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nodejs/lib/fs.js

949 lines
22 KiB
JavaScript

var util = require('util');
var binding = process.binding('fs');
var constants = process.binding('constants');
var fs = exports;
var Stream = require('stream').Stream;
var kMinPoolSpace = 128;
var kPoolSize = 40 * 1024;
fs.Stats = binding.Stats;
fs.Stats.prototype._checkModeProperty = function (property) {
return ((this.mode & constants.S_IFMT) === property);
};
fs.Stats.prototype.isDirectory = function () {
return this._checkModeProperty(constants.S_IFDIR);
};
fs.Stats.prototype.isFile = function () {
return this._checkModeProperty(constants.S_IFREG);
};
fs.Stats.prototype.isBlockDevice = function () {
return this._checkModeProperty(constants.S_IFBLK);
};
fs.Stats.prototype.isCharacterDevice = function () {
return this._checkModeProperty(constants.S_IFCHR);
};
fs.Stats.prototype.isSymbolicLink = function () {
return this._checkModeProperty(constants.S_IFLNK);
};
fs.Stats.prototype.isFIFO = function () {
return this._checkModeProperty(constants.S_IFIFO);
};
fs.Stats.prototype.isSocket = function () {
return this._checkModeProperty(constants.S_IFSOCK);
};
fs.readFile = function (path, encoding_) {
var encoding = typeof(encoding_) === 'string' ? encoding_ : null;
var callback = arguments[arguments.length-1];
if (typeof(callback) !== 'function') callback = noop;
var readStream = fs.createReadStream(path);
var buffers = [];
var nread = 0;
readStream.on("data", function (chunk) {
buffers.push(chunk);
nread += chunk.length;
});
readStream.on("error", function (er) {
callback(er);
readStream.destroy();
});
readStream.on("end", function () {
// copy all the buffers into one
var buffer;
switch (buffers.length) {
case 0: buffer = new Buffer(0); break;
case 1: buffer = buffers[0]; break;
default: // concat together
buffer = new Buffer(nread);
var n = 0;
buffers.forEach(function (b) {
var l = b.length;
b.copy(buffer, n, 0, l);
n += l;
});
break;
}
if (encoding) {
try {
buffer = buffer.toString(encoding);
} catch (er) {
return callback(er);
}
}
callback(null, buffer);
});
};
fs.readFileSync = function (path, encoding) {
var fd = fs.openSync(path, constants.O_RDONLY, 0666);
var buffer = new Buffer(4048);
var buffers = [];
var nread = 0;
var lastRead = 0;
do {
if (lastRead) {
buffer._bytesRead = lastRead;
nread += lastRead;
buffers.push(buffer);
}
var buffer = new Buffer(4048);
lastRead = fs.readSync(fd, buffer, 0, buffer.length, null);
} while (lastRead > 0);
fs.closeSync(fd);
if (buffers.length > 1) {
var offset = 0;
var i;
buffer = new Buffer(nread);
buffers.forEach(function (i) {
if (!i._bytesRead) return;
i.copy(buffer,offset,0,i._bytesRead);
offset += i._bytesRead;
});
} else if (buffers.length) {
//buffers has exactly 1 (possibly zero length) buffer, so this should be a shortcut
buffer = buffers[0].slice(0, buffers[0]._bytesRead);
} else {
buffer = new Buffer(0);
}
if (encoding) buffer = buffer.toString(encoding);
return buffer;
};
// Used by binding.open and friends
function stringToFlags(flag) {
// Only mess with strings
if (typeof flag !== 'string') {
return flag;
}
switch (flag) {
case "r": return constants.O_RDONLY;
case "r+": return constants.O_RDWR;
case "w": return constants.O_CREAT | constants.O_TRUNC | constants.O_WRONLY;
case "w+": return constants.O_CREAT | constants.O_TRUNC | constants.O_RDWR;
case "a": return constants.O_APPEND | constants.O_CREAT | constants.O_WRONLY;
case "a+": return constants.O_APPEND | constants.O_CREAT | constants.O_RDWR;
default: throw new Error("Unknown file open flag: " + flag);
}
}
function noop () {}
// Yes, the follow could be easily DRYed up but I provide the explicit
// list to make the arguments clear.
