java/com/google/flatbuffers/Table.java - third_party/flatbuffers - Git at Google

 /*
  * 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;
 import java.nio.CharBuffer;
 import java.nio.charset.CharacterCodingException;
 import java.nio.charset.Charset;
 import java.nio.charset.CharsetDecoder;
 import java.nio.charset.CoderResult;

 /// @cond FLATBUFFERS_INTERNAL

 /**
  * All tables in the generated code derive from this class, and add their own accessors.
  */
 public class Table {
   private final static ThreadLocal<CharsetDecoder> UTF8_DECODER = new ThreadLocal<CharsetDecoder>() {
     @Override
     protected CharsetDecoder initialValue() {
       return Charset.forName("UTF-8").newDecoder();
     }
   };
   public final static ThreadLocal<Charset> UTF8_CHARSET = new ThreadLocal<Charset>() {
     @Override
     protected Charset initialValue() {
       return Charset.forName("UTF-8");
     }
   };
   private final static ThreadLocal<CharBuffer> CHAR_BUFFER = new ThreadLocal<CharBuffer>();
   /** Used to hold the position of the `bb` buffer. */
   protected int bb_pos;
   /** The underlying ByteBuffer to hold the data of the Table. */
   protected ByteBuffer bb;

   /**
    * Get the underlying ByteBuffer.
    *
    * @return Returns the Table's ByteBuffer.
    */
   public ByteBuffer getByteBuffer() { return bb; }

   /**
    * Look up a field in the vtable.
    *
    * @param vtable_offset An `int` offset to the vtable in the Table's ByteBuffer.
    * @return Returns 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;
   }

   protected static int __offset(int vtable_offset, int offset, ByteBuffer bb) {
     int vtable = bb.array().length - offset;
     return bb.getShort(vtable + vtable_offset - bb.getInt(vtable)) + vtable;
   }

   /**
    * Retrieve a relative offset.
    *
    * @param offset An `int` index into the Table's ByteBuffer containing the relative offset.
    * @return Returns the relative offset stored at `offset`.
    */
   protected int __indirect(int offset) {
     return offset + bb.getInt(offset);
   }

   protected static int __indirect(int offset, ByteBuffer bb) {
     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.
    *
    * @param offset An `int` index into the Table's ByteBuffer.
    * @return Returns a `String` from the data stored inside the FlatBuffer at `offset`.
    */
   protected String __string(int offset) {
     CharsetDecoder decoder = UTF8_DECODER.get();
     decoder.reset();

     offset += bb.getInt(offset);
     ByteBuffer src = bb.duplicate().order(ByteOrder.LITTLE_ENDIAN);
     int length = src.getInt(offset);
     src.position(offset + SIZEOF_INT);
     src.limit(offset + SIZEOF_INT + length);

     int required = (int)((float)length * decoder.maxCharsPerByte());
     CharBuffer dst = CHAR_BUFFER.get();
     if (dst == null || dst.capacity() < required) {
       dst = CharBuffer.allocate(required);
       CHAR_BUFFER.set(dst);
     }

     dst.clear();

     try {
       CoderResult cr = decoder.decode(src, dst, true);
       if (!cr.isUnderflow()) {
         cr.throwException();
       }
     } catch (CharacterCodingException x) {
       throw new Error(x);
     }

     return dst.flip().toString();
   }

   /**
    * Get the length of a vector.
    *
    * @param offset An `int` index into the Table's ByteBuffer.
    * @return Returns the length of the vector whose offset is stored at `offset`.
    */
   protected int __vector_len(int offset) {
     offset += bb_pos;
     offset += bb.getInt(offset);
     return bb.getInt(offset);
   }

   /**
    * Get the start data of a vector.
    *
    * @param offset An `int` index into the Table's ByteBuffer.
    * @return Returns the start of the vector data whose offset is stored at `offset`.
    */
   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 {@link 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.
    *
    * @param vector_offset The position of the vector in the byte buffer
    * @param elem_size The size of each element in the array
    * @return The {@link ByteBuffer} for the array
    */
   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`.
    *
    * @param t A `Table`-derived type that should point to the union at `offset`.
    * @param offset An `int` index into the Table's ByteBuffer.
    * @return Returns the Table that points to the union at `offset`.
    */
   protected Table __union(Table t, int offset) {
     offset += bb_pos;
     t.bb_pos = offset + bb.getInt(offset);
     t.bb = bb;
     return t;
   }

   /**
    * Check if a {@link ByteBuffer} contains a file identifier.
    *
    * @param bb A {@code ByteBuffer} to check if it contains the identifier
    * `ident`.
    * @param ident A `String` identifier of the FlatBuffer file.
    * @return True if the buffer contains the file identifier
    */
   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;
   }

