forked from BigfootDev/flatbuffers
Revert "Create a maven like project structure for java development. Make it OSGi compliant. Generate the flatbuffers code for testing (example)."
This reverts commit 9875b0e0f8.
This commit is contained in:
Romain Gilles
781
java/com/google/flatbuffers/FlatBufferBuilder.java
Normal file
781
java/com/google/flatbuffers/FlatBufferBuilder.java
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@@ -0,0 +1,781 @@
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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.Constants.*;
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import java.nio.CharBuffer;
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import java.nio.charset.CharacterCodingException;
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import java.nio.charset.CharsetEncoder;
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import java.nio.charset.CoderResult;
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import java.util.Arrays;
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import java.nio.ByteBuffer;
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import java.nio.ByteOrder;
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import java.nio.charset.Charset;
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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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* Class that helps you build a FlatBuffer. See the section
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* "Use in Java/C#" in the main FlatBuffers documentation.
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*/
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public class FlatBufferBuilder {
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/// @cond FLATBUFFERS_INTERNAL
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ByteBuffer bb; // Where we construct the FlatBuffer.
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int space; // Remaining space in the ByteBuffer.
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static final Charset utf8charset = Charset.forName("UTF-8"); // The UTF-8 character set used by FlatBuffers.
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int minalign = 1; // Minimum alignment encountered so far.
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int[] vtable = null; // The vtable for the current table.
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int vtable_in_use = 0; // The amount of fields we're actually using.
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boolean nested = false; // Whether we are currently serializing a table.
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boolean finished = false; // Whether the buffer is finished.
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int object_start; // Starting offset of the current struct/table.
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int[] vtables = new int[16]; // List of offsets of all vtables.
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int num_vtables = 0; // Number of entries in `vtables` in use.
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int vector_num_elems = 0; // For the current vector being built.
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boolean force_defaults = false; // False omits default values from the serialized data.
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CharsetEncoder encoder = utf8charset.newEncoder();
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ByteBuffer dst;
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/// @endcond
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/**
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* Start with a buffer of size `initial_size`, then grow as required.
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*
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* @param initial_size The initial size of the internal buffer to use.
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*/
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public FlatBufferBuilder(int initial_size) {
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if (initial_size <= 0) initial_size = 1;
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space = initial_size;
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bb = newByteBuffer(initial_size);
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}
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/**
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* Start with a buffer of 1KiB, then grow as required.
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*/
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public FlatBufferBuilder() {
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this(1024);
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}
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/**
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* Alternative constructor allowing reuse of {@link ByteBuffer}s. The builder
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* can still grow the buffer as necessary. User classes should make sure
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* to call {@link #dataBuffer()} to obtain the resulting encoded message.
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*
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* @param existing_bb The byte buffer to reuse.
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*/
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public FlatBufferBuilder(ByteBuffer existing_bb) {
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init(existing_bb);
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}
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/**
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* Alternative initializer that allows reusing this object on an existing
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* `ByteBuffer`. This method resets the builder's internal state, but keeps
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* objects that have been allocated for temporary storage.
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*
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* @param existing_bb The byte buffer to reuse.
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* @return Returns `this`.
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*/
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public FlatBufferBuilder init(ByteBuffer existing_bb){
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bb = existing_bb;
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bb.clear();
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bb.order(ByteOrder.LITTLE_ENDIAN);
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minalign = 1;
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space = bb.capacity();
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vtable_in_use = 0;
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nested = false;
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finished = false;
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object_start = 0;
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num_vtables = 0;
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vector_num_elems = 0;
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return this;
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}
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/// @cond FLATBUFFERS_INTERNAL
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/**
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* Create a `ByteBuffer` with a given capacity.
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*
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* @param capacity The size of the `ByteBuffer` to allocate.
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* @return Returns the new `ByteBuffer` that was allocated.
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*/
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static ByteBuffer newByteBuffer(int capacity) {
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ByteBuffer newbb = ByteBuffer.allocate(capacity);
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newbb.order(ByteOrder.LITTLE_ENDIAN);
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return newbb;
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}
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/**
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* Doubles the size of the backing {@link ByteBuffer} and copies the old data towards the
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* end of the new buffer (since we build the buffer backwards).
