fs-walk.js/lib/node-type-emitter.js

89 lines
2.5 KiB
JavaScript

(function () {
"use strict";
// "FIFO" isn't easy to convert to camelCase and back reliably
var isFnodeTypes = [
"isFile", "isDirectory", "isSymbolicLink", "isBlockDevice", "isCharacterDevice", "isFIFO", "isSocket"
],
fnodeTypes = [
"file", "directory", "symbolicLink", "blockDevice", "characterDevice", "FIFO", "socket"
],
fnodeTypesPlural = [
"files", "directories", "symbolicLinks", "blockDevices", "characterDevices", "FIFOs", "sockets"
];
//
function createNodeGroups() {
var nodeGroups = {};
fnodeTypesPlural.concat("nodes", "errors").forEach(function (fnodeTypePlural) {
nodeGroups[fnodeTypePlural] = [];
});
return nodeGroups;
}
// Determine each file node's type
//
function sortFnodesByType(stat, fnodes) {
var i, isType;
for (i = 0; i < isFnodeTypes.length; i += 1) {
isType = isFnodeTypes[i];
if (stat[isType]()) {
stat.type = fnodeTypes[i];
fnodes[fnodeTypesPlural[i]].push(stat);
return;
}
}
}
// 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(emitter, 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(emitter, 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();
}
module.exports = {
emitNodeType: emitSingleEvents,
emitNodeTypeGroups: emitPluralEvents,
isFnodeTypes: isFnodeTypes,
fnodeTypes: fnodeTypes,
fnodeTypesPlural: fnodeTypesPlural,
sortFnodesByType: sortFnodesByType,
createNodeGroups: createNodeGroups
};
}());