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Diffstat (limited to 'dom/system/IOUtils.cpp')
| -rw-r--r-- | dom/system/IOUtils.cpp | 2902 |
1 files changed, 2902 insertions, 0 deletions
diff --git a/dom/system/IOUtils.cpp b/dom/system/IOUtils.cpp new file mode 100644 index 0000000000..09ec5ee897 --- /dev/null +++ b/dom/system/IOUtils.cpp @@ -0,0 +1,2902 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "IOUtils.h" + +#include <cstdint> + +#include "ErrorList.h" +#include "js/ArrayBuffer.h" +#include "js/JSON.h" +#include "js/Utility.h" +#include "js/experimental/TypedData.h" +#include "jsfriendapi.h" +#include "mozilla/Assertions.h" +#include "mozilla/AutoRestore.h" +#include "mozilla/CheckedInt.h" +#include "mozilla/Compression.h" +#include "mozilla/Encoding.h" +#include "mozilla/EndianUtils.h" +#include "mozilla/ErrorNames.h" +#include "mozilla/FileUtils.h" +#include "mozilla/Maybe.h" +#include "mozilla/ResultExtensions.h" +#include "mozilla/Services.h" +#include "mozilla/Span.h" +#include "mozilla/StaticPtr.h" +#include "mozilla/TextUtils.h" +#include "mozilla/Unused.h" +#include "mozilla/Utf8.h" +#include "mozilla/dom/BindingUtils.h" +#include "mozilla/dom/IOUtilsBinding.h" +#include "mozilla/dom/Promise.h" +#include "mozilla/dom/WorkerCommon.h" +#include "mozilla/dom/WorkerRef.h" +#include "mozilla/ipc/LaunchError.h" +#include "PathUtils.h" +#include "nsCOMPtr.h" +#include "nsError.h" +#include "nsFileStreams.h" +#include "nsIDirectoryEnumerator.h" +#include "nsIFile.h" +#include "nsIGlobalObject.h" +#include "nsIInputStream.h" +#include "nsISupports.h" +#include "nsLocalFile.h" +#include "nsNetUtil.h" +#include "nsNSSComponent.h" +#include "nsPrintfCString.h" +#include "nsReadableUtils.h" +#include "nsString.h" +#include "nsStringFwd.h" +#include "nsTArray.h" +#include "nsThreadManager.h" +#include "nsXULAppAPI.h" +#include "prerror.h" +#include "prio.h" +#include "prtime.h" +#include "prtypes.h" +#include "ScopedNSSTypes.h" +#include "secoidt.h" + +#if defined(XP_UNIX) && !defined(ANDROID) +# include "nsSystemInfo.h" +#endif + +#if defined(XP_WIN) +# include "nsILocalFileWin.h" +#elif defined(XP_MACOSX) +# include "nsILocalFileMac.h" +#endif + +#ifdef XP_UNIX +# include "base/process_util.h" +#endif + +#define REJECT_IF_INIT_PATH_FAILED(_file, _path, _promise) \ + do { \ + if (nsresult _rv = PathUtils::InitFileWithPath((_file), (_path)); \ + NS_FAILED(_rv)) { \ + (_promise)->MaybeRejectWithOperationError( \ + FormatErrorMessage(_rv, "Could not parse path (%s)", \ + NS_ConvertUTF16toUTF8(_path).get())); \ + return; \ + } \ + } while (0) + +static constexpr auto SHUTDOWN_ERROR = + "IOUtils: Shutting down and refusing additional I/O tasks"_ns; + +namespace mozilla::dom { + +// static helper functions + +/** + * Platform-specific (e.g. Windows, Unix) implementations of XPCOM APIs may + * report I/O errors inconsistently. For convenience, this function will attempt + * to match a |nsresult| against known results which imply a file cannot be + * found. + * + * @see nsLocalFileWin.cpp + * @see nsLocalFileUnix.cpp + */ +static bool IsFileNotFound(nsresult aResult) { + return aResult == NS_ERROR_FILE_NOT_FOUND; +} +/** + * Like |IsFileNotFound|, but checks for known results that suggest a file + * is not a directory. + */ +static bool IsNotDirectory(nsresult aResult) { + return aResult == NS_ERROR_FILE_DESTINATION_NOT_DIR || + aResult == NS_ERROR_FILE_NOT_DIRECTORY; +} + +/** + * Formats an error message and appends the error name to the end. + */ +template <typename... Args> +static nsCString FormatErrorMessage(nsresult