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*
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* @param bb The current buffer with the existing data.
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* @return A new byte buffer with the old data copied copied to it. The data is
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* located at the end of the buffer.
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*/
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static ByteBuffer growByteBuffer(ByteBuffer bb) {
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int old_buf_size = bb.capacity();
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if ((old_buf_size & 0xC0000000) != 0) // Ensure we don't grow beyond what fits in an int.
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throw new AssertionError("FlatBuffers: cannot grow buffer beyond 2 gigabytes.");
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int new_buf_size = old_buf_size << 1;
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bb.position(0);
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ByteBuffer nbb = newByteBuffer(new_buf_size);
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nbb.position(new_buf_size - old_buf_size);
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nbb.put(bb);
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return nbb;
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}
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/**
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* Offset relative to the end of the buffer.
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*
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* @return Offset relative to the end of the buffer.
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*/
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public int offset() {
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return bb.capacity() - space;
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}
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/**
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* Add zero valued bytes to prepare a new entry to be added.
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*
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* @param byte_size Number of bytes to add.
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*/
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public void pad(int byte_size) {
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for (int i = 0; i < byte_size; i++) bb.put(--space, (byte)0);
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}
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/**
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* Prepare to write an element of `size` after `additional_bytes`
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* have been written, e.g. if you write a string, you need to align such
|
||||
* the int length field is aligned to {@link com.google.flatbuffers.Constants#SIZEOF_INT}, and
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||||
* the string data follows it directly. If all you need to do is alignment, `additional_bytes`
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||||
* will be 0.
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||||
*
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||||
* @param size This is the of the new element to write.
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* @param additional_bytes The padding size.
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*/
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public void prep(int size, int additional_bytes) {
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// Track the biggest thing we've ever aligned to.
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if (size > minalign) minalign = size;
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||||
// Find the amount of alignment needed such that `size` is properly
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||||
// aligned after `additional_bytes`
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||||
int align_size = ((~(bb.capacity() - space + additional_bytes)) + 1) & (size - 1);
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// Reallocate the buffer if needed.
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while (space < align_size + size + additional_bytes) {
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int old_buf_size = bb.capacity();
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bb = growByteBuffer(bb);
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space += bb.capacity() - old_buf_size;
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||||
}
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pad(align_size);
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||||
}
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||||
|
||||
/**
|
||||
* Add a `boolean` to the buffer, backwards from the current location. Doesn't align nor
|
||||
* check for space.
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||||
*
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||||
* @param x A `boolean` to put into the buffer.
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||||
*/
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||||
public void putBoolean(boolean x) { bb.put (space -= 1, (byte)(x ? 1 : 0)); }
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||||
|
||||
/**
|
||||
* Add a `byte` to the buffer, backwards from the current location. Doesn't align nor
|
||||
* check for space.
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||||
*
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||||
* @param x A `byte` to put into the buffer.
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||||
*/
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||||
public void putByte (byte x) { bb.put (space -= 1, x); }
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||||
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||||
/**
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||||
* Add a `short` to the buffer, backwards from the current location. Doesn't align nor
|
||||
* check for space.
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||||
*
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||||
* @param x A `short` to put into the buffer.
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||||
*/
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||||
public void putShort (short x) { bb.putShort (space -= 2, x); }
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||||
|
||||
/**
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||||
* Add an `int` to the buffer, backwards from the current location. Doesn't align nor
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* check for space.
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||||
*
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* @param x An `int` to put into the buffer.
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||||
*/
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public void putInt (int x) { bb.putInt (space -= 4, x); }
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||||
/**
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||||
* Add a `long` to the buffer, backwards from the current location. Doesn't align nor
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* check for space.
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||||
*
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* @param x A `long` to put into the buffer.
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*/
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public void putLong (long x) { bb.putLong (space -= 8, x); }
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/**
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||||
* Add a `float` to the buffer, backwards from the current location. Doesn't align nor
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||||
* check for space.
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||||
*
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* @param x A `float` to put into the buffer.
