tech.deplant.java4ever.binding.ffi.NativeStrings Maven / Gradle / Ivy

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package tech.deplant.java4ever.binding.ffi;

import java.lang.foreign.Arena;
import java.lang.foreign.MemorySegment;
import java.nio.charset.StandardCharsets;

import static java.lang.foreign.ValueLayout.JAVA_BYTE;
import static tech.deplant.java4ever.binding.ffi.tc_string_data_t.*;

class NativeStrings {
	public static MemorySegment toRust(final String text, final Arena nativeSession) {
		MemorySegment nativeString = nativeSession.allocateFrom(text);
		int strlen = ((int) nativeString.byteSize()) - 1; // minus 1 because last symbol is u0000 in UTF-8
		MemorySegment stringDataSegment = nativeSession.allocate(tc_string_data_t.layout());
		tc_string_data_t.content(stringDataSegment, nativeString);
		tc_string_data_t.len(stringDataSegment, strlen);
		return stringDataSegment;
	}

	public static String toJava(MemorySegment seg) {
		if (tc_string_data_t.len(seg) > 0) {
			final MemorySegment content = tc_string_data_t.content(seg).asSlice(0, len(seg));
			return new String(content.toArray(JAVA_BYTE), StandardCharsets.UTF_8);
		} else {
			return "";
		}
	}
}