aError, const char* const aMessage, + Args... aArgs) { + nsPrintfCString msg(aMessage, aArgs...); + + if (const char* errName = GetStaticErrorName(aError)) { + msg.AppendPrintf(": %s", errName); + } else { + // In the exceptional case where there is no error name, print the literal + // integer value of the nsresult as an upper case hex value so it can be + // located easily in searchfox. + msg.AppendPrintf(": 0x%" PRIX32, static_cast<uint32_t>(aError)); + } + + return std::move(msg); +} + +static nsCString FormatErrorMessage(nsresult aError, + const char* const aMessage) { + const char* errName = GetStaticErrorName(aError); + if (errName) { + return nsPrintfCString("%s: %s", aMessage, errName); + } + // In the exceptional case where there is no error name, print the literal + // integer value of the nsresult as an upper case hex value so it can be + // located easily in searchfox. + return nsPrintfCString("%s: 0x%" PRIX32, aMessage, + static_cast<uint32_t>(aError)); +} + +[[nodiscard]] inline bool ToJSValue( + JSContext* aCx, const IOUtils::InternalFileInfo& aInternalFileInfo, + JS::MutableHandle<JS::Value> aValue) { + FileInfo info; + info.mPath.Construct(aInternalFileInfo.mPath); + info.mType.Construct(aInternalFileInfo.mType); + info.mSize.Construct(aInternalFileInfo.mSize); + + if (aInternalFileInfo.mCreationTime.isSome()) { + info.mCreationTime.Construct(aInternalFileInfo.mCreationTime.ref()); + } + info.mLastAccessed.Construct(aInternalFileInfo.mLastAccessed); + info.mLastModified.Construct(aInternalFileInfo.mLastModified); + + info.mPermissions.Construct(aInternalFileInfo.mPermissions); + + return ToJSValue(aCx, info, aValue); +} + +template <typename T> +static void ResolveJSPromise(Promise* aPromise, T&& aValue) { + if constexpr (std::is_same_v<T, Ok>) { + aPromise->MaybeResolveWithUndefined(); + } else if constexpr (std::is_same_v<T, nsTArray<uint8_t>>) { + TypedArrayCreator<Uint8Array> array(aValue); + aPromise->MaybeResolve(array); + } else { + aPromise->MaybeResolve(std::forward<T>(aValue)); + } +} + +static void RejectJSPromise(Promise* aPromise, const IOUtils::IOError& aError) { + const auto& errMsg = aError.Message(); + + switch (aError.Code()) { + case NS_ERROR_FILE_UNRESOLVABLE_SYMLINK: + [[fallthrough]]; // to NS_ERROR_FILE_INVALID_PATH + case NS_ERROR_FILE_NOT_FOUND: + [[fallthrough]]; // to NS_ERROR_FILE_INVALID_PATH + case NS_ERROR_FILE_INVALID_PATH: + aPromise->MaybeRejectWithNotFoundError(errMsg.refOr("File not found"_ns)); + break; + case NS_ERROR_FILE_IS_LOCKED: + [[fallthrough]]; // to NS_ERROR_FILE_ACCESS_DENIED + case NS_ERROR_FILE_ACCESS_DENIED: + aPromise->MaybeRejectWithNotAllowedError( + errMsg.refOr("Access was denied to the target file"_ns)); + break; + case NS_ERROR_FILE_TOO_BIG: + aPromise->MaybeRejectWithNotReadableError( + errMsg.refOr("Target file is too big"_ns)); + break; + case NS_ERROR_FILE_NO_DEVICE_SPACE: + aPromise->MaybeRejectWithNotReadableError( + errMsg.refOr("Target device is full"_ns)); + break; + case NS_ERROR_FILE_ALREADY_EXISTS: + aPromise->MaybeRejectWithNoModificationAllowedError( + errMsg.refOr("Target file already exists"_ns)); + break; + case NS_ERROR_FILE_COPY_OR_MOVE_FAILED: + aPromise->MaybeRejectWithOperationError( + errMsg.refOr("Failed to copy or move the target file"_ns)); + break; + case NS_ERROR_FILE_READ_ONLY: + aPromise->MaybeRejectWithReadOnlyError( + errMsg.refOr("Target file is read only"_ns)); + break; + case NS_ERROR_FILE_NOT_DIRECTORY: + [[fallthrough]]; // to NS_ERROR_FILE_DESTINATION_NOT_DIR + case NS_ERROR_FILE_DESTINATION_NOT_DIR: + aPromise->MaybeRejectWithInvalidAccessError( + errMsg.refOr("Target file is not a directory"_ns)); + break; + case NS_ERROR_FILE_IS_DIRECTORY: + aPromise->MaybeRejectWithInvalidAccessError( + errMsg.refOr("Target file is a directory"_ns)); + break; + case NS_ERROR_FILE_UNKNOWN_TYPE: + aPromise->MaybeRejectWithInvalidAccessError( + errMsg.refOr("Target file is of unknown type"_ns)); + break; + case NS_ERROR_FILE_NAME_TOO_LONG: + aPromise->MaybeRejectWithOperationError( + errMsg.refOr("Target file path is too long"_ns)); + break; + case NS_ERROR_FILE_UNRECOGNIZED_PATH: + aPromise->MaybeRejectWithOperationError( + errMsg.refOr("Target file path is not recognized"_ns)); + break; + case NS_ERROR_FILE_DIR_NOT_EMPTY: + aPromise->MaybeRejectWithOperationError( + errMsg.refOr("Target directory is not empty"_ns)); + break; + case NS_ERROR_FILE_DEVICE_FAILURE: + [[fallthrough]]; // to NS_ERROR_FILE_FS_CORRUPTED + case NS_ERROR_FILE_FS_CORRUPTED: + aPromise->MaybeRejectWithNotReadableError( + errMsg.refOr("Target file system may be corrupt or unavailable"_ns)); + break; + case NS_ERROR_FILE_CORRUPTED: + aPromise->MaybeRejectWithNotReadableError( + errMsg.refOr("Target file could not be read and may be corrupt"_ns)); + break; + case NS_ERROR_ILLEGAL_INPUT: + [[fallthrough]]; // NS_ERROR_ILLEGAL_VALUE + case NS_ERROR_ILLEGAL_VALUE: + aPromise->MaybeRejectWithDataError( + errMsg.refOr("Argument is not allowed"_ns)); + break; + case NS_ERROR_NOT_AVAILABLE: + aPromise->MaybeRejectWithNotFoundError(errMsg.refOr("Unavailable"_ns)); + break; + case NS_ERROR_ABORT: + aPromise->MaybeRejectWithAbortError(errMsg.refOr("Operation aborted"_ns)); + break; + default: + aPromise->MaybeRejectWithUnknownError(FormatErrorMessage( + aError.Code(), errMsg.refOr("Unexpected error"_ns).get())); + } +} + +static void RejectShuttingDown(Promise* aPromise) { + RejectJSPromise(aPromise, + IOUtils::IOError(NS_ERROR_ABORT).WithMessage(SHUTDOWN_ERROR)); +} + +static bool AssertParentProcessWithCallerLocationImpl(GlobalObject& aGlobal, + nsCString& reason) { + if (MOZ_LIKELY(XRE_IsParentProcess())) { + return true; + } + + AutoJSAPI jsapi; + nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports()); + MOZ_ALWAYS_TRUE(global); + MOZ_ALWAYS_TRUE(jsapi.Init(global)); + + JSContext* cx = jsapi.cx(); + + JS::AutoFilename scriptFilename; + unsigned lineNo = 0; + unsigned colNo = 0; + + NS_ENSURE_TRUE( + JS::DescribeScriptedCaller(cx, &scriptFilename, &lineNo, &colNo), false); + + NS_ENSURE_TRUE(scriptFilename.get(), false); + + reason.AppendPrintf(" Called from %s:%d:%d.", scriptFilename.get(), lineNo, + colNo); + return false; +} + +static void AssertParentProcessWithCallerLocation(GlobalObject& aGlobal) { + nsCString reason = "IOUtils can only be used in the parent process."_ns; + if (!AssertParentProcessWithCallerLocationImpl(aGlobal, reason)) { + MOZ_CRASH_UNSAFE_PRINTF("%s", reason.get()); + } +} + +// IOUtils implementation +/* static */ +IOUtils::StateMutex IOUtils::sState{"IOUtils::sState"}; + +/* static */ +template <typename Fn> +already_AddRefed<Promise> IOUtils::WithPromiseAndState(GlobalObject& aGlobal, + ErrorResult& aError, + Fn aFn) { + AssertParentProcessWithCallerLocation(aGlobal); + + RefPtr<Promise> promise = CreateJSPromise(aGlobal, aError); + if (!promise) { + return nullptr; + } + + if (auto state = GetState()) { + aFn(promise, state.ref()); + } else { + RejectShuttingDown(promise); + } + return promise.forget(); +} + +/* static */ +template <typename OkT, typename Fn> +void IOUtils::DispatchAndResolve(IOUtils::EventQueue* aQueue, Promise* aPromise, + Fn