forked from BigfootDev/flatbuffers
[FlexBuffers][Java] Implementation of FlexBuffers API (#5476)
* [FlexBuffers][Java] Implementation of FlexBuffers API This is the initial attemp to implement FlexBuffer on Java. There is some limitations as compared to the C++ implementation: 1 - No mutations implemented yet 2 - Does not parse from json Also, this initial implementation is not focused and performance, but get the basics write. So there is many opportunities for optimization, for instance, remove all enums, return CharSequence instead of Strings and object pooling. * [FlexBuffers][Java] Optimizations and simplification of the Builder API. This change removes BitWidth enum in favor of static ints. Also make all "reads" APIs closer to C++ implementation (try to cast or convert as much as possible, assuming user knows what he is doing). Finally, we remove the helper classes for building vectors and maps. There is no official benchmarks, but the unit tests are running in less than 50% for previous runs, which mean those optimizations are worth it. * [FlexBuffers][Java] Fix Reference::asString behavior There was a incorrect assumption that strings would be null-terminated, which could lead to truncated strings. S now it relies size instead of null-termination. Other minor improvements
This commit is contained in:
Paulo Pinheiro
committed by
Wouter van Oortmerssen
Wouter van Oortmerssen
parent
bd31dd2425
commit
8e6cabb31b
869
java/com/google/flatbuffers/FlexBuffers.java
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869
java/com/google/flatbuffers/FlexBuffers.java
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@@ -0,0 +1,869 @@
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/*
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* Copyright 2014 Google Inc. All rights reserved.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.google.flatbuffers;
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import static com.google.flatbuffers.FlexBuffers.Unsigned.byteToUnsignedInt;
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import static com.google.flatbuffers.FlexBuffers.Unsigned.intToUnsignedLong;
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import static com.google.flatbuffers.FlexBuffers.Unsigned.shortToUnsignedInt;
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import java.math.BigInteger;
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import java.nio.ByteBuffer;
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import java.nio.charset.StandardCharsets;
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/**
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* This class can be used to parse FlexBuffer messages.
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* <p>
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* For generating FlexBuffer messages, use {@link FlexBuffersBuilder}.
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* <p>
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* Example of usage:
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* ByteBuffer bb = ... // load message from file or network
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* FlexBuffers.Reference r = FlexBuffers.getRoot(bb); // Reads the root element
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* FlexBuffers.Map map = r.asMap(); // We assumed root object is a map
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* System.out.println(map.get("name").asString()); // prints element with key "name"
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*/
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public class FlexBuffers {
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// These are used as the upper 6 bits of a type field to indicate the actual
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// type.
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public static final int FBT_NULL = 0;
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public static final int FBT_INT = 1;
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public static final int FBT_UINT = 2;
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public static final int FBT_FLOAT = 3; // Types above stored inline, types below store an offset.
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public static final int FBT_KEY = 4;
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public static final int FBT_STRING = 5;
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public static final int FBT_INDIRECT_INT = 6;
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public static final int FBT_INDIRECT_UINT = 7;
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public static final int FBT_INDIRECT_FLOAT = 8;
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public static final int FBT_MAP = 9;
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public static final int FBT_VECTOR = 10; // Untyped.
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public static final int FBT_VECTOR_INT = 11; // Typed any size = stores no type table).
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public static final int FBT_VECTOR_UINT = 12;
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public static final int FBT_VECTOR_FLOAT = 13;
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public static final int FBT_VECTOR_KEY = 14;
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public static final int FBT_VECTOR_STRING = 15;
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public static final int FBT_VECTOR_INT2 = 16; // Typed tuple = no type table; no size field).
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public static final int FBT_VECTOR_UINT2 = 17;
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public static final int FBT_VECTOR_FLOAT2 = 18;
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public static final int FBT_VECTOR_INT3 = 19; // Typed triple = no type table; no size field).
