php - Generate ID based on file and line in (or something similar) -

in program need way create unique identifiers (like hash). important ids not random, same between calls same function or method. thus, if in line in file generated identifier xyz, in place should generated same identifier.

i use code such instruction:

$id = sha1(__file__ . __ line__); 

but not enough comfortable. i'd prefer use function or macro in c/c++ (i know php not have macros) follows:

$id = generate_id(); 

the generate_id implemented below. works fine, i'm not convinced use function debug_backtrace in production code. maybe there's better solution?

function generate_id() {    $backtrace = debug_backtrace();    return sha1($backtrace[0]['file'] . $backtrace[0]['line']); } 

if intention have repeatable hash based on file, php has md5_file() method should need.

$file = 'myfile.txt'; echo 'md5 file hash of ' . $file . ': ' . md5_file($file); 

as long file contents not change, md5 hash same each time generate it.