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- 变量与类型相关扩展
- Quickhash
- QuickHashIntStringHash
QuickHashIntStringHash::loadFromFile
(PECL quickhash >= Unknown)
QuickHashIntStringHash::loadFromFile — This factory method creates a hash from a file
说明
public static QuickHashIntStringHash::loadFromFile ( string$filename
[, int $size = 0
[, int $options = 0
]] ) : QuickHashIntStringHash
This factory method creates a new hash from a definition file on disk. The file format consists of a signature 'QH\0x12\0', the number of elements as a 32 bit signed integer in system Endianness, an unsigned 32 bit integer containing the number of element data to follow in characters. This element data contains all the strings. After the header and the strings, the elements follow in pairs of two unsigned 32 bit integers where the first one is the key, and the second one the index in the element data string. An example could be:
Example #1 QuickHash IntString file format
00000000 51 48 12 00 02 00 00 00 09 00 00 00 4f 4e 45 00 |QH..........ONE.| 00000010 4e 49 4e 45 00 01 00 00 00 00 00 00 00 03 00 00 |NINE............| 00000020 00 04 00 00 00 |.....| 00000025
Example #2 QuickHash IntString file format
header signature ('QH'; key type: 1; value type: 2; filler: \0x00)
00000000 51 48 12 00
number of elements:
00000004 02 00 00 00
length of string values (9 characters):
00000008 09 00 00 00
string values:
0000000C 4f 4e 45 00 4e 49 4e 45 00
data string:
00000015 01 00 00 00 00 00 00 00 03 00 00 00 04 00 00 00
key/value 1 (key = 1, string index = 0 ("ONE")):
01 00 00 00 00 00 00 00
key/value 2 (key = 3, string index = 4 ("NINE")):
03 00 00 00 04 00 00 00
参数
-
filename -
The filename of the file to read the hash from.
-
size -
The amount of bucket lists to configure. The number you pass in will be automatically rounded up to the next power of two. It is also automatically limited from 4 to 4194304.
-
options -
The same options that the class' constructor takes; except that the size option is ignored. It is automatically calculated to be the same as the number of entries in the hash, rounded up to the nearest power of two with a maximum limit of 4194304.
返回值
Returns a new QuickHashIntStringHash.
范例
Example #3 QuickHashIntStringHash::loadFromFile() example
<?php
$file = dirname( __FILE__ ) . "/simple.string.hash";
$hash = QuickHashIntStringHash::loadFromFile(
$file,
QuickHashIntStringHash::DO_NOT_USE_ZEND_ALLOC
);
foreach( range( 0, 0x0f ) as $key )
{
printf( "Key %3d (%2x) is %s\n",
$key, $key,
$hash->exists( $key ) ? 'set' : 'unset'
);
}
?>
以上例程的输出类似于：
Key 0 ( 0) is unset Key 1 ( 1) is set Key 2 ( 2) is set Key 3 ( 3) is set Key 4 ( 4) is unset Key 5 ( 5) is set Key 6 ( 6) is unset Key 7 ( 7) is set Key 8 ( 8) is unset Key 9 ( 9) is unset Key 10 ( a) is unset Key 11 ( b) is set Key 12 ( c) is unset Key 13 ( d) is set Key 14 ( e) is unset Key 15 ( f) is unset
User Contributed Notes
There are no user contributed notes for this page.官方地址：https://www.php.net/manual/en/quickhashintstringhash.loadfromfile.php