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<?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.
*/
/// @file
/// @addtogroup flatbuffers_php_api
/// @{
namespace Google\FlatBuffers;
final class FlatbufferBuilder
{
/**
* Internal ByteBuffer for the FlatBuffer data.
* @var ByteBuffer $bb
*/
public $bb;
/// @cond FLATBUFFERS_INTERNAL
/**
* @var int $space
*/
protected $space;
/**
* @var int $minalign
*/
protected $minalign = 1;
/**
* @var array $vtable
*/
protected $vtable;
/**
* @var int $vtable_in_use
*/
protected $vtable_in_use = 0;
/**
* @var bool $nested
*/
protected $nested = false;
/**
* @var int $object_start
*/
protected $object_start;
/**
* @var array $vtables
*/
protected $vtables = array();
/**
* @var int $num_vtables
*/
protected $num_vtables = 0;
/**
* @var int $vector_num_elems
*/
protected $vector_num_elems = 0;
/**
* @var bool $force_defaults
*/
protected $force_defaults = false;
/// @endcond
/**
* Create a FlatBufferBuilder with a given initial size.
*
* @param $initial_size initial byte buffer size.
*/
public function __construct($initial_size)
{
if ($initial_size <= 0) {
$initial_size = 1;
}
$this->space = $initial_size;
$this->bb = $this->newByteBuffer($initial_size);
}
/// @cond FLATBUFFERS_INTERNAL
/**
* create new bytebuffer
*
* @param $size
* @return ByteBuffer
*/
private function newByteBuffer($size)
{
return new ByteBuffer($size);
}
/**
* Returns the current ByteBuffer offset.
*
* @return int
*/
public function offset()
{
return $this->bb->capacity() - $this->space;
}
/**
* padding buffer
*
* @param $byte_size
*/
public function pad($byte_size)
{
for ($i = 0; $i < $byte_size; $i++) {
$this->bb->putByte(--$this->space, "\0");
}
}
/**
* prepare bytebuffer
*
* @param $size
* @param $additional_bytes
* @throws \Exception
*/
public function prep($size, $additional_bytes)
{
if ($size > $this->minalign) {
$this->minalign = $size;
}
$align_size = ((~($this->bb->capacity() - $this->space + $additional_bytes)) + 1) & ($size - 1);
while ($this->space < $align_size + $size + $additional_bytes) {
$old_buf_size = $this->bb->capacity();
$this->bb = $this->growByteBuffer($this->bb);
$this->space += $this->bb->capacity() - $old_buf_size;
}
$this->pad($align_size);
}
/**
* @param ByteBuffer $bb
* @return ByteBuffer
* @throws \Exception
*/
private static function growByteBuffer(ByteBuffer $bb)
{
$old_buf_size = $bb->capacity();
if (($old_buf_size & 0xC0000000) != 0) {
throw new \Exception("FlatBuffers: cannot grow buffer beyond 2 gigabytes");
}
$new_buf_size = $old_buf_size << 1;
$bb->setPosition(0);
$nbb = new ByteBuffer($new_buf_size);
$nbb->setPosition($new_buf_size - $old_buf_size);
// TODO(chobie): is this little bit faster?
