node-index issues

node-index-snippet1

// You can run this file again and again and it will:
// 1) Keep inserting the same keys over and over again
// 2) You can't no longer trust the variables outside of the callbacks passed to index.set, context is needed
var generate_uuid = require('node-uuid');
var index_file = 'data/test.index';
var index;
console.log('run it twice, it should fail the second time as it keeps adding keys as if they were new');
var on_index_created = function(err) {
    if ( err ) {
        console.log(err);
        process.exit(1);
    }

    var key = '6D22000D-5D4E-4EC3-9685-2323EF25B487';
    var value = 'foo';
    index.set( key, value, function(err) {
            if ( err ) {
                console.log( err );
                process.exit(0);
            }

            if ( key ==  'E18EFDFD-ACC4-42CB-8261-E8139886DA1C')  {
                console.log('I see key ' + key + ' but I\'m really ' + '6D22000D-5D4E-4EC3-9685-2323EF25B487!');
            }

        });


    var key = 'E18EFDFD-ACC4-42CB-8261-E8139886DA1C';
    var value = 'foo';
    index.set( key, value, function(err) {
            if ( err ) {
                console.log( err );
                process.exit(0);
            }


        } );


};

string_sort = function(a, b) {
    return (a === null || a < b) ? -1 : a == b ? 0 : -1;
};

index = require('index').createIndex({
        order: 32, // Maximum number of items in page
            // Tree's height depends on that
            storage: require('index').storage.file // Place where all tree data will be stored
            .createStorage({filename:index_file}, on_index_created),          // (see more description below)
            sort: string_sort
        // Function that will be used to compare keys
        // Note that null is a system value and sort should always return negative
        // result if first argument is null
});