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||||
*/
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||||
public void putFloat (float x) { bb.putFloat (space -= 4, x); }
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/**
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||||
* Add a `double` to the buffer, backwards from the current location. Doesn't align nor
|
||||
* check for space.
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||||
*
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* @param x A `double` to put into the buffer.
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||||
*/
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||||
public void putDouble (double x) { bb.putDouble(space -= 8, x); }
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/// @endcond
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/**
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* Add a `boolean` to the buffer, properly aligned, and grows the buffer (if necessary).
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*
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* @param x A `boolean` to put into the buffer.
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*/
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public void addBoolean(boolean x) { prep(1, 0); putBoolean(x); }
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/**
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* Add a `byte` to the buffer, properly aligned, and grows the buffer (if necessary).
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*
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* @param x A `byte` to put into the buffer.
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*/
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public void addByte (byte x) { prep(1, 0); putByte (x); }
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/**
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* Add a `short` to the buffer, properly aligned, and grows the buffer (if necessary).
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*
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* @param x A `short` to put into the buffer.
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*/
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public void addShort (short x) { prep(2, 0); putShort (x); }
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/**
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* Add an `int` to the buffer, properly aligned, and grows the buffer (if necessary).
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*
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* @param x An `int` to put into the buffer.
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*/
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public void addInt (int x) { prep(4, 0); putInt (x); }
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/**
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* Add a `long` to the buffer, properly aligned, and grows the buffer (if necessary).
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*
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* @param x A `long` to put into the buffer.
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*/
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public void addLong (long x) { prep(8, 0); putLong (x); }
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/**
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* Add a `float` to the buffer, properly aligned, and grows the buffer (if necessary).
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*
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* @param x A `float` to put into the buffer.
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||||
*/
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public void addFloat (float x) { prep(4, 0); putFloat (x); }
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||||
|
||||
/**
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* Add a `double` to the buffer, properly aligned, and grows the buffer (if necessary).
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*
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* @param x A `double` to put into the buffer.
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*/
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public void addDouble (double x) { prep(8, 0); putDouble (x); }
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||||
/**
|
||||
* Adds on offset, relative to where it will be written.
|
||||
*
|
||||
* @param off The offset to add.
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||||
*/
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public void addOffset(int off) {
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prep(SIZEOF_INT, 0); // Ensure alignment is already done.
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||||
assert off <= offset();
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off = offset() - off + SIZEOF_INT;
|
||||
putInt(off);
|
||||
}
|
||||
|
||||
/// @cond FLATBUFFERS_INTERNAL
|
||||
/**
|
||||
* Start a new array/vector of objects. Users usually will not call
|
||||
* this directly. The `FlatBuffers` compiler will create a start/end
|
||||
* method for vector types in generated code.
|
||||
* <p>
|
||||
* The expected sequence of calls is:
|
||||
* <ol>
|
||||
* <li>Start the array using this method.</li>
|
||||
* <li>Call {@link #addOffset(int)} `num_elems` number of times to set
|
||||
* the offset of each element in the array.</li>
|
||||
* <li>Call {@link #endVector()} to retrieve the offset of the array.</li>
|
||||
* </ol>
|
||||
* <p>
|
||||
* For example, to create an array of strings, do:
|
||||
* <pre>{@code
|
||||
* // Need 10 strings
|
||||
* FlatBufferBuilder builder = new FlatBufferBuilder(existingBuffer);
|
||||
* int[] offsets = new int[10];
|
||||
*
|
||||
* for (int i = 0; i < 10; i++) {
|
||||
* offsets[i] = fbb.createString(" " + i);
|
||||
* }
|
||||
*
|
||||
* // Have the strings in the buffer, but don't have a vector.
|
||||
* // Add a vector that references the newly created strings:
|
||||
* builder.startVector(4, offsets.length, 4);
|
||||
*
|
||||
* // Add each string to the newly created vector
|
||||
* // The strings are added in reverse order since the buffer
|
||||
* // is filled in back to front
|
||||
* for (int i = offsets.length - 1; i >= 0; i--) {
|
||||
* builder.addOffset(offsets[i]);
|
||||
* }
|
||||
*
|
||||
* // Finish off the vector
|
||||
* int offsetOfTheVector = fbb.endVector();
|
||||
* }</pre>
|
||||
*
|
||||
* @param elem_size The size of each element in the array.
