Buffer::jumpto() - Code Metrics - Austinb/GameQ - Measure and Improve Code Quality continuously with Scrutinizer

Buffer::jumpto() A
last analyzed 2025-02-19 14:42 UTC

↳ Parent: Buffer

Complexity

Conditions	1
Paths	1

Size

Total Lines	3
Code Lines	1

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	1

Importance

Changes	1
Bugs	1	Features	0

Metric	Value
eloc	1
c	1
b	1
f	0
dl	0
loc	3
ccs	2
cts	2
cp	1
rs	10
cc	1
nc	1
nop	1
crap	1

<?php
/**
 * This file is part of GameQ.
 *
 * GameQ is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * GameQ is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 */

namespace GameQ;

use GameQ\Exception\Protocol as Exception;

/**
 * Class Buffer
 *
 * Read specific byte sequences from a provided string or Buffer
 *
 * @package GameQ
 *
 * @author  Austin Bischoff <[email protected]>
 * @author  Aidan Lister <[email protected]>
 * @author  Tom Buskens <[email protected]>
 */
class Buffer
{
    /**
     * Constants for the byte code types we need to read as
     */
    const NUMBER_TYPE_BIGENDIAN = 'be',
        NUMBER_TYPE_LITTLEENDIAN = 'le',
        NUMBER_TYPE_MACHINE = 'm';

    /**
     * The number type we use for reading integers.  Defaults to little endian
     *
     * @var string
     */
    private $number_type = self::NUMBER_TYPE_LITTLEENDIAN;

    /**
     * The original data
     *
     * @var string
     */
    private $data;

    /**
     * The original data
     *
     * @var int
     */
    private $length;

    /**
     * Position of pointer
     *
     * @var int
     */
    private $index = 0;

    /**
     * Constructor
     *
     * @param string $data
     * @param string $number_type
     */
    public function __construct($data, $number_type = self::NUMBER_TYPE_LITTLEENDIAN)
    {
        $this->number_type = $number_type;
        $this->data = $data;
        $this->length = strlen($data);
    }

    /**
     * Return all the data
     *
     * @return  string    The data
     */
    public function getData()
    {
        return $this->data;
    }

    /**
     * Return data currently in the buffer
     *
     * @return  string    The data currently in the buffer
     */
    public function getBuffer()
    {
        return substr($this->data, $this->index);
    }

    /**
     * Returns the number of bytes in the buffer
     *
     * @return  int  Length of the buffer
     */
    public function getLength()
    {
        return max($this->length - $this->index, 0);
    }

    /**
     * Read from the buffer
     *
     * @param int $length
     *
     * @return string
     * @throws \GameQ\Exception\Protocol
     */
    public function read($length = 1)
    {
        if (($length + $this->index) > $this->length) {
            throw new Exception("Unable to read length={$length} from buffer.  Bad protocol format or return?");
        }

        $string = substr($this->data, $this->index, $length);
        $this->index += $length;

        return $string;
    }

    /**
     * Read the last character from the buffer
     *
     * Unlike the other read functions, this function actually removes
     * the character from the buffer.
     *
     * @return string
     */
    public function readLast()
    {
        $len = strlen($this->data);
        $string = $this->data[strlen($this->data) - 1];
        $this->data = substr($this->data, 0, $len - 1);
        $this->length -= 1;

        return $string;
    }

    /**
     * Look at the buffer, but don't remove
     *
     * @param int $length
     *
     * @return string
     */
    public function lookAhead($length = 1)
    {
        return substr($this->data, $this->index, $length);
    }

    /**
     * Skip forward in the buffer
     *
     * @param int $length
     */
    public function skip($length = 1)
    {
        $this->index += $length;
    }

    /**
     * Jump to a specific position in the buffer,
     * will not jump past end of buffer
     *
     * @param $index
     */
    public function jumpto($index)
    {
        $this->index = min($index, $this->length - 1);
    }

    /**
     * Get the current pointer position
     *
     * @return int
     */
    public function getPosition()
    {
        return $this->index;
    }

