreamOutput method for serializing
Exceptions needs to accept Throwables too as Throwables can be the cause
of serialized Exceptions. Yet, we do not serialize Throwables in the
Error sub-hierarchy in a way that they can be deserialized into their
initial type. This leads to an asymmetry in the StreamOutput method for
serializing Exceptions and the StreamInput method for writing
Excpetions. Namely, the former will accept Throwables but the latter
will only return Exceptions. A goal with the stream methods has always
been symmetry in the method names so that serialization/deserialization
routines appear symmetrical in code. It is this asymmetry on the
input/output types for Exceptions on StreamOutput/StreamInput that
clashes with the desired symmetry of naming. Despite this, we should
favor symmetry in the naming of the methods. This commit renames
StreamOutput#writeThrowable to StreamOutput#writeException which leaves
us with Exception StreamInput#readException and void
StreamOutput#writeException(Throwable).
Today throughout the codebase, catch throwable is used with reckless
abandon. This is dangerous because the throwable could be a fatal
virtual machine error resulting from an internal error in the JVM, or an
out of memory error or a stack overflow error that leaves the virtual
machine in an unstable and unpredictable state. This commit removes
catch throwable from the codebase and removes the temptation to use it
by modifying listener APIs to receive instances of Exception instead of
the top-level Throwable.
Relates #19231
Ryan Ernst
Jack Conradson
Martijn van Groningen
Isabel Drost-Fromm
Adrien Grand
Jason Tedor
Nik Everett
javanna
Tanguy Leroux
Simon Willnauer
Jay Modi
Tim Brooks
Daniel Mitterdorfer
Luca Cavanna
Boaz Leskes
Christoph Büscher
Simon Willnauer
David Pilato
Alexander Reelsen
Lee Hinman