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public static final int FBT_VECTOR_UINT3 = 20;
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public static final int FBT_VECTOR_FLOAT3 = 21;
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public static final int FBT_VECTOR_INT4 = 22; // Typed quad = no type table; no size field).
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public static final int FBT_VECTOR_UINT4 = 23;
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public static final int FBT_VECTOR_FLOAT4 = 24;
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public static final int FBT_BLOB = 25;
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public static final int FBT_BOOL = 26;
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public static final int FBT_VECTOR_BOOL = 36; // To Allow the same type of conversion of type to vector type
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private static final ByteBuffer EMPTY_BB = ByteBuffer.allocate(0).asReadOnlyBuffer();
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/**
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* Checks where a type is a typed vector
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*
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* @param type type to be checked
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* @return true if typed vector
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*/
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static boolean isTypedVector(int type) {
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return (type >= FBT_VECTOR_INT && type <= FBT_VECTOR_STRING) || type == FBT_VECTOR_BOOL;
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}
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/**
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* Check whether you can access type directly (no indirection) or not.
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*
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* @param type type to be checked
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* @return true if inline type
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*/
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static boolean isTypeInline(int type) {
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return type <= FBT_FLOAT || type == FBT_BOOL;
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}
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static int toTypedVectorElementType(int original_type) {
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return original_type - FBT_VECTOR_INT + FBT_INT;
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}
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/**
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* Return a vector type our of a original element type
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*
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* @param type element type
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* @param fixedLength size of elment
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* @return typed vector type
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*/
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static int toTypedVector(int type, int fixedLength) {
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assert (isTypedVectorElementType(type));
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switch (fixedLength) {
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case 0: return type - FBT_INT + FBT_VECTOR_INT;
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case 2: return type - FBT_INT + FBT_VECTOR_INT2;
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case 3: return type - FBT_INT + FBT_VECTOR_INT3;
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case 4: return type - FBT_INT + FBT_VECTOR_INT4;
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default:
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assert (false);
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return FBT_NULL;
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}
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}
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static boolean isTypedVectorElementType(int type) {
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return (type >= FBT_INT && type <= FBT_STRING) || type == FBT_BOOL;
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}
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// return position of the element that the offset is pointing to
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private static int indirect(ByteBuffer bb, int offset, int byteWidth) {
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//TODO: we assume all offset fits on a int, since ByteBuffer operates with that assumption
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return (int) (offset - readUInt(bb, offset, byteWidth));
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}
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// read unsigned int with size byteWidth and return as a 64-bit integer
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private static long readUInt(ByteBuffer buff, int end, int byteWidth) {
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switch (byteWidth) {
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case 1: return byteToUnsignedInt(buff.get(end));
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case 2: return shortToUnsignedInt(buff.getShort(end));
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case 4: return intToUnsignedLong(buff.getInt(end));
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case 8: return buff.getLong(end); // We are passing signed long here. Losing information (user should know)
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default: return -1; // we should never reach here
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}
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}
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// read signed int of size byteWidth and return as 32-bit int
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private static int readInt(ByteBuffer buff, int end, int byteWidth) {
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return (int) readLong(buff, end, byteWidth);
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}
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// read signed int of size byteWidth and return as 64-bit int
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private static long readLong(ByteBuffer buff, int end, int byteWidth) {
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switch (byteWidth) {
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case 1: return buff.get(end);
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case 2: return buff.getShort(end);
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case 4: return buff.getInt(end);
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case 8: return buff.getLong(end);
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default: return -1; // we should never reach here
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}
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}
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private static double readDouble(ByteBuffer buff, int end, int byteWidth) {
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switch (byteWidth) {
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case 4: return buff.getFloat(end);
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case 8: return buff.getDouble(end);
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default: return -1; // we should never reach here
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}
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}
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/**
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* Reads a FlexBuffer message in ByteBuffer and returns {@link Reference} to
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* the root element.
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* @param buffer ByteBuffer containing FlexBuffer message
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* @return {@link Reference} to the root object
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*/
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public static Reference getRoot(ByteBuffer buffer) {
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// See Finish() below for the serialization counterpart of this.