//$nbb->_buffer = substr_replace($nbb->_buffer, $bb->_buffer, $new_buf_size - $old_buf_size, strlen($bb->_buffer));
for ($i = $new_buf_size - $old_buf_size, $j = 0; $j < strlen($bb->_buffer); $i++, $j++) {
$nbb->_buffer[$i] = $bb->_buffer[$j];
}
return $nbb;
}
/**
* @param $x
*/
public function putBool($x)
{
$this->bb->put($this->space -= 1, chr((int)(bool)($x)));
}
/**
* @param $x
*/
public function putByte($x)
{
$this->bb->put($this->space -= 1, chr($x));
}
/**
* @param $x
*/
public function putSbyte($x)
{
$this->bb->put($this->space -= 1, chr($x));
}
/**
* @param $x
*/
public function putShort($x)
{
$this->bb->putShort($this->space -= 2, $x);
}
/**
* @param $x
*/
public function putUshort($x)
{
$this->bb->putUshort($this->space -= 2, $x);
}
/**
* @param $x
*/
public function putInt($x)
{
$this->bb->putInt($this->space -= 4, $x);
}
/**
* @param $x
*/
public function putUint($x)
{
if ($x > PHP_INT_MAX) {
throw new \InvalidArgumentException("your platform can't handle uint correctly. use 64bit machine.");
}
$this->bb->putUint($this->space -= 4, $x);
}
/**
* @param $x
*/
public function putLong($x)
{
if ($x > PHP_INT_MAX) {
throw new \InvalidArgumentException("Your platform can't handle long correctly. Use a 64bit machine.");
}
$this->bb->putLong($this->space -= 8, $x);
}
/**
* @param $x
*/
public function putUlong($x)
{
if ($x > PHP_INT_MAX) {
throw new \InvalidArgumentException("Your platform can't handle ulong correctly. This is a php limitation. Please wait for the extension release.");
}
$this->bb->putUlong($this->space -= 8, $x);
}
/**
* @param $x
*/
public function putFloat($x)
{
$this->bb->putFloat($this->space -= 4, $x);
}
/**
* @param $x
*/
public function putDouble($x)
{
$this->bb->putDouble($this->space -= 8, $x);
}
/**
* @param $off
*/
public function putOffset($off)
{
$new_off = $this->offset() - $off + Constants::SIZEOF_INT;
$this->putInt($new_off);
}
/// @endcond
/**
* Add a `bool` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `bool` to add to the buffer.
*/
public function addBool($x)
{
$this->prep(1, 0);
$this->putBool($x);
}
/**
* Add a `byte` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `byte` to add to the buffer.
*/
public function addByte($x)
{
$this->prep(1, 0);
$this->putByte($x);
}
/**
* Add a `signed byte` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `signed byte` to add to the buffer.
*/
public function addSbyte($x)
{
$this->prep(1, 0);
$this->putSbyte($x);
}
/**
* Add a `short` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `short` to add to the buffer.
*/
public function addShort($x)
{
$this->prep(2, 0);
$this->putShort($x);
}
/**
* Add an `unsigned short` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `unsigned short` to add to the buffer.
*/
public function addUshort($x)
{
$this->prep(2, 0);
$this->putUshort($x);
}
/**
* Add an `int` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `int` to add to the buffer.
*/
public function addInt($x)
{
$this->prep(4, 0);
$this->putInt($x);
}
/**
* Add an `unsigned int` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `unsigned int` to add to the buffer.
*/
public function addUint($x)
{
$this->prep(4, 0);
$this->putUint($x);
}
/**
* Add a `long` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `long` to add to the buffer.
*/
public function addLong($x)
{
$this->prep(8, 0);
$this->putLong($x);
}
/**
* Add an `unsigned long` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `unsigned long` to add to the buffer.
*/
public function addUlong($x)
{
$this->prep(8, 0);
$this->putUlong($x);
}
/**
* Add a `float` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `float` to add to the buffer.
*/
public function addFloat($x)
{
$this->prep(4, 0);
$this->putFloat($x);
}
/**
* Add a `double` to the buffer, properly aligned, and grows the buffer (if necessary).
* @param $x The `double` to add to the buffer.
*/
public function addDouble($x)
{
$this->prep(8, 0);
$this->putDouble($x);
}
/// @cond FLATBUFFERS_INTERNAL
/**
* @param $o
* @param $x
* @param $d
*/
public function addBoolX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addBool($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addByteX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addByte($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addSbyteX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addSbyte($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addShortX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addShort($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addUshortX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addUshort($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addIntX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addInt($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addUintX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addUint($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addLongX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addLong($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addUlongX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addUlong($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addFloatX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addFloat($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
*/
public function addDoubleX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addDouble($x);
$this->slot($o);
}
}
/**
* @param $o
* @param $x
* @param $d
* @throws \Exception
*/
public function addOffsetX($o, $x, $d)
{
if ($this->force_defaults || $x != $d) {
$this->addOffset($x);
$this->slot($o);
}
}
/// @endcond
/**
* Adds on offset, relative to where it will be written.