    /**
     * Read from buffer until delimiter is reached
     *
     * If not found, return everything
     *
     * @param string $delim
     *
     * @return string
     * @throws \GameQ\Exception\Protocol
     */
    public function readString($delim = "\x00")
    {
        // Get position of delimiter
        $len = strpos($this->data, $delim, min($this->index, $this->length));

        // If it is not found then return whole buffer
        if ($len === false) {
            return $this->read(strlen($this->data) - $this->index);
        }

        // Read the string and remove the delimiter
        $string = $this->read($len - $this->index);
        ++$this->index;

        return $string;
    }

    /**
     * Reads a pascal string from the buffer
     *
     * @param int  $offset      Number of bits to cut off the end
     * @param bool $read_offset True if the data after the offset is to be read
     *
     * @return string
     * @throws \GameQ\Exception\Protocol
     */
    public function readPascalString($offset = 0, $read_offset = false)
    {
        // Get the proper offset
        $len = $this->readInt8();
        $offset = max($len - $offset, 0);

        // Read the data
        if ($read_offset) {
            return $this->read($offset);
        } else {
            return substr($this->read($len), 0, $offset);
        }
    }

    /**
     * Read from buffer until any of the delimiters is reached
     *
     * If not found, return everything
     *
     * @param              $delims
     * @param null|string &$delimfound
     *
     * @return string
     * @throws \GameQ\Exception\Protocol
     *
     * @todo: Check to see if this is even used anymore
     */
    public function readStringMulti($delims, &$delimfound = null)
    {
        // Get position of delimiters
        $pos = [];
        foreach ($delims as $delim) {
            if ($index = strpos($this->data, $delim, min($this->index, $this->length))) {
                $pos[] = $index;
            }
        }

        // If none are found then return whole buffer
        if (empty($pos)) {
            return $this->read(strlen($this->data) - $this->index);
        }

        // Read the string and remove the delimiter
        sort($pos);
        $string = $this->read($pos[0] - $this->index);
        $delimfound = $this->read();

        return $string;
    }

    /**
     * Read an 8-bit unsigned integer
     *
     * @return int
     * @throws \GameQ\Exception\Protocol
     */
    public function readInt8()
    {
        $int = unpack('Cint', $this->read(1));

        return $int['int'];
    }

    /**
     * Read and 8-bit signed integer
     *
     * @return int
     * @throws \GameQ\Exception\Protocol
     */
    public function readInt8Signed()
    {
        $int = unpack('cint', $this->read(1));

        return $int['int'];
    }

    /**
     * Read a 16-bit unsigned integer
     *
     * @return int
     * @throws \GameQ\Exception\Protocol
     */
    public function readInt16()
    {
        // Change the integer type we are looking up
        switch ($this->number_type) {
            case self::NUMBER_TYPE_BIGENDIAN:
                $type = 'nint';
                break;

            case self::NUMBER_TYPE_LITTLEENDIAN:
                $type = 'vint';
                break;

            default:
                $type = 'Sint';
        }

        $int = unpack($type, $this->read(2));

        return $int['int'];
    }

    /**
     * Read a 16-bit signed integer
     *
     * @return int
     * @throws \GameQ\Exception\Protocol
     */
    public function readInt16Signed()
    {
        // Read the data into a string
        $string = $this->read(2);

        // For big endian we need to reverse the bytes
        if ($this->number_type == self::NUMBER_TYPE_BIGENDIAN) {
            $string = strrev($string);
        }

        $int = unpack('sint', $string);

        unset($string);

        return $int['int'];
    }

    /**
     * Read a 32-bit unsigned integer
     *
     * @return int
     * @throws \GameQ\Exception\Protocol
     */
    public function readInt32($length = 4)
    {
        // Change the integer type we are looking up
        $littleEndian = null;
        switch ($this->number_type) {
            case self::NUMBER_TYPE_BIGENDIAN:
                $type = 'N';
                $littleEndian = false;
                break;

            case self::NUMBER_TYPE_LITTLEENDIAN:
                $type = 'V';
                $littleEndian = true;
                break;

            default:
                $type = 'L';
        }

        // read from the buffer and append/prepend empty bytes for shortened int32
        $corrected = $this->read($length);

