QuickHashIntStringHash::loadFromFile

This factory method creates a hash from a file

&reftitle.description; public static `QuickHashIntStringHash` `QuickHashIntStringHash::loadFromFile` `string` `filename` `int` `size` 0 `int` `options` 0

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:

### 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

### 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

&reftitle.parameters;

`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`.

&reftitle.returnvalues;

Returns a new `QuickHashIntStringHash`.

&reftitle.examples;

### `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'
        );
    }
    ?>

&example.outputs.similar;

    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