* @param $off The offset to add to the buffer.
* @throws \Exception Throws an exception if `$off` is greater than the underlying ByteBuffer's
* offest.
*/
public function addOffset($off)
{
$this->prep(Constants::SIZEOF_INT, 0); // Ensure alignment is already done
if ($off > $this->offset()) {
throw new \Exception("");
}
$this->putOffset($off);
}
/// @cond FLATBUFFERS_INTERNAL
/**
* @param $elem_size
* @param $num_elems
* @param $alignment
* @throws \Exception
*/
public function startVector($elem_size, $num_elems, $alignment)
{
$this->notNested();
$this->vector_num_elems = $num_elems;
$this->prep(Constants::SIZEOF_INT, $elem_size * $num_elems);
$this->prep($alignment, $elem_size * $num_elems); // Just in case alignemnt > int;
}
/**
* @return int
*/
public function endVector()
{
$this->putUint($this->vector_num_elems);
return $this->offset();
}
protected function is_utf8($bytes)
{
if (function_exists('mb_detect_encoding')) {
return (bool) mb_detect_encoding($bytes, 'UTF-8', true);
}
$len = strlen($bytes);
if ($len < 1) {
/* NOTE: always return 1 when passed string is null */
return true;
}
for ($j = 0, $i = 0; $i < $len; $i++) {
// check ACII
if ($bytes[$j] == "\x09" ||
$bytes[$j] == "\x0A" ||
$bytes[$j] == "\x0D" ||
($bytes[$j] >= "\x20" && $bytes[$j] <= "\x7E")) {
$j++;
continue;
}
/* non-overlong 2-byte */
if ((($i+1) <= $len) &&
($bytes[$j] >= "\xC2" && $bytes[$j] <= "\xDF" &&
($bytes[$j+1] >= "\x80" && $bytes[$j+1] <= "\xBF"))) {
$j += 2;
$i++;
continue;
}
/* excluding overlongs */
if ((($i + 2) <= $len) &&
$bytes[$j] == "\xE0" &&
($bytes[$j+1] >= "\xA0" && $bytes[$j+1] <= "\xBF" &&
($bytes[$j+2] >= "\x80" && $bytes[$j+2] <= "\xBF"))) {
$bytes += 3;
$i +=2;
continue;
}
/* straight 3-byte */
if ((($i+2) <= $len) &&
(($bytes[$j] >= "\xE1" && $bytes[$j] <= "\xEC") ||
$bytes[$j] == "\xEE" ||
$bytes[$j] = "\xEF") &&
($bytes[$j+1] >= "\x80" && $bytes[$j+1] <= "\xBF") &&
($bytes[$j+2] >= "\x80" && $bytes[$j+2] <= "\xBF")) {
$j += 3;
$i += 2;
continue;
}
/* excluding surrogates */
if ((($i+2) <= $len) &&
$bytes[$j] == "\xED" &&
($bytes[$j+1] >= "\x80" && $bytes[$j+1] <= "\x9f" &&
($bytes[$j+2] >= "\x80" && $bytes[$j+2] <= "\xBF"))) {
$j += 3;
$i += 2;
continue;
}
/* planes 1-3 */
if ((($i + 3) <= $len) &&
$bytes[$j] == "\xF0" &&
($bytes[$j+1] >= "\x90" && $bytes[$j+1] <= "\xBF") &&
($bytes[$j+2] >= "\x80" && $bytes[$j+2] <= "\xBF") &&
($bytes[$j+3] >= "\x80" && $bytes[$j+3] <= "\xBF")) {
$j += 4;
$i += 3;
continue;
}
/* planes 4-15 */
if ((($i+3) <= $len) &&
$bytes[$j] >= "\xF1" && $bytes[$j] <= "\xF3" &&
$bytes[$j+1] >= "\x80" && $bytes[$j+1] <= "\xBF" &&
$bytes[$j+2] >= "\x80" && $bytes[$j+2] <= "\xBF" &&
$bytes[$j+3] >= "\x80" && $bytes[$j+3] <= "\xBF"
) {
$j += 4;
$i += 3;
continue;
}
/* plane 16 */
if ((($i+3) <= $len) &&
$bytes[$j] == "\xF4" &&
($bytes[$j+1] >= "\x80" && $bytes[$j+1] <= "\x8F") &&
($bytes[$j+2] >= "\x80" && $bytes[$j+2] <= "\xBF") &&
($bytes[$j+3] >= "\x80" && $bytes[$j+3] <= "\xBF")
) {
$bytes += 4;
$i += 3;
continue;
}
return false;
}
return true;
}
/// @endcond
/**
* Encode the string `$s` in the buffer using UTF-8.
