Squashed 'third_party/flatbuffers/' content from commit acc9990ab

Change-Id: I48550d40d78fea996ebe74e9723a5d1f910de491
git-subtree-dir: third_party/flatbuffers
git-subtree-split: acc9990abd2206491480291b0f85f925110102ea
diff --git a/php/ByteBuffer.php b/php/ByteBuffer.php
new file mode 100644
index 0000000..9929a7d
--- /dev/null
+++ b/php/ByteBuffer.php
@@ -0,0 +1,493 @@
+<?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;
+
+class ByteBuffer
+{
+    /**
+     * @var string $_buffer;
+     */
+    public $_buffer;
+
+    /**
+     * @var int $_pos;
+     */
+    private $_pos;
+
+    /**
+     * @var bool $_is_little_endian
+     */
+    private static $_is_little_endian = null;
+
+    public static function wrap($bytes)
+    {
+        $bb = new ByteBuffer(0);
+        $bb->_buffer = $bytes;
+
+        return $bb;
+    }
+
+    /**
+     * @param $size
+     */
+    public function __construct($size)
+    {
+        $this->_buffer = str_repeat("\0", $size);
+    }
+
+    /**
+     * @return int
+     */
+    public function capacity()
+    {
+        return strlen($this->_buffer);
+    }
+
+    /**
+     * @return int
+     */
+    public function getPosition()
+    {
+        return $this->_pos;
+    }
+
+    /**
+     * @param $pos
+     */
+    public function setPosition($pos)
+    {
+        $this->_pos = $pos;
+    }
+
+    /**
+     *
+     */
+    public function reset()
+    {
+        $this->_pos = 0;
+    }
+
+    /**
+     * @return int
+     */
+    public function length()
+    {
+        return strlen($this->_buffer);
+    }
+
+    /**
+     * @return string
+     */
+    public function data()
+    {
+        return substr($this->_buffer, $this->_pos);
+    }
+
+    /**
+     * @return bool
+     */
+    public static function isLittleEndian()
+    {
+        if (ByteBuffer::$_is_little_endian === null) {
+            ByteBuffer::$_is_little_endian = unpack('S', "\x01\x00")[1] === 1;
+        }
+
+        return ByteBuffer::$_is_little_endian;
+    }
+
+    /**
+     * write little endian value to the buffer.
+     *
+     * @param $offset
+     * @param $count byte length
+     * @param $data actual values
+     */
+    public function writeLittleEndian($offset, $count, $data)
+    {
+        if (ByteBuffer::isLittleEndian()) {
+            for ($i = 0; $i < $count; $i++) {
+                $this->_buffer[$offset + $i] = chr($data >> $i * 8);
+            }
+        } else {
+            for ($i = 0; $i < $count; $i++) {
+                $this->_buffer[$offset + $count - 1 - $i] = chr($data >> $i * 8);
+            }
+        }
+    }
+
+    /**
+     * read little endian value from the buffer
+     *
+     * @param $offset
+     * @param $count acutal size
+     * @return int
+     */
+    public function readLittleEndian($offset, $count, $force_bigendian = false)
+    {
+        $this->assertOffsetAndLength($offset, $count);
+        $r = 0;
+
+        if (ByteBuffer::isLittleEndian() && $force_bigendian == false) {
+            for ($i = 0; $i < $count; $i++) {
+                $r |= ord($this->_buffer[$offset + $i]) << $i * 8;
+            }
+        } else {
+            for ($i = 0; $i < $count; $i++) {
+                $r |= ord($this->_buffer[$offset + $count -1 - $i]) << $i * 8;
+            }
+        }
+
+        return $r;
+    }
+
+    /**
+     * @param $offset
+     * @param $length
+     */
+    public function assertOffsetAndLength($offset, $length)
+    {
+        if ($offset < 0 ||
+            $offset >= strlen($this->_buffer) ||
+            $offset + $length > strlen($this->_buffer)) {
+            throw new \OutOfRangeException(sprintf("offset: %d, length: %d, buffer; %d", $offset, $length, strlen($this->_buffer)));
+        }
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     * @return mixed
+     */
+    public function putSbyte($offset, $value)
+    {
+        self::validateValue(-128, 127, $value, "sbyte");
+
+        $length = strlen($value);
+        $this->assertOffsetAndLength($offset, $length);
+        return $this->_buffer[$offset] = $value;