   /**
    * Sort tables by the key.
    *
    * @param offsets An 'int' indexes of the tables into the bb.
    * @param bb A {@code ByteBuffer} to get the tables.
    */
   protected void sortTables(int[] offsets, final ByteBuffer bb) {
     Integer[] off = new Integer[offsets.length];
     for (int i = 0; i < offsets.length; i++) off[i] = offsets[i];
     java.util.Arrays.sort(off, new java.util.Comparator<Integer>() {
       public int compare(Integer o1, Integer o2) {
         return keysCompare(o1, o2, bb);
       }
     });
     for (int i = 0; i < offsets.length; i++) offsets[i] = off[i];
   }

   /**
    * Compare two tables by the key.
    *
    * @param o1 An 'Integer' index of the first key into the bb.
    * @param o2 An 'Integer' index of the second key into the bb.
    * @param bb A {@code ByteBuffer} to get the keys.
    */
   protected int keysCompare(Integer o1, Integer o2, ByteBuffer bb) { return 0; }

   /**
    * Compare two strings in the buffer.
    *
    * @param offset_1 An 'int' index of the first string into the bb.
    * @param offset_2 An 'int' index of the second string into the bb.
    * @param bb A {@code ByteBuffer} to get the strings.
    */
   protected static int compareStrings(int offset_1, int offset_2, ByteBuffer bb) {
     offset_1 += bb.getInt(offset_1);
     offset_2 += bb.getInt(offset_2);
     int len_1 = bb.getInt(offset_1);
     int len_2 = bb.getInt(offset_2);
     int startPos_1 = offset_1 + SIZEOF_INT;
     int startPos_2 = offset_2 + SIZEOF_INT;
     int len = Math.min(len_1, len_2);
     byte[] bbArray = bb.array();
     for(int i = 0; i < len; i++) {
       if (bbArray[i + startPos_1] != bbArray[i + startPos_2])
         return bbArray[i + startPos_1] - bbArray[i + startPos_2];
     }
     return len_1 - len_2;
   }

   /**
    * Compare string from the buffer with the 'String' object.
    *
    * @param offset_1 An 'int' index of the first string into the bb.
    * @param key Second string as a byte array.
    * @param bb A {@code ByteBuffer} to get the first string.
    */
   protected static int compareStrings(int offset_1, byte[] key, ByteBuffer bb) {
     offset_1 += bb.getInt(offset_1);
     int len_1 = bb.getInt(offset_1);
     int len_2 = key.length;
     int startPos_1 = offset_1 + Constants.SIZEOF_INT;
     int len = Math.min(len_1, len_2);
     byte[] bbArray = bb.array();
     for (int i = 0; i < len; i++) {
       if (bbArray[i + startPos_1] != key[i])
         return bbArray[i + startPos_1] - key[i];
     }
     return len_1 - len_2;
   }
 }

 /// @endcond
	/*
	* 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;
	import java.nio.CharBuffer;
	import java.nio.charset.CharacterCodingException;
	import java.nio.charset.Charset;
	import java.nio.charset.CharsetDecoder;
	import java.nio.charset.CoderResult;

	/// @cond FLATBUFFERS_INTERNAL

	/**
	* All tables in the generated code derive from this class, and add their own accessors.
	*/
	public class Table {
	private final static ThreadLocal<CharsetDecoder> UTF8_DECODER = new ThreadLocal<CharsetDecoder>() {
	@Override
	protected CharsetDecoder initialValue() {
	return Charset.forName("UTF-8").newDecoder();
	}
	};
	public final static ThreadLocal<Charset> UTF8_CHARSET = new ThreadLocal<Charset>() {
	@Override
	protected Charset initialValue() {
	return Charset.forName("UTF-8");
	}
	};
	private final static ThreadLocal<CharBuffer> CHAR_BUFFER = new ThreadLocal<CharBuffer>();
	/** Used to hold the position of the `bb` buffer. */
	protected int bb_pos;
	/** The underlying ByteBuffer to hold the data of the Table. */
	protected ByteBuffer bb;

	/**
	* Get the underlying ByteBuffer.
	*
	* @return Returns the Table's ByteBuffer.
	*/
	public ByteBuffer getByteBuffer() { return bb; }

	/**
	* Look up a field in the vtable.
	*
	* @param vtable_offset An `int` offset to the vtable in the Table's ByteBuffer.
	* @return Returns 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;
	}

	protected static int __offset(int vtable_offset, int offset, ByteBuffer bb) {
	int vtable = bb.array().length - offset;
	return bb.getShort(vtable + vtable_offset - bb.getInt(vtable)) + vtable;
	}

