This factory method creates a new hash from a definition file on disk. The file format consists of a signature 'QH\0x11\0', the number of elements as a 32 bit signed integer in system Endianness, followed by 32 bit signed integers packed together in the Endianness that the system that the code runs on uses. For each hash element there are two 32 bit signed integers stored. The first of each element is the key, and the second is the value belonging to the key. An example could be:
Example #1 QuickHash IntHash file format
00000000 51 48 11 00 02 00 00 00 01 00 00 00 01 00 00 00 |QH..............| 00000010 03 00 00 00 09 00 00 00 |........| 00000018
Example #2 QuickHash IntHash file format
header signature ('QH'; key type: 1; value type: 1; filler: \0x00)
00000000 51 48 11 00
number of elements:
00000004 02 00 00 00
data string:
00000000 01 00 00 00 01 00 00 00 03 00 00 00 09 00 00 00
key/value 1 (key = 1, value = 1)
01 00 00 00 01 00 00 00
key/value 2 (key = 3, value = 9)
03 00 00 00 09 00 00 00 The filename of the file to read the hash from.
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.
Returns a new QuickHashIntHash.
00000000 51 48 11 00 02 00 00 00 01 00 00 00 01 00 00 00 |QH..............| 00000010 03 00 00 00 09 00 00 00 |........| 00000018
header signature ('QH'; key type: 1; value type: 1; filler: \0x00)
00000000 51 48 11 00
number of elements:
00000004 02 00 00 00
data string:
00000000 01 00 00 00 01 00 00 00 03 00 00 00 09 00 00 00
key/value 1 (key = 1, value = 1)
01 00 00 00 01 00 00 00
key/value 2 (key = 3, value = 9)
03 00 00 00 09 00 00 00
<?php
$file = dirname( __FILE__ ) . "/simple.hash";
$hash = QuickHashIntHash::loadFromFile(
$file,
QuickHashIntHash::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'
);
}
?>
The above example will output something similar to:
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
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