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// The root ends at the end of the buffer, so we parse backwards from there.
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int end = buffer.limit();
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int byteWidth = buffer.get(--end);
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int packetType = byteToUnsignedInt(buffer.get(--end));
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end -= byteWidth; // The root data item.
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return new Reference(buffer, end, byteWidth, packetType);
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}
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public static class Reference {
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private static final Reference NULL_REFERENCE = new Reference(EMPTY_BB, 0, 1, 0);
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private ByteBuffer bb;
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private int end;
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private int parentWidth;
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private int byteWidth;
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private int type;
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Reference(ByteBuffer bb, int end, int parentWidth, int packedType) {
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this(bb, end, parentWidth, (1 << (packedType & 3)), packedType >> 2);
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}
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Reference(ByteBuffer bb, int end, int parentWidth, int byteWidth, int type) {
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this.bb = bb;
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this.end = end;
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this.parentWidth = parentWidth;
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this.byteWidth = byteWidth;
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this.type = type;
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}
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public int getType() {
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return type;
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}
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public boolean isNull() {
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return type == FBT_NULL;
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}
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public boolean isBoolean() {
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return type == FBT_BOOL;
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}
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public boolean isNumeric() {
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return isIntOrUInt() || isFloat();
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}
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public boolean isIntOrUInt() {
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return isInt() || isUInt();
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}
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public boolean isFloat() {
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return type == FBT_FLOAT || type == FBT_INDIRECT_FLOAT;
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}
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public boolean isInt() {
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return type == FBT_INT || type == FBT_INDIRECT_INT;
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}
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public boolean isUInt() {
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return type == FBT_UINT || type == FBT_INDIRECT_UINT;
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}
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public boolean isString() {
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return type == FBT_STRING;
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}
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public boolean isKey() {
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return type == FBT_KEY;
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}
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public boolean isVector() {
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return type == FBT_VECTOR || type == FBT_MAP;
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}
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public boolean isTypedVector() {
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return (type >= FBT_VECTOR_INT && type <= FBT_VECTOR_STRING) ||
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type == FBT_VECTOR_BOOL;
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}
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public boolean isMap() {
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return type == FBT_MAP;
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}
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public boolean isBlob() {
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return type == FBT_BLOB;
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}
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public int asInt() {
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if (type == FBT_INT) {
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// A fast path for the common case.
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return readInt(bb, end, parentWidth);
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} else
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switch (type) {
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case FBT_INDIRECT_INT: return readInt(bb, indirect(bb, end, parentWidth), byteWidth);
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case FBT_UINT: return (int) readUInt(bb, end, parentWidth);
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case FBT_INDIRECT_UINT: return (int) readUInt(bb, indirect(bb, end, parentWidth), parentWidth);
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case FBT_FLOAT: return (int) readDouble(bb, end, parentWidth);
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case FBT_INDIRECT_FLOAT: return (int) readDouble(bb, indirect(bb, end, parentWidth), byteWidth);
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case FBT_NULL: return 0;
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case FBT_STRING: return Integer.parseInt(asString());
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case FBT_VECTOR: return asVector().size();
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case FBT_BOOL: return readInt(bb, end, parentWidth);
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default:
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// Convert other things to int.
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return 0;
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}
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}
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public long asUInt() {
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if (type == FBT_UINT) {
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// A fast path for the common case.
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return readUInt(bb, end, parentWidth);
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} else
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switch (type) {
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case FBT_INDIRECT_UINT: return readUInt(bb, indirect(bb, end, parentWidth), byteWidth);
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case FBT_INT: return readLong(bb, end, parentWidth);
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case FBT_INDIRECT_INT: return readLong(bb, indirect(bb, end, parentWidth), byteWidth);
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case FBT_FLOAT: return (long) readDouble(bb, end, parentWidth);
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case FBT_INDIRECT_FLOAT: return (long) readDouble(bb, indirect(bb, end, parentWidth), parentWidth);
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case FBT_NULL: return 0;
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case FBT_STRING: return Long.parseLong(asString());
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case FBT_VECTOR: return asVector().size();
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case FBT_BOOL: readInt(bb, end, parentWidth);
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default:
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// Convert other things to uint.