fs.close = function (fd, callback) {
binding.close(fd, callback || noop);
};
fs.closeSync = function (fd) {
return binding.close(fd);
};
fs.open = function (path, flags, mode_, callback) {
var mode = (typeof(mode_) == 'number' ? mode_ : 0666);
var callback_ = arguments[arguments.length - 1];
var callback = (typeof(callback_) == 'function' ? callback_ : null);
binding.open(path, stringToFlags(flags), mode, callback || noop);
};
fs.openSync = function (path, flags, mode) {
if (mode === undefined) { mode = 0666; }
return binding.open(path, stringToFlags(flags), mode);
};
fs.read = function (fd, buffer, offset, length, position, callback) {
if (!Buffer.isBuffer(buffer)) {
// legacy string interface (fd, length, position, encoding, callback)
var cb = arguments[4],
encoding = arguments[3];
position = arguments[2];
length = arguments[1];
buffer = new Buffer(length);
offset = 0;
callback = function(err, bytesRead) {
if (!cb) return;
var str = (bytesRead > 0)
? buffer.toString(encoding, 0, bytesRead)
: '';
(cb)(err, str, bytesRead);
};
}
binding.read(fd, buffer, offset, length, position, callback || noop);
};
fs.readSync = function (fd, buffer, offset, length, position) {
var legacy = false;
if (!Buffer.isBuffer(buffer)) {
// legacy string interface (fd, length, position, encoding, callback)
legacy = true;
encoding = arguments[3];
position = arguments[2];
length = arguments[1];
buffer = new Buffer(length);
offset = 0;
}
var r = binding.read(fd, buffer, offset, length, position);
if (!legacy) {
return r;
}
var str = (r > 0)
? buffer.toString(encoding, 0, r)
: '';
return [str, r];
};
fs.write = function (fd, buffer, offset, length, position, callback) {
if (!Buffer.isBuffer(buffer)) {
// legacy string interface (fd, data, position, encoding, callback)
callback = arguments[4];
position = arguments[2];
buffer = new Buffer(''+arguments[1], arguments[3]);
offset = 0;
length = buffer.length;
}
if (!length) {
if (typeof callback == 'function') {
process.nextTick(function() {
callback(undefined, 0);
});
}
return;
}
binding.write(fd, buffer, offset, length, position, callback || noop);
};
fs.writeSync = function (fd, buffer, offset, length, position) {
if (!Buffer.isBuffer(buffer)) {
// legacy string interface (fd, data, position, encoding)
position = arguments[2];
buffer = new Buffer(''+arguments[1], arguments[3]);
offset = 0;
length = buffer.length;
}
if(!length) return 0;
return binding.write(fd, buffer, offset, length, position);
};
fs.rename = function (oldPath, newPath, callback) {
binding.rename(oldPath, newPath, callback || noop);
};
fs.renameSync = function (oldPath, newPath) {
return binding.rename(oldPath, newPath);
};
fs.truncate = function (fd, len, callback) {
binding.truncate(fd, len, callback || noop);
};
fs.truncateSync = function (fd, len) {
return binding.truncate(fd, len);
};
fs.rmdir = function (path, callback) {
binding.rmdir(path, callback || noop);
};
fs.rmdirSync = function (path) {
return binding.rmdir(path);
};
fs.fdatasync = function (fd, callback) {
binding.fdatasync(fd, callback || noop);
};
fs.fdatasyncSync = function (fd) {
return binding.fdatasync(fd);
};
fs.fsync = function (fd, callback) {
binding.fsync(fd, callback || noop);
};
fs.fsyncSync = function (fd) {
return binding.fsync(fd);
};
fs.mkdir = function (path, mode, callback) {
binding.mkdir(path, mode, callback || noop);
};
fs.mkdirSync = function (path, mode) {
return binding.mkdir(path, mode);
};
fs.sendfile = function (outFd, inFd, inOffset, length, callback) {
binding.sendfile(outFd, inFd, inOffset, length, callback || noop);
};
fs.sendfileSync = function (outFd, inFd, inOffset, length) {
return binding.sendfile(outFd, inFd, inOffset, length);
};
fs.readdir = function (path, callback) {
binding.readdir(path, callback || noop);
};
fs.readdirSync = function (path) {
return binding.readdir(path);
};
fs.fstat = function (fd, callback) {
binding.fstat(fd, callback || noop);
};
fs.lstat = function (path, callback) {
binding.lstat(path, callback || noop);
};
fs.stat = function (path, callback) {
binding.stat(path, callback || noop);
};
fs.fstatSync = function (fd) {
return binding.fstat(fd);
};
fs.lstatSync = function (path) {
return binding.lstat(path);
};