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     * @return mixed
+     */
+    public function putByte($offset, $value)
+    {
+        self::validateValue(0, 255, $value, "byte");
+
+        $length = strlen($value);
+        $this->assertOffsetAndLength($offset, $length);
+        return $this->_buffer[$offset] = $value;
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     */
+    public function put($offset, $value)
+    {
+        $length = strlen($value);
+        $this->assertOffsetAndLength($offset, $length);
+        for ($i = 0; $i < $length; $i++) {
+            $this->_buffer[$offset + $i] = $value[$i];
+        }
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     */
+    public function putShort($offset, $value)
+    {
+        self::validateValue(-32768, 32767, $value, "short");
+
+        $this->assertOffsetAndLength($offset, 2);
+        $this->writeLittleEndian($offset, 2, $value);
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     */
+    public function putUshort($offset, $value)
+    {
+        self::validateValue(0, 65535, $value, "short");
+
+        $this->assertOffsetAndLength($offset, 2);
+        $this->writeLittleEndian($offset, 2, $value);
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     */
+    public function putInt($offset, $value)
+    {
+        // 2147483647 = (1 << 31) -1 = Maximum signed 32-bit int
+        // -2147483648 = -1 << 31 = Minimum signed 32-bit int
+        self::validateValue(-2147483648, 2147483647, $value, "int");
+
+        $this->assertOffsetAndLength($offset, 4);
+        $this->writeLittleEndian($offset, 4, $value);
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     */
+    public function putUint($offset, $value)
+    {
+        // NOTE: We can't put big integer value. this is PHP limitation.
+        // 4294967295 = (1 << 32) -1 = Maximum unsigned 32-bin int
+        self::validateValue(0, 4294967295, $value, "uint",  " php has big numbers limitation. check your PHP_INT_MAX");
+
+        $this->assertOffsetAndLength($offset, 4);
+        $this->writeLittleEndian($offset, 4, $value);
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     */
+    public function putLong($offset, $value)
+    {
+        // NOTE: We can't put big integer value. this is PHP limitation.
+        self::validateValue(~PHP_INT_MAX, PHP_INT_MAX, $value, "long",  " php has big numbers limitation. check your PHP_INT_MAX");
+
+        $this->assertOffsetAndLength($offset, 8);
+        $this->writeLittleEndian($offset, 8, $value);
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     */
+    public function putUlong($offset, $value)
+    {
+        // NOTE: We can't put big integer value. this is PHP limitation.
+        self::validateValue(0, PHP_INT_MAX, $value, "long", " php has big numbers limitation. check your PHP_INT_MAX");
+
+        $this->assertOffsetAndLength($offset, 8);
+        $this->writeLittleEndian($offset, 8, $value);
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     */
+    public function putFloat($offset, $value)
+    {
+        $this->assertOffsetAndLength($offset, 4);
+
+        $floathelper = pack("f", $value);
+        $v = unpack("V", $floathelper);
+        $this->writeLittleEndian($offset, 4, $v[1]);
+    }
+
+    /**
+     * @param $offset
+     * @param $value
+     */
+    public function putDouble($offset, $value)
+    {
+        $this->assertOffsetAndLength($offset, 8);
+
+        $floathelper = pack("d", $value);
+        $v = unpack("V*", $floathelper);
+
+        $this->writeLittleEndian($offset, 4, $v[1]);
+        $this->writeLittleEndian($offset + 4, 4, $v[2]);
+    }
+
+    /**
+     * @param $index
+     * @return mixed
+     */
+    public function getByte($index)
+    {
+        return ord($this->_buffer[$index]);
+    }
+
+    /**
+     * @param $index
+     * @return mixed
+     */
+    public function getSbyte($index)
+    {
+        $v = unpack("c", $this->_buffer[$index]);
+        return $v[1];
+    }
+
+    /**
+     * @param $buffer
+     */
+    public function getX(&$buffer)
