mirror of
https://github.com/google/flatbuffers.git
synced 2026-06-02 12:05:50 +00:00
925fab6b15
The original implementation of map access is very naive: - Encode String to UTF8 byte[] - Creates a new KeyVector - Performs a binary search to find the key - return value So every access to the Map there was useless allocations of Keys and KeyVector and complete encoding of the search key, which for most comparisons would be wasteful. This changes completely removes the use of KeyVector and compute the key positions on the spot. Besides that, it compares keys codepoint-by-codepoint, avoiding unnecessary allocations and reducing encoding for most cases. Some benchmarks result in a 2.75x speedup.
1212 lines
41 KiB
Java
1212 lines
41 KiB
Java
/*
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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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/// @file
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/// @addtogroup flatbuffers_java_api
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/// @{
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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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* <pre>
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* ReadBuf 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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* </pre>
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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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/** Represent a null type */
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public static final int FBT_NULL = 0;
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/** Represent a signed integer type */
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public static final int FBT_INT = 1;
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/** Represent a unsigned type */
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public static final int FBT_UINT = 2;
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/** Represent a float type */
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public static final int FBT_FLOAT = 3; // Types above stored inline, types below store an offset.
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/** Represent a key to a map type */
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public static final int FBT_KEY = 4;
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/** Represent a string type */
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public static final int FBT_STRING = 5;
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/** Represent a indirect signed integer type */
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public static final int FBT_INDIRECT_INT = 6;
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/** Represent a indirect unsigned integer type */
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public static final int FBT_INDIRECT_UINT = 7;
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/** Represent a indirect float type */
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public static final int FBT_INDIRECT_FLOAT = 8;
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/** Represent a map type */
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public static final int FBT_MAP = 9;
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/** Represent a vector type */
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public static final int FBT_VECTOR = 10; // Untyped.
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/** Represent a vector of signed integers type */
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public static final int FBT_VECTOR_INT = 11; // Typed any size = stores no type table).
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/** Represent a vector of unsigned integers type */
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public static final int FBT_VECTOR_UINT = 12;
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/** Represent a vector of floats type */
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public static final int FBT_VECTOR_FLOAT = 13;
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/** Represent a vector of keys type */
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public static final int FBT_VECTOR_KEY = 14;
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/** Represent a vector of strings type */
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// DEPRECATED, use FBT_VECTOR or FBT_VECTOR_KEY instead.
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// more info on thttps://github.com/google/flatbuffers/issues/5627.
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public static final int FBT_VECTOR_STRING_DEPRECATED = 15;
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/// @cond FLATBUFFERS_INTERNAL
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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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/// @endcond FLATBUFFERS_INTERNAL
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/** Represent a blob type */
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public static final int FBT_BLOB = 25;
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/** Represent a boolean type */
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public static final int FBT_BOOL = 26;
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/** Represent a vector of booleans type */
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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 ReadBuf EMPTY_BB = new ArrayReadWriteBuf(new byte[] {0}, 1);
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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_DEPRECATED) || 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 element
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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_KEY) || 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(ReadBuf bb, int offset, int byteWidth) {
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// we assume all offset fits on a int, since ReadBuf 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(ReadBuf 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(ReadBuf 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(ReadBuf 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(ReadBuf 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 ReadBuf and returns {@link Reference} to
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* the root element.
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* @param buffer ReadBuf containing FlexBuffer message
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* @return {@link Reference} to the root object
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*/
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@Deprecated
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public static Reference getRoot(ByteBuffer buffer) {
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return getRoot( buffer.hasArray() ? new ArrayReadWriteBuf(buffer.array(), buffer.limit()) : new ByteBufferReadWriteBuf(buffer));
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}
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/**
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* Reads a FlexBuffer message in ReadBuf and returns {@link Reference} to
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* the root element.
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* @param buffer ReadBuf 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(ReadBuf 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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/**
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* Represents an generic element in the buffer.