fs.statSync = function (path) {
return binding.stat(path);
};
fs.readlink = function (path, callback) {
binding.readlink(path, callback || noop);
};
fs.readlinkSync = function (path) {
return binding.readlink(path);
};
fs.symlink = function (destination, path, callback) {
binding.symlink(destination, path, callback || noop);
};
fs.symlinkSync = function (destination, path) {
return binding.symlink(destination, path);
};
fs.link = function (srcpath, dstpath, callback) {
binding.link(srcpath, dstpath, callback || noop);
};
fs.linkSync = function (srcpath, dstpath) {
return binding.link(srcpath, dstpath);
};
fs.unlink = function (path, callback) {
binding.unlink(path, callback || noop);
};
fs.unlinkSync = function (path) {
return binding.unlink(path);
};
fs.chmod = function (path, mode, callback) {
binding.chmod(path, mode, callback || noop);
};
fs.chmodSync = function (path, mode) {
return binding.chmod(path, mode);
};
fs.chown = function(path, uid, gid, callback) {
binding.chown(path, uid, gid, callback || noop);
};
fs.chownSync = function(path, uid, gid) {
return binding.chown(path, uid, gid);
};
function writeAll (fd, buffer, callback) {
fs.write(fd, buffer, 0, buffer.length, null, function (writeErr, written) {
if (writeErr) {
fs.close(fd, function () {
if (callback) callback(writeErr);
});
} else {
if (written === buffer.length) {
fs.close(fd, callback);
} else {
writeAll(fd, buffer.slice(written), callback);
}
}
});
}
fs.writeFile = function (path, data, encoding_, callback) {
var encoding = (typeof(encoding_) == 'string' ? encoding_ : 'utf8');
var callback_ = arguments[arguments.length - 1];
var callback = (typeof(callback_) == 'function' ? callback_ : null);
fs.open(path, 'w', 0666, function (openErr, fd) {
if (openErr) {
if (callback) callback(openErr);
} else {
var buffer = Buffer.isBuffer(data) ? data : new Buffer(data, encoding);
writeAll(fd, buffer, callback);
}
});
};
fs.writeFileSync = function (path, data, encoding) {
encoding = encoding || "utf8"; // default to utf8
var fd = fs.openSync(path, "w");
var written = 0;
while (written < data.length) {
written += fs.writeSync(fd, data, 0, encoding);
data = data.slice(written);
}
fs.closeSync(fd);
};
// Stat Change Watchers
var statWatchers = {};
fs.watchFile = function (filename) {
var stat;
var options;
var listener;
if ("object" == typeof arguments[1]) {
options = arguments[1];
listener = arguments[2];
} else {
options = {};
listener = arguments[1];
}
if (options.persistent === undefined) options.persistent = true;
if (options.interval === undefined) options.interval = 0;
if (statWatchers[filename]) {
stat = statWatchers[filename];
} else {
statWatchers[filename] = new binding.StatWatcher();
stat = statWatchers[filename];
stat.start(filename, options.persistent, options.interval);
}
stat.addListener("change", listener);
return stat;
};
fs.unwatchFile = function (filename) {
var stat;
if (statWatchers[filename]) {
stat = statWatchers[filename];
stat.stop();
statWatchers[filename] = undefined;
}
};
// Realpath
var path = require('path');
var normalize = path.normalize;
var normalizeArray = path.normalizeArray;
// realpath
// Not using realpath(2) because it's bad.
// See: http://insanecoding.blogspot.com/2007/11/pathmax-simply-isnt.html
fs.realpathSync = realpathSync;
fs.realpath = realpath;
function realpathSync (p) {
if (p.charAt(0) !== '/') {
p = path.join(process.cwd(), p);
}
p = p.split('/');
var buf = [ '' ];
var seenLinks = {};
var knownHard = {};
// walk down the path, swapping out linked pathparts for their real
// values, and pushing non-link path bits onto the buffer.
// then return the buffer.
// NB: path.length changes.
for (var i = 0; i < p.length; i ++) {
// skip over empty path parts.
if (p[i] === '') continue;
var part = buf.join('/')+'/'+p[i];
if (knownHard[part]) {
buf.push( p[i] );
continue;
}
var stat = fs.lstatSync(part);
if (!stat.isSymbolicLink()) {
// not a symlink. easy.
knownHard[ part ] = true;
buf.push(p[i]);
continue;
}
var id = stat.dev.toString(32)+':'+stat.ino.toString(32);
if (!seenLinks[id]) {
fs.statSync(part);
seenLinks[id] = fs.readlinkSync(part);
}
var target = seenLinks[id];
if (target.charAt(0) === '/') {
// absolute. Start over.
