flatbuffers/php/Table.php

146 lines
3.6 KiB
PHP

<?php
/*
* Copyright 2015 Google Inc.
*
* 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.
*/
namespace Google\FlatBuffers;
abstract class Table
{
/**
* @var int $bb_pos
*/
protected $bb_pos;
/**
* @var ByteBuffer $bb
*/
protected $bb;
public function __construct()
{
}
public function setByteBufferPos($pos)
{
$this->bb_pos = $pos;
}
public function setByteBuffer($bb)
{
$this->bb = $bb;
}
/**
* returns actual vtable offset
*
* @param $vtable_offset
* @return int offset > 0 means exist value. 0 means not exist
*/
protected function __offset($vtable_offset)
{
$vtable = $this->bb_pos - $this->bb->getInt($this->bb_pos);
return $vtable_offset < $this->bb->getShort($vtable) ? $this->bb->getShort($vtable + $vtable_offset) : 0;
}
/**
* @param $offset
* @return mixed
*/
protected function __indirect($offset)
{
return $offset + $this->bb->getInt($offset);
}
/**
* fetch utf8 encoded string.
*
* @param $offset
* @return string
*/
protected function __string($offset)
{
$offset += $this->bb->getInt($offset);
$len = $this->bb->getInt($offset);
$startPos = $offset + Constants::SIZEOF_INT;
return substr($this->bb->_buffer, $startPos, $len);
}
/**
* @param $offset
* @return int
*/
protected function __vector_len($offset)
{
$offset += $this->bb_pos;
$offset += $this->bb->getInt($offset);
return $this->bb->getInt($offset);
}
/**
* @param $offset
* @return int
*/
protected function __vector($offset)
{
$offset += $this->bb_pos;
// data starts after the length
return $offset + $this->bb->getInt($offset) + Constants::SIZEOF_INT;
}
protected function __vector_as_bytes($vector_offset, $elem_size=1)
{
$o = $this->__offset($vector_offset);
if ($o == 0) {
return null;
}
return substr($this->bb->_buffer, $this->__vector($o), $this->__vector_len($o) * $elem_size);
}
/**
* @param Table $table
* @param int $offset
* @return Table
*/
protected function __union($table, $offset)
{
$offset += $this->bb_pos;
$table->setByteBufferPos($offset + $this->bb->getInt($offset));
$table->setByteBuffer($this->bb);
return $table;
}
/**
* @param ByteBuffer $bb
* @param string $ident
* @return bool
* @throws \ArgumentException
*/
protected static function __has_identifier($bb, $ident)
{
if (strlen($ident) != Constants::FILE_IDENTIFIER_LENGTH) {
throw new \ArgumentException("FlatBuffers: file identifier must be length " . Constants::FILE_IDENTIFIER_LENGTH);
}
for ($i = 0; $i < 4; $i++) {
if ($ident[$i] != $bb->get($bb->getPosition() + Constants::SIZEOF_INT + $i)) {
return false;
}
}
return true;
}
}