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return 0;
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}
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}
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public long asLong() {
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if (type == FBT_INT) {
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// A fast path for the common case.
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return readLong(bb, end, parentWidth);
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} else
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switch (type) {
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case FBT_INDIRECT_INT: return readLong(bb, indirect(bb, end, parentWidth), byteWidth);
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case FBT_UINT: return readUInt(bb, end, parentWidth);
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case FBT_INDIRECT_UINT: return readUInt(bb, indirect(bb, end, parentWidth), parentWidth);
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case FBT_FLOAT: return (long) readDouble(bb, end, parentWidth);
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case FBT_INDIRECT_FLOAT: return (long) readDouble(bb, indirect(bb, end, parentWidth), byteWidth);
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case FBT_NULL: return 0;
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case FBT_STRING: {
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try {
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return Long.parseLong(asString());
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} catch (NumberFormatException nfe) {
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return 0; //same as C++ implementation
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}
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}
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case FBT_VECTOR: return asVector().size();
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case FBT_BOOL: return readInt(bb, end, parentWidth);
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default:
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// Convert other things to int.
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return 0;
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}
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}
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public double asFloat() {
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if (type == FBT_FLOAT) {
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// A fast path for the common case.
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return readDouble(bb, end, parentWidth);
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} else
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switch (type) {
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case FBT_INDIRECT_FLOAT: return readDouble(bb, indirect(bb, end, parentWidth), byteWidth);
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case FBT_INT: return readInt(bb, end, parentWidth);
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case FBT_UINT:
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case FBT_BOOL:
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return readUInt(bb, end, parentWidth);
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case FBT_INDIRECT_INT: return readInt(bb, indirect(bb, end, parentWidth), byteWidth);
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case FBT_INDIRECT_UINT: return readUInt(bb, indirect(bb, end, parentWidth), byteWidth);
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case FBT_NULL: return 0.0;
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case FBT_STRING: return Double.parseDouble(asString());
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case FBT_VECTOR: return asVector().size();
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default:
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// Convert strings and other things to float.
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return 0;
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}
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}
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public Key asKey() {
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if (isKey()) {
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return new Key(bb, indirect(bb, end, parentWidth), byteWidth);
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} else {
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return Key.empty();
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}
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}
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public String asString() {
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if (isString()) {
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int start = indirect(bb, end, byteWidth);
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int size = readInt(bb, start - byteWidth, byteWidth);
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return Utf8.getDefault().decodeUtf8(bb, start, size);
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}
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else if (isKey()){
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int start = indirect(bb, end, byteWidth);
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for (int i = start; ; i++) {
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if (bb.get(i) == 0) {
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return Utf8.getDefault().decodeUtf8(bb, start, i - start);
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}
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}
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} else {
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return "";
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}
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}
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public Map asMap() {
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if (isMap()) {
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return new Map(bb, indirect(bb, end, parentWidth), byteWidth);
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} else {
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return Map.empty();
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}
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}
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public Vector asVector() {
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if (isVector()) {
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return new Vector(bb, indirect(bb, end, parentWidth), byteWidth);
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} else if (FlexBuffers.isTypedVector(type)) {
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return new TypedVector(bb, indirect(bb, end, parentWidth), byteWidth, FlexBuffers.toTypedVectorElementType(type));
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} else {
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return Vector.empty();
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}
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}
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public Blob asBlob() {
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if (isBlob() || isString()) {
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return new Blob(bb, indirect(bb, end, parentWidth), byteWidth);
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} else {
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return Blob.empty();
|
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}
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}
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public boolean asBoolean() {
|
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if (isBoolean()) {
|
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return bb.get(end) != 0;
|
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}
|
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return asUInt() != 0;
|
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}
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@Override
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public String toString() {
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return toString(new StringBuilder(128)).toString();
|
||||
}
|
||||
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StringBuilder toString(StringBuilder sb) {
|
||||
//TODO: Original C++ implementation escape strings.