buf = [''];
p = path.normalizeArray(target.split('/').concat(p.slice(i + 1)));
i = 0;
continue;
}
// not absolute. join and splice.
target = target.split('/');
Array.prototype.splice.apply(p, [i, 1].concat(target));
p = path.normalizeArray(p);
i = 0;
buf = [''];
}
return buf.join('/') || '/';
}
function realpath (p, cb) {
if (p.charAt(0) !== '/') {
p = path.join(process.cwd(), p);
}
p = p.split('/');
var buf = [ '' ];
var seenLinks = {};
var knownHard = {};
// walk down the path, swapping out linked pathparts for their real
// values, and pushing non-link path bits onto the buffer.
// then return the buffer.
// NB: path.length changes.
var i = 0;
var part;
LOOP();
function LOOP () {
i ++;
if (!(i < p.length)) return exit();
// skip over empty path parts.
if (p[i] === '') return process.nextTick(LOOP);
part = buf.join('/')+'/'+p[i];
if (knownHard[part]) {
buf.push( p[i] );
return process.nextTick(LOOP);
}
return fs.lstat(part, gotStat);
}
function gotStat (er, stat) {
if (er) return cb(er);
if (!stat.isSymbolicLink()) {
// not a symlink. easy.
knownHard[ part ] = true;
buf.push(p[i]);
return process.nextTick(LOOP);
}
var id = stat.dev.toString(32)+':'+stat.ino.toString(32);
if (seenLinks[id]) return gotTarget(null, seenLinks[id]);
fs.stat(part, function (er) {
if (er) return cb(er)
fs.readlink(part, function (er, target) {
gotTarget(er, seenLinks[id] = target);
});
})
}
function gotTarget (er, target) {
if (er) return cb(er);
if (target.charAt(0) === '/') {
// absolute. Start over.
buf = [''];
p = path.normalizeArray(target.split('/').concat(p.slice(i + 1)));
i = 0;
return process.nextTick(LOOP);
}
// not absolute. join and splice.
target = target.split('/');
Array.prototype.splice.apply(p, [i, 1].concat(target));
p = path.normalizeArray(p);
i = 0;
buf = [''];
return process.nextTick(LOOP);
}
function exit () {
cb(null, buf.join('/') || '/');
}
}
var pool;
function allocNewPool () {
pool = new Buffer(kPoolSize);
pool.used = 0;
}
fs.createReadStream = function(path, options) {
return new ReadStream(path, options);
};
var ReadStream = fs.ReadStream = function(path, options) {
if (!(this instanceof ReadStream)) return new ReadStream(path, options);
Stream.call(this);
var self = this;
this.path = path;
this.fd = null;
this.readable = true;
this.paused = false;
this.flags = 'r';
this.mode = 0666;
this.bufferSize = 64 * 1024;
options = options || {};
// Mixin options into this
var keys = Object.keys(options);
for (var index = 0, length = keys.length; index < length; index++) {
var key = keys[index];
this[key] = options[key];
}
if(this.encoding) this.setEncoding(this.encoding);
if (this.start !== undefined || this.end !== undefined) {
if (this.start === undefined || this.end === undefined) {
this.emit('error',
new Error('Both start and end are needed for range streaming.'));
} else if (this.start > this.end) {
this.emit('error', new Error('start must be <= end'));
} else {
this._firstRead = true;
}
}
if (this.fd !== null) {
return;
}
fs.open(this.path, this.flags, this.mode, function(err, fd) {
if (err) {
self.emit('error', err);
self.readable = false;
return;
}
self.fd = fd;
self.emit('open', fd);
self._read();
});
};
util.inherits(ReadStream, Stream);
fs.FileReadStream = fs.ReadStream; // support the legacy name
ReadStream.prototype.setEncoding = function (encoding) {
var StringDecoder = require("string_decoder").StringDecoder; // lazy load
this._decoder = new StringDecoder(encoding);
};
ReadStream.prototype._read = function () {
var self = this;
if (!self.readable || self.paused) return;
if (!pool || pool.length - pool.used < kMinPoolSpace) {
// discard the old pool. Can't add to the free list because
// users might have refernces to slices on it.
pool = null;
allocNewPool();
}
if (self.start !== undefined && self._firstRead) {
self.pos = self.start;
self._firstRead = false;
}
// Grab another reference to the pool in the case that while we're in the
// thread pool another read() finishes up the pool, and allocates a new
// one.
var thisPool = pool;
var toRead = Math.min(pool.length - pool.used, this.bufferSize);
var start = pool.used;
if (this.pos !== undefined) {
toRead = Math.min(this.end - this.pos + 1, toRead);
}
function afterRead (err, bytesRead) {
if (err) {
self.emit('error', err);
self.readable = false;
return;
}
if (bytesRead === 0) {
self.emit('end');
self.destroy();
return;
}
var b = thisPool.slice(start, start+bytesRead);
// Possible optimizition here?