        // Unpack the number
        $int = unpack($type . 'int', self::extendBinaryString($corrected, 4, $littleEndian));

        return $int['int'];
    }

    /**
     * Read a 32-bit signed integer
     *
     * @return int
     * @throws \GameQ\Exception\Protocol
     */
    public function readInt32Signed()
    {
        // Read the data into a string
        $string = $this->read(4);

        // For big endian we need to reverse the bytes
        if ($this->number_type == self::NUMBER_TYPE_BIGENDIAN) {
            $string = strrev($string);
        }

        $int = unpack('lint', $string);

        unset($string);

        return $int['int'];
    }

    /**
     * Read a 64-bit unsigned integer
     *
     * @return int
     * @throws \GameQ\Exception\Protocol
     */
    public function readInt64()
    {
        // We have the pack 64-bit codes available. See: http://php.net/manual/en/function.pack.php
        if (version_compare(PHP_VERSION, '5.6.3') >= 0 && PHP_INT_SIZE == 8) {
            // Change the integer type we are looking up
            switch ($this->number_type) {
                case self::NUMBER_TYPE_BIGENDIAN:
                    $type = 'Jint';
                    break;

                case self::NUMBER_TYPE_LITTLEENDIAN:
                    $type = 'Pint';
                    break;

                default:
                    $type = 'Qint';
            }

            $int64 = unpack($type, $this->read(8));

            $int = $int64['int'];

            unset($int64);
        } else {
            if ($this->number_type == self::NUMBER_TYPE_BIGENDIAN) {
                $high = $this->readInt32();
                $low = $this->readInt32();
            } else {
                $low = $this->readInt32();
                $high = $this->readInt32();
            }

            // We have to determine the number via bitwise
            $int = ($high << 32) | $low;

            unset($low, $high);
        }

        return $int;
    }

    /**
     * Read a 32-bit float
     *
     * @return float
     * @throws \GameQ\Exception\Protocol
     */
    public function readFloat32()
    {
        // Read the data into a string
        $string = $this->read(4);

        // For big endian we need to reverse the bytes
        if ($this->number_type == self::NUMBER_TYPE_BIGENDIAN) {
            $string = strrev($string);
        }

        $float = unpack('ffloat', $string);

        unset($string);

        return $float['float'];
    }

    private static function extendBinaryString($input, $length = 4, $littleEndian = null)
    {
        if (is_null($littleEndian)) {
            $littleEndian = self::isLittleEndian();
        }

        $extension = str_repeat(pack($littleEndian ? 'V' : 'N', 0b0000), $length - strlen($input));

        if ($littleEndian) {
            return $input . $extension;
        } else {
            return $extension . $input;
        }
    }

    private static function isLittleEndian()
    {
        return 0x00FF === current(unpack('v', pack('S', 0x00FF)));
    }
}


