Upload files to 'includes'
This commit is contained in:
374
includes/Decoder.php
Normal file
374
includes/Decoder.php
Normal file
@ -0,0 +1,374 @@
|
||||
<?php
|
||||
|
||||
declare(strict_types=1);
|
||||
|
||||
namespace MaxMind\Db\Reader;
|
||||
|
||||
// @codingStandardsIgnoreLine
|
||||
use RuntimeException;
|
||||
|
||||
class Decoder
|
||||
{
|
||||
/**
|
||||
* @var resource
|
||||
*/
|
||||
private $fileStream;
|
||||
/**
|
||||
* @var int
|
||||
*/
|
||||
private $pointerBase;
|
||||
/**
|
||||
* @var float
|
||||
*/
|
||||
private $pointerBaseByteSize;
|
||||
/**
|
||||
* This is only used for unit testing.
|
||||
*
|
||||
* @var bool
|
||||
*/
|
||||
private $pointerTestHack;
|
||||
/**
|
||||
* @var bool
|
||||
*/
|
||||
private $switchByteOrder;
|
||||
|
||||
private const _EXTENDED = 0;
|
||||
private const _POINTER = 1;
|
||||
private const _UTF8_STRING = 2;
|
||||
private const _DOUBLE = 3;
|
||||
private const _BYTES = 4;
|
||||
private const _UINT16 = 5;
|
||||
private const _UINT32 = 6;
|
||||
private const _MAP = 7;
|
||||
private const _INT32 = 8;
|
||||
private const _UINT64 = 9;
|
||||
private const _UINT128 = 10;
|
||||
private const _ARRAY = 11;
|
||||
private const _CONTAINER = 12;
|
||||
private const _END_MARKER = 13;
|
||||
private const _BOOLEAN = 14;
|
||||
private const _FLOAT = 15;
|
||||
|
||||
/**
|
||||
* @param resource $fileStream
|
||||
*/
|
||||
public function __construct(
|
||||
$fileStream,
|
||||
int $pointerBase = 0,
|
||||
bool $pointerTestHack = false
|
||||
) {
|
||||
$this->fileStream = $fileStream;
|
||||
$this->pointerBase = $pointerBase;
|
||||
|
||||
$this->pointerBaseByteSize = $pointerBase > 0 ? log($pointerBase, 2) / 8 : 0;
|
||||
$this->pointerTestHack = $pointerTestHack;
|
||||
|
||||
$this->switchByteOrder = $this->isPlatformLittleEndian();
|
||||
}
|
||||
|
||||
public function decode(int $offset): array
|
||||
{
|
||||
$ctrlByte = \ord(Util::read($this->fileStream, $offset, 1));
|
||||
++$offset;
|
||||
|
||||
$type = $ctrlByte >> 5;
|
||||
|
||||
// Pointers are a special case, we don't read the next $size bytes, we
|
||||
// use the size to determine the length of the pointer and then follow
|
||||
// it.
|
||||
if ($type === self::_POINTER) {
|
||||
[$pointer, $offset] = $this->decodePointer($ctrlByte, $offset);
|
||||
|
||||
// for unit testing
|
||||
if ($this->pointerTestHack) {
|
||||
return [$pointer];
|
||||
}
|
||||
|
||||
[$result] = $this->decode($pointer);
|
||||
|
||||
return [$result, $offset];
|
||||
}
|
||||
|
||||
if ($type === self::_EXTENDED) {
|
||||
$nextByte = \ord(Util::read($this->fileStream, $offset, 1));
|
||||
|
||||
$type = $nextByte + 7;
|
||||
|
||||
if ($type < 8) {
|
||||
throw new InvalidDatabaseException(
|
||||
'Something went horribly wrong in the decoder. An extended type '
|
||||
. 'resolved to a type number < 8 ('
|
||||
. $type
|
||||
. ')'
|
||||
);
|
||||
}
|
||||
|
||||
++$offset;
|
||||
}
|
||||
|
||||
[$size, $offset] = $this->sizeFromCtrlByte($ctrlByte, $offset);
|
||||
|
||||
return $this->decodeByType($type, $offset, $size);
|
||||
}
|
||||
|
||||
private function decodeByType(int $type, int $offset, int $size): array
|
||||
{
|
||||
switch ($type) {
|
||||
case self::_MAP:
|
||||
return $this->decodeMap($size, $offset);
|
||||
|
||||
case self::_ARRAY:
|
||||
return $this->decodeArray($size, $offset);
|
||||
|
||||
case self::_BOOLEAN:
|
||||
return [$this->decodeBoolean($size), $offset];
|
||||
}
|
||||
|
||||
$newOffset = $offset + $size;
|
||||
$bytes = Util::read($this->fileStream, $offset, $size);
|
||||
|
||||
switch ($type) {
|
||||
case self::_BYTES:
|
||||
case self::_UTF8_STRING:
|
||||
