Tie::SubstrHash - phpMan

NAME
    Tie::SubstrHash - Fixed-table-size, fixed-key-length hashing

SYNOPSIS
        require Tie::SubstrHash;

        tie %myhash, 'Tie::SubstrHash', $key_len, $value_len, $table_size;

DESCRIPTION
    The Tie::SubstrHash package provides a hash-table-like interface to an
    array of determinate size, with constant key size and record size.

    Upon tying a new hash to this package, the developer must specify the
    size of the keys that will be used, the size of the value fields that
    the keys will index, and the size of the overall table (in terms of
    key-value pairs, not size in hard memory). *These values will not change
    for the duration of the tied hash*. The newly-allocated hash table may
    now have data stored and retrieved. Efforts to store more than
    $table_size elements will result in a fatal error, as will efforts to
    store a value not exactly $value_len characters in length, or reference
    through a key not exactly $key_len characters in length. While these
    constraints may seem excessive, the result is a hash table using much
    less internal memory than an equivalent freely-allocated hash table.

CAVEATS
    Because the current implementation uses the table and key sizes for the
    hashing algorithm, there is no means by which to dynamically change the
    value of any of the initialization parameters.

    The hash does not support exists().