* @param string $s The string to encode.
* @return int The offset in the buffer where the encoded string starts.
* @throws InvalidArgumentException Thrown if the input string `$s` is not
* UTF-8.
*/
public function createString($s)
{
if (!$this->is_utf8($s)) {
throw new \InvalidArgumentException("string must be utf-8 encoded value.");
}
$this->notNested();
$this->addByte(0); // null terminated
$this->startVector(1, strlen($s), 1);
$this->space -= strlen($s);
for ($i = $this->space, $j = 0 ; $j < strlen($s) ; $i++, $j++) {
$this->bb->_buffer[$i] = $s[$j];
}
return $this->endVector();
}
/// @cond FLATBUFFERS_INTERNAL
/**
* @throws \Exception
*/
public function notNested()
{
if ($this->nested) {
throw new \Exception("FlatBuffers; object serialization must not be nested");
}
}
/**
* @param $obj
* @throws \Exception
*/
public function nested($obj)
{
if ($obj != $this->offset()) {
throw new \Exception("FlatBuffers: struct must be serialized inline");
}
}
/**
* @param $numfields
* @throws \Exception
*/
public function startObject($numfields)
{
$this->notNested();
if ($this->vtable == null || count($this->vtable) < $numfields) {
$this->vtable = array();
}
$this->vtable_in_use = $numfields;
for ($i = 0; $i < $numfields; $i++) {
$this->vtable[$i] = 0;
}
$this->nested = true;
$this->object_start = $this->offset();
}
/**
* @param $voffset
* @param $x
* @param $d
* @throws \Exception
*/
public function addStructX($voffset, $x, $d)
{
if ($x != $d) {
$this->nested($x);
$this->slot($voffset);
}
}
/**
* @param $voffset
* @param $x
* @param $d
* @throws \Exception
*/
public function addStruct($voffset, $x, $d)
{
if ($x != $d) {
$this->nested($x);
$this->slot($voffset);
}
}
/**
* @param $voffset
*/
public function slot($voffset)
{
$this->vtable[$voffset] = $this->offset();
}
/**
* @return int
* @throws \Exception
*/
public function endObject()
{
if ($this->vtable == null || !$this->nested) {
throw new \Exception("FlatBuffers: endObject called without startObject");
}
$this->addInt(0);
$vtableloc = $this->offset();
$i = $this->vtable_in_use -1;
// Trim trailing zeroes.
for (; $i >= 0 && $this->vtable[$i] == 0; $i--) {}
$trimmed_size = $i + 1;
for (; $i >= 0; $i--) {
$off = ($this->vtable[$i] != 0) ? $vtableloc - $this->vtable[$i] : 0;
$this->addShort($off);
}
$standard_fields = 2; // the fields below
$this->addShort($vtableloc - $this->object_start);
$this->addShort(($trimmed_size + $standard_fields) * Constants::SIZEOF_SHORT);
// search for an existing vtable that matches the current one.