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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 ReadBuf 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(ReadBuf 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(ReadBuf 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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/**
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* Return element type
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* @return element type as integer
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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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/**
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* Checks whether the element is null type
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* @return true if null 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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/**
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* Checks whether the element is boolean type
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* @return true if boolean type
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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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/**
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* Checks whether the element type is numeric (signed/unsigned integers and floats)
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* @return true if numeric type
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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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/**
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* Checks whether the element type is signed or unsigned integers
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* @return true if an integer type
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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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/**
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* Checks whether the element type is float
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* @return true if a float type
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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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/**
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* Checks whether the element type is signed integer
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* @return true if a signed integer type
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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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/**
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* Checks whether the element type is signed integer
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* @return true if a signed integer type
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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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/**
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* Checks whether the element type is string
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* @return true if a string type
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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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/**
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* Checks whether the element type is key
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* @return true if a key type
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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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/**
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* Checks whether the element type is vector
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* @return true if a vector type
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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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/**
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* Checks whether the element type is typed vector
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* @return true if a typed vector type
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*/
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public boolean isTypedVector() {
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return FlexBuffers.isTypedVector(type);
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}
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/**
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* Checks whether the element type is a map
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* @return true if a map type
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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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/**
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* Checks whether the element type is a blob
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* @return true if a blob type
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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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/**
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* Returns element as 32-bit integer.
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* <p> For vector element, it will return size of the vector</p>
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* <p> For String element, it will type to be parsed as integer</p>
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* <p> Unsigned elements will become negative</p>
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* <p> Float elements will be casted to integer </p>
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* @return 32-bit integer or 0 if fail to convert element to integer.
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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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/**
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* Returns element as unsigned 64-bit integer.
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* <p> For vector element, it will return size of the vector</p>
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* <p> For String element, it will type to be parsed as integer</p>
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* <p> Negative signed elements will become unsigned counterpart</p>
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* <p> Float elements will be casted to integer </p>
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* @return 64-bit integer or 0 if fail to convert element to integer.
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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: return 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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/**
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* Returns element as 64-bit integer.
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* <p> For vector element, it will return size of the vector</p>
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* <p> For String element, it will type to be parsed as integer</p>
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* <p> Unsigned elements will become negative</p>
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* <p> Float elements will be casted to integer </p>
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* @return 64-bit integer or 0 if fail to convert element to long.
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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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/**
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* Returns element as 64-bit integer.
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* <p> For vector element, it will return size of the vector</p>
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* <p> For String element, it will type to be parsed as integer</p>
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* @return 64-bit integer or 0 if fail to convert element to long.
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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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/**
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* Returns element as a {@link Key}
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* @return key or {@link Key#empty()} if element is not a key
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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);
|
|
} else {
|
|
return Key.empty();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns element as a `String`
|
|
* @return element as `String` or empty `String` if fail
|
|
*/
|
|
public String asString() {
|
|
if (isString()) {
|
|
int start = indirect(bb, end, parentWidth);
|
|
int size = (int) readUInt(bb, start - byteWidth, byteWidth);
|
|
return bb.getString(start, size);
|
|
}
|
|
else if (isKey()){
|
|
int start = indirect(bb, end, byteWidth);
|
|
for (int i = start; ; i++) {
|
|
if (bb.get(i) == 0) {
|
|
return bb.getString(start, i - start);
|
|
}
|
|
}
|
|
} else {
|
|
return "";
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns element as a {@link Map}
|
|
* @return element as {@link Map} or empty {@link Map} if fail
|
|
*/
|
|
public Map asMap() {
|
|
if (isMap()) {
|
|
return new Map(bb, indirect(bb, end, parentWidth), byteWidth);
|
|
} else {
|
|
return Map.empty();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns element as a {@link Vector}
|
|
* @return element as {@link Vector} or empty {@link Vector} if fail
|
|
*/
|
|
public Vector asVector() {
|
|
if (isVector()) {
|
|
