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import Foundation
import SystemPackage
struct FileAccessMode: OptionSet {
let rawValue: UInt32
static let read = FileAccessMode(rawValue: 1)
static let write = FileAccessMode(rawValue: 1 << 1)
}
protocol WASIEntry {
func attributes() throws -> WASIAbi.Filestat
func fileType() throws -> WASIAbi.FileType
func status() throws -> WASIAbi.Fdflags
func setTimes(
atim: WASIAbi.Timestamp, mtim: WASIAbi.Timestamp,
fstFlags: WASIAbi.FstFlags
) throws
func advise(
offset: WASIAbi.FileSize, length: WASIAbi.FileSize, advice: WASIAbi.Advice
) throws
func close() throws
}
protocol WASIFile: WASIEntry {
func fdStat() throws -> WASIAbi.FdStat
func setFdStatFlags(_ flags: WASIAbi.Fdflags) throws
func setFilestatSize(_ size: WASIAbi.FileSize) throws
func tell() throws -> WASIAbi.FileSize
func seek(offset: WASIAbi.FileDelta, whence: WASIAbi.Whence) throws -> WASIAbi.FileSize
func write<Buffer: Sequence>(
vectored buffer: Buffer
) throws -> WASIAbi.Size where Buffer.Element == WASIAbi.IOVec
func pwrite<Buffer: Sequence>(
vectored buffer: Buffer, offset: WASIAbi.FileSize
) throws -> WASIAbi.Size where Buffer.Element == WASIAbi.IOVec
func read<Buffer: Sequence>(
into buffer: Buffer
) throws -> WASIAbi.Size where Buffer.Element == WASIAbi.IOVec
func pread<Buffer: Sequence>(
into buffer: Buffer, offset: WASIAbi.FileSize
) throws -> WASIAbi.Size where Buffer.Element == WASIAbi.IOVec
}
protocol WASIDir: WASIEntry {
typealias ReaddirElement = (dirent: WASIAbi.Dirent, name: String)
var preopenPath: String? { get }
func openFile(
symlinkFollow: Bool,
path: String,
oflags: WASIAbi.Oflags,
accessMode: FileAccessMode,
fdflags: WASIAbi.Fdflags
) throws -> FileDescriptor
func createDirectory(atPath path: String) throws
func removeDirectory(atPath path: String) throws
func removeFile(atPath path: String) throws
func symlink(from sourcePath: String, to destPath: String) throws
func readEntries(cookie: WASIAbi.DirCookie) throws -> AnyIterator<Result<ReaddirElement, any Error>>
func attributes(path: String, symlinkFollow: Bool) throws -> WASIAbi.Filestat
func setFilestatTimes(
path: String,
atim: WASIAbi.Timestamp, mtim: WASIAbi.Timestamp,
fstFlags: WASIAbi.FstFlags, symlinkFollow: Bool
) throws
}
enum FdEntry {
case file(any WASIFile)
case directory(any WASIDir)
func asEntry() -> any WASIEntry {
switch self {
case .file(let entry):
return entry
case .directory(let directory):
return directory
}
}
}
/// A table that maps file descriptor to actual resource in host environment
struct FdTable {
private var map: [WASIAbi.Fd: FdEntry]
private var nextFd: WASIAbi.Fd
init() {
self.map = [:]
// 0, 1 and 2 are reserved for stdio
self.nextFd = 3
}
/// Inserts a resource as the given file descriptor
subscript(_ fd: WASIAbi.Fd) -> FdEntry? {
get { self.map[fd] }
set { self.map[fd] = newValue }
}
/// Inserts an entry and returns the corresponding file descriptor
mutating func push(_ entry: FdEntry) throws -> WASIAbi.Fd {
guard map.count < WASIAbi.Fd.max else {
throw WASIAbi.Errno.ENFILE
}
// Find a free fd
while true {
let fd = self.nextFd
// Wrapping to find fd again from 0 after overflow
self.nextFd &+= 1
if self.map[fd] != nil {
continue
}
self.map[fd] = entry
return fd
}
}
}
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