Revision 4ae305542c80f31b06c5e8325c63ade2bb4a3f33 authored by Alon Zakai on 29 May 2014, 20:44:16 UTC, committed by Alon Zakai on 29 May 2014, 20:44:16 UTC
1 parent 975882c
library_memfs.js
mergeInto(LibraryManager.library, {
$MEMFS__deps: ['$FS'],
$MEMFS: {
ops_table: null,
// content modes
CONTENT_OWNING: 1, // contains a subarray into the heap, and we own it, without copying (note: someone else needs to free() it, if that is necessary)
CONTENT_FLEXIBLE: 2, // has been modified or never set to anything, and is a flexible js array that can grow/shrink
CONTENT_FIXED: 3, // contains some fixed-size content written into it, in a typed array
mount: function(mount) {
return MEMFS.createNode(null, '/', {{{ cDefine('S_IFDIR') }}} | 511 /* 0777 */, 0);
},
createNode: function(parent, name, mode, dev) {
if (FS.isBlkdev(mode) || FS.isFIFO(mode)) {
// no supported
throw new FS.ErrnoError(ERRNO_CODES.EPERM);
}
if (!MEMFS.ops_table) {
MEMFS.ops_table = {
dir: {
node: {
getattr: MEMFS.node_ops.getattr,
setattr: MEMFS.node_ops.setattr,
lookup: MEMFS.node_ops.lookup,
mknod: MEMFS.node_ops.mknod,
rename: MEMFS.node_ops.rename,
unlink: MEMFS.node_ops.unlink,
rmdir: MEMFS.node_ops.rmdir,
readdir: MEMFS.node_ops.readdir,
symlink: MEMFS.node_ops.symlink
},
stream: {
llseek: MEMFS.stream_ops.llseek
}
},
file: {
node: {
getattr: MEMFS.node_ops.getattr,
setattr: MEMFS.node_ops.setattr
},
stream: {
llseek: MEMFS.stream_ops.llseek,
read: MEMFS.stream_ops.read,
write: MEMFS.stream_ops.write,
allocate: MEMFS.stream_ops.allocate,
mmap: MEMFS.stream_ops.mmap
}
},
link: {
node: {
getattr: MEMFS.node_ops.getattr,
setattr: MEMFS.node_ops.setattr,
readlink: MEMFS.node_ops.readlink
},
stream: {}
},
chrdev: {
node: {
getattr: MEMFS.node_ops.getattr,
setattr: MEMFS.node_ops.setattr
},
stream: FS.chrdev_stream_ops
},
};
}
var node = FS.createNode(parent, name, mode, dev);
if (FS.isDir(node.mode)) {
node.node_ops = MEMFS.ops_table.dir.node;
node.stream_ops = MEMFS.ops_table.dir.stream;
node.contents = {};
} else if (FS.isFile(node.mode)) {
node.node_ops = MEMFS.ops_table.file.node;
node.stream_ops = MEMFS.ops_table.file.stream;
node.contents = [];
node.contentMode = MEMFS.CONTENT_FLEXIBLE;
} else if (FS.isLink(node.mode)) {
node.node_ops = MEMFS.ops_table.link.node;
node.stream_ops = MEMFS.ops_table.link.stream;
} else if (FS.isChrdev(node.mode)) {
node.node_ops = MEMFS.ops_table.chrdev.node;
node.stream_ops = MEMFS.ops_table.chrdev.stream;
}
node.timestamp = Date.now();
// add the new node to the parent
if (parent) {
parent.contents[name] = node;
}
return node;
},
ensureFlexible: function(node) {
if (node.contentMode !== MEMFS.CONTENT_FLEXIBLE) {
var contents = node.contents;
node.contents = Array.prototype.slice.call(contents);
node.contentMode = MEMFS.CONTENT_FLEXIBLE;
}
},
node_ops: {
getattr: function(node) {
var attr = {};
// device numbers reuse inode numbers.
attr.dev = FS.isChrdev(node.mode) ? node.id : 1;
attr.ino = node.id;
attr.mode = node.mode;
attr.nlink = 1;
attr.uid = 0;
attr.gid = 0;
attr.rdev = node.rdev;
if (FS.isDir(node.mode)) {
attr.size = 4096;
} else if (FS.isFile(node.mode)) {
attr.size = node.contents.length;
} else if (FS.isLink(node.mode)) {
attr.size = node.link.length;
} else {
attr.size = 0;
}
attr.atime = new Date(node.timestamp);
attr.mtime = new Date(node.timestamp);
attr.ctime = new Date(node.timestamp);
// NOTE: In our implementation, st_blocks = Math.ceil(st_size/st_blksize),
// but this is not required by the standard.
attr.blksize = 4096;
attr.blocks = Math.ceil(attr.size / attr.blksize);
return attr;
},
setattr: function(node, attr) {
if (attr.mode !== undefined) {
node.mode = attr.mode;
}
if (attr.timestamp !== undefined) {
node.timestamp = attr.timestamp;
}
if (attr.size !== undefined) {
MEMFS.ensureFlexible(node);
var contents = node.contents;
if (attr.size < contents.length) contents.length = attr.size;
else while (attr.size > contents.length) contents.push(0);
}
},
lookup: function(parent, name) {
throw FS.genericErrors[ERRNO_CODES.ENOENT];
},
mknod: function(parent, name, mode, dev) {
return MEMFS.createNode(parent, name, mode, dev);
},
rename: function(old_node, new_dir, new_name) {
// if we're overwriting a directory at new_name, make sure it's empty.
