| /* |
| * Copyright 2014 Google Inc. All rights reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.google.flatbuffers; |
| |
| import static com.google.flatbuffers.Constants.*; |
| import java.nio.ByteBuffer; |
| import java.nio.ByteOrder; |
| |
| // All tables in the generated code derive from this class, and add their own accessors. |
| public class Table { |
| protected int bb_pos; |
| protected ByteBuffer bb; |
| |
| public ByteBuffer getByteBuffer() { return bb; } |
| |
| // Look up a field in the vtable, return an offset into the object, or 0 if the field is not |
| // present. |
| protected int __offset(int vtable_offset) { |
| int vtable = bb_pos - bb.getInt(bb_pos); |
| return vtable_offset < bb.getShort(vtable) ? bb.getShort(vtable + vtable_offset) : 0; |
| } |
| |
| // Retrieve the relative offset stored at "offset" |
| protected int __indirect(int offset) { |
| return offset + bb.getInt(offset); |
| } |
| |
| // Create a java String from UTF-8 data stored inside the flatbuffer. |
| // This allocates a new string and converts to wide chars upon each access, |
| // which is not very efficient. Instead, each FlatBuffer string also comes with an |
| // accessor based on __vector_as_bytebuffer below, which is much more efficient, |
| // assuming your Java program can handle UTF-8 data directly. |
| protected String __string(int offset) { |
| offset += bb.getInt(offset); |
| if (bb.hasArray()) { |
| return new String(bb.array(), bb.arrayOffset() + offset + SIZEOF_INT, bb.getInt(offset), FlatBufferBuilder.utf8charset); |
| } else { |
| // We can't access .array(), since the ByteBuffer is read-only, |
| // off-heap or a memory map |
| ByteBuffer bb = this.bb.duplicate().order(ByteOrder.LITTLE_ENDIAN); |
| // We're forced to make an extra copy: |
| byte[] copy = new byte[bb.getInt(offset)]; |
| bb.position(offset + SIZEOF_INT); |
| bb.get(copy); |
| return new String(copy, 0, copy.length, FlatBufferBuilder.utf8charset); |
| } |
| } |
| |
| // Get the length of a vector whose offset is stored at "offset" in this object. |
| protected int __vector_len(int offset) { |
| offset += bb_pos; |
| offset += bb.getInt(offset); |
| return bb.getInt(offset); |
| } |
| |
| // Get the start of data of a vector whose offset is stored at "offset" in this object. |
| protected int __vector(int offset) { |
| offset += bb_pos; |
| return offset + bb.getInt(offset) + SIZEOF_INT; // data starts after the length |
| } |
| |
| // Get a whole vector as a ByteBuffer. This is efficient, since it only allocates a new |
| // bytebuffer object, but does not actually copy the data, it still refers to the same |
| // bytes as the original ByteBuffer. |
| // Also useful with nested FlatBuffers etc. |
| protected ByteBuffer __vector_as_bytebuffer(int vector_offset, int elem_size) { |
| int o = __offset(vector_offset); |
| if (o == 0) return null; |
| ByteBuffer bb = this.bb.duplicate().order(ByteOrder.LITTLE_ENDIAN); |
| int vectorstart = __vector(o); |
| bb.position(vectorstart); |
| bb.limit(vectorstart + __vector_len(o) * elem_size); |
| return bb; |
| } |
| |
| // Initialize any Table-derived type to point to the union at the given offset. |
| protected Table __union(Table t, int offset) { |
| offset += bb_pos; |
| t.bb_pos = offset + bb.getInt(offset); |
| t.bb = bb; |
| return t; |
| } |
| |
| protected static boolean __has_identifier(ByteBuffer bb, String ident) { |
| if (ident.length() != FILE_IDENTIFIER_LENGTH) |
| throw new AssertionError("FlatBuffers: file identifier must be length " + |
| FILE_IDENTIFIER_LENGTH); |
| for (int i = 0; i < FILE_IDENTIFIER_LENGTH; i++) { |
| if (ident.charAt(i) != (char)bb.get(bb.position() + SIZEOF_INT + i)) return false; |
| } |
| return true; |
| } |
| } |