return new Vector(bb, indirect(bb, end, parentWidth), byteWidth);
|
|
} else if(type == FlexBuffers.FBT_VECTOR_STRING_DEPRECATED) {
|
|
// deprecated. Should be treated as key vector
|
|
return new TypedVector(bb, indirect(bb, end, parentWidth), byteWidth, FlexBuffers.FBT_KEY);
|
|
} else if (FlexBuffers.isTypedVector(type)) {
|
|
return new TypedVector(bb, indirect(bb, end, parentWidth), byteWidth, FlexBuffers.toTypedVectorElementType(type));
|
|
} else {
|
|
return Vector.empty();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns element as a {@link Blob}
|
|
* @return element as {@link Blob} or empty {@link Blob} if fail
|
|
*/
|
|
public Blob asBlob() {
|
|
if (isBlob() || isString()) {
|
|
return new Blob(bb, indirect(bb, end, parentWidth), byteWidth);
|
|
} else {
|
|
return Blob.empty();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns element as a boolean
|
|
* <p>If element type is not boolean, it will be casted to integer and compared against 0</p>
|
|
* @return element as boolean
|
|
*/
|
|
public boolean asBoolean() {
|
|
if (isBoolean()) {
|
|
return bb.get(end) != 0;
|
|
}
|
|
return asUInt() != 0;
|
|
}
|
|
|
|
/**
|
|
* Returns text representation of the element (JSON)
|
|
* @return String containing text representation of the element
|
|
*/
|
|
@Override
|
|
public String toString() {
|
|
return toString(new StringBuilder(128)).toString();
|
|
}
|
|
|
|
/**
|
|
* Appends a text(JSON) representation to a `StringBuilder`
|
|
*/
|
|
StringBuilder toString(StringBuilder sb) {
|
|
//TODO: Original C++ implementation escape strings.
|
|
// probably we should do it as well.
|
|
switch (type) {
|
|
case FBT_NULL:
|
|
return sb.append("null");
|
|
case FBT_INT:
|
|
case FBT_INDIRECT_INT:
|
|
return sb.append(asLong());
|
|
case FBT_UINT:
|
|
case FBT_INDIRECT_UINT:
|
|
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_DEPRECATED:
|
|
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 {
|
|
ReadBuf bb;
|
|
int end;
|
|
int byteWidth;
|
|
|
|
Object(ReadBuf 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 {
|
|
|
|
protected final int size;
|
|
|
|
Sized(ReadBuf buff, int end, int byteWidth) {
|
|
super(buff, end, byteWidth);
|
|
size = readInt(bb, end - byteWidth, byteWidth);
|
|
}
|
|
|
|
public int size() {
|
|
return size;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Represents a array of bytes element in the buffer
|
|
*
|
|
* <p>It can be converted to `ReadBuf` using {@link data()},
|
|
* copied into a byte[] using {@link getBytes()} or
|
|
* have individual bytes accessed individually using {@link get(int)}</p>
|
|
*/
|
|
public static class Blob extends Sized {
|
|
static final Blob EMPTY = new Blob(EMPTY_BB, 1, 1);
|
|
|
|
Blob(ReadBuf buff, int end, int byteWidth) {
|
|
super(buff, end, byteWidth);
|
|
}
|
|
|
|
/** Return an empty {@link Blob} */
|
|
public static Blob empty() {
|
|
return EMPTY;
|
|
}
|
|
|
|
/**
|
|
* Return {@link Blob} as `ReadBuf`
|
|
* @return blob as `ReadBuf`
|
|
*/
|
|
public ByteBuffer data() {
|
|
ByteBuffer dup = ByteBuffer.wrap(bb.data());
|
|
dup.position(end);
|
|
dup.limit(end + size());
|
|
return dup.asReadOnlyBuffer().slice();
|
|
}
|
|
|
|
/**
|
|
* Copy blob into a byte[]
|
|
* @return blob as a byte[]
|
|
*/
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* Return individual byte at a given position
|
|
* @param pos position of the byte to be read
|
|
*/
|
|
public byte get(int pos) {
|
|
assert pos >=0 && pos <= size();
|
|
return bb.get(end + pos);
|
|
}
|
|
|
|
/**
|
|
* Returns a text(JSON) representation of the {@link Blob}
|
|
*/
|
|
@Override
|
|
public String toString() {
|
|
return bb.getString(end, size());
|
|
}
|
|
|
|
/**
|
|
* Append a text(JSON) representation of the {@link Blob} into a `StringBuilder`
|
|
*/
|
|
@Override
|
|
public StringBuilder toString(StringBuilder sb) {
|
|
sb.append('"');
|
|
sb.append(bb.getString(end, size()));
|
|
return sb.append('"');
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Represents a key element in the buffer. Keys are
|
|
* used to reference objects in a {@link Map}
|
|
*/
|
|
public static class Key extends Object {
|
|
|
|
private static final Key EMPTY = new Key(EMPTY_BB, 0, 0);
|
|
|
|
Key(ReadBuf buff, int end, int byteWidth) {
|
|
super(buff, end, byteWidth);
|
|
}
|
|
|
|
/**
|
|
* Return an empty {@link Key}
|
|
* @return empty {@link Key}
|
|
* */
|
|
public static Key empty() {
|
|
return Key.EMPTY;
|
|
}
|
|
|
|
/**
|
|
* Appends a text(JSON) representation to a `StringBuilder`
|
|
*/
|
|
@Override
|
|
public StringBuilder toString(StringBuilder sb) {
|
|
return sb.append(toString());
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
int size;
|
|
for (int i = end; ; i++) {
|
|
if (bb.get(i) == 0) {
|
|
size = i - end;
|
|
break;
|
|
}
|
|
}
|
|
return bb.getString(end, size);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* Compare keys
|
|
* @param obj other key to compare
|
|
* @return true if keys are the same
|