1		<?php
2		/**
3		* This file is part of GameQ.
4		*
5		* GameQ is free software; you can redistribute it and/or modify
6		* it under the terms of the GNU Lesser General Public License as published by
7		* the Free Software Foundation; either version 3 of the License, or
8		* (at your option) any later version.
9		*
10		* GameQ is distributed in the hope that it will be useful,
11		* but WITHOUT ANY WARRANTY; without even the implied warranty of
12		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13		* GNU Lesser General Public License for more details.
14		*
15		* You should have received a copy of the GNU Lesser General Public License
16		* along with this program. If not, see <http://www.gnu.org/licenses/>.
17		*
18		*
19		*/
20
21		namespace GameQ;
22
23		use GameQ\Exception\Protocol as Exception;
24
25		/**
26		* Class Buffer
27		*
28		* Read specific byte sequences from a provided string or Buffer
29		*
30		* @package GameQ
31		*
32		* @author Austin Bischoff <[email protected]>
33		* @author Aidan Lister <[email protected]>
34		* @author Tom Buskens <[email protected]>
35		*/
36		class Buffer
37		{
38		/**
39		* Constants for the byte code types we need to read as
40		*/
41		const NUMBER_TYPE_BIGENDIAN = 'be',
42		NUMBER_TYPE_LITTLEENDIAN = 'le',
43		NUMBER_TYPE_MACHINE = 'm';
44
45		/**
46		* The number type we use for reading integers. Defaults to little endian
47		*
48		* @var string
49		*/
50		private $number_type = self::NUMBER_TYPE_LITTLEENDIAN;
51
52		/**
53		* The original data
54		*
55		* @var string
56		*/
57		private $data;
58
59		/**
60		* The original data
61		*
62		* @var int
63		*/
64		private $length;
65
66		/**
67		* Position of pointer
68		*
69		* @var int
70		*/
71		private $index = 0;
72
73		/**
74		* Constructor
75		*
76		* @param string $data
77		* @param string $number_type
78		*/
79	2076	public function __construct($data, $number_type = self::NUMBER_TYPE_LITTLEENDIAN)
80		{
81	2076	$this->number_type = $number_type;
82	2076	$this->data = $data;
83	2076	$this->length = strlen($data);
84		}
85
86		/**
87		* Return all the data
88		*
89		* @return string The data
90		*/
91	12	public function getData()
92		{
93	12	return $this->data;
94		}
95
96		/**
97		* Return data currently in the buffer
98		*
99		* @return string The data currently in the buffer
100		*/
101	1488	public function getBuffer()
102		{
103	1488	return substr($this->data, $this->index);
104		}
105
106		/**
107		* Returns the number of bytes in the buffer
108		*
109		* @return int Length of the buffer
110		*/
111	1404	public function getLength()
112		{
113	1404	return max($this->length - $this->index, 0);
114		}
115
116		/**
117		* Read from the buffer
118		*
119		* @param int $length
120		*
121		* @return string
122		* @throws \GameQ\Exception\Protocol
123		*/
124	1992	public function read($length = 1)
125		{
126	1992	if (($length + $this->index) > $this->length) {
127	12	throw new Exception("Unable to read length={$length} from buffer. Bad protocol format or return?");
128		}
129
130	1980	$string = substr($this->data, $this->index, $length);
131	1980	$this->index += $length;
132
133	1980	return $string;
134		}
135
136		/**
137		* Read the last character from the buffer
138		*
139		* Unlike the other read functions, this function actually removes
140		* the character from the buffer.
141		*
142		* @return string
143		*/
144	6	public function readLast()
145		{
146	6	$len = strlen($this->data);
147	6	$string = $this->data[strlen($this->data) - 1];
148	6	$this->data = substr($this->data, 0, $len - 1);
149	6	$this->length -= 1;
150
151	6	return $string;
152		}
153
154		/**
155		* Look at the buffer, but don't remove
156		*
157		* @param int $length
158		*
159		* @return string
160		*/
161	1104	public function lookAhead($length = 1)
162		{
163	1104	return substr($this->data, $this->index, $length);
164		}
165
166		/**
167		* Skip forward in the buffer
168		*
169		* @param int $length
170		*/
171	486	public function skip($length = 1)
172		{
173	486	$this->index += $length;
174		}
175
176		/**
