securityos/node_modules/@cowasm/memfs/lib/node.js

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2024-09-06 15:32:35 +00:00
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.File = exports.Link = exports.Node = exports.SEP = void 0;
const process_1 = require("./process");
const buffer_1 = require("./internal/buffer");
const constants_1 = require("./constants");
const events_1 = require("events");
const Stats_1 = require("./Stats");
const { S_IFMT, S_IFDIR, S_IFREG, S_IFLNK, O_APPEND } = constants_1.constants;
const getuid = () => process_1.default.getuid?.() ?? 0;
const getgid = () => process_1.default.getgid?.() ?? 0;
exports.SEP = "/";
/**
* Node in a file system (like i-node, v-node).
*/
class Node extends events_1.EventEmitter {
constructor(ino, perm = 0o666) {
super();
// User ID and group ID.
this.uid = getuid();
this.gid = getgid();
this.atime = new Date();
this.mtime = new Date();
this.ctime = new Date();
this.perm = 0o666; // Permissions `chmod`, `fchmod`
this.mode = S_IFREG; // S_IFDIR, S_IFREG, etc.. (file by default?)
// Number of hard links pointing at this Node.
this.nlink = 1;
this.perm = perm;
this.mode |= perm;
this.ino = ino;
}
getString(encoding = "utf8") {
return this.getBuffer().toString(encoding);
}
setString(str) {
// this.setBuffer(bufferFrom(str, 'utf8'));
this.buf = (0, buffer_1.bufferFrom)(str, "utf8");
this.touch();
}
getBuffer() {
if (!this.buf)
this.setBuffer((0, buffer_1.bufferAllocUnsafe)(0));
return (0, buffer_1.bufferFrom)(this.buf); // Return a copy.
}
setBuffer(buf) {
this.buf = (0, buffer_1.bufferFrom)(buf); // Creates a copy of data.
this.touch();
}
getSize() {
return this.buf ? this.buf.length : 0;
}
setModeProperty(property) {
this.mode = (this.mode & ~S_IFMT) | property;
}
setIsFile() {
this.setModeProperty(S_IFREG);
}
setIsDirectory() {
this.setModeProperty(S_IFDIR);
}
setIsSymlink() {
this.setModeProperty(S_IFLNK);
}
isFile() {
return (this.mode & S_IFMT) === S_IFREG;
}
isDirectory() {
return (this.mode & S_IFMT) === S_IFDIR;
}
isSymlink() {
// return !!this.symlink;
return (this.mode & S_IFMT) === S_IFLNK;
}
makeSymlink(steps) {
this.symlink = steps;
this.setIsSymlink();
}
write(buf, off = 0, len = buf.length, pos = 0) {
if (!this.buf)
this.buf = (0, buffer_1.bufferAllocUnsafe)(0);
if (pos + len > this.buf.length) {
const newBuf = (0, buffer_1.bufferAllocUnsafe)(pos + len);
this.buf.copy(newBuf, 0, 0, this.buf.length);
this.buf = newBuf;
}
buf.copy(this.buf, pos, off, off + len);
this.touch();
return len;
}
// Returns the number of bytes read.
read(buf, off = 0, len = buf.byteLength, pos = 0) {
if (!this.buf)
this.buf = (0, buffer_1.bufferAllocUnsafe)(0);
let actualLen = len;
if (actualLen > buf.byteLength) {
actualLen = buf.byteLength;
}
if (actualLen + pos > this.buf.length) {
actualLen = this.buf.length - pos;
}
this.buf.copy(buf, off, pos, pos + actualLen);
return actualLen;
}
truncate(len = 0) {
if (!len)
this.buf = (0, buffer_1.bufferAllocUnsafe)(0);
else {
if (!this.buf)
this.buf = (0, buffer_1.bufferAllocUnsafe)(0);
if (len <= this.buf.length) {
this.buf = this.buf.slice(0, len);
}
else {
const buf = (0, buffer_1.bufferAllocUnsafe)(0);
this.buf.copy(buf);
buf.fill(0, len);
}
}
this.touch();
}
chmod(perm) {
this.perm = perm;
this.mode = (this.mode & ~0o777) | perm;
this.touch();
}
chown(uid, gid) {
this.uid = uid;
this.gid = gid;
this.touch();
}
touch() {
this.mtime = new Date();
this.emit("change", this);
}
canRead(uid = getuid(), gid = getgid()) {
if (this.perm & 4 /* S.IROTH */) {
return true;
}
if (gid === this.gid) {
if (this.perm & 32 /* S.IRGRP */) {
return true;
}
}
if (uid === this.uid) {
if (this.perm & 256 /* S.IRUSR */) {
return true;
}
}
return false;
}
canWrite(uid = getuid(), gid = getgid()) {
if (this.perm & 2 /* S.IWOTH */) {
return true;
}
if (gid === this.gid) {
if (this.perm & 16 /* S.IWGRP */) {
return true;
}
}
if (uid === this.uid) {
if (this.perm & 128 /* S.IWUSR */) {
return true;
}
}
return false;
}
del() {
this.emit("delete", this);
}
toJSON() {
return {
ino: this.ino,
uid: this.uid,
gid: this.gid,
atime: this.atime.getTime(),
mtime: this.mtime.getTime(),
ctime: this.ctime.getTime(),
perm: this.perm,
mode: this.mode,
nlink: this.nlink,
symlink: this.symlink,
data: this.getString(),
};
}
}
exports.Node = Node;
/**
* Represents a hard link that points to an i-node `node`.