return [$bytes, $newOffset];
|
||||
|
||||
case self::_DOUBLE:
|
||||
$this->verifySize(8, $size);
|
||||
|
||||
return [$this->decodeDouble($bytes), $newOffset];
|
||||
|
||||
case self::_FLOAT:
|
||||
$this->verifySize(4, $size);
|
||||
|
||||
return [$this->decodeFloat($bytes), $newOffset];
|
||||
|
||||
case self::_INT32:
|
||||
return [$this->decodeInt32($bytes, $size), $newOffset];
|
||||
|
||||
case self::_UINT16:
|
||||
case self::_UINT32:
|
||||
case self::_UINT64:
|
||||
case self::_UINT128:
|
||||
return [$this->decodeUint($bytes, $size), $newOffset];
|
||||
|
||||
default:
|
||||
throw new InvalidDatabaseException(
|
||||
'Unknown or unexpected type: ' . $type
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
private function verifySize(int $expected, int $actual): void
|
||||
{
|
||||
if ($expected !== $actual) {
|
||||
throw new InvalidDatabaseException(
|
||||
"The MaxMind DB file's data section contains bad data (unknown data type or corrupt data)"
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
private function decodeArray(int $size, int $offset): array
|
||||
{
|
||||
$array = [];
|
||||
|
||||
for ($i = 0; $i < $size; ++$i) {
|
||||
[$value, $offset] = $this->decode($offset);
|
||||
$array[] = $value;
|
||||
}
|
||||
|
||||
return [$array, $offset];
|
||||
}
|
||||
|
||||
private function decodeBoolean(int $size): bool
|
||||
{
|
||||
return $size !== 0;
|
||||
}
|
||||
|
||||
private function decodeDouble(string $bytes): float
|
||||
{
|
||||
// This assumes IEEE 754 doubles, but most (all?) modern platforms
|
||||
// use them.
|
||||
[, $double] = unpack('E', $bytes);
|
||||
|
||||
return $double;
|
||||
}
|
||||
|
||||
private function decodeFloat(string $bytes): float
|
||||
{
|
||||
// This assumes IEEE 754 floats, but most (all?) modern platforms
|
||||
// use them.
|
||||
[, $float] = unpack('G', $bytes);
|
||||
|
||||
return $float;
|
||||
}
|
||||
|
||||
private function decodeInt32(string $bytes, int $size): int
|
||||
{
|
||||
switch ($size) {
|
||||
case 0:
|
||||
return 0;
|
||||
|
||||
case 1:
|
||||
case 2:
|
||||
case 3:
|
||||
$bytes = str_pad($bytes, 4, "\x00", \STR_PAD_LEFT);
|
||||
|
||||
break;
|
||||
|
||||
case 4:
|
||||
break;
|
||||
|
||||
default:
|
||||
throw new InvalidDatabaseException(
|
||||
"The MaxMind DB file's data section contains bad data (unknown data type or corrupt data)"
|
||||
);
|
||||
}
|
||||
|
||||
[, $int] = unpack('l', $this->maybeSwitchByteOrder($bytes));
|
||||
|
||||
return $int;
|
||||
}
|
||||
|
||||
private function decodeMap(int $size, int $offset): array
|
||||
{
|
||||
$map = [];
|
||||
|
||||
for ($i = 0; $i < $size; ++$i) {
|
||||
[$key, $offset] = $this->decode($offset);
|
||||
[$value, $offset] = $this->decode($offset);
|
||||
$map[$key] = $value;
|
||||
}
|
||||
|
||||
return [$map, $offset];
|
||||
}
|
||||
|
||||
private function decodePointer(int $ctrlByte, int $offset): array
|
||||
{
|
||||
$pointerSize = (($ctrlByte >> 3) & 0x3) + 1;
|
||||
|
||||
$buffer = Util::read($this->fileStream, $offset, $pointerSize);
|
||||
$offset = $offset + $pointerSize;
|
||||
|
||||
switch ($pointerSize) {
|
||||
case 1:
|
||||
$packed = \chr($ctrlByte & 0x7) . $buffer;
|
||||
[, $pointer] = unpack('n', $packed);
|
||||
$pointer += $this->pointerBase;
|
||||
|
||||
break;
|
||||
|
||||
case 2:
|
||||
$packed = "\x00" . \chr($ctrlByte & 0x7) . $buffer;
|
||||
[, $pointer] = unpack('N', $packed);
|
||||
$pointer += $this->pointerBase + 2048;
|
||||
|
||||
break;
|
||||
|
||||
case 3:
|
||||
$packed = \chr($ctrlByte & 0x7) . $buffer;
|
||||
|
||||
// It is safe to use 'N' here, even on 32 bit machines as the
|
||||
// first bit is 0.