// Reclaim some bytes if bytesRead < toRead?
// Would need to ensure that pool === thisPool.
// do not emit events if the stream is paused
if (self.paused) {
self.buffer = b;
return;
}
// do not emit events anymore after we declared the stream unreadable
if (!self.readable) return;
self._emitData(b);
self._read();
}
fs.read(self.fd, pool, pool.used, toRead, self.pos, afterRead);
if (self.pos !== undefined) {
self.pos += toRead;
}
pool.used += toRead;
};
ReadStream.prototype._emitData = function (d) {
if (this._decoder) {
var string = this._decoder.write(d);
if (string.length) this.emit('data', string);
} else {
this.emit('data', d);
}
};
ReadStream.prototype.destroy = function (cb) {
var self = this;
this.readable = false;
function close() {
fs.close(self.fd, function(err) {
if (err) {
if (cb) cb(err);
self.emit('error', err);
return;
}
if (cb) cb(null);
self.emit('close');
});
}
if (this.fd) {
close();
} else {
this.addListener('open', close);
}
};
ReadStream.prototype.pause = function() {
this.paused = true;
};
ReadStream.prototype.resume = function() {
this.paused = false;
if (this.buffer) {
this._emitData(this.buffer);
this.buffer = null;
}
this._read();
};
fs.createWriteStream = function(path, options) {
return new WriteStream(path, options);
};
var WriteStream = fs.WriteStream = function(path, options) {
if (!(this instanceof WriteStream)) return new WriteStream(path, options);
Stream.call(this);
this.path = path;
this.fd = null;
this.writable = true;
this.flags = 'w';
this.encoding = 'binary';
this.mode = 0666;
options = options || {};
// Mixin options into this
var keys = Object.keys(options);
for (var index = 0, length = keys.length; index < length; index++) {
var key = keys[index];
this[key] = options[key];
}
this.busy = false;
this._queue = [];
if (this.fd === null) {
this._queue.push([fs.open, this.path, this.flags, this.mode, undefined]);
this.flush();
}
};
util.inherits(WriteStream, Stream);
fs.FileWriteStream = fs.WriteStream; // support the legacy name
WriteStream.prototype.flush = function () {
if (this.busy) return;
var self = this;
var args = this._queue.shift();
if (!args) {
if (this.drainable) { self.emit('drain'); }
return;
}
this.busy = true;
var method = args.shift(),
cb = args.pop();
var self = this;
args.push(function(err) {
self.busy = false;
if (err) {
self.writable = false;
if (cb) {
cb(err);
}
self.emit('error', err);
return;
}
// stop flushing after close
if (method === fs.close) {
if (cb) {
cb(null);
}
self.emit('close');
return;
}
// save reference for file pointer
if (method === fs.open) {
self.fd = arguments[1];
self.emit('open', self.fd);
} else if (cb) {
// write callback
cb(null, arguments[1]);
}
self.flush();
});
// Inject the file pointer
if (method !== fs.open) {
args.unshift(self.fd);
}
method.apply(this, args);
};
WriteStream.prototype.write = function (data) {
if (!this.writable) {
throw new Error('stream not writable');
}
this.drainable = true;
var cb;
if (typeof(arguments[arguments.length-1]) == 'function') {
cb = arguments[arguments.length-1];
}
if (Buffer.isBuffer(data)) {
this._queue.push([fs.write, data, 0, data.length, null, cb]);
} else {
var encoding = 'utf8';
if (typeof(arguments[1]) == 'string') encoding = arguments[1];
this._queue.push([fs.write, data, undefined, encoding, cb]);
}
this.flush();
return false;
};
WriteStream.prototype.end = function (cb) {
this.writable = false;
this._queue.push([fs.close, cb]);
this.flush();
};
WriteStream.prototype.destroy = function (cb) {
var self = this;
this.writable = false;
function close() {
fs.close(self.fd, function(err) {
if (err) {
if (cb) { cb(err); }
self.emit('error', err);
return;
}
if (cb) { cb(null); }
self.emit('close');
});
}
if (this.fd) {
close();
} else {
this.addListener('open', close);
}
};