+    {
+        for ($i = $this->_pos, $j = 0; $j < strlen($buffer); $i++, $j++) {
+            $buffer[$j] = $this->_buffer[$i];
+        }
+    }
+
+    /**
+     * @param $index
+     * @return mixed
+     */
+    public function get($index)
+    {
+        $this->assertOffsetAndLength($index, 1);
+        return $this->_buffer[$index];
+    }
+
+
+    /**
+     * @param $index
+     * @return mixed
+     */
+    public function getBool($index)
+    {
+        return (bool)ord($this->_buffer[$index]);
+    }
+
+    /**
+     * @param $index
+     * @return int
+     */
+    public function getShort($index)
+    {
+        $result = $this->readLittleEndian($index, 2);
+
+        $sign = $index + (ByteBuffer::isLittleEndian() ? 1 : 0);
+        $issigned = isset($this->_buffer[$sign]) && ord($this->_buffer[$sign]) & 0x80;
+
+        // 65536 = 1 << 16 = Maximum unsigned 16-bit int
+        return $issigned ? $result - 65536 : $result;
+    }
+
+    /**
+     * @param $index
+     * @return int
+     */
+    public function getUShort($index)
+    {
+        return $this->readLittleEndian($index, 2);
+    }
+
+    /**
+     * @param $index
+     * @return int
+     */
+    public function getInt($index)
+    {
+        $result = $this->readLittleEndian($index, 4);
+
+        $sign = $index + (ByteBuffer::isLittleEndian() ? 3 : 0);
+        $issigned = isset($this->_buffer[$sign]) && ord($this->_buffer[$sign]) & 0x80;
+
+        if (PHP_INT_SIZE > 4) {
+            // 4294967296 = 1 << 32 = Maximum unsigned 32-bit int
+            return $issigned ? $result - 4294967296 : $result;
+        } else {
+            // 32bit / Windows treated number as signed integer.
+            return $result;
+        }
+    }
+
+    /**
+     * @param $index
+     * @return int
+     */
+    public function getUint($index)
+    {
+        return $this->readLittleEndian($index, 4);
+    }
+
+    /**
+     * @param $index
+     * @return int
+     */
+    public function getLong($index)
+    {
+        return $this->readLittleEndian($index, 8);
+    }
+
+    /**
+     * @param $index
+     * @return int
+     */
+    public function getUlong($index)
+    {
+        return $this->readLittleEndian($index, 8);
+    }
+
+    /**
+     * @param $index
+     * @return mixed
+     */
+    public function getFloat($index)
+    {
+        $i = $this->readLittleEndian($index, 4);
+
+        return self::convertHelper(self::__FLOAT, $i);
+    }
+
+    /**
+     * @param $index
+     * @return float
+     */
+    public function getDouble($index)
+    {
+        $i = $this->readLittleEndian($index, 4);
+        $i2 = $this->readLittleEndian($index + 4, 4);
+
+        return self::convertHelper(self::__DOUBLE, $i, $i2);
+    }
+
+    const __SHORT = 1;
+    const __INT = 2;
+    const __LONG = 3;
+    const __FLOAT = 4;
+    const __DOUBLE = 5;
+    private static function convertHelper($type, $value, $value2 = null) {
+        // readLittleEndian construct unsigned integer value from bytes. we have to encode this value to
+        // correct bytes, and decode as expected types with `unpack` function.
+        // then it returns correct type value.
+        // see also: http://php.net/manual/en/function.pack.php
+
+        switch ($type) {
+            case self::__FLOAT:
+                $inthelper = pack("V", $value);
+                $v = unpack("f", $inthelper);
+                return $v[1];
+                break;
+            case self::__DOUBLE:
+                $inthelper = pack("VV", $value, $value2);
+                $v = unpack("d", $inthelper);
+                return $v[1];
+                break;
+            default:
+                throw new \Exception(sprintf("unexpected type %d specified", $type));
+        }
+    }
+
+    private static function validateValue($min, $max, $value, $type, $additional_notes = "") {
+        if(!($min <= $value && $value <= $max)) {
+            throw new \InvalidArgumentException(sprintf("bad number %s for type %s.%s", $value, $type, $additional_notes));
+        }
+    }
+}