|
||||
[, $pointer] = unpack('N', $packed);
|
||||
$pointer += $this->pointerBase + 526336;
|
||||
|
||||
break;
|
||||
|
||||
case 4:
|
||||
// We cannot use unpack here as we might overflow on 32 bit
|
||||
// machines
|
||||
$pointerOffset = $this->decodeUint($buffer, $pointerSize);
|
||||
|
||||
$pointerBase = $this->pointerBase;
|
||||
|
||||
if (\PHP_INT_MAX - $pointerBase >= $pointerOffset) {
|
||||
$pointer = $pointerOffset + $pointerBase;
|
||||
} else {
|
||||
throw new RuntimeException(
|
||||
'The database offset is too large to be represented on your platform.'
|
||||
);
|
||||
}
|
||||
|
||||
break;
|
||||
|
||||
default:
|
||||
throw new InvalidDatabaseException(
|
||||
'Unexpected pointer size ' . $pointerSize
|
||||
);
|
||||
}
|
||||
|
||||
return [$pointer, $offset];
|
||||
}
|
||||
|
||||
// @phpstan-ignore-next-line
|
||||
private function decodeUint(string $bytes, int $byteLength)
|
||||
{
|
||||
if ($byteLength === 0) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
$integer = 0;
|
||||
|
||||
// PHP integers are signed. PHP_INT_SIZE - 1 is the number of
|
||||
// complete bytes that can be converted to an integer. However,
|
||||
// we can convert another byte if the leading bit is zero.
|
||||
$useRealInts = $byteLength <= \PHP_INT_SIZE - 1
|
||||
|| ($byteLength === \PHP_INT_SIZE && (\ord($bytes[0]) & 0x80) === 0);
|
||||
|
||||
for ($i = 0; $i < $byteLength; ++$i) {
|
||||
$part = \ord($bytes[$i]);
|
||||
|
||||
// We only use gmp or bcmath if the final value is too big
|
||||
if ($useRealInts) {
|
||||
$integer = ($integer << 8) + $part;
|
||||
} elseif (\extension_loaded('gmp')) {
|
||||
$integer = gmp_strval(gmp_add(gmp_mul((string) $integer, '256'), $part));
|
||||
} elseif (\extension_loaded('bcmath')) {
|
||||
$integer = bcadd(bcmul((string) $integer, '256'), (string) $part);
|
||||
} else {
|
||||
throw new RuntimeException(
|
||||
'The gmp or bcmath extension must be installed to read this database.'
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
return $integer;
|
||||
}
|
||||
|
||||
private function sizeFromCtrlByte(int $ctrlByte, int $offset): array
|
||||
{
|
||||
$size = $ctrlByte & 0x1F;
|
||||
|
||||
if ($size < 29) {
|
||||
return [$size, $offset];
|
||||
}
|
||||
|
||||
$bytesToRead = $size - 28;
|
||||
$bytes = Util::read($this->fileStream, $offset, $bytesToRead);
|
||||
|
||||
if ($size === 29) {
|
||||
$size = 29 + \ord($bytes);
|
||||
} elseif ($size === 30) {
|
||||
[, $adjust] = unpack('n', $bytes);
|
||||
$size = 285 + $adjust;
|
||||
} else {
|
||||
[, $adjust] = unpack('N', "\x00" . $bytes);
|
||||
$size = $adjust + 65821;
|
||||
}
|
||||
|
||||
return [$size, $offset + $bytesToRead];
|
||||
}
|
||||
|
||||
private function maybeSwitchByteOrder(string $bytes): string
|
||||
{
|
||||
return $this->switchByteOrder ? strrev($bytes) : $bytes;
|
||||
}
|
||||
|
||||
private function isPlatformLittleEndian(): bool
|
||||
{
|
||||
$testint = 0x00FF;
|
||||
$packed = pack('S', $testint);
|
||||
|
||||
return $testint === current(unpack('v', $packed));
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user