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Jan 30, 2019
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Foundation: port FileHandle to Windows #1848

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230 changes: 221 additions & 9 deletions Foundation/FileHandle.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -10,11 +10,21 @@
import CoreFoundation

open class FileHandle : NSObject, NSSecureCoding {
#if os(Windows)
private var _handle: HANDLE
#else
private var _fd: Int32
#endif
private var _closeOnDealloc: Bool

@available(windows, unavailable,
message: "cannot perform non-owning handle to fd conversion")
open var fileDescriptor: Int32 {
#if os(Windows)
return -1
#else
return _fd
#endif
}

open var readabilityHandler: ((FileHandle) -> Void)? = {
Expand Down Expand Up @@ -47,6 +57,80 @@ open class FileHandle : NSObject, NSSecureCoding {
}

internal func _readDataOfLength(_ length: Int, untilEOF: Bool, options: NSData.ReadingOptions = []) throws -> NSData.NSDataReadResult {
#if os(Windows)
precondition(_handle != INVALID_HANDLE_VALUE, "invalid file handle")

if length == 0 && !untilEOF {
// Nothing requested, return empty response
return NSData.NSDataReadResult(bytes: nil, length: 0, deallocator: nil)
}

var fiFileInfo: BY_HANDLE_FILE_INFORMATION = BY_HANDLE_FILE_INFORMATION()
if GetFileInformationByHandle(_handle, &fiFileInfo) == FALSE {
throw NSError(domain: NSPOSIXErrorDomain, code: Int(GetLastError()),
userInfo: nil)
}

if fiFileInfo.dwFileAttributes & DWORD(FILE_ATTRIBUTE_NORMAL) == FILE_ATTRIBUTE_NORMAL {
if options.contains(.alwaysMapped) {
let hMapping: HANDLE =
CreateFileMappingA(_handle, nil, DWORD(PAGE_READONLY), 0, 0, nil)
if hMapping == HANDLE(bitPattern: 0) {
fatalError("CreateFileMappingA failed")
}

let szFileSize: UInt64 = (UInt64(fiFileInfo.nFileSizeHigh) << 32) | UInt64(fiFileInfo.nFileSizeLow << 0)
let szMapSize: UInt64 = Swift.min(UInt64(length), szFileSize)
let pData: UnsafeMutableRawPointer =
MapViewOfFile(hMapping, DWORD(FILE_MAP_READ), 0, 0, szMapSize)

return NSData.NSDataReadResult(bytes: pData, length: Int(szMapSize)) { buffer, length in
if UnmapViewOfFile(buffer) == FALSE {
fatalError("UnmapViewOfFile failed")
}
if CloseHandle(hMapping) == FALSE {
fatalError("CloseHandle failed")
}
}
}
}

let blockSize: Int = 8 * 1024
var allocated: Int = blockSize
var buffer: UnsafeMutableRawPointer = malloc(allocated)!
var total: Int = 0

while total < length {
let remaining = length - total
let BytesToRead: DWORD = DWORD(min(blockSize, remaining))

if (allocated - total) < BytesToRead {
allocated *= 2
buffer = _CFReallocf(buffer, allocated)
}

var BytesRead: DWORD = 0
if ReadFile(_handle, buffer.advanced(by: total), BytesToRead, &BytesRead, nil) == FALSE {
free(buffer)
throw NSError(domain: NSPOSIXErrorDomain, code: Int(GetLastError()), userInfo: nil)
}
total += Int(BytesRead)
if BytesRead == 0 || !untilEOF {
break
}
}

if total == 0 {
free(buffer)
return NSData.NSDataReadResult(bytes: nil, length: 0, deallocator: nil)
}

buffer = _CFReallocf(buffer, total)
let data = buffer.bindMemory(to: UInt8.self, capacity: total)
return NSData.NSDataReadResult(bytes: data, length: total) { buffer, length in
free(buffer)
}
#else
precondition(_fd >= 0, "Bad file descriptor")
if length == 0 && !untilEOF {
// Nothing requested, return empty response
Expand Down Expand Up @@ -114,9 +198,22 @@ open class FileHandle : NSObject, NSSecureCoding {
return NSData.NSDataReadResult(bytes: bytePtr, length: total) { buffer, length in
free(buffer)
}
#endif
}