|
||||
* @param num_elems The number of elements in the array.
|
||||
* @param alignment The alignment of the array.
|
||||
*/
|
||||
public void startVector(int elem_size, int num_elems, int alignment) {
|
||||
notNested();
|
||||
vector_num_elems = num_elems;
|
||||
prep(SIZEOF_INT, elem_size * num_elems);
|
||||
prep(alignment, elem_size * num_elems); // Just in case alignment > int.
|
||||
nested = true;
|
||||
}
|
||||
|
||||
/**
|
||||
* Finish off the creation of an array and all its elements. The array
|
||||
* must be created with {@link #startVector(int, int, int)}.
|
||||
*
|
||||
* @return The offset at which the newly created array starts.
|
||||
* @see #startVector(int, int, int)
|
||||
*/
|
||||
public int endVector() {
|
||||
if (!nested)
|
||||
throw new AssertionError("FlatBuffers: endVector called without startVector");
|
||||
nested = false;
|
||||
putInt(vector_num_elems);
|
||||
return offset();
|
||||
}
|
||||
/// @endcond
|
||||
|
||||
/**
|
||||
* Encode the string `s` in the buffer using UTF-8. If {@code s} is
|
||||
* already a {@link CharBuffer}, this method is allocation free.
|
||||
*
|
||||
* @param s The string to encode.
|
||||
* @return The offset in the buffer where the encoded string starts.
|
||||
*/
|
||||
public int createString(CharSequence s) {
|
||||
int length = s.length();
|
||||
int estimatedDstCapacity = (int) (length * encoder.maxBytesPerChar());
|
||||
if (dst == null || dst.capacity() < estimatedDstCapacity) {
|
||||
dst = ByteBuffer.allocate(Math.max(128, estimatedDstCapacity));
|
||||
}
|
||||
|
||||
dst.clear();
|
||||
|
||||
CharBuffer src = s instanceof CharBuffer ? (CharBuffer) s :
|
||||
CharBuffer.wrap(s);
|
||||
CoderResult result = encoder.encode(src, dst, true);
|
||||
if (result.isError()) {
|
||||
try {
|
||||
result.throwException();
|
||||
} catch (CharacterCodingException x) {
|
||||
throw new Error(x);
|
||||
}
|
||||
}
|
||||
|
||||
dst.flip();
|
||||
return createString(dst);
|
||||
}
|
||||
|
||||
/**
|
||||
* Create a string in the buffer from an already encoded UTF-8 string in a ByteBuffer.
|
||||
*
|
||||
* @param s An already encoded UTF-8 string as a `ByteBuffer`.
|
||||
* @return The offset in the buffer where the encoded string starts.
|
||||
*/
|
||||
public int createString(ByteBuffer s) {
|
||||
int length = s.remaining();
|
||||
addByte((byte)0);
|
||||
startVector(1, length, 1);
|
||||
bb.position(space -= length);
|
||||
bb.put(s);
|
||||
return endVector();
|
||||
}
|
||||
|
||||
/// @cond FLATBUFFERS_INTERNAL
|
||||
/**
|
||||
* Should not be accessing the final buffer before it is finished.
|
||||
*/
|
||||
public void finished() {
|
||||
if (!finished)
|
||||
throw new AssertionError(
|
||||
"FlatBuffers: you can only access the serialized buffer after it has been" +
|
||||
" finished by FlatBufferBuilder.finish().");
|
||||
}
|
||||
|
||||
/**
|
||||
* Should not be creating any other object, string or vector
|
||||
* while an object is being constructed.
|
||||
*/
|
||||
public void notNested() {
|
||||
if (nested)
|
||||
throw new AssertionError("FlatBuffers: object serialization must not be nested.");
|
||||
}
|
||||
|
||||
/**
|
||||
* Structures are always stored inline, they need to be created right
|
||||
* where they're used. You'll get this assertion failure if you
|
||||
* created it elsewhere.