177		* Jump to a specific position in the buffer,
178		* will not jump past end of buffer
179		*
180		* @param $index
181		*/
182	54	public function jumpto($index)
183		{
184	54	$this->index = min($index, $this->length - 1);
185		}
186
187		/**
188		* Get the current pointer position
189		*
190		* @return int
191		*/
192	6	public function getPosition()
193		{
194	6	return $this->index;
195		}
196
197		/**
198		* Read from buffer until delimiter is reached
199		*
200		* If not found, return everything
201		*
202		* @param string $delim
203		*
204		* @return string
205		* @throws \GameQ\Exception\Protocol
206		*/
207	1482	public function readString($delim = "\x00")
208		{
209		// Get position of delimiter
210	1482	$len = strpos($this->data, $delim, min($this->index, $this->length));
211
212		// If it is not found then return whole buffer
213	1482	if ($len === false) {
214	180	return $this->read(strlen($this->data) - $this->index);
215		}
216
217		// Read the string and remove the delimiter
218	1482	$string = $this->read($len - $this->index);
219	1482	++$this->index;
220
221	1482	return $string;
222		}
223
224		/**
225		* Reads a pascal string from the buffer
226		*
227		* @param int $offset Number of bits to cut off the end
228		* @param bool $read_offset True if the data after the offset is to be read
229		*
230		* @return string
231		* @throws \GameQ\Exception\Protocol
232		*/
233	78	public function readPascalString($offset = 0, $read_offset = false)
234		{
235		// Get the proper offset
236	78	$len = $this->readInt8();
237	78	$offset = max($len - $offset, 0);
238
239		// Read the data
240	78	if ($read_offset) {
241	36	return $this->read($offset);
242		} else {
243	42	return substr($this->read($len), 0, $offset);
244		}
245		}
246
247		/**
248		* Read from buffer until any of the delimiters is reached
249		*
250		* If not found, return everything
251		*
252		* @param $delims
253		* @param null\|string &$delimfound
254		*
255		* @return string
256		* @throws \GameQ\Exception\Protocol
257		*
258		* @todo: Check to see if this is even used anymore
259		*/
260	204	public function readStringMulti($delims, &$delimfound = null)
261		{
262		// Get position of delimiters
263	204	$pos = [];
264	204	foreach ($delims as $delim) {
265	204	if ($index = strpos($this->data, $delim, min($this->index, $this->length))) {
266	204	$pos[] = $index;
267		}
268		}
269
270		// If none are found then return whole buffer
271	204	if (empty($pos)) {
272	204	return $this->read(strlen($this->data) - $this->index);
273		}
274
275		// Read the string and remove the delimiter
276	204	sort($pos);
277	204	$string = $this->read($pos[0] - $this->index);
278	204	$delimfound = $this->read();
279
280	204	return $string;
281		}
282
283		/**
284		* Read an 8-bit unsigned integer
285		*
286		* @return int
287		* @throws \GameQ\Exception\Protocol
288		*/
289	1182	public function readInt8()
290		{
291	1182	$int = unpack('Cint', $this->read(1));
292
293	1182	return $int['int'];
294		}
295
296		/**
297		* Read and 8-bit signed integer
298		*
299		* @return int
300		* @throws \GameQ\Exception\Protocol
301		*/
302	30	public function readInt8Signed()
303		{
304	30	$int = unpack('cint', $this->read(1));
305
306	30	return $int['int'];
307		}
308
309		/**
310		* Read a 16-bit unsigned integer
311		*
312		* @return int
313		* @throws \GameQ\Exception\Protocol
314		*/
315	930	public function readInt16()
316		{
317		// Change the integer type we are looking up
318	930	switch ($this->number_type) {
319	310	case self::NUMBER_TYPE_BIGENDIAN:
320	30	$type = 'nint';
321	30	break;
322
323	300	case self::NUMBER_TYPE_LITTLEENDIAN:
324	888	$type = 'vint';
325	888	break;
326
327		default:
328	12	$type = 'Sint';
329		}
330
331	930	$int = unpack($type, $this->read(2));
332
333	930	return $int['int'];
334		}
335
336		/**
337		* Read a 16-bit signed integer
338		*
339		* @return int
340		* @throws \GameQ\Exception\Protocol
341		*/
342	882	public function readInt16Signed()
343		{
344		// Read the data into a string
345	882	$string = $this->read(2);
346