open func write(_ data: Data) {
#if os(Windows)
precondition(_handle != INVALID_HANDLE_VALUE, "invalid file handle")
data.enumerateBytes() { (bytes, range, stop) in
do {
try NSData.write(toHandle: self._handle, path: nil,
buf: UnsafeRawPointer(bytes.baseAddress!),
length: bytes.count)
} catch {
fatalError("Write failure")
}
}
#else
guard _fd >= 0 else { return }
data.enumerateBytes() { (bytes, range, stop) in
do {
Expand All @@ -125,44 +222,136 @@ open class FileHandle : NSObject, NSSecureCoding {
fatalError("Write failure")
}
}
#endif
}

// TODO: Error handling.

open var offsetInFile: UInt64 {
#if os(Windows)
precondition(_handle != INVALID_HANDLE_VALUE, "invalid file handle")
var liPointer: LARGE_INTEGER = LARGE_INTEGER(QuadPart: 0)
if SetFilePointerEx(_handle, LARGE_INTEGER(QuadPart: 0),
&liPointer, DWORD(FILE_CURRENT)) == FALSE {
fatalError("SetFilePointerEx failed")
}
return UInt64(liPointer.QuadPart)
#else
precondition(_fd >= 0, "Bad file descriptor")
return UInt64(lseek(_fd, 0, SEEK_CUR))
#endif
}

@discardableResult
open func seekToEndOfFile() -> UInt64 {
#if os(Windows)
precondition(_handle != INVALID_HANDLE_VALUE, "invalid file handle")
var liPointer: LARGE_INTEGER = LARGE_INTEGER(QuadPart: 0)
if SetFilePointerEx(_handle, LARGE_INTEGER(QuadPart: 0),
&liPointer, DWORD(FILE_END)) == FALSE {
fatalError("SetFilePointerEx failed")
}
return UInt64(liPointer.QuadPart)
#else
precondition(_fd >= 0, "Bad file descriptor")
return UInt64(lseek(_fd, 0, SEEK_END))
#endif
}

open func seek(toFileOffset offset: UInt64) {
#if os(Windows)
precondition(_handle != INVALID_HANDLE_VALUE, "invalid file handle")
if SetFilePointerEx(_handle, LARGE_INTEGER(QuadPart: LONGLONG(offset)),
nil, DWORD(FILE_BEGIN)) == FALSE {
fatalError("SetFilePointerEx failed")
}
#else
precondition(_fd >= 0, "Bad file descriptor")
lseek(_fd, off_t(offset), SEEK_SET)
#endif
}

open func truncateFile(atOffset offset: UInt64) {
#if os(Windows)
precondition(_handle != INVALID_HANDLE_VALUE, "invalid file handle")
if SetFilePointerEx(_handle, LARGE_INTEGER(QuadPart: LONGLONG(offset)),
nil, DWORD(FILE_BEGIN)) == FALSE {
fatalError("SetFilePointerEx failed")
}
if SetEndOfFile(_handle) == FALSE {
fatalError("SetEndOfFile failed")
}
#else
precondition(_fd >= 0, "Bad file descriptor")
if lseek(_fd, off_t(offset), SEEK_SET) < 0 { fatalError("lseek() failed.") }
if ftruncate(_fd, off_t(offset)) < 0 { fatalError("ftruncate() failed.") }
#endif
}

open func synchronizeFile() {
#if os(Windows)
precondition(_handle != INVALID_HANDLE_VALUE, "invalid file handle")
if FlushFileBuffers(_handle) == FALSE {
fatalError("FlushFileBuffers failed: \(GetLastError())")
}
#else
precondition(_fd >= 0, "Bad file descriptor")
fsync(_fd)
#endif
}

open func closeFile() {
#if os(Windows)
if _handle != INVALID_HANDLE_VALUE {
if CloseHandle(_handle) == FALSE {
fatalError("CloseHandle failed")
}
_handle = INVALID_HANDLE_VALUE
}
#else
if _fd >= 0 {
close(_fd)
_fd = -1
}
#endif
}