aFunc) { + RefPtr<StrongWorkerRef> workerRef; + if (!NS_IsMainThread()) { + // We need to manually keep the worker alive until the promise returned by + // Dispatch() resolves or rejects. + workerRef = StrongWorkerRef::CreateForcibly(GetCurrentThreadWorkerPrivate(), + __func__); + } + + if (RefPtr<IOPromise<OkT>> p = aQueue->Dispatch<OkT, Fn>(std::move(aFunc))) { + p->Then( + GetCurrentSerialEventTarget(), __func__, + [workerRef, promise = RefPtr(aPromise)](OkT&& ok) { + ResolveJSPromise(promise, std::forward<OkT>(ok)); + }, + [workerRef, promise = RefPtr(aPromise)](const IOError& err) { + RejectJSPromise(promise, err); + }); + } +} + +/* static */ +already_AddRefed<Promise> IOUtils::Read(GlobalObject& aGlobal, + const nsAString& aPath, + const ReadOptions& aOptions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + Maybe<uint32_t> toRead = Nothing(); + if (!aOptions.mMaxBytes.IsNull()) { + if (aOptions.mMaxBytes.Value() == 0) { + // Resolve with an empty buffer. + nsTArray<uint8_t> arr(0); + promise->MaybeResolve(TypedArrayCreator<Uint8Array>(arr)); + return; + } + toRead.emplace(aOptions.mMaxBytes.Value()); + } + + DispatchAndResolve<JsBuffer>( + state->mEventQueue, promise, + [file = std::move(file), offset = aOptions.mOffset, toRead, + decompress = aOptions.mDecompress]() { + return ReadSync(file, offset, toRead, decompress, + BufferKind::Uint8Array); + }); + }); +} + +/* static */ +RefPtr<SyncReadFile> IOUtils::OpenFileForSyncReading(GlobalObject& aGlobal, + const nsAString& aPath, + ErrorResult& aRv) { + MOZ_DIAGNOSTIC_ASSERT(XRE_IsParentProcess()); + + // This API is only exposed to workers, so we should not be on the main + // thread here. + MOZ_RELEASE_ASSERT(!NS_IsMainThread()); + + nsCOMPtr<nsIFile> file = new nsLocalFile(); + if (nsresult rv = PathUtils::InitFileWithPath(file, aPath); NS_FAILED(rv)) { + aRv.ThrowOperationError(FormatErrorMessage( + rv, "Could not parse path (%s)", NS_ConvertUTF16toUTF8(aPath).get())); + return nullptr; + } + + RefPtr<nsFileRandomAccessStream> stream = new nsFileRandomAccessStream(); + if (nsresult rv = + stream->Init(file, PR_RDONLY | nsIFile::OS_READAHEAD, 0666, 0); + NS_FAILED(rv)) { + aRv.ThrowOperationError( + FormatErrorMessage(rv, "Could not open the file at %s", + NS_ConvertUTF16toUTF8(aPath).get())); + return nullptr; + } + + int64_t size = 0; + if (nsresult rv = stream->GetSize(&size); NS_FAILED(rv)) { + aRv.ThrowOperationError(FormatErrorMessage( + rv, "Could not get the stream size for the file at %s", + NS_ConvertUTF16toUTF8(aPath).get())); + return nullptr; + } + + return new SyncReadFile(aGlobal.GetAsSupports(), std::move(stream), size); +} + +/* static */ +already_AddRefed<Promise> IOUtils::ReadUTF8(GlobalObject& aGlobal, + const nsAString& aPath, + const ReadUTF8Options& aOptions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<JsBuffer>( + state->mEventQueue, promise, + [file = std::move(file), decompress = aOptions.mDecompress]() { + return ReadUTF8Sync(file, decompress); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::ReadJSON(GlobalObject& aGlobal, + const nsAString& aPath, + const ReadUTF8Options& aOptions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + RefPtr<StrongWorkerRef> workerRef; + if (!NS_IsMainThread()) { + // We need to manually keep the worker alive until the promise + // returned by Dispatch() resolves or rejects. + workerRef = StrongWorkerRef::CreateForcibly( + GetCurrentThreadWorkerPrivate(), __func__); + } + + state->mEventQueue + ->template Dispatch<JsBuffer>( + [file, decompress = aOptions.mDecompress]() { + return