1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
// Copyright 2021 The Emscripten Authors. All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License. Both these licenses can be
// found in the LICENSE file.
// This file defines the open file table of the new file system.
// Current Status: Work in Progress.
// See https://github.com/emscripten-core/emscripten/issues/15041.
#include "file_table.h"
#include "special_files.h"
namespace wasmfs {
FileTable::FileTable() {
entries.emplace_back();
(void)OpenFileState::create(
SpecialFiles::getStdin(), O_RDONLY, entries.back());
entries.emplace_back();
(void)OpenFileState::create(
SpecialFiles::getStdout(), O_WRONLY, entries.back());
entries.emplace_back();
(void)OpenFileState::create(
SpecialFiles::getStderr(), O_WRONLY, entries.back());
}
std::shared_ptr<OpenFileState> FileTable::Handle::getEntry(__wasi_fd_t fd) {
if (fd >= fileTable.entries.size() || fd < 0) {
return nullptr;
}
return fileTable.entries[fd];
}
std::shared_ptr<DataFile>
FileTable::Handle::setEntry(__wasi_fd_t fd,
std::shared_ptr<OpenFileState> openFile) {
assert(fd >= 0);
if (fd >= fileTable.entries.size()) {
fileTable.entries.resize(fd + 1);
}
if (openFile) {
++openFile->uses;
}
std::shared_ptr<DataFile> ret;
if (fileTable.entries[fd] && --fileTable.entries[fd]->uses == 0) {
ret = fileTable.entries[fd]->locked().getFile()->dynCast<DataFile>();
}
fileTable.entries[fd] = openFile;
return ret;
}
__wasi_fd_t
FileTable::Handle::addEntry(std::shared_ptr<OpenFileState> openFileState) {
// TODO: add freelist to avoid linear lookup time.
for (__wasi_fd_t i = 0;; i++) {
if (!getEntry(i)) {
(void)setEntry(i, openFileState);
return i;
}
}
return -EBADF;
}
int OpenFileState::create(std::shared_ptr<File> file,
oflags_t flags,
std::shared_ptr<OpenFileState>& out) {
assert(file);
std::vector<Directory::Entry> dirents;
if (auto f = file->dynCast<DataFile>()) {
if (int err = f->locked().open(flags & O_ACCMODE)) {
return err;
}
} else if (auto d = file->dynCast<Directory>()) {
// We are opening a directory; cache its contents for subsequent reads.
auto lockedDir = d->locked();
dirents = {{".", File::DirectoryKind, d->getIno()},
{"..", File::DirectoryKind, lockedDir.getParent()->getIno()}};
auto entries = lockedDir.getEntries();
if (int err = entries.getError()) {
return err;
}
dirents.insert(dirents.end(), entries->begin(), entries->end());
}
out = std::make_shared<OpenFileState>(
private_key{0}, flags, file, std::move(dirents));
return 0;
}
} // namespace wasmfs
|