|
||||
*
|
||||
* @param obj The offset of the created object.
|
||||
*/
|
||||
public void Nested(int obj) {
|
||||
if (obj != offset())
|
||||
throw new AssertionError("FlatBuffers: struct must be serialized inline.");
|
||||
}
|
||||
|
||||
/**
|
||||
* Start encoding a new object in the buffer. Users will not usually need to
|
||||
* call this directly. The `FlatBuffers` compiler will generate helper methods
|
||||
* that call this method internally.
|
||||
* <p>
|
||||
* For example, using the "Monster" code found on the "landing page". An
|
||||
* object of type `Monster` can be created using the following code:
|
||||
*
|
||||
* <pre>{@code
|
||||
* int testArrayOfString = Monster.createTestarrayofstringVector(fbb, new int[] {
|
||||
* fbb.createString("test1"),
|
||||
* fbb.createString("test2")
|
||||
* });
|
||||
*
|
||||
* Monster.startMonster(fbb);
|
||||
* Monster.addPos(fbb, Vec3.createVec3(fbb, 1.0f, 2.0f, 3.0f, 3.0,
|
||||
* Color.Green, (short)5, (byte)6));
|
||||
* Monster.addHp(fbb, (short)80);
|
||||
* Monster.addName(fbb, str);
|
||||
* Monster.addInventory(fbb, inv);
|
||||
* Monster.addTestType(fbb, (byte)Any.Monster);
|
||||
* Monster.addTest(fbb, mon2);
|
||||
* Monster.addTest4(fbb, test4);
|
||||
* Monster.addTestarrayofstring(fbb, testArrayOfString);
|
||||
* int mon = Monster.endMonster(fbb);
|
||||
* }</pre>
|
||||
* <p>
|
||||
* Here:
|
||||
* <ul>
|
||||
* <li>The call to `Monster#startMonster(FlatBufferBuilder)` will call this
|
||||
* method with the right number of fields set.</li>
|
||||
* <li>`Monster#endMonster(FlatBufferBuilder)` will ensure {@link #endObject()} is called.</li>
|
||||
* </ul>
|
||||
* <p>
|
||||
* It's not recommended to call this method directly. If it's called manually, you must ensure
|
||||
* to audit all calls to it whenever fields are added or removed from your schema. This is
|
||||
* automatically done by the code generated by the `FlatBuffers` compiler.
|
||||
*
|
||||
* @param numfields The number of fields found in this object.
|
||||
*/
|
||||
public void startObject(int numfields) {
|
||||
notNested();
|
||||
if (vtable == null || vtable.length < numfields) vtable = new int[numfields];
|
||||
vtable_in_use = numfields;
|
||||
Arrays.fill(vtable, 0, vtable_in_use, 0);
|
||||
nested = true;
|
||||
object_start = offset();
|
||||
}
|
||||
|
||||
/**
|
||||
* Add a `boolean` to a table at `o` into its vtable, with value `x` and default `d`.
|
||||
*
|
||||
* @param o The index into the vtable.
|
||||
* @param x A `boolean` to put into the buffer, depending on how defaults are handled. If
|
||||
* `force_defaults` is `false`, compare `x` against the default value `d`. If `x` contains the
|
||||
* default value, it can be skipped.
|
||||
* @param d A `boolean` default value to compare against when `force_defaults` is `false`.
|
||||
*/
|
||||
public void addBoolean(int o, boolean x, boolean d) { if(force_defaults || x != d) { addBoolean(x); slot(o); } }
|
||||
|
||||
/**
|
||||
* Add a `byte` to a table at `o` into its vtable, with value `x` and default `d`.
|
||||
*
|
||||
* @param o The index into the vtable.
|
||||
* @param x A `byte` to put into the buffer, depending on how defaults are handled. If
|
||||
* `force_defaults` is `false`, compare `x` against the default value `d`. If `x` contains the
|
||||
* default value, it can be skipped.
|
||||
* @param d A `byte` default value to compare against when `force_defaults` is `false`.
