fs-walk.js/old/lib/walk-recurse.js

166 lines
4.9 KiB
JavaScript

// TODO
// * add types by listener dynamically
// * unroll loops for better readability?
// * should emitted errors wait for `next()`?
(function (undefined) {
var fs = require('fs'),
upath = require('path'),
util = require('util'),
Futures = require('futures'),
events = require('events'),
noop = function () {},
// "FIFO" isn't easy to convert to camelCame and back reliably
isFnodeTypes = [
"isFile", "isDirectory", "isBlockDevice", "isCharacterDevice", "isSymbolicLink", "isFIFO", "isSocket"
],
fnodeTypes = [
"file", "directory", "blockDevice", "characterDevice", "symbolicLink", "FIFO", "socket"
],
fnodeTypesPlural = [
"files", "directories", "blockDevices", "characterDevices", "symbolicLinks", "FIFOs", "sockets"
];
function newVersion() {
throw new Error("New Version. Please see API on github.com/coolaj86/node-walk");
}
// Create a new walk instance
function create(path, options, cb) {
if (cb) {
newVersion();
}
var emitter = new events.EventEmitter(),
fstat = (options||{}).followLinks ? fs.stat : fs.lstat;
// Get the current number of listeners (which may change)
// Emit events to each listener
// Wait for all listeners to `next()` before continueing
// (in theory this may avoid disk thrashing)
function emitSingleEvents(path, stats, next) {
var num = 1 + emitter.listeners(stats.type).length + emitter.listeners("node").length;
function nextWhenReady() {
num -= 1;
if (0 === num) { next(); }
}
emitter.emit(stats.type, path, stats, nextWhenReady);
emitter.emit("node", path, stats, nextWhenReady);
nextWhenReady();
}
// Since the risk for disk thrashing among anything
// other than files is relatively low, all types are
// emitted at once, but all must complete before advancing
function emitPluralEvents(path, nodes, next) {
var num = 1;
function nextWhenReady() {
num -= 1;
if (0 === num) { next(); }
}
fnodeTypesPlural.concat(["nodes", "errors"]).forEach(function (fnodeType) {
if (0 === nodes[fnodeType].length) { return; }
num += emitter.listeners(fnodeType).length;
emitter.emit(fnodeType, path, nodes[fnodeType], nextWhenReady);
});
nextWhenReady();
}
// Determine each file node's type
//
function sortFnodesByType(path, stats, fnodes, nextFile) {
isFnodeTypes.forEach(function (isType, i) {
if (stats[isType]()) {
if (stats.type) { throw new Error("is_" + type + " and " + isType); }
stats.type = fnodeTypes[i];
fnodes[fnodeTypesPlural[i]].push(stats);
// TODO throw to break;
}
});
if (!stats.type) { throw new Error(upath.join(path, stats.name) + ' isAnUndefinedType'); }
emitSingleEvents(path, stats, nextFile);
}
// Asynchronously get the stats
//
function getStats(path, files, walkDirs) {
var nodeGroups = {};
fnodeTypesPlural.concat("nodes", "errors").forEach(function (fnodeTypePlural) {
nodeGroups[fnodeTypePlural] = [];
});
function nextFile() {
var file = files.pop(), dirs = [], fnames = [];
if (undefined === file) {
emitPluralEvents(path, nodeGroups, function () {
nodeGroups.directories.forEach(function (dir) {
dirs.push(dir.name);
});
walkDirs(dirs);
});
return;
}
fstat(upath.join(path, file), function (err, stats) {
stats = stats || {};
stats.name = file;
nodeGroups.nodes.push(stats);
if (err) {
stats.error = err;
stats.type = 'error';
nodeGroups.errors.push(stats);
//emitter.emit('fileError', path, stats, noop);
return nextFile();
}
sortFnodesByType(path, stats, nodeGroups, nextFile);
});
}
nextFile();
}
function walk(path, next) {
fs.readdir(path, function (err, nodes) {
if (err) {
emitter.emit('directoryError', path, { error: err, name: path }, noop);
return next(); /*TODO*/ throw err;
}
getStats(path, nodes, function (dirs) {
walkDirs(path, dirs, next);
});
});
}
function walkDirs(path, dirs, cb) {
function nextDir() {
var dir = dirs.pop();
if (undefined === dir) {
delete dirs;
return cb();
}
walk(upath.join(path, dir), nextDir);
}
nextDir();
}
walk(upath.normalize(path), function () {
emitter.emit('end');
});
emitter.walk = newVersion;
emitter.whenever = newVersion;
return emitter;
}
module.exports = create;
module.exports.isFnodeTypes = isFnodeTypes;
module.exports.fnodeTypes = fnodeTypes;
module.exports.fnodeTypesPlural = fnodeTypesPlural;
}());