347		// For big endian we need to reverse the bytes
348	882	if ($this->number_type == self::NUMBER_TYPE_BIGENDIAN) {
349	18	$string = strrev($string);
350		}
351
352	882	$int = unpack('sint', $string);
353
354	882	unset($string);
355
356	882	return $int['int'];
357		}
358
359		/**
360		* Read a 32-bit unsigned integer
361		*
362		* @return int
363		* @throws \GameQ\Exception\Protocol
364		*/
365	330	public function readInt32($length = 4)
366		{
367		// Change the integer type we are looking up
368	330	$littleEndian = null;
369	330	switch ($this->number_type) {
370	110	case self::NUMBER_TYPE_BIGENDIAN:
371	144	$type = 'N';
372	144	$littleEndian = false;
373	144	break;
374
375	62	case self::NUMBER_TYPE_LITTLEENDIAN:
376	174	$type = 'V';
377	174	$littleEndian = true;
378	174	break;
379
380		default:
381	12	$type = 'L';
382		}
383
384		// read from the buffer and append/prepend empty bytes for shortened int32
385	330	$corrected = $this->read($length);
386
387		// Unpack the number
388	330	$int = unpack($type . 'int', self::extendBinaryString($corrected, 4, $littleEndian));
389
390	330	return $int['int'];
391		}
392
393		/**
394		* Read a 32-bit signed integer
395		*
396		* @return int
397		* @throws \GameQ\Exception\Protocol
398		*/
399	900	public function readInt32Signed()
400		{
401		// Read the data into a string
402	900	$string = $this->read(4);
403
404		// For big endian we need to reverse the bytes
405	900	if ($this->number_type == self::NUMBER_TYPE_BIGENDIAN) {
406	18	$string = strrev($string);
407		}
408
409	900	$int = unpack('lint', $string);
410
411	900	unset($string);
412
413	900	return $int['int'];
414		}
415
416		/**
417		* Read a 64-bit unsigned integer
418		*
419		* @return int
420		* @throws \GameQ\Exception\Protocol
421		*/
422	858	public function readInt64()
423		{
424		// We have the pack 64-bit codes available. See: http://php.net/manual/en/function.pack.php
425	858	if (version_compare(PHP_VERSION, '5.6.3') >= 0 && PHP_INT_SIZE == 8) {
426		// Change the integer type we are looking up
427	858	switch ($this->number_type) {
428	286	case self::NUMBER_TYPE_BIGENDIAN:
429	18	$type = 'Jint';
430	18	break;
431
432	280	case self::NUMBER_TYPE_LITTLEENDIAN:
433	828	$type = 'Pint';
434	828	break;
435
436		default:
437	12	$type = 'Qint';
438		}
439
440	858	$int64 = unpack($type, $this->read(8));
441
442	858	$int = $int64['int'];
443
444	858	unset($int64);
445		} else {
446		if ($this->number_type == self::NUMBER_TYPE_BIGENDIAN) {
447		$high = $this->readInt32();
448		$low = $this->readInt32();
449		} else {
450		$low = $this->readInt32();
451		$high = $this->readInt32();
452		}
453
454		// We have to determine the number via bitwise
455		$int = ($high << 32) \| $low;
456
457		unset($low, $high);
458		}
459
460	858	return $int;
461		}
462
463		/**
464		* Read a 32-bit float
465		*
466		* @return float
467		* @throws \GameQ\Exception\Protocol
468		*/
469	624	public function readFloat32()
470		{
471		// Read the data into a string
472	624	$string = $this->read(4);
473
474		// For big endian we need to reverse the bytes
475	624	if ($this->number_type == self::NUMBER_TYPE_BIGENDIAN) {
476	18	$string = strrev($string);
477		}
478
479	624	$float = unpack('ffloat', $string);
480
481	624	unset($string);
482
483	624	return $float['float'];
484		}
485
486	330	private static function extendBinaryString($input, $length = 4, $littleEndian = null)
487		{
488	330	if (is_null($littleEndian)) {
489	12	$littleEndian = self::isLittleEndian();
490		}
491
492	330	$extension = str_repeat(pack($littleEndian ? 'V' : 'N', 0b0000), $length - strlen($input));
493
494	330	if ($littleEndian) {
495	186	return $input . $extension;
496		} else {
497	144	return $extension . $input;
498		}
499		}
500
501	12	private static function isLittleEndian()
502		{
503	12	return 0x00FF === current(unpack('v', pack('S', 0x00FF)));
504		}
505		}
506

Austinb / GameQ

Buffer::jumpto() A last analyzed 2025-02-19 14:42 UTC

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Buffer::jumpto() A
last analyzed 2025-02-19 14:42 UTC