|
||||
*/
|
||||
public void addByte (int o, byte x, int d) { if(force_defaults || x != d) { addByte (x); slot(o); } }
|
||||
|
||||
/**
|
||||
* Add a `short` to a table at `o` into its vtable, with value `x` and default `d`.
|
||||
*
|
||||
* @param o The index into the vtable.
|
||||
* @param x A `short` to put into the buffer, depending on how defaults are handled. If
|
||||
* `force_defaults` is `false`, compare `x` against the default value `d`. If `x` contains the
|
||||
* default value, it can be skipped.
|
||||
* @param d A `short` default value to compare against when `force_defaults` is `false`.
|
||||
*/
|
||||
public void addShort (int o, short x, int d) { if(force_defaults || x != d) { addShort (x); slot(o); } }
|
||||
|
||||
/**
|
||||
* Add an `int` to a table at `o` into its vtable, with value `x` and default `d`.
|
||||
*
|
||||
* @param o The index into the vtable.
|
||||
* @param x An `int` to put into the buffer, depending on how defaults are handled. If
|
||||
* `force_defaults` is `false`, compare `x` against the default value `d`. If `x` contains the
|
||||
* default value, it can be skipped.
|
||||
* @param d An `int` default value to compare against when `force_defaults` is `false`.
|
||||
*/
|
||||
public void addInt (int o, int x, int d) { if(force_defaults || x != d) { addInt (x); slot(o); } }
|
||||
|
||||
/**
|
||||
* Add a `long` to a table at `o` into its vtable, with value `x` and default `d`.
|
||||
*
|
||||
* @param o The index into the vtable.
|
||||
* @param x A `long` to put into the buffer, depending on how defaults are handled. If
|
||||
* `force_defaults` is `false`, compare `x` against the default value `d`. If `x` contains the
|
||||
* default value, it can be skipped.
|
||||
* @param d A `long` default value to compare against when `force_defaults` is `false`.
|
||||
*/
|
||||
public void addLong (int o, long x, long d) { if(force_defaults || x != d) { addLong (x); slot(o); } }
|
||||
|
||||
/**
|
||||
* Add a `float` to a table at `o` into its vtable, with value `x` and default `d`.
|
||||
*
|
||||
* @param o The index into the vtable.
|
||||
* @param x A `float` to put into the buffer, depending on how defaults are handled. If
|
||||
* `force_defaults` is `false`, compare `x` against the default value `d`. If `x` contains the
|
||||
* default value, it can be skipped.
|
||||
* @param d A `float` default value to compare against when `force_defaults` is `false`.
|
||||
*/
|
||||
public void addFloat (int o, float x, double d) { if(force_defaults || x != d) { addFloat (x); slot(o); } }
|
||||
|
||||
/**
|
||||
* Add a `double` to a table at `o` into its vtable, with value `x` and default `d`.
|
||||
*
|
||||
* @param o The index into the vtable.
|
||||
* @param x A `double` to put into the buffer, depending on how defaults are handled. If
|
||||
* `force_defaults` is `false`, compare `x` against the default value `d`. If `x` contains the
|
||||
* default value, it can be skipped.
|
||||
* @param d A `double` default value to compare against when `force_defaults` is `false`.
|
||||
*/
|
||||
public void addDouble (int o, double x, double d) { if(force_defaults || x != d) { addDouble (x); slot(o); } }
|
||||
|
||||
/**
|
||||
* Add an `offset` to a table at `o` into its vtable, with value `x` and default `d`.
|
||||
*
|
||||
* @param o The index into the vtable.
|
||||
* @param x An `offset` to put into the buffer, depending on how defaults are handled. If
|
||||
* `force_defaults` is `false`, compare `x` against the default value `d`. If `x` contains the
|
||||
* default value, it can be skipped.
|
||||
* @param d An `offset` default value to compare against when `force_defaults` is `false`.
|
||||
*/
|
||||
public void addOffset (int o, int x, int d) { if(force_defaults || x != d) { addOffset (x); slot(o); } }
|
||||
|
||||
/**
|
||||
* Add a struct to the table. Structs are stored inline, so nothing additional is being added.
|
||||
*
|
||||
* @param voffset The index into the vtable.
|
||||
* @param x The offset of the created struct.
