1<?php
2/*
3 * Copyright 2015 Google Inc.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18namespace Google\FlatBuffers;
19
20abstract class Table
21{
22 /**
23 * @var int $bb_pos
24 */
25 protected $bb_pos;
26 /**
27 * @var ByteBuffer $bb
28 */
29 protected $bb;
30
31 public function __construct()
32 {
33 }
34
35 public function setByteBufferPos($pos)
36 {
37 $this->bb_pos = $pos;
38 }
39
40 public function setByteBuffer($bb)
41 {
42 $this->bb = $bb;
43 }
44
45 /**
46 * returns actual vtable offset
47 *
48 * @param $vtable_offset
49 * @return int offset > 0 means exist value. 0 means not exist
50 */
51 protected function __offset($vtable_offset)
52 {
53 $vtable = $this->bb_pos - $this->bb->getInt($this->bb_pos);
54 return $vtable_offset < $this->bb->getShort($vtable) ? $this->bb->getShort($vtable + $vtable_offset) : 0;
55 }
56
57 /**
58 * @param $offset
59 * @return mixed
60 */
61 protected function __indirect($offset)
62 {
63 return $offset + $this->bb->getInt($offset);
64 }
65
66 /**
67 * fetch utf8 encoded string.
68 *
69 * @param $offset
70 * @return string
71 */
72 protected function __string($offset)
73 {
74 $offset += $this->bb->getInt($offset);
75 $len = $this->bb->getInt($offset);
76 $startPos = $offset + Constants::SIZEOF_INT;
77 return substr($this->bb->_buffer, $startPos, $len);
78 }
79
80 /**
81 * @param $offset
82 * @return int
83 */
84 protected function __vector_len($offset)
85 {
86 $offset += $this->bb_pos;
87 $offset += $this->bb->getInt($offset);
88 return $this->bb->getInt($offset);
89 }
90
91 /**
92 * @param $offset
93 * @return int
94 */
95 protected function __vector($offset)
96 {
97 $offset += $this->bb_pos;
98 // data starts after the length
99 return $offset + $this->bb->getInt($offset) + Constants::SIZEOF_INT;
100 }
101
102 protected function __vector_as_bytes($vector_offset, $elem_size=1)
103 {
104 $o = $this->__offset($vector_offset);
105 if ($o == 0) {
106 return null;
107 }
108
109 return substr($this->bb->_buffer, $this->__vector($o), $this->__vector_len($o) * $elem_size);
110 }
111
112 /**
113 * @param Table $table
114 * @param int $offset
115 * @return Table
116 */
117 protected function __union($table, $offset)
118 {
119 $offset += $this->bb_pos;
120 $table->setByteBufferPos($offset + $this->bb->getInt($offset));
121 $table->setByteBuffer($this->bb);
122 return $table;
123 }
124
125 /**
126 * @param ByteBuffer $bb
127 * @param string $ident
128 * @return bool
129 * @throws \ArgumentException
130 */
131 protected static function __has_identifier($bb, $ident)
132 {
133 if (strlen($ident) != Constants::FILE_IDENTIFIER_LENGTH) {
134 throw new \ArgumentException("FlatBuffers: file identifier must be length " . Constants::FILE_IDENTIFIER_LENGTH);
135 }
136
137 for ($i = 0; $i < 4; $i++) {
138 if ($ident[$i] != $bb->get($bb->getPosition() + Constants::SIZEOF_INT + $i)) {
139 return false;
140 }
141 }
142
143 return true;
144 }
145}
View as plain text