88 lines
3.6 KiB
Java
88 lines
3.6 KiB
Java
// Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
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// Licensed under the MIT License:
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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package org.capnproto;
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import java.nio.ByteBuffer;
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final class WirePointer {
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public static final byte STRUCT = 0;
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public static final byte LIST = 1;
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public static final byte FAR = 2;
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public static final byte OTHER = 3;
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public static boolean isNull(long wirePointer) {
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return wirePointer == 0;
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}
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public static int offsetAndKind(long wirePointer) {
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return (int)(wirePointer & 0xffffffff);
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}
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public static byte kind(long wirePointer) {
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return (byte)(offsetAndKind(wirePointer) & 3);
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}
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public static int target(int offset, long wirePointer) {
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return offset + 1 + (offsetAndKind(wirePointer) >>> 2);
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}
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public static void setKindAndTarget(ByteBuffer buffer, int offset, byte kind, int targetOffset) {
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buffer.putInt(offset * 8,
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(((targetOffset - offset) - 1) << 2) | kind);
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}
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public static void setKindWithZeroOffset(ByteBuffer buffer, int offset, byte kind) {
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buffer.putInt(offset * Constants.BYTES_PER_WORD, kind);
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}
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public static void setKindAndTargetForEmptyStruct(ByteBuffer buffer, int offset) {
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//# This pointer points at an empty struct. Assuming the
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//# WirePointer itself is in-bounds, we can set the target to
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//# point either at the WirePointer itself or immediately after
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//# it. The latter would cause the WirePointer to be "null"
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//# (since for an empty struct the upper 32 bits are going to
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//# be zero). So we set an offset of -1, as if the struct were
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//# allocated immediately before this pointer, to distinguish
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//# it from null.
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buffer.putInt(offset * 8, 0xfffffffc);
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}
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public static void setOffsetAndKind(ByteBuffer buffer, int offset, int offsetAndKind) {
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buffer.putInt(offset * 8, offsetAndKind);
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}
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public static int inlineCompositeListElementCount(long wirePointer) {
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return offsetAndKind(wirePointer) >>> 2;
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}
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public static void setKindAndInlineCompositeListElementCount(ByteBuffer buffer,
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int offset,
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byte kind,
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int elementCount) {
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buffer.putInt(offset * 8, (elementCount << 2) | kind);
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}
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public static int upper32Bits(long wirePointer) {
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return (int)(wirePointer >>> 32);
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}
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}
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