|
||||
* @param d The default value is always `0`.
|
||||
*/
|
||||
public void addStruct(int voffset, int x, int d) {
|
||||
if(x != d) {
|
||||
Nested(x);
|
||||
slot(voffset);
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Set the current vtable at `voffset` to the current location in the buffer.
|
||||
*
|
||||
* @param voffset The index into the vtable to store the offset relative to the end of the
|
||||
* buffer.
|
||||
*/
|
||||
public void slot(int voffset) {
|
||||
vtable[voffset] = offset();
|
||||
}
|
||||
|
||||
/**
|
||||
* Finish off writing the object that is under construction.
|
||||
*
|
||||
* @return The offset to the object inside {@link #dataBuffer()}.
|
||||
* @see #startObject(int)
|
||||
*/
|
||||
public int endObject() {
|
||||
if (vtable == null || !nested)
|
||||
throw new AssertionError("FlatBuffers: endObject called without startObject");
|
||||
addInt(0);
|
||||
int vtableloc = offset();
|
||||
// Write out the current vtable.
|
||||
for (int i = vtable_in_use - 1; i >= 0 ; i--) {
|
||||
// Offset relative to the start of the table.
|
||||
short off = (short)(vtable[i] != 0 ? vtableloc - vtable[i] : 0);
|
||||
addShort(off);
|
||||
}
|
||||
|
||||
final int standard_fields = 2; // The fields below:
|
||||
addShort((short)(vtableloc - object_start));
|
||||
addShort((short)((vtable_in_use + standard_fields) * SIZEOF_SHORT));
|
||||
|
||||
// Search for an existing vtable that matches the current one.
|
||||
int existing_vtable = 0;
|
||||
outer_loop:
|
||||
for (int i = 0; i < num_vtables; i++) {
|
||||
int vt1 = bb.capacity() - vtables[i];
|
||||
int vt2 = space;
|
||||
short len = bb.getShort(vt1);
|
||||
if (len == bb.getShort(vt2)) {
|
||||
for (int j = SIZEOF_SHORT; j < len; j += SIZEOF_SHORT) {
|
||||
if (bb.getShort(vt1 + j) != bb.getShort(vt2 + j)) {
|
||||
continue outer_loop;
|
||||
}
|
||||
}
|
||||
existing_vtable = vtables[i];
|
||||
break outer_loop;
|
||||
}
|
||||
}
|
||||
|
||||
if (existing_vtable != 0) {
|
||||
// Found a match:
|
||||
// Remove the current vtable.
|
||||
space = bb.capacity() - vtableloc;
|
||||
// Point table to existing vtable.
|
||||
bb.putInt(space, existing_vtable - vtableloc);
|
||||
} else {
|
||||
// No match:
|
||||
// Add the location of the current vtable to the list of vtables.
|
||||
if (num_vtables == vtables.length) vtables = Arrays.copyOf(vtables, num_vtables * 2);
|
||||
vtables[num_vtables++] = offset();
|
||||
// Point table to current vtable.
|
||||
bb.putInt(bb.capacity() - vtableloc, offset() - vtableloc);
|
||||
}
|
||||
|
||||
nested = false;
|
||||
return vtableloc;
|
||||
}
|
||||
|
||||
/**
|
||||
* Checks that a required field has been set in a given table that has
|
||||
* just been constructed.
|
||||
*
|
||||
* @param table The offset to the start of the table from the `ByteBuffer` capacity.
|
||||
* @param field The offset to the field in the vtable.
|
||||
*/
|
||||
public void required(int table, int field) {
|
||||
int table_start = bb.capacity() - table;
|
||||
int vtable_start = table_start - bb.getInt(table_start);
|
||||
boolean ok = bb.getShort(vtable_start + field) != 0;
|
||||
// If this fails, the caller will show what field needs to be set.
|
||||
if (!ok)
|
||||
throw new AssertionError("FlatBuffers: field " + field + " must be set");
|
||||
}
|
||||
/// @endcond
|
||||
|
||||
/**
|
||||
* Finalize a buffer, pointing to the given `root_table`.
