LayoutFFITypeTable.cpp

/*******************************************************************************
 * Copyright IBM Corp. and others 2024
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 * or the Apache License, Version 2.0 which accompanies this distribution and
 * is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following
 * Secondary Licenses when the conditions for such availability set
 * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 * General Public License, version 2 with the GNU Classpath
 * Exception [1] and GNU General Public License, version 2 with the
 * OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] https://openjdk.org/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
 *******************************************************************************/

#include "j9.h"
#include "j9protos.h"

extern "C" {

#if JAVA_SPEC_VERSION >= 16

/**
 * @brief Return the hash value for an entry in the layout string table.
 *
 * @param entry the layout string entry
 * @param userData is NULL for this hashtable
 * @returns the hash value
 */
static UDATA
layoutStrFFITypeHashFn(void *entry, void *userData)
{
	J9LayoutStrFFITypeEntry *layoutStrEntry = (J9LayoutStrFFITypeEntry *)entry;

	return computeHashForUTF8(layoutStrEntry->layoutStr, layoutStrEntry->layoutStrLength);
}

/**
 * @brief Compare two layout string entries for equality.
 *
 * @param leftEntry the first entry to compare
 * @param rightEntry the second entry to compare
 * @param userData is NULL for this hashtable
 * @returns 1 if the entries match, otherwise return 0
 */
static UDATA
layoutStrFFITypeHashEqualFn(void *leftEntry, void *rightEntry, void *userData)
{
	J9LayoutStrFFITypeEntry *leftLayoutStrEntry = (J9LayoutStrFFITypeEntry *)leftEntry;
	J9LayoutStrFFITypeEntry *rightLayoutStrEntry = (J9LayoutStrFFITypeEntry *)rightEntry;

	return J9UTF8_DATA_EQUALS(
			leftLayoutStrEntry->layoutStr, leftLayoutStrEntry->layoutStrLength,
			rightLayoutStrEntry->layoutStr, rightLayoutStrEntry->layoutStrLength);
}

/**
 * @brief Delete an entry from the layout string hashtable.
 *
 * @param entry the entry to be deleted
 * @param userData is NULL for this hashtable
 * @return TRUE after the entry is deallocated
 */
static UDATA
freeLayoutStrFFIDoFn(void *entry, void *userData)
{
	PORT_ACCESS_FROM_PORT((J9PortLibrary *)userData);
	J9LayoutStrFFITypeEntry *layoutStrEntry = (J9LayoutStrFFITypeEntry *)entry;
	j9mem_free_memory(layoutStrEntry->layoutStr);
	j9mem_free_memory(layoutStrEntry);
	return TRUE;
}

/**
 * @brief Create the layout string hashtable.
 *
 * @param vm a pointer to J9JavaVM
 * @return the hasthable
 */
J9HashTable *
createLayoutStrFFITypeTable(J9JavaVM *vm)
{
	return hashTableNew(
			OMRPORT_FROM_J9PORT(vm->portLibrary),
			"Layout string table",
			0,
			sizeof(J9LayoutStrFFITypeEntry),
			0,
			0,
			J9MEM_CATEGORY_VM_FFI,
			layoutStrFFITypeHashFn,
			layoutStrFFITypeHashEqualFn,
			NULL,
			NULL);
}

/**
 * @brief Release the layout string hashtable.
 *
 * @param hashtable a pointer to J9HashTable
 */
void
releaseLayoutStrFFITypeTable(J9HashTable *hashtable)
{
	hashTableForEachDo(hashtable, freeLayoutStrFFIDoFn, NULL);
	hashTableFree(hashtable);
}

/**
 * @brief Search the layout string hashtable for the entry with the specified key.
 *
 * @param hashtable a pointer to J9HashTable
 * @param entry a pointer to J9LayoutStrFFITypeEntry
 * @return the requested entry if found; NULL otherwise
 */
J9LayoutStrFFITypeEntry *
findLayoutStrFFIType(J9HashTable *hashtable, J9LayoutStrFFITypeEntry *entry)
{
	return (J9LayoutStrFFITypeEntry *)hashTableFind(hashtable, entry);
}

/**
 * @brief Add the entry with the populated key & value to the layout string hashtable.
 *
 * @param hashtable a pointer to J9HashTable
 * @param entry a pointer to J9LayoutStrFFITypeEntry
 * @return the same entry if done successfully; NULL otherwise
 */
J9LayoutStrFFITypeEntry *
addLayoutStrFFIType(J9HashTable *hashtable, J9LayoutStrFFITypeEntry *entry)
{
	return (J9LayoutStrFFITypeEntry *)hashTableAdd(hashtable, entry);
}

#endif /* JAVA_SPEC_VERSION >= 16 */

} /* extern "C" */