Change ByteBuffer implementation of reading and writing doubles to av…

…oid longs
Vertispan · Dec 11, 2019 · a48b7c9 · a48b7c9
1 parent b84986d
commit a48b7c9
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Showing 2 changed files with 45 additions and 6 deletions.
diff --git a/src/main/java/java/nio/ByteBuffer.java b/src/main/java/java/nio/ByteBuffer.java
@@ -19,6 +19,7 @@
 
 import elemental2.core.ArrayBuffer;
 import elemental2.core.ArrayBufferView;
+import elemental2.core.Float64Array;
 import elemental2.core.Int8Array;
 import org.gwtproject.nio.HasArrayBufferView;
 import org.gwtproject.nio.TypedArrayHelper;
@@ -376,7 +377,14 @@ public final char getChar (int index) {
      * @exception BufferUnderflowException if the position is greater than {@code limit - 8}.
      */
     public final double getDouble () {
-        return Numbers.longBitsToDouble(getLong());
+        int newPosition = position() + 8;
+//if (newPosition > limit) {
+//throw new BufferUnderflowException();
+//}
+
+        double value = getDouble(position());
+        position = newPosition;
+        return value;
     }
 
     /** Returns the double at the specified index.
@@ -388,7 +396,7 @@ public final double getDouble () {
      * @exception IndexOutOfBoundsException if {@code index} is invalid.
      */
     public final double getDouble (int index) {
-        return Numbers.longBitsToDouble(getLong(index));
+        return Numbers.readDoubleBytes(byteArray, index, order);
     }
 
     /** Returns the float at the current position and increases the position by 4.
@@ -723,7 +731,13 @@ public final ByteBuffer putChar (int index, char value) {
      * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
      */
     public ByteBuffer putDouble (double value) {
-        return putLong(Numbers.doubleToRawLongBits(value));
+        int newPosition = position() + 8;
+//if (newPosition > limit) {
+//throw new BufferOverflowException();
+//}
+        putDouble(position(), value);
+        position = newPosition;
+        return this;
     }
 
     /** Writes the given double to the specified index of this buffer.
@@ -738,7 +752,8 @@ public ByteBuffer putDouble (double value) {
      * @exception ReadOnlyBufferException if no changes may be made to the contents of this buffer.
      */
     public ByteBuffer putDouble (int index, double value) {
-        return putLong(index, Numbers.doubleToRawLongBits(value));
+        Numbers.writeDoubleBytes(byteArray, index, value, order);
+        return this;
     }
 
     /** Writes the given float to the current position and increases the position by 4.

diff --git a/src/main/java/java/nio/Numbers.java b/src/main/java/java/nio/Numbers.java
@@ -37,11 +37,11 @@ public static final float intBitsToFloat(int i) {
     }
 
     public static final double longBitsToDouble(long i) {
-        throw new RuntimeException("longBitsToDouble NYI");
+        return Double.longBitsToDouble(i);
     }
 
     public static final long doubleToRawLongBits(double i) {
-        throw new RuntimeException("doubleToRawLongBits NYI");
+        return Double.doubleToLongBits(i);
     }
 
     // TODO(jgw): Ugly hack to avoid longs.
@@ -68,4 +68,28 @@ public static final void setLoInt(int i) {
     public static final void setHiInt(int i) {
         wia.setAt(1, (double)i);
     }
+
+    /**
+     * Helper which writes a double value to the common buffer, then copies the specific
+     * bytes back to the specified array at the given offset.
+     */
+    public static final void writeDoubleBytes(Int8Array byteArray, int offset, double value, ByteOrder order) {
+        //TODO compare order with nativeOrder, if they don't match then copy data backward
+        wda.setAt(0, value);
+        for (int i = 0; i < 8; i++) {
+            byteArray.setAt(i + offset, wba.getAt(i));
+        }
+    }
+
+    /**
+     * Helper which copies the specified bytes to the common buffer, then reads out
+     * the double value that those bytes represent.
+     */
+    public static final double readDoubleBytes(Int8Array byteArray, int offset, ByteOrder order) {
+        //TODO compare order with nativeOrder, if they don't match then copy data backward
+        for (int i = 0; i < 8; i++) {
+            wba.setAt(i, byteArray.getAt(offset + i));
+        }
+        return wda.getAt(0);
+    }
 }