|
||||
*
|
||||
* @param root_table An offset to be added to the buffer.
|
||||
*/
|
||||
public void finish(int root_table) {
|
||||
prep(minalign, SIZEOF_INT);
|
||||
addOffset(root_table);
|
||||
bb.position(space);
|
||||
finished = true;
|
||||
}
|
||||
|
||||
/**
|
||||
* Finalize a buffer, pointing to the given `root_table`.
|
||||
*
|
||||
* @param root_table An offset to be added to the buffer.
|
||||
* @param file_identifier A FlatBuffer file identifier to be added to the buffer before
|
||||
* `root_table`.
|
||||
*/
|
||||
public void finish(int root_table, String file_identifier) {
|
||||
prep(minalign, SIZEOF_INT + FILE_IDENTIFIER_LENGTH);
|
||||
if (file_identifier.length() != FILE_IDENTIFIER_LENGTH)
|
||||
throw new AssertionError("FlatBuffers: file identifier must be length " +
|
||||
FILE_IDENTIFIER_LENGTH);
|
||||
for (int i = FILE_IDENTIFIER_LENGTH - 1; i >= 0; i--) {
|
||||
addByte((byte)file_identifier.charAt(i));
|
||||
}
|
||||
finish(root_table);
|
||||
}
|
||||
|
||||
/**
|
||||
* In order to save space, fields that are set to their default value
|
||||
* don't get serialized into the buffer. Forcing defaults provides a
|
||||
* way to manually disable this optimization.
|
||||
*
|
||||
* @param forceDefaults When set to `true`, always serializes default values.
|
||||
* @return Returns `this`.
|
||||
*/
|
||||
public FlatBufferBuilder forceDefaults(boolean forceDefaults){
|
||||
this.force_defaults = forceDefaults;
|
||||
return this;
|
||||
}
|
||||
|
||||
/**
|
||||
* Get the ByteBuffer representing the FlatBuffer. Only call this after you've
|
||||
* called `finish()`. The actual data starts at the ByteBuffer's current position,
|
||||
* not necessarily at `0`.
|
||||
*
|
||||
* @return The {@link ByteBuffer} representing the FlatBuffer
|
||||
*/
|
||||
public ByteBuffer dataBuffer() {
|
||||
finished();
|
||||
return bb;
|
||||
}
|
||||
|
||||
/**
|
||||
* The FlatBuffer data doesn't start at offset 0 in the {@link ByteBuffer}, but
|
||||
* now the {@code ByteBuffer}'s position is set to that location upon {@link #finish(int)}.
|
||||
*
|
||||
* @return The {@link ByteBuffer#position() position} the data starts in {@link #dataBuffer()}
|
||||
* @deprecated This method should not be needed anymore, but is left
|
||||
* here for the moment to document this API change. It will be removed in the future.
|
||||
*/
|
||||
@Deprecated
|
||||
private int dataStart() {
|
||||
finished();
|
||||
return space;
|
||||
}
|
||||
|
||||
/**
|
||||
* A utility function to copy and return the ByteBuffer data from `start` to
|
||||
* `start` + `length` as a `byte[]`.
|
||||
*
|
||||
* @param start Start copying at this offset.
|
||||
* @param length How many bytes to copy.
|
||||
* @return A range copy of the {@link #dataBuffer() data buffer}.
|
||||
* @throws IndexOutOfBoundsException If the range of bytes is ouf of bound.
|
||||
*/
|
||||
public byte[] sizedByteArray(int start, int length){
|
||||
finished();
|
||||
byte[] array = new byte[length];
|
||||
bb.position(start);
|
||||
bb.get(array);
|
||||
return array;
|
||||
}
|
||||
|
||||
/**
|
||||
* A utility function to copy and return the ByteBuffer data as a `byte[]`.
|
||||
*
|
||||
* @return A full copy of the {@link #dataBuffer() data buffer}.
|
||||
*/
|
||||
public byte[] sizedByteArray() {
|
||||
return sizedByteArray(space, bb.capacity() - space);
|
||||
}
|
||||
}
|
||||
|
||||
/// @}
|
||||
Reference in New Issue
Block a user