|
*/
|
|
@Override
|
|
public boolean equals(java.lang.Object obj) {
|
|
if (!(obj instanceof Key))
|
|
return false;
|
|
|
|
return ((Key) obj).end == end && ((Key) obj).byteWidth == byteWidth;
|
|
}
|
|
|
|
public int hashCode() {
|
|
return end ^ 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, 1, 1);
|
|
// cache for converting UTF-8 codepoints into
|
|
// Java chars. Used to speed up String comparison
|
|
private final byte[] comparisonBuffer = new byte[4];
|
|
|
|
Map(ReadBuf bb, int end, int byteWidth) {
|
|
super(bb, end, byteWidth);
|
|
}
|
|
|
|
/**
|
|
* Returns an empty {@link Map}
|
|
* @return an empty {@link Map}
|
|
*/
|
|
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) {
|
|
int index = binarySearch(key);
|
|
if (index >= 0 && index < size) {
|
|
return get(index);
|
|
}
|
|
return Reference.NULL_REFERENCE;
|
|
}
|
|
|
|
/**
|
|
* @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) {
|
|
int index = binarySearch(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(CharSequence searchedKey) {
|
|
int low = 0;
|
|
int high = size - 1;
|
|
final int num_prefixed_fields = 3;
|
|
int keysOffset = end - (byteWidth * num_prefixed_fields);
|
|
int keysStart = indirect(bb, keysOffset, byteWidth);
|
|
int keyByteWidth = readInt(bb, keysOffset + byteWidth, byteWidth);
|
|
while (low <= high) {
|
|
int mid = (low + high) >>> 1;
|
|
int keyPos = indirect(bb, keysStart + mid * keyByteWidth, keyByteWidth);
|
|
int cmp = compareCharSequence(keyPos, 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
|
|
}
|
|
|
|
private int binarySearch(byte[] searchedKey) {
|
|
int low = 0;
|
|
int high = size - 1;
|
|
final int num_prefixed_fields = 3;
|
|
int keysOffset = end - (byteWidth * num_prefixed_fields);
|
|
int keysStart = indirect(bb, keysOffset, byteWidth);
|
|
int keyByteWidth = readInt(bb, keysOffset + byteWidth, byteWidth);
|
|
|
|
while (low <= high) {
|
|
int mid = (low + high) >>> 1;
|
|
int keyPos = indirect(bb, keysStart + mid * keyByteWidth, keyByteWidth);
|
|
int cmp = compareBytes(bb, keyPos, 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
|
|
}
|
|
|
|
// compares a byte[] against a FBT_KEY
|
|
private int compareBytes(ReadBuf bb, int start, byte[] other) {
|
|
int l1 = start;
|
|
int l2 = 0;
|
|
byte c1, c2;
|
|
do {
|
|
c1 = bb.get(l1);
|
|
c2 = other[l2];
|
|
if (c1 == '\0')
|
|
return c1 - c2;
|
|
l1++;
|
|
l2++;
|
|
if (l2 == 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;
|
|
}
|
|
|
|
// compares a CharSequence against a FBT_KEY
|
|
private int compareCharSequence(int start, CharSequence other) {
|
|
int bufferPos = start;
|
|
int otherPos = 0;
|
|
int limit = bb.limit();
|
|
int otherLimit = other.length();
|
|
|
|
// special loop for ASCII characters. Most of keys should be ASCII only, so this
|
|
// loop should be optimized for that.
|
|
// breaks if a multi-byte character is found
|
|
while (otherPos < otherLimit) {
|
|
char c2 = other.charAt(otherPos);
|
|
|
|
if (c2 >= 0x80) {
|
|
// not a single byte codepoint
|
|
break;
|
|
}
|
|
|
|
byte b = bb.get(bufferPos);
|
|
|
|
if (b == 0) {
|
|
return -c2;
|
|
} else if (b < 0) {
|
|
break;
|
|
} else if ((char) b != c2) {
|
|
return b - c2;
|
|
}
|
|
++bufferPos;
|
|
++otherPos;
|
|
}
|
|
|
|
while (bufferPos < limit) {
|
|
|
|
int sizeInBuff = Utf8.encodeUtf8CodePoint(other, otherPos, comparisonBuffer);
|
|
|
|
if (sizeInBuff == 0) {
|
|
// That means we finish with other and there are not more chars to
|
|
// compare. String in the buffer is bigger.
|
|
return bb.get(bufferPos);
|
|
}
|
|
|
|
for (int i = 0; i < sizeInBuff; i++) {
|
|
byte bufferByte = bb.get(bufferPos++);
|
|
byte otherByte = comparisonBuffer[i];
|
|
if (bufferByte == 0) {
|
|
// Our key is finished, so other is bigger
|
|
return -otherByte;
|
|
} else if (bufferByte != otherByte) {
|
|
return bufferByte - otherByte;
|
|
}
|
|
}
|
|
|
|
otherPos += sizeInBuff == 4 ? 2 : 1;
|
|
}
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Object that represents a set of elements in the buffer
|
|
*/
|
|
public static class Vector extends Sized {
|
|
|
|
private static final Vector EMPTY_VECTOR = new Vector(EMPTY_BB, 1, 1);
|
|
|
|
Vector(ReadBuf bb, int end, int byteWidth) {
|
|
super(bb, end, byteWidth);
|
|
}
|
|
|
|
/**
|
|
* Returns an empty {@link Map}
|
|
* @return an empty {@link Map}
|
|
*/
|
|
public static Vector empty() {
|
|
return EMPTY_VECTOR;
|
|
}
|
|
|
|
/**
|
|
* Checks if the vector is empty
|
|
* @return true if vector is empty
|
|
*/
|
|
public boolean isEmpty() {
|
|
return this == EMPTY_VECTOR;
|
|
}
|
|
|
|
/**
|
|
* Appends a text(JSON) representation to a `StringBuilder`
|
|
*/
|
|
@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, 1, 1, FBT_INT);
|
|
|
|
private final int elemType;
|
|
|
|
TypedVector(ReadBuf 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();
|
|
}
|
|
|
|
/**
|
|
* Returns a text(JSON) representation
|
|
*/
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
/// @}
|