|
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// probably we should do it as well.
|
||||
switch (type) {
|
||||
case FBT_NULL:
|
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return sb.append("null");
|
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case FBT_INT:
|
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case FBT_INDIRECT_INT:
|
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return sb.append(asLong());
|
||||
case FBT_UINT:
|
||||
case FBT_INDIRECT_UINT:
|
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return sb.append(asUInt());
|
||||
case FBT_INDIRECT_FLOAT:
|
||||
case FBT_FLOAT:
|
||||
return sb.append(asFloat());
|
||||
case FBT_KEY:
|
||||
return asKey().toString(sb.append('"')).append('"');
|
||||
case FBT_STRING:
|
||||
return sb.append('"').append(asString()).append('"');
|
||||
case FBT_MAP:
|
||||
return asMap().toString(sb);
|
||||
case FBT_VECTOR:
|
||||
return asVector().toString(sb);
|
||||
case FBT_BLOB:
|
||||
return asBlob().toString(sb);
|
||||
case FBT_BOOL:
|
||||
return sb.append(asBoolean());
|
||||
case FBT_VECTOR_INT:
|
||||
case FBT_VECTOR_UINT:
|
||||
case FBT_VECTOR_FLOAT:
|
||||
case FBT_VECTOR_KEY:
|
||||
case FBT_VECTOR_STRING:
|
||||
case FBT_VECTOR_BOOL:
|
||||
return sb.append(asVector());
|
||||
case FBT_VECTOR_INT2:
|
||||
case FBT_VECTOR_UINT2:
|
||||
case FBT_VECTOR_FLOAT2:
|
||||
case FBT_VECTOR_INT3:
|
||||
case FBT_VECTOR_UINT3:
|
||||
case FBT_VECTOR_FLOAT3:
|
||||
case FBT_VECTOR_INT4:
|
||||
case FBT_VECTOR_UINT4:
|
||||
case FBT_VECTOR_FLOAT4:
|
||||
|
||||
throw new FlexBufferException("not_implemented:" + type);
|
||||
default:
|
||||
return sb;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Base class of all types below.
|
||||
* Points into the data buffer and allows access to one type.
|
||||
*/
|
||||
private static abstract class Object {
|
||||
ByteBuffer bb;
|
||||
int end;
|
||||
int byteWidth;
|
||||
|
||||
Object(ByteBuffer buff, int end, int byteWidth) {
|
||||
this.bb = buff;
|
||||
this.end = end;
|
||||
this.byteWidth = byteWidth;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
return toString(new StringBuilder(128)).toString();
|
||||
}
|
||||
|
||||
public abstract StringBuilder toString(StringBuilder sb);
|
||||
}
|
||||
|
||||
// Stores size in `byte_width_` bytes before end position.