	/**
	* Retrieve a relative offset.
	*
	* @param offset An `int` index into the Table's ByteBuffer containing the relative offset.
	* @return Returns the relative offset stored at `offset`.
	*/
	protected int __indirect(int offset) {
	return offset + bb.getInt(offset);
	}

	protected static int __indirect(int offset, ByteBuffer bb) {
	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.
	*
	* @param offset An `int` index into the Table's ByteBuffer.
	* @return Returns a `String` from the data stored inside the FlatBuffer at `offset`.
	*/
	protected String __string(int offset) {
	CharsetDecoder decoder = UTF8_DECODER.get();
	decoder.reset();

	offset += bb.getInt(offset);
	ByteBuffer src = bb.duplicate().order(ByteOrder.LITTLE_ENDIAN);
	int length = src.getInt(offset);
	src.position(offset + SIZEOF_INT);
	src.limit(offset + SIZEOF_INT + length);

	int required = (int)((float)length * decoder.maxCharsPerByte());
	CharBuffer dst = CHAR_BUFFER.get();
	if (dst == null \|\| dst.capacity() < required) {
	dst = CharBuffer.allocate(required);
	CHAR_BUFFER.set(dst);
	}

	dst.clear();

	try {
	CoderResult cr = decoder.decode(src, dst, true);
	if (!cr.isUnderflow()) {
	cr.throwException();
	}
	} catch (CharacterCodingException x) {
	throw new Error(x);
	}

	return dst.flip().toString();
	}

	/**
	* Get the length of a vector.
	*
	* @param offset An `int` index into the Table's ByteBuffer.
	* @return Returns the length of the vector whose offset is stored at `offset`.
	*/
	protected int __vector_len(int offset) {
	offset += bb_pos;
	offset += bb.getInt(offset);
	return bb.getInt(offset);
	}

	/**
	* Get the start data of a vector.
	*
	* @param offset An `int` index into the Table's ByteBuffer.
	* @return Returns the start of the vector data whose offset is stored at `offset`.
	*/
	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 {@link 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.
	*
	* @param vector_offset The position of the vector in the byte buffer
	* @param elem_size The size of each element in the array
	* @return The {@link ByteBuffer} for the array
	*/
	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`.
	*
	* @param t A `Table`-derived type that should point to the union at `offset`.
	* @param offset An `int` index into the Table's ByteBuffer.
	* @return Returns the Table that points to the union at `offset`.
	*/
	protected Table __union(Table t, int offset) {
	offset += bb_pos;
	t.bb_pos = offset + bb.getInt(offset);
	t.bb = bb;
	return t;
	}

	/**
	* Check if a {@link ByteBuffer} contains a file identifier.
	*
	* @param bb A {@code ByteBuffer} to check if it contains the identifier
	* `ident`.
	* @param ident A `String` identifier of the FlatBuffer file.
	* @return True if the buffer contains the file identifier
	*/
	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;
	}

	/**
	* Sort tables by the key.
	*
	* @param offsets An 'int' indexes of the tables into the bb.
	* @param bb A {@code ByteBuffer} to get the tables.
	*/
	protected void sortTables(int[] offsets, final ByteBuffer bb) {
	Integer[] off = new Integer[offsets.length];
	for (int i = 0; i < offsets.length; i++) off[i] = offsets[i];
	java.util.Arrays.sort(off, new java.util.Comparator<Integer>() {
	public int compare(Integer o1, Integer o2) {
	return keysCompare(o1, o2, bb);
	}
	});
	for (int i = 0; i < offsets.length; i++) offsets[i] = off[i];
	}

	/**
	* Compare two tables by the key.
	*
	* @param o1 An 'Integer' index of the first key into the bb.
	* @param o2 An 'Integer' index of the second key into the bb.
	* @param bb A {@code ByteBuffer} to get the keys.
	*/
	protected int keysCompare(Integer o1, Integer o2, ByteBuffer bb) { return 0; }

	/**
	* Compare two strings in the buffer.
	*
	* @param offset_1 An 'int' index of the first string into the bb.
	* @param offset_2 An 'int' index of the second string into the bb.
	* @param bb A {@code ByteBuffer} to get the strings.
	*/
	protected static int compareStrings(int offset_1, int offset_2, ByteBuffer bb) {
	offset_1 += bb.getInt(offset_1);
	offset_2 += bb.getInt(offset_2);
	int len_1 = bb.getInt(offset_1);
	int len_2 = bb.getInt(offset_2);
	int startPos_1 = offset_1 + SIZEOF_INT;
	int startPos_2 = offset_2 + SIZEOF_INT;
	int len = Math.min(len_1, len_2);
	byte[] bbArray = bb.array();
	for(int i = 0; i < len; i++) {
	if (bbArray[i + startPos_1] != bbArray[i + startPos_2])
	return bbArray[i + startPos_1] - bbArray[i + startPos_2];
	}
	return len_1 - len_2;
	}

	/**
	* Compare string from the buffer with the 'String' object.
	*
	* @param offset_1 An 'int' index of the first string into the bb.
	* @param key Second string as a byte array.
	* @param bb A {@code ByteBuffer} to get the first string.
	*/
	protected static int compareStrings(int offset_1, byte[] key, ByteBuffer bb) {
	offset_1 += bb.getInt(offset_1);
	int len_1 = bb.getInt(offset_1);
	int len_2 = key.length;
	int startPos_1 = offset_1 + Constants.SIZEOF_INT;
	int len = Math.min(len_1, len_2);
	byte[] bbArray = bb.array();
	for (int i = 0; i < len; i++) {
	if (bbArray[i + startPos_1] != key[i])
	return bbArray[i + startPos_1] - key[i];
	}
	return len_1 - len_2;
	}
	}

	/// @endcond