Simplify ScriptSession dependencies (#4190)

This removes the only python init script, and removes an unused groovy
init script. The config variables are left in place for now, though
they will default to blank.

One slightly unexpected change that this results in is that the jpy,
sys, and os modules are no longer imported by default into a python
script session - this probably should be considered a feature, but
does need to be documented.

Partial #4040

engine/table/build.gradle

@@ -6,23 +6,6 @@ plugins {
 
 description 'Engine Table: Implementation and closely-coupled utilities'
 
-sourceSets {
- main {
- resources {
- srcDir 'groovy'
- include 'core/*.groovy'
- }
- resources {
- srcDir 'python'
- include 'core/*.py'
- }
- resources {
- srcDir 'src/main/resources'
- include '**'
- }
- }
-}
-
 configurations {
  // Ensure jmh picks up the same dependencies as tests
  jmhImplementation.extendsFrom testImplementation

engine/table/src/main/java/io/deephaven/engine/util/jpy/JpyInit.java

@@ -61,7 +61,8 @@ private static void markReadyAndCheckEnv() {
  try (
  final PyModule deephavenJpyModule = PyModule.importModule("deephaven_internal.jvm");
  final PyObject readyObj = deephavenJpyModule.callMethod("ready");
- final PyObject checkObj = deephavenJpyModule.callMethod("check_py_env")) {
+ final PyObject checkObj = deephavenJpyModule.callMethod("check_py_env");
+ final PyObject initObj = deephavenJpyModule.callMethod("init_py")) {
  // empty
  }
  }

props/configs/src/main/resources/dh-defaults.prop

@@ -35,9 +35,9 @@ QueryPerformanceRecorder.packageFilter.internal=defaultPackageFilters.qpr
 
 ########## Deephaven Groovy and Python Session defaults ##########
 
-GroovyDeephavenSession.initScripts=core/deephaven_core_utils.groovy
+GroovyDeephavenSession.initScripts=
 
-PythonDeephavenSession.initScripts=core/deephaven_jpy_init.py
+PythonDeephavenSession.initScripts=
 
 default.processEnvironmentFactory=io.deephaven.util.process.DefaultProcessEnvironment$Factory
 

props/test-configs/src/main/resources/dh-tests.prop

@@ -57,9 +57,9 @@ QueryPerformanceRecorder.packageFilter.internal=defaultPackageFilters.qpr
 
 ########## Deephaven Groovy and Python Session defaults ##########
 
-GroovyDeephavenSession.initScripts=core/deephaven_core_utils.groovy
+GroovyDeephavenSession.initScripts=
 
-PythonDeephavenSession.initScripts=core/deephaven_jpy_init.py
+PythonDeephavenSession.initScripts=
 
 ###### Measurement Options ######
 statsdriver.enabled=false

py/server/deephaven_internal/jvm/__init__.py

@@ -66,3 +66,25 @@ def init_jvm(*args, **kwargs):
  "Unable to initialize JVM, try setting the environment variable JAVA_HOME (JDK 11+ required)") from e
  ready()
  return result
+
+def init_py():
+ """Finishes starting Python to be usable from inside of a Java process. Not intended to be called in cases
+ where the process was started as Python, and Java was started from inside Python.
+ """
+
+ import jpy
+ import os
+ import sys
+ from deephaven_internal.stream import TeeStream
+
+ # Set stdin to /dev/null to prevent functions (like help()) that attempt to read from stdin from hanging python
+ # execution from within Java.
+ os.dup2(os.open("/dev/null", os.O_RDONLY), 0)
+
+ jpy.VerboseExceptions.enabled = True
+ # If you want jpy to tell you about all that it is doing, change this
+ # jpy.diag.flags = jpy.diag.F_ALL
+
+ j_sys = jpy.get_type('java.lang.System')
+ sys.stdout = TeeStream.redirect(sys.stdout, j_sys.out)
+ sys.stderr = TeeStream.redirect(sys.stderr, j_sys.err)

python-engine-test/src/test/java/io/deephaven/engine/util/WorkerPythonEnvironment.java

@@ -68,8 +68,8 @@ public enum WorkerPythonEnvironment {
  .getStringWithDefault("WorkerPythonEnvironment.defaultScriptPath", ".");
 
  final ScriptFinder scriptFinder = new ScriptFinder(defaultScriptPath);
- final String initScript = Configuration.getInstance().getStringWithDefault("WorkerPythonEnvironment.initScript",
- "core/deephaven_jpy_init.py");
+ final String initScript =
+ Configuration.getInstance().getStringWithDefault("WorkerPythonEnvironment.initScript", "");
 
  final ScriptFinder.FileOrStream file;
  try {