ReadUTF8Sync(file, decompress); + }) + ->Then( + GetCurrentSerialEventTarget(), __func__, + [workerRef, promise = RefPtr{promise}, + file](JsBuffer&& aBuffer) { + AutoJSAPI jsapi; + if (NS_WARN_IF(!jsapi.Init(promise->GetGlobalObject()))) { + promise->MaybeRejectWithUnknownError( + "Could not initialize JS API"); + return; + } + JSContext* cx = jsapi.cx(); + + JS::Rooted<JSString*> jsonStr( + cx, + IOUtils::JsBuffer::IntoString(cx, std::move(aBuffer))); + if (!jsonStr) { + RejectJSPromise(promise, IOError(NS_ERROR_OUT_OF_MEMORY)); + return; + } + + JS::Rooted<JS::Value> val(cx); + if (!JS_ParseJSON(cx, jsonStr, &val)) { + JS::Rooted<JS::Value> exn(cx); + if (JS_GetPendingException(cx, &exn)) { + JS_ClearPendingException(cx); + promise->MaybeReject(exn); + } else { + RejectJSPromise( + promise, + IOError(NS_ERROR_DOM_UNKNOWN_ERR) + .WithMessage( + "ParseJSON threw an uncatchable exception " + "while parsing file(%s)", + file->HumanReadablePath().get())); + } + + return; + } + + promise->MaybeResolve(val); + }, + [workerRef, promise = RefPtr{promise}](const IOError& aErr) { + RejectJSPromise(promise, aErr); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::Write(GlobalObject& aGlobal, + const nsAString& aPath, + const Uint8Array& aData, + const WriteOptions& aOptions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + aData.ComputeState(); + auto buf = + Buffer<uint8_t>::CopyFrom(Span(aData.Data(), aData.Length())); + if (buf.isNothing()) { + promise->MaybeRejectWithOperationError( + "Out of memory: Could not allocate buffer while writing to file"); + return; + } + + auto opts = InternalWriteOpts::FromBinding(aOptions); + if (opts.isErr()) { + RejectJSPromise(promise, opts.unwrapErr()); + return; + } + + DispatchAndResolve<uint32_t>( + state->mEventQueue, promise, + [file = std::move(file), buf = std::move(*buf), + opts = opts.unwrap()]() { return WriteSync(file, buf, opts); }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::WriteUTF8(GlobalObject& aGlobal, + const nsAString& aPath, + const nsACString& aString, + const WriteOptions& aOptions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + auto opts = InternalWriteOpts::FromBinding(aOptions); + if (opts.isErr()) { + RejectJSPromise(promise, opts.unwrapErr()); + return; + } + + DispatchAndResolve<uint32_t>( + state->mEventQueue, promise, + [file = std::move(file), str = nsCString(aString), + opts = opts.unwrap()]() { + return WriteSync(file, AsBytes(Span(str)), opts); + }); + }); +} + +static bool AppendJsonAsUtf8(const char16_t* aData, uint32_t aLen, void* aStr) { + nsCString* str = static_cast<nsCString*>(aStr); + return AppendUTF16toUTF8(Span<const char16_t>(aData, aLen), *str, fallible); +} + +/* static */ +already_AddRefed<Promise> IOUtils::WriteJSON(GlobalObject& aGlobal, + const nsAString& aPath, + JS::Handle<JS::Value> aValue, + const WriteOptions& aOptions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + auto opts = InternalWriteOpts::FromBinding(aOptions); + if (opts.isErr()) { + RejectJSPromise(promise, opts.unwrapErr()); + return; + } + + if (opts.inspect().mMode == WriteMode::Append || + opts.inspect().mMode == WriteMode::AppendOrCreate) { + promise->MaybeRejectWithNotSupportedError( + "IOUtils.writeJSON does not support appending to files."