#if os(Windows)
public init(handle: HANDLE, closeOnDealloc closeopt: Bool) {
_handle = handle
_closeOnDealloc = closeopt
}

public init(fileDescriptor fd: Int32, closeOnDealloc closeopt: Bool) {
if (closeopt) {
var handle: HANDLE?
if DuplicateHandle(GetCurrentProcess(),
HANDLE(bitPattern: _get_osfhandle(fd))!,
GetCurrentProcess(), &handle,
DWORD(DUPLICATE_SAME_ACCESS), FALSE, 0) == FALSE {
fatalError("DuplicateHandle() failed")
}
_close(fd)
_handle = handle!
_closeOnDealloc = true
} else {
_handle = HANDLE(bitPattern: _get_osfhandle(fd))!
_closeOnDealloc = false
}
}

public convenience init(fileDescriptor fd: Int32) {
self.init(handle: HANDLE(bitPattern: _get_osfhandle(fd))!,
closeOnDealloc: false)
}

internal convenience init?(path: String, flags: Int32, createMode: Int) {
self.init(fileDescriptor: _CFOpenFileWithMode(path, flags,
mode_t(createMode)),
closeOnDealloc: true)
if _handle == INVALID_HANDLE_VALUE { return nil }
}
#else
public init(fileDescriptor fd: Int32, closeOnDealloc closeopt: Bool) {
_fd = fd
_closeOnDealloc = closeopt
Expand All @@ -180,14 +369,25 @@ open class FileHandle : NSObject, NSSecureCoding {
return nil
}
}

#endif

deinit {
if _fd >= 0 && _closeOnDealloc {
guard _closeOnDealloc == true else { return }
#if os(Windows)
if _handle != INVALID_HANDLE_VALUE {
if CloseHandle(_handle) == FALSE {
fatalError("CloseHandle failed")
}
_handle = INVALID_HANDLE_VALUE
}
#else
if _fd >= 0 {
close(_fd)
_fd = -1
}
#endif
}

public required init?(coder: NSCoder) {
NSUnimplemented()
}
Expand Down Expand Up @@ -362,6 +562,17 @@ open class Pipe: NSObject {
public let fileHandleForWriting: FileHandle

public override init() {
#if os(Windows)
var hReadPipe: HANDLE?
var hWritePipe: HANDLE?
if CreatePipe(&hReadPipe, &hWritePipe, nil, 0) == FALSE {
fatalError("CreatePipe failed")
}
self.fileHandleForReading = FileHandle(handle: hReadPipe!,
closeOnDealloc: true)
self.fileHandleForWriting = FileHandle(handle: hWritePipe!,
closeOnDealloc: true)
#else
/// the `pipe` system call creates two `fd` in a malloc'ed area
var fds = UnsafeMutablePointer<Int32>.allocate(capacity: 2)
defer {
Expand All @@ -383,6 +594,7 @@ open class Pipe: NSObject {
default:
fatalError("Error calling pipe(): \(errno)")
}
#endif
super.init()
}
}
4 changes: 4 additions & 0 deletions Foundation/NSSwiftRuntime.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,10 @@ import CoreFoundation

@_exported import Dispatch

#if os(Windows)
import WinSDK
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Where did we end up on this? Will this cause people importing Foundation to also get WinSDK?

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Yeah, I think that currently it does currently result in WinSDK getting pulled in, since we do not yet have the private import (I think that @jrose-apple was working on the that?). If there is a way to avoid that, I'm happy to try that out. I don't think that going with Shims for this is very good though because as we start using more interfaces across Windows, we will effectively end up re-creating the SDK.

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It's probably reasonable in the end; on Darwin it's not like you can't help but import standard Darwin headers if you import Foundation.

#endif

#if os(Android) // shim required for bzero
@_transparent func bzero(_ ptr: UnsafeMutableRawPointer, _ size: size_t) {
memset(ptr, 0, size)
Expand Down