|
||||
private static abstract class Sized extends Object {
|
||||
Sized(ByteBuffer buff, int end, int byteWidth) {
|
||||
super(buff, end, byteWidth);
|
||||
}
|
||||
|
||||
public int size() {
|
||||
return readInt(bb, end - byteWidth, byteWidth);
|
||||
}
|
||||
}
|
||||
|
||||
public static class Blob extends Sized {
|
||||
static final Blob EMPTY = new Blob(EMPTY_BB, 0, 1);
|
||||
|
||||
Blob(ByteBuffer buff, int end, int byteWidth) {
|
||||
super(buff, end, byteWidth);
|
||||
}
|
||||
|
||||
public static Blob empty() {
|
||||
return EMPTY;
|
||||
}
|
||||
|
||||
/**
|
||||
* @return blob as a {@link ByteBuffer}
|
||||
*/
|
||||
public ByteBuffer data() {
|
||||
ByteBuffer dup = bb.duplicate();
|
||||
dup.position(end);
|
||||
dup.limit(end + size());
|
||||
return dup.asReadOnlyBuffer().slice();
|
||||
}
|
||||
|
||||
/**
|
||||
* @return blob as a byte array
|
||||
*/
|
||||
public byte[] getBytes() {
|
||||
int size = size();
|
||||
byte[] result = new byte[size];
|
||||
for (int i = 0; i < size; i++) {
|
||||
result[i] = bb.get(end + i);
|
||||
}
|
||||
return result;
|
||||
}
|
||||
|
||||
public byte get(int pos) {
|
||||
assert pos >=0 && pos <= size();
|
||||
return bb.get(end + pos);
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
return Utf8.getDefault().decodeUtf8(bb, end, size());
|
||||
}
|
||||
|
||||
@Override
|
||||
public StringBuilder toString(StringBuilder sb) {
|
||||
sb.append('"');
|
||||
sb.append(Utf8.getDefault().decodeUtf8(bb, end, size()));
|
||||
return sb.append('"');
|
||||
}
|
||||
}
|
||||
|
||||
public static class Key extends Object {
|
||||
|
||||
private static final Key EMPTY = new Key(EMPTY_BB, 0, 0);
|
||||
|
||||
Key(ByteBuffer buff, int end, int byteWidth) {
|
||||
super(buff, end, byteWidth);
|
||||
}
|
||||
|
||||
public static Key empty() {
|
||||
return Key.EMPTY;
|
||||
}
|
||||
|
||||
@Override
|
||||
public StringBuilder toString(StringBuilder sb) {
|
||||
int size;
|
||||
for (int i = end; ; i++) {
|
||||
if (bb.get(i) == 0) {
|
||||
size = i - end;
|
||||
break;
|
||||
}
|
||||
}
|
||||
sb.append(Utf8.getDefault().decodeUtf8(bb, end, size));
|
||||
return sb;
|
||||
}
|
||||
|
||||
int compareTo(byte[] other) {
|
||||
int ia = end;
|
||||
int io = 0;
|
||||
byte c1, c2;
|
||||
do {
|
||||
c1 = bb.get(ia);
|
||||
c2 = other[io];
|
||||
if (c1 == '\0')
|
||||
return c1 - c2;
|
||||
ia++;
|
||||
io++;
|
||||
if (io == other.length) {
|
||||
// in our buffer we have an additional \0 byte
|
||||
// but this does not exist in regular Java strings, so we return now
|
||||
return c1 - c2;
|
||||
}
|
||||
}
|
||||
while (c1 == c2);
|
||||
return c1 - c2;
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean equals(java.lang.Object obj) {
|
||||
if (!(obj instanceof Key))
|
||||
return false;
|
||||
|
||||
return ((Key) obj).end == end && ((Key) obj).byteWidth == byteWidth;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Map object representing a set of key-value pairs.