$existing_vtable = 0;
for ($i = 0; $i < $this->num_vtables; $i++) {
$vt1 = $this->bb->capacity() - $this->vtables[$i];
$vt2 = $this->space;
$len = $this->bb->getShort($vt1);
if ($len == $this->bb->getShort($vt2)) {
for ($j = Constants::SIZEOF_SHORT; $j < $len; $j += Constants::SIZEOF_SHORT) {
if ($this->bb->getShort($vt1 + $j) != $this->bb->getShort($vt2 + $j)) {
continue 2;
}
}
$existing_vtable = $this->vtables[$i];
break;
}
}
if ($existing_vtable != 0) {
// Found a match:
// Remove the current vtable
$this->space = $this->bb->capacity() - $vtableloc;
$this->bb->putInt($this->space, $existing_vtable - $vtableloc);
} else {
// No Match:
// Add the location of the current vtable to the list of vtables
if ($this->num_vtables == count($this->vtables)) {
$vtables = $this->vtables;
$this->vtables = array();
// copy of
for ($i = 0; $i < count($vtables) * 2; $i++) {
$this->vtables[$i] = ($i < count($vtables)) ? $vtables[$i] : 0;
}
}
$this->vtables[$this->num_vtables++] = $this->offset();
$this->bb->putInt($this->bb->capacity() - $vtableloc, $this->offset() - $vtableloc);
}
$this->nested = false;
$this->vtable = null;
return $vtableloc;
}
/**
* @param $table
* @param $field
* @throws \Exception
*/
public function required($table, $field)
{
$table_start = $this->bb->capacity() - $table;
$vtable_start = $table_start - $this->bb->getInt($table_start);
$ok = $this->bb->getShort($vtable_start + $field) != 0;
if (!$ok) {
throw new \Exception("FlatBuffers: field " . $field . " must be set");
}
}
/// @endcond
/**
* Finalize a buffer, pointing to the given `$root_table`.
* @param $root_table An offest to be added to the buffer.
* @param $file_identifier A FlatBuffer file identifier to be added to the
* buffer before `$root_table`. This defaults to `null`.
* @throws InvalidArgumentException Thrown if an invalid `$identifier` is
* given, where its length is not equal to
* `Constants::FILE_IDENTIFIER_LENGTH`.
*/
public function finish($root_table, $identifier = null)
{
if ($identifier == null) {
$this->prep($this->minalign, Constants::SIZEOF_INT);
$this->addOffset($root_table);
$this->bb->setPosition($this->space);
} else {
$this->prep($this->minalign, Constants::SIZEOF_INT + Constants::FILE_IDENTIFIER_LENGTH);
if (strlen($identifier) != Constants::FILE_IDENTIFIER_LENGTH) {
throw new \InvalidArgumentException(
sprintf("FlatBuffers: file identifier must be length %d",
Constants::FILE_IDENTIFIER_LENGTH));
}
for ($i = Constants::FILE_IDENTIFIER_LENGTH - 1; $i >= 0;
$i--) {
$this->addByte(ord($identifier[$i]));
}
$this->finish($root_table);
}
}
/**
* In order to save space, fields that are set to their default value don't
* get serialized into the buffer.
* @param bool $forceDefaults When set to `true`, always serializes default
* values.
*/
public function forceDefaults($forceDefaults)
{
$this->force_defaults = $forceDefaults;
}
/**
* Get the ByteBuffer representing the FlatBuffer.
* @return ByteBuffer The ByteBuffer containing the FlatBuffer data.
*/
public function dataBuffer()
{
return $this->bb;
}
/// @cond FLATBUFFERS_INTERNAL
/**
* @return int
*/
public function dataStart()
{
return $this->space;
}
/// @endcond
/**
* Utility function to copy and return the FlatBuffer data from the
* underlying ByteBuffer.
* @return string A string (representing a byte[]) that contains a copy
* of the FlatBuffer data.
*/
public function sizedByteArray()
{
$start = $this->space;
$length = $this->bb->capacity() - $this->space;
$result = str_repeat("\0", $length);
$this->bb->setPosition($start);
$this->bb->getX($result);
return $result;
}
}
/// @}