*/
class Link extends events_1.EventEmitter {
constructor(vol, parent, name) {
super();
this.children = {};
// Path to this node as Array: ['usr', 'bin', 'node'].
this._steps = [];
// "i-node" number of the node.
this.ino = 0;
// Number of children.
this.length = 0;
this.vol = vol;
this.parent = parent;
this.name = name;
this.syncSteps();
}
get steps() {
return this._steps;
}
// Recursively sync children steps, e.g. in case of dir rename
set steps(val) {
this._steps = val;
for (const child of Object.values(this.children)) {
child?.syncSteps();
}
}
setNode(node) {
this.node = node;
this.ino = node.ino;
}
getNode() {
return this.node;
}
createChild(name, node = this.vol.createNode()) {
const link = new Link(this.vol, this, name);
link.setNode(node);
if (node.isDirectory()) {
// link.setChild('.', link);
// link.getNode().nlink++;
// link.setChild('..', this);
// this.getNode().nlink++;
}
this.setChild(name, link);
return link;
}
childrenChanged() {
// When a file or directory gets created, mtime and ctime should
// get updated. See https://github.com/sagemathinc/memfs-js/issues/4
// atime isn't updated since access isn't happening (?). I'm just
// copying what happens on MacOS natively.
this.node.mtime = this.node.ctime = new Date();
}
setChild(name, link = new Link(this.vol, this, name)) {
this.children[name] = link;
this.childrenChanged();
link.parent = this;
this.length++;
this.emit("child:add", link, this);
return link;
}
deleteChild(link) {
delete this.children[link.getName()];
this.childrenChanged();
this.length--;
this.emit("child:delete", link, this);
}
getChild(name) {
if (Object.hasOwnProperty.call(this.children, name)) {
return this.children[name];
}
}
getPath() {
return this.steps.join(exports.SEP);
}
getName() {
return this.steps[this.steps.length - 1];
}
// del() {
// const parent = this.parent;
// if(parent) {
// parent.deleteChild(link);
// }
// this.parent = null;
// this.vol = null;
// }
/**
* Walk the tree path and return the `Link` at that location, if any.
* @param steps {string[]} Desired location.
* @param stop {number} Max steps to go into.
* @param i {number} Current step in the `steps` array.
*
* @return {Link|null}
*/
walk(steps, stop = steps.length, i = 0) {
if (i >= steps.length)
return this;
if (i >= stop)
return this;
const step = steps[i];
const link = this.getChild(step);
if (!link)
return null;
return link.walk(steps, stop, i + 1);
}
toJSON() {
return {
steps: this.steps,
ino: this.ino,
children: Object.keys(this.children),
};
}
syncSteps() {
this.steps = this.parent
? this.parent.steps.concat([this.name])
: [this.name];
}
}
exports.Link = Link;
/**
* Represents an open file (file descriptor) that points to a `Link` (Hard-link) and a `Node`.
*/
class File {
/**
* Open a Link-Node pair. `node` is provided separately as that might be a different node
* rather the one `link` points to, because it might be a symlink.
* @param link
* @param node
* @param flags
* @param fd
*/
constructor(link, node, flags, fd) {
/**
* A cursor/offset position in a file, where data will be written on write.
* User can "seek" this position.
*/
this.position = 0;
this.link = link;
this.node = node;
this.flags = flags;
this.fd = fd;
}
getString(encoding = "utf8") {
return this.node.getString();
}
setString(str) {
this.node.setString(str);
}
getBuffer() {
return this.node.getBuffer();
}
setBuffer(buf) {
this.node.setBuffer(buf);
}
getSize() {
return this.node.getSize();
}
truncate(len) {
this.node.truncate(len);
}
seekTo(position) {
this.position = position;
}
stats() {
return Stats_1.default.build(this.node);
}
write(buf, offset = 0, length = buf.length, position) {
if (typeof position !== "number")
position = this.position;
if (this.flags & O_APPEND)
position = this.getSize();
const bytes = this.node.write(buf, offset, length, position);
this.position = position + bytes;
return bytes;
}
read(buf, offset = 0, length = buf.byteLength, position) {
if (typeof position !== "number")
position = this.position;
const bytes = this.node.read(buf, offset, length, position);
this.position = position + bytes;
return bytes;
}
chmod(perm) {
this.node.chmod(perm);
}
chown(uid, gid) {
this.node.chown(uid, gid);
}
}
exports.File = File;