|
||||
*/
|
||||
public static class Map extends Vector {
|
||||
private static final Map EMPTY_MAP = new Map(EMPTY_BB, 0, 0);
|
||||
|
||||
Map(ByteBuffer bb, int end, int byteWidth) {
|
||||
super(bb, end, byteWidth);
|
||||
}
|
||||
|
||||
public static Map empty() {
|
||||
return EMPTY_MAP;
|
||||
}
|
||||
|
||||
/**
|
||||
* @param key access key to element on map
|
||||
* @return reference to value in map
|
||||
*/
|
||||
public Reference get(String key) {
|
||||
return get(key.getBytes(StandardCharsets.UTF_8));
|
||||
}
|
||||
|
||||
/**
|
||||
* @param key access key to element on map. Keys are assumed to be encoded in UTF-8
|
||||
* @return reference to value in map
|
||||
*/
|
||||
public Reference get(byte[] key) {
|
||||
KeyVector keys = keys();
|
||||
int size = keys.size();
|
||||
int index = binarySearch(keys, key);
|
||||
if (index >= 0 && index < size) {
|
||||
return get(index);
|
||||
}
|
||||
return Reference.NULL_REFERENCE;
|
||||
}
|
||||
|
||||
/**
|
||||
* Get a vector or keys in the map
|
||||
*
|
||||
* @return vector of keys
|
||||
*/
|
||||
public KeyVector keys() {
|
||||
final int num_prefixed_fields = 3;
|
||||
int keysOffset = end - (byteWidth * num_prefixed_fields);
|
||||
return new KeyVector(new TypedVector(bb,
|
||||
indirect(bb, keysOffset, byteWidth),
|
||||
readInt(bb, keysOffset + byteWidth, byteWidth),
|
||||
FBT_KEY));
|
||||
}
|
||||
|
||||
/**
|
||||
* @return {@code Vector} of values from map
|
||||
*/
|
||||
public Vector values() {
|
||||
return new Vector(bb, end, byteWidth);
|
||||
}
|
||||
|
||||
/**
|
||||
* Writes text (json) representation of map in a {@code StringBuilder}.
|
||||
*
|
||||
* @param builder {@code StringBuilder} to be appended to
|
||||
* @return Same {@code StringBuilder} with appended text
|
||||
*/
|
||||
public StringBuilder toString(StringBuilder builder) {
|
||||
builder.append("{ ");
|
||||
KeyVector keys = keys();
|
||||
int size = size();
|
||||
Vector vals = values();
|
||||
for (int i = 0; i < size; i++) {
|
||||
builder.append('"')
|
||||
.append(keys.get(i).toString())
|
||||
.append("\" : ");
|
||||
builder.append(vals.get(i).toString());
|
||||
if (i != size - 1)
|
||||
builder.append(", ");
|
||||
}
|
||||
builder.append(" }");
|
||||
return builder;
|
||||
}
|
||||
|
||||
// Performs a binary search on a key vector and return index of the key in key vector
|
||||
private int binarySearch(KeyVector keys, byte[] searchedKey) {
|
||||
int low = 0;
|
||||
int high = keys.size() - 1;
|
||||
|
||||
while (low <= high) {
|
||||
int mid = (low + high) >>> 1;
|
||||
Key k = keys.get(mid);
|
||||
int cmp = k.compareTo(searchedKey);
|
||||
if (cmp < 0)
|
||||
low = mid + 1;
|
||||
else if (cmp > 0)
|
||||
high = mid - 1;
|
||||
else
|
||||
return mid; // key found
|
||||
}
|
||||
return -(low + 1); // key not found
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Object that represents a set of elements in the buffer
|
||||
*/
|
||||
public static class Vector extends Sized {
|
||||
|
||||
private static final Vector EMPTY_VECTOR = new Vector(ByteBuffer.allocate(0), 1, 1);
|
||||
|
||||
Vector(ByteBuffer bb, int end, int byteWidth) {
|
||||
super(bb, end, byteWidth);
|
||||
}
|
||||
|
||||
public static Vector empty() {
|
||||
return EMPTY_VECTOR;
|
||||
}
|
||||
|
||||
public boolean isEmpty() {
|
||||
return this == EMPTY_VECTOR;
|
||||
}
|
||||
|
||||
@Override
|
||||
public StringBuilder toString(StringBuilder sb) {
|
||||
sb.append("[ ");
|
||||
int size = size();
|
||||
for (int i = 0; i < size; i++) {
|
||||
get(i).toString(sb);
|
||||
if (i != size - 1) {
|
||||
sb.append(", ");
|
||||
}
|
||||
}
|
||||
sb.append(" ]");
|
||||
return sb;
|
||||
}
|
||||
|
||||
/**
|
||||
* Get a element in a vector by index
|
||||
*
|
||||
* @param index position of the element
|
||||
* @return {@code Reference} to the element
|
||||
*/
|
||||
public Reference get(int index) {
|
||||
long len = size();
|
||||
if (index >= len) {
|
||||
return Reference.NULL_REFERENCE;
|
||||
}
|
||||
int packedType = byteToUnsignedInt(bb.get((int) (end + (len * byteWidth) + index)));
|
||||
int obj_end = end + index * byteWidth;
|
||||
return new Reference(bb, obj_end, byteWidth, packedType);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Object that represents a set of elements with the same type
|
||||
*/
|
||||
public static class TypedVector extends Vector {
|
||||
|
||||
private static final TypedVector EMPTY_VECTOR = new TypedVector(EMPTY_BB, 0, 1, FBT_INT);
|
||||
|
||||
private final int elemType;
|
||||
|
||||
TypedVector(ByteBuffer bb, int end, int byteWidth, int elemType) {
|
||||
super(bb, end, byteWidth);
|
||||
this.elemType = elemType;
|
||||
}
|
||||
|
||||
public static TypedVector empty() {
|
||||
return EMPTY_VECTOR;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns whether the vector is empty
|
||||
*
|
||||
* @return true if empty
|
||||
*/
|
||||
public boolean isEmptyVector() {
|
||||
return this == EMPTY_VECTOR;
|
||||
}
|
||||
|
||||
/**
|
||||
* Return element type for all elements in the vector
|
||||
*
|
||||
* @return element type
|
||||
*/
|
||||
public int getElemType() {
|
||||
return elemType;
|
||||
}
|
||||
|
||||
/**
|
||||
* Get reference to an object in the {@code Vector}
|
||||
*
|
||||
* @param pos position of the object in {@code Vector}
|
||||
* @return reference to element
|
||||
*/
|
||||
@Override
|
||||
public Reference get(int pos) {
|
||||
int len = size();
|
||||
if (pos >= len) return Reference.NULL_REFERENCE;
|
||||
int childPos = end + pos * byteWidth;
|
||||
return new Reference(bb, childPos, byteWidth, 1, elemType);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Represent a vector of keys in a map
|
||||
*/
|
||||
public static class KeyVector {
|
||||
|
||||
private final TypedVector vec;
|
||||
|
||||
KeyVector(TypedVector vec) {
|
||||
this.vec = vec;
|
||||
}
|
||||
|
||||
/**
|
||||
* Return key
|
||||
*
|
||||
* @param pos position of the key in key vector
|
||||
* @return key
|
||||
*/
|
||||
public Key get(int pos) {
|
||||
int len = size();
|
||||
if (pos >= len) return Key.EMPTY;
|
||||
int childPos = vec.end + pos * vec.byteWidth;
|
||||
return new Key(vec.bb, indirect(vec.bb, childPos, vec.byteWidth), 1);
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns size of key vector
|
||||
*
|
||||
* @return size
|
||||
*/
|
||||
public int size() {
|
||||
return vec.size();
|
||||
}
|
||||
|
||||
public String toString() {
|
||||
StringBuilder b = new StringBuilder();
|
||||
b.append('[');
|
||||
for (int i = 0; i < vec.size(); i++) {
|
||||
vec.get(i).toString(b);
|
||||
if (i != vec.size() - 1) {
|
||||
b.append(", ");
|
||||
}
|
||||
}
|
||||
return b.append("]").toString();
|
||||
}
|
||||
}
|
||||
|
||||
public static class FlexBufferException extends RuntimeException {
|
||||
FlexBufferException(String msg) {
|
||||
super(msg);
|
||||
}
|
||||
}
|
||||
|
||||
static class Unsigned {
|
||||
|
||||
static int byteToUnsignedInt(byte x) {
|
||||
return ((int) x) & 0xff;
|
||||
}
|
||||
|
||||
static int shortToUnsignedInt(short x) {
|
||||
return ((int) x) & 0xffff;
|
||||
}
|
||||
|
||||
static long intToUnsignedLong(int x) {
|
||||
return ((long) x) & 0xffffffffL;
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user