_ns); + return; + } + + JSContext* cx = aGlobal.Context(); + JS::Rooted<JS::Value> rootedValue(cx, aValue); + nsCString utf8Str; + + if (!JS_Stringify(cx, &rootedValue, nullptr, JS::NullHandleValue, + AppendJsonAsUtf8, &utf8Str)) { + JS::Rooted<JS::Value> exn(cx, JS::UndefinedValue()); + if (JS_GetPendingException(cx, &exn)) { + JS_ClearPendingException(cx); + promise->MaybeReject(exn); + } else { + RejectJSPromise( + promise, + IOError(NS_ERROR_DOM_UNKNOWN_ERR) + .WithMessage("Could not serialize object to JSON")); + } + return; + } + + DispatchAndResolve<uint32_t>( + state->mEventQueue, promise, + [file = std::move(file), utf8Str = std::move(utf8Str), + opts = opts.unwrap()]() { + return WriteSync(file, AsBytes(Span(utf8Str)), opts); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::Move(GlobalObject& aGlobal, + const nsAString& aSourcePath, + const nsAString& aDestPath, + const MoveOptions& aOptions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> sourceFile = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(sourceFile, aSourcePath, promise); + + nsCOMPtr<nsIFile> destFile = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(destFile, aDestPath, promise); + + DispatchAndResolve<Ok>( + state->mEventQueue, promise, + [sourceFile = std::move(sourceFile), destFile = std::move(destFile), + noOverwrite = aOptions.mNoOverwrite]() { + return MoveSync(sourceFile, destFile, noOverwrite); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::Remove(GlobalObject& aGlobal, + const nsAString& aPath, + const RemoveOptions& aOptions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<Ok>( + state->mEventQueue, promise, + [file = std::move(file), ignoreAbsent = aOptions.mIgnoreAbsent, + recursive = aOptions.mRecursive, + retryReadonly = aOptions.mRetryReadonly]() { + return RemoveSync(file, ignoreAbsent, recursive, retryReadonly); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::MakeDirectory( + GlobalObject& aGlobal, const nsAString& aPath, + const MakeDirectoryOptions& aOptions, ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<Ok>(state->mEventQueue, promise, + [file = std::move(file), + createAncestors = aOptions.mCreateAncestors, + ignoreExisting = aOptions.mIgnoreExisting, + permissions = aOptions.mPermissions]() { + return MakeDirectorySync(file, createAncestors, + ignoreExisting, + permissions); + }); + }); +} + +already_AddRefed<Promise> IOUtils::Stat(GlobalObject& aGlobal, + const nsAString& aPath, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<InternalFileInfo>( + state->mEventQueue, promise, + [file = std::move(file)]() { return StatSync(file); }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::Copy(GlobalObject& aGlobal, + const nsAString& aSourcePath, + const nsAString& aDestPath, + const CopyOptions& aOptions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> sourceFile = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(sourceFile, aSourcePath, promise); + + nsCOMPtr<nsIFile> destFile = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(destFile, aDestPath, promise); + + DispatchAndResolve<Ok>( + state->mEventQueue, promise, + [sourceFile = std::move(sourceFile), destFile = std::move(destFile), + noOverwrite = aOptions.mNoOverwrite, + recursive = aOptions.mRecursive]() { + return CopySync(sourceFile, destFile, noOverwrite, recursive); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::SetAccessTime( + GlobalObject& aGlobal, const nsAString& aPath, + const Optional<int64_t>& aAccess, ErrorResult& aError) { + return SetTime(aGlobal, aPath, aAccess, &nsIFile::SetLastAccessedTime, + aError); +} + +/* static */ +already_AddRefed<Promise> IOUtils::SetModificationTime( + GlobalObject& aGlobal, const nsAString& aPath, + const Optional<int64_t>& aModification, ErrorResult& aError) { + return SetTime(aGlobal, aPath, aModification, &nsIFile::SetLastModifiedTime, + aError); +} + +/* static */ +already_AddRefed<Promise> IOUