GlueGen Struct [2]: Add CodeUnit: Representing a generated C or Java file, covering multiple FunctionEmitter allowing to unify output, decoration and dynamic helper code injection per unit

- Handles file open and have public ctor emitAutogeneratedWarning(..), being self-contained

- Includes `JVMUtil_NewDirectByteBufferCopy(..)` implementation in CCodeUnit,
  may be injected if required in customCode via emitHeader(..)

4 files changed, 261 insertions, 1 deletions

diff --git a/src/java/com/jogamp/gluegen/CCodeUnit.java b/src/java/com/jogamp/gluegen/CCodeUnit.java
new file mode 100644
index 0000000..df5c6e7
--- /dev/null
+++ b/src/java/com/jogamp/gluegen/CCodeUnit.java
@@ -0,0 +1,97 @@
+/**
+ * Copyright 2023 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+package com.jogamp.gluegen;
+
+import java.io.IOException;
+import java.util.List;
+
+/**
+ * C code unit (a generated C source file),
+ * covering multiple {@link FunctionEmitter} allowing to unify output, decoration and dynamic helper code injection per unit.
+ **/
+public class CCodeUnit extends CodeUnit {
+    /** base c-unit name with suffix. */
+    public final String cUnitName;
+
+    /**
+     * @param filename the class's full filename to open w/ write access
+     * @param cUnitName the base c-unit name, i.e. c-file basename with suffix
+     * @param generator informal optional object that is creating this unit, used to be mentioned in a warning message if not null.
+     * @throws IOException
+     */
+    public CCodeUnit(final String filename, final String cUnitName, final Object generator) throws IOException {
+        super(filename, generator);
+        this.cUnitName = cUnitName;
+        CodeGenUtils.emitAutogeneratedWarning(output, generator, "C-Unit: "+cUnitName+", "+filename);
+    }
+
+    public void emitHeader(final String packageName, final String className, final List<String> customCode) {
+        emitln("#include <jni.h>");
+        emitln("#include <stdlib.h>");
+        emitln("#include <string.h>");
+        emitln("#include <assert.h>");
+        emitln("#include <stddef.h>");
+        emitln();
+        emitln("static jobject JVMUtil_NewDirectByteBufferCopy(JNIEnv *env, jclass clazzBuffers, void * source_address, size_t capacity); /* forward decl. */");
+        emitln();
+
+        boolean addNewDirectByteBufferCopyUnitCode = false;
+        for (final String code : customCode) {
+            emitln(code);
+            addNewDirectByteBufferCopyUnitCode = addNewDirectByteBufferCopyUnitCode || code.contains("JVMUtil_NewDirectByteBufferCopy");
+        }
+        emitln();
+        if( addNewDirectByteBufferCopyUnitCode ) {
+            addTailCode(NewDirectByteBufferCopyUnitCode); // potentially used...
+        }
+    }
+
+    @Override
+    public String toString() { return "CCodeUnit[unit "+cUnitName+", file "+filename+"]"; }
+
+    public static final String NewDirectByteBufferCopyUnitCode =
+        "static const char * nameCopyNativeToDirectByteBuffer = \"copyNativeToDirectByteBuffer\";\n"+
+        "static const char * nameCopyNativeToDirectByteBufferSignature = \"(JJ)Ljava/nio/ByteBuffer;\";\n"+
+        "\n"+
+        "static jobject JVMUtil_NewDirectByteBufferCopy(JNIEnv *env, jclass clazzBuffers, void * source_address, size_t capacity) {\n"+
+        "    jmethodID cstrBuffersNew = (*env)->GetStaticMethodID(env, clazzBuffers, nameCopyNativeToDirectByteBuffer, nameCopyNativeToDirectByteBufferSignature);\n"+
+        "    if(NULL==cstrBuffersNew) {\n"+
+        "        fprintf(stderr, \"Can't get method Buffers.%s(%s)\\n\", nameCopyNativeToDirectByteBuffer, nameCopyNativeToDirectByteBufferSignature);\n"+
+        "        (*env)->FatalError(env, nameCopyNativeToDirectByteBuffer);\n"+
+        "        return JNI_FALSE;\n"+
+        "    }\n"+
+        "    jobject jbyteBuffer  = (*env)->CallStaticObjectMethod(env, clazzBuffers, cstrBuffersNew, (jlong)(intptr_t)source_address, (jlong)capacity);\n"+
+        "    if( (*env)->ExceptionCheck(env) ) {\n"+
+        "        (*env)->ExceptionDescribe(env);\n"+
+        "        (*env)->ExceptionClear(env);\n"+
+        "        (*env)->FatalError(env, \"Exception occurred\");\n"+
+        "        return NULL;\n"+
+        "    }\n"+
+        "    return jbyteBuffer;\n"+
+        "}\n";
+}
diff --git a/src/java/com/jogamp/gluegen/CodeGenUtils.java b/src/java/com/jogamp/gluegen/CodeGenUtils.java
index 221256b..76116f1 100644
--- a/src/java/com/jogamp/gluegen/CodeGenUtils.java
+++ b/src/java/com/jogamp/gluegen/CodeGenUtils.java
@@ -56,8 +56,9 @@ public class CodeGenUtils {
     /**
      * @param generator the object that is emitting the autogenerated code. If
      * null, the generator will not be mentioned in the warning message.
+     * @param customLine maybe null
      */
-    public static void emitAutogeneratedWarning(final PrintWriter w, final Object generator) {
+    public static void emitAutogeneratedWarning(final PrintWriter w, final Object generator, final String customLine) {
         w.print("/* !---- DO NOT EDIT: This file autogenerated ");
         if (generator != null) {
             w.print("by ");
@@ -67,6 +68,11 @@ public class CodeGenUtils {
         w.print("on ");
         w.print((new Date()).toString());
         w.println(" ----! */");
+        if( null != customLine && customLine.length() > 0 ) {
+            w.print("/* !---- ");
+            w.print(customLine);
+            w.println(" ----! */");
+        }
         w.println();
     }
 
diff --git a/src/java/com/jogamp/gluegen/CodeUnit.java b/src/java/com/jogamp/gluegen/CodeUnit.java
new file mode 100644
index 0000000..e6c31d5
--- /dev/null
+++ b/src/java/com/jogamp/gluegen/CodeUnit.java
@@ -0,0 +1,99 @@
+/**
+ * Copyright 2023 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+package com.jogamp.gluegen;
+
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * General code unit (a generated C or Java source file),
+ * covering multiple {@link FunctionEmitter} allowing to unify output, decoration and dynamic helper code injection per unit.
+ **/
+public class CodeUnit {
+    public final String filename;
+    public final PrintWriter output;
+    private final Set<String> tailCode = new HashSet<String>();
+
+    /**
+     * @param filename the class's full filename to open w/ write access
+     * @param generator informal optional object that is creating this unit, used to be mentioned in a warning message if not null.
+     * @throws IOException
+     */
+    protected CodeUnit(final String filename, final Object generator) throws IOException {
+        this.filename = filename;
+        this.output = openFile(filename);
+    }
+
+    private static PrintWriter openFile(final String filename) throws IOException {
+        final File file = new File(filename);
+        final String parentDir = file.getParent();
+        if (parentDir != null) {
+            new File(parentDir).mkdirs();
+        }
+        return new PrintWriter(new BufferedWriter(new FileWriter(file)));
+    }
+
+    /**
+     * Add a tail code to this unit
+     * @param c the code to be added to the tail of this code unit
+     * @return true if the `tailCode` set did not already contain the specified code `c`
+     */
+    public boolean addTailCode(final String c) {
+        return tailCode.add(c);
+    }
+
+    public void emitln() {
+        output.println();
+    }
+    public void emitln(final String s) {
+        output.println(s);
+    }
+    public void emit(final String s) {
+        output.print(s);
+    }
+    public void emitf(final String s, final Object... args) {
+        output.printf(s, args);
+    }
+    public void emitTailCode() {
+        tailCode.forEach( (final String t) -> { output.write(t); output.println(); } );
+        tailCode.clear();
+    }
+    public void close() {
+        emitTailCode();
+        output.flush();
+        output.close();
+    }
+
+    @Override
+    public String toString() { return "CodeUnit[file "+filename+"]"; }
+}
diff --git a/src/java/com/jogamp/gluegen/JavaCodeUnit.java b/src/java/com/jogamp/gluegen/JavaCodeUnit.java
new file mode 100644
index 0000000..5010584
--- /dev/null
+++ b/src/java/com/jogamp/gluegen/JavaCodeUnit.java
@@ -0,0 +1,58 @@
+/**
+ * Copyright 2023 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+package com.jogamp.gluegen;
+
+import java.io.IOException;
+
+/**
+ * Java code unit (a generated Java source file),
+ * covering multiple {@link FunctionEmitter} allowing to unify output, decoration and dynamic helper code injection per unit.
+ **/
+public class JavaCodeUnit extends CodeUnit {
+    /** Package name of this Java unit */
+    public final String pkgName;
+    /** Simple class name of this Java unit */
+    public final String className;
+
+    /**
+     * @param filename the class's full filename to open w/ write access
+     * @param packageName the package name of the class
+     * @param simpleClassName the simple class name, i.e. w/o package name or c-file basename
+     * @param generator informal optional object that is creating this unit, used to be mentioned in a warning message if not null.
+     * @throws IOException
+     */
+    public JavaCodeUnit(final String filename, final String packageName, final String simpleClassName, final Object generator) throws IOException {
+        super(filename, generator);
+        this.pkgName = packageName;
+        this.className = simpleClassName;
+        CodeGenUtils.emitAutogeneratedWarning(output, generator, "Java-Unit: [pkg "+packageName+", cls "+simpleClassName+"], "+filename);
+    }
+
+    @Override
+    public String toString() { return "JavaCodeUnit[unit "+pkgName+"."+className+", file "+filename+"]"; }
+}