Support for configuration cache

[britter]

Instant execution is one of the upcoming features in Gradle. The plugin should support this.

[nedtwigg]

For now this workaround seems to be enough

tasks.named('generateMavenPluginHelpMojoSources') {
  notCompatibleWithConfigurationCache('https://github.com/britter/maven-plugin-development/issues/8')
}

[britter]

Yes, that's true, but it will disable the configuration cache whenever this plugin is part of the build 😕

[Goooler]

Gradle 7.6.1

- Task `:plugin-maven:generateMavenPluginHelpMojoSources` of type `de.benediktritter.maven.plugin.development.task.GenerateHelpMojoSourcesTask`: cannot serialize object of type 'org.gradle.internal.io.LinePerThreadBufferingOutputStream', a subtype of 'java.io.OutputStream', as these are not supported with the configuration cache.
  See https://docs.gradle.org/7.6.1/userguide/configuration_cache.html#config_cache:requirements:disallowed_types
- Task `:plugin-maven:generateMavenPluginHelpMojoSources` of type `de.benediktritter.maven.plugin.development.task.GenerateHelpMojoSourcesTask`: value '[classpath, site]' failed Java Object Serialization
  See https://docs.gradle.org/7.6.1/userguide/configuration_cache.html#config_cache:not_yet_implemented:java_serialization
- Task `:plugin-maven:generateMavenPluginHelpMojoSources` of type `de.benediktritter.maven.plugin.development.task.GenerateHelpMojoSourcesTask`: value '[java.lang.Class, java.lang.ClassLoader, java.lang.Compiler, java.lang.InheritableThreadLocal, java.lang.Package, java.lang.Process, java.lang.Runtime, java.lang.RuntimePermission, java.lang.SecurityManager, java.lang.System, java.lang.Thread, java.lang.ThreadGroup, java.lang.ThreadLocal]' failed Java Object Serialization
  See https://docs.gradle.org/7.6.1/userguide/configuration_cache.html#config_cache:not_yet_implemented:java_serialization
- Task `:plugin-maven:generateMavenPluginHelpMojoSources` of type `de.benediktritter.maven.plugin.development.task.GenerateHelpMojoSourcesTask`: value '[org.apache.velocity.runtime.log.AvalonLogChute, org.apache.velocity.runtime.log.Log4JLogChute, org.apache.velocity.runtime.log.CommonsLogLogChute, org.apache.velocity.runtime.log.ServletLogChute, org.apache.velocity.runtime.log.JdkLogChute]' failed Java Object Serialization
  See https://docs.gradle.org/7.6.1/userguide/configuration_cache.html#config_cache:not_yet_implemented:java_serialization

* What went wrong: Configuration cache state could not be cached: field `inputStream` of `org.apache.velocity.runtime.parser.VelocityCharStream` bean found in field `input_stream` of `org.apache.velocity.runtime.parser.ParserTokenManager` bean found in field `token_source` of `org.apache.velocity.runtime.parser.Parser` bean found in field `pool` of `org.apache.velocity.util.SimplePool` bean found in field `pool` of `org.apache.velocity.runtime.ParserPoolImpl` bean found in field `parserPool` of `org.apache.velocity.runtime.RuntimeInstance` bean found in field `ri` of `org.apache.velocity.app.VelocityEngine` bean found in field `engine` of `org.codehaus.plexus.velocity.DefaultVelocityComponent` bean found in field `velocityComponent` of `org.apache.maven.tools.plugin.generator.PluginHelpGenerator` bean found in field `generator` of task `:plugin-maven:generateMavenPluginHelpMojoSources` of type `de.benediktritter.maven.plugin.development.task.GenerateHelpMojoSourcesTask`: error writing value of type 'java.io.InputStreamReader'
> Unable to make field private final sun.nio.cs.StreamDecoder java.io.InputStreamReader.sd accessible: module java.base does not "opens java.io" to unnamed module @15e5409c

[britter]

This is not possible without breaking API, so I'll put this into the 1.0 milestone.

[sschuberth]

Just to chime in what I'm running into:

* What went wrong:
Configuration cache state could not be cached: field `configuration` of `org.apache.velocity.runtime.RuntimeInstance` bean found in field `ri` of `org.apache.velocity.app.VelocityEngine` bean found in field `engine` of `org.codehaus.plexus.velocity.DefaultVelocityComponent` bean found in field `velocityComponent` of `org.apache.maven.tools.plugin.generator.PluginHelpGenerator` bean found in field `generator` of task `:plugins:package-managers:maven-plugin:generateMavenPluginHelpMojoSources` of type `de.benediktritter.maven.plugin.development.task.GenerateHelpMojoSourcesTask`: error writing value of type 'org.apache.commons.collections.ExtendedProperties'
> 'ObjectOutputStream.putFields' is not supported by the Gradle configuration cache. See https://docs.gradle.org/8.10/userguide/configuration_cache.html#config_cache:not_yet_implemented:java_serialization for details.

[britter]

yeah, this is still on my backlog. I hope to have some more time to work on this project again in the near future. For now the only workaround is to explicitly disable to configuration cache for the tasks in the plugin.

[sschuberth]

Does it make sense to finish and merge #148 until then?

[britter]

No, #148 is going to replaced by a different approach. The challenge with the current state of the code is that the tasks unnecessarily reference types that can't be serialized into the configuration cache. My plan is to change that while moving to the org.gradlex namespace because then binary compatibility will be broken anyway.