if (FS.isDir(old_node.mode)) {
var new_node;
try {
new_node = FS.lookupNode(new_dir, new_name);
} catch (e) {
}
if (new_node) {
for (var i in new_node.contents) {
throw new FS.ErrnoError(ERRNO_CODES.ENOTEMPTY);
}
}
}
// do the internal rewiring
delete old_node.parent.contents[old_node.name];
old_node.name = new_name;
new_dir.contents[new_name] = old_node;
old_node.parent = new_dir;
},
unlink: function(parent, name) {
delete parent.contents[name];
},
rmdir: function(parent, name) {
var node = FS.lookupNode(parent, name);
for (var i in node.contents) {
throw new FS.ErrnoError(ERRNO_CODES.ENOTEMPTY);
}
delete parent.contents[name];
},
readdir: function(node) {
var entries = ['.', '..']
for (var key in node.contents) {
if (!node.contents.hasOwnProperty(key)) {
continue;
}
entries.push(key);
}
return entries;
},
symlink: function(parent, newname, oldpath) {
var node = MEMFS.createNode(parent, newname, 511 /* 0777 */ | {{{ cDefine('S_IFLNK') }}}, 0);
node.link = oldpath;
return node;
},
readlink: function(node) {
if (!FS.isLink(node.mode)) {
throw new FS.ErrnoError(ERRNO_CODES.EINVAL);
}
return node.link;
},
},
stream_ops: {
read: function(stream, buffer, offset, length, position) {
var contents = stream.node.contents;
if (position >= contents.length)
return 0;
var size = Math.min(contents.length - position, length);
assert(size >= 0);
#if USE_TYPED_ARRAYS == 2
if (size > 8 && contents.subarray) { // non-trivial, and typed array
buffer.set(contents.subarray(position, position + size), offset);
} else
#endif
{
for (var i = 0; i < size; i++) {
buffer[offset + i] = contents[position + i];
}
}
return size;
},
write: function(stream, buffer, offset, length, position, canOwn) {
var node = stream.node;
node.timestamp = Date.now();
var contents = node.contents;
#if USE_TYPED_ARRAYS == 2
if (length && contents.length === 0 && position === 0 && buffer.subarray) {
// just replace it with the new data
#if ASSERTIONS
assert(buffer.length);
#endif
if (canOwn && offset === 0) {
node.contents = buffer; // this could be a subarray of Emscripten HEAP, or allocated from some other source.
node.contentMode = (buffer.buffer === HEAP8.buffer) ? MEMFS.CONTENT_OWNING : MEMFS.CONTENT_FIXED;
} else {
node.contents = new Uint8Array(buffer.subarray(offset, offset+length));
node.contentMode = MEMFS.CONTENT_FIXED;
}
return length;
}
#endif
MEMFS.ensureFlexible(node);
var contents = node.contents;
while (contents.length < position) contents.push(0);
for (var i = 0; i < length; i++) {
contents[position + i] = buffer[offset + i];
}
return length;
},
llseek: function(stream, offset, whence) {
var position = offset;
if (whence === 1) { // SEEK_CUR.
position += stream.position;
} else if (whence === 2) { // SEEK_END.
if (FS.isFile(stream.node.mode)) {
position += stream.node.contents.length;
}
}
if (position < 0) {
throw new FS.ErrnoError(ERRNO_CODES.EINVAL);
}
stream.ungotten = [];
stream.position = position;
return position;
},
allocate: function(stream, offset, length) {
MEMFS.ensureFlexible(stream.node);
var contents = stream.node.contents;
var limit = offset + length;
while (limit > contents.length) contents.push(0);
},
mmap: function(stream, buffer, offset, length, position, prot, flags) {
if (!FS.isFile(stream.node.mode)) {
throw new FS.ErrnoError(ERRNO_CODES.ENODEV);
}
var ptr;
var allocated;
var contents = stream.node.contents;
// Only make a new copy when MAP_PRIVATE is specified.
if ( !(flags & {{{ cDefine('MAP_PRIVATE') }}}) &&
(contents.buffer === buffer || contents.buffer === buffer.buffer) ) {
// We can't emulate MAP_SHARED when the file is not backed by the buffer
// we're mapping to (e.g. the HEAP buffer).
allocated = false;
ptr = contents.byteOffset;
} else {
// Try to avoid unnecessary slices.
if (position > 0 || position + length < contents.length) {
if (contents.subarray) {
contents = contents.subarray(position, position + length);
} else {
contents = Array.prototype.slice.call(contents, position, position + length);
}
}
allocated = true;
ptr = _malloc(length);
if (!ptr) {
throw new FS.ErrnoError(ERRNO_CODES.ENOMEM);
}
buffer.set(contents, ptr);
}
return { ptr: ptr, allocated: allocated };
},
}
}
});
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