Add Decoder#encode roundtrip tests and fix the bugs discovered.
Change-Id: I21447306d9fc7768e07fafe5bed1d92a3eb42e53
diff --git a/jgvariant-core/src/main/java/eu/mulk/jgvariant/core/Decoder.java b/jgvariant-core/src/main/java/eu/mulk/jgvariant/core/Decoder.java
index a28d792..f605b09 100644
--- a/jgvariant-core/src/main/java/eu/mulk/jgvariant/core/Decoder.java
+++ b/jgvariant-core/src/main/java/eu/mulk/jgvariant/core/Decoder.java
@@ -5,6 +5,7 @@
package eu.mulk.jgvariant.core;
import static java.lang.Math.max;
+import static java.nio.ByteOrder.BIG_ENDIAN;
import static java.nio.ByteOrder.LITTLE_ENDIAN;
import static java.nio.charset.StandardCharsets.UTF_8;
import static java.util.Objects.requireNonNullElse;
@@ -440,12 +441,16 @@
ArrayList<Integer> framingOffsets = new ArrayList<>(value.size());
int startOffset = byteWriter.position();
for (var element : value) {
+ // Align the element.
+ var lastRelativeEnd = byteWriter.position() - startOffset;
+ byteWriter.write(new byte[align(lastRelativeEnd, alignment()) - lastRelativeEnd]);
+
+ // Encode the element.
elementDecoder.encode(element, byteWriter);
+
+ // Record the framing offset of the element.
var relativeEnd = byteWriter.position() - startOffset;
framingOffsets.add(relativeEnd);
-
- // Align the next element.
- byteWriter.write(new byte[align(relativeEnd, alignment()) - relativeEnd]);
}
// Write the framing offsets.
@@ -710,21 +715,30 @@
@Override
@SuppressWarnings("unchecked")
void encode(Object[] value, ByteWriter byteWriter) {
+ // The unit type is encoded as a single zero byte.
+ if (value.length == 0) {
+ byteWriter.write((byte) 0);
+ return;
+ }
+
int startOffset = byteWriter.position();
ArrayList<Integer> framingOffsets = new ArrayList<>(value.length);
for (int i = 0; i < value.length; ++i) {
var componentDecoder = (Decoder<Object>) componentDecoders[i];
+
+ // Align the element.
+ var lastRelativeEnd = byteWriter.position() - startOffset;
+ byteWriter.write(new byte[align(lastRelativeEnd, componentDecoder.alignment()) - lastRelativeEnd]);
+
+ // Encode the element.
componentDecoder.encode(value[i], byteWriter);
- var relativeEnd = byteWriter.position() - startOffset;
-
+ // Record the framing offset of the element if it is of variable size.
var fixedComponentSize = componentDecoders[i].fixedSize();
if (fixedComponentSize == null && i < value.length - 1) {
+ var relativeEnd = byteWriter.position() - startOffset;
framingOffsets.add(relativeEnd);
}
-
- // Align the next element.
- byteWriter.write(new byte[align(relativeEnd, alignment()) - relativeEnd]);
}
// Write the framing offsets in reverse order.
@@ -732,6 +746,12 @@
for (int i = framingOffsets.size() - 1; i >= 0; --i) {
byteWriter.writeIntN(framingOffsets.get(i), framingOffsetSize);
}
+
+ // Pad the structure to its alignment if it is of fixed size.
+ if (fixedSize() != null) {
+ var lastRelativeEnd = byteWriter.position() - startOffset;
+ byteWriter.write(new byte[align(lastRelativeEnd, alignment()) - lastRelativeEnd]);
+ }
}
}
@@ -975,7 +995,7 @@
@Override
void encode(String value, ByteWriter byteWriter) {
- byteWriter.write(charset.encode(value));
+ byteWriter.write(charset.encode(value).rewind());
byteWriter.write((byte) 0);
}
}
@@ -1044,7 +1064,7 @@
var innerByteWriter = new ByteWriter();
Decoder.this.encode(value, innerByteWriter);
var transformedBuffer = encodingFunction.apply(innerByteWriter.toByteBuffer());
- byteWriter.write(transformedBuffer);
+ byteWriter.write(transformedBuffer.rewind());
}
}
@@ -1136,7 +1156,7 @@
}
private static class ByteWriter {
- private ByteOrder byteOrder = ByteOrder.nativeOrder();
+ private ByteOrder byteOrder = BIG_ENDIAN;
private final ByteArrayOutputStream outputStream;
ByteWriter() {
@@ -1167,19 +1187,19 @@
}
void write(int value) {
- write(ByteBuffer.allocate(4).order(byteOrder).putInt(value));
+ write(ByteBuffer.allocate(4).order(byteOrder).putInt(value).rewind());
}
void write(long value) {
- write(ByteBuffer.allocate(8).order(byteOrder).putLong(value));
+ write(ByteBuffer.allocate(8).order(byteOrder).putLong(value).rewind());
}
void write(short value) {
- write(ByteBuffer.allocate(2).order(byteOrder).putShort(value));
+ write(ByteBuffer.allocate(2).order(byteOrder).putShort(value).rewind());
}
void write(double value) {
- write(ByteBuffer.allocate(8).order(byteOrder).putDouble(value));
+ write(ByteBuffer.allocate(8).order(byteOrder).putDouble(value).rewind());
}
private void writeIntN(int value, int byteCount) {
@@ -1195,7 +1215,7 @@
default ->
throw new IllegalArgumentException("invalid byte count: %d".formatted(byteCount));
}
- write(byteBuffer);
+ write(byteBuffer.rewind());
}
ByteWriter duplicate() {