MoneyNetworkAPI: z_file_get wrapper

Add fileGet wrapper to MoneyNetworkAPI. Now three different implementations in MoneyNetworkAPI, MN and W2. From MN:
// ZeroFrame fileGet wrapper. first fileGet request must wait for mergerSiteAdd operation to finish
var inner_path_re1 = /^data\/users\// ; // invalid inner_path. old before merger-site syntax
var inner_path_re2 = /^merged-MoneyNetwork\/(.*?)\/data\/users\/(.*?)$/ ; // extract hub and auth_address
function z_file_get (pgm, options, cb) {
    var inner_path, match2, hub, pos, filename, optional_file, get_optional_file_info ;
    inner_path = options.inner_path ;

    // check inner_path.
    if (inner_path.match(inner_path_re1)) throw pgm + 'Invalid fileGet path. Not a merger-site path. inner_path = ' + inner_path ;
    match2 = inner_path.match(inner_path_re2) ;
    if (match2) {
        hub = match2[1] ;
        if (new_user_data_hub_cbs[hub]) {
            console.log(pgm + 'new data hub ' + hub + '. waiting with fileGet request for ' + inner_path) ;
            new_user_data_hub_cbs[hub].push(function() { z_file_get (pgm, options, cb) }) ;
            return ;
        }
    }
    else throw pgm + 'Invalid fileGet path. Not a merger-site path. inner_path = ' + inner_path ;

    // optional fileGet operation? Some issues with optional fileGet calls
    // problem with fileGet operation for delete optional files. timeout after > 60 seconds. should be solved now. null file_info is returned for deleted optional files
    // also a problem with fileGet operation for optional files without any peer (peer information is not always 100% correct)
    pos = inner_path.lastIndexOf('/') ;
    filename = inner_path.substr(pos+1, inner_path.length-pos) ;
    optional_file = (['content.json', 'data.json', 'status.json', 'like.json', 'avatar.jpg', 'avatar.png', 'wallet.json'].indexOf(filename) == -1);
    debug('z_file_get', pgm + 'filename = ' + JSON.stringify(filename) + ', optional_file = ' + optional_file) ;

    // optional step. get info about optional file before fileGet operation
    // "!file_info.is_downloaded && !file_info.peer" should be not downloaded optional files without any peers
    // but the information is not already correct. peer can be 0 and other client is ready to serve optional file.
    // try a fileGet with required and a "short" timeout
    get_optional_file_info = function (cb) {
        if (!optional_file) return cb(null) ;
        ZeroFrame.cmd("optionalFileInfo", [inner_path], function (file_info) {
            debug('z_file_get', pgm + 'file_info = ' + JSON.stringify(file_info)) ;
            cb(file_info) ;
        }) ; // optionalFileInfo
    } ; // get_optional_file_info
    get_optional_file_info(function(file_info) {
        var cb2_done, cb2, timeout, process_id, debug_seq, warnings, old_options ;
        if (optional_file && !file_info) {
            debug('z_file_get', pgm + 'optional fileGet and no optional file info. must be a deleted optional file. abort fileGet operation') ;
            return cb(null) ;
        }
        if (optional_file) {
            // some additional checks and warnings.
            if (!file_info) {
                debug('z_file_get', pgm + 'optional fileGet and no optional file info. must be a deleted optional file. abort fileGet operation') ;
                return cb(null) ;
            }
            if (!file_info.is_downloaded && !file_info.peer) {
                // not downloaded optional files and (maybe) no peers! peer information is not always correct
                debug('z_file_get', pgm + 'warning. starting fileGet operation for optional file without any peers. file_info = ' + JSON.stringify(file_info)) ;
                warnings = [] ;
                old_options = JSON.stringify(options) ;
                if (!options.required) {
                    options.required = true ;
                    warnings.push('added required=true to fileGet operation') ;
                }
                if (!options.timeout) {
                    options.timeout = 60 ;
                    warnings.push('added timeout=60 to fileGet operation') ;
                }
                if (warnings.length) debug('z_file_get', pgm + 'Warning: ' + warnings.join('. ') + '. old options = ' + old_options + ', new_options = ' + JSON.stringify(options)) ;
            }
        }

        // extend cb. add ZeroNet API debug messages + timeout processing.
        // cb2 is run as fileGet callback or is run by $timeout (sometimes problem with optional fileGet operation running forever)
        cb2_done = false ;
        cb2 = function (data) {
            if (process_id) {
                try {$timeout.cancel(process_id)}
                catch (e) {}
                process_id = null ;
            }
            if (cb2_done) return ; // cb2 has already run
            cb2_done = true ;
            // MoneyNetworkHelper.debug_z_api_operation_end(debug_seq);
            debug_z_api_operation_end(debug_seq, data ? 'OK' : 'Not found');
            cb(data) ;
        } ; // fileGet callback

        timeout = options.timeout || 60 ; // timeout in seconds
        process_id = $timeout(cb2, timeout*1000) ;
        // debug_seq = MoneyNetworkHelper.debug_z_api_operation_start('z_file_get', pgm + inner_path + ' fileGet') ;
        debug_seq = debug_z_api_operation_start(pgm, inner_path, 'fileGet', show_debug('z_file_get')) ;
        ZeroFrame.cmd("fileGet", options, cb2) ;

    }) ; // get_optional_file_info callback

} // z_file_get
jaros1 / Money-Network

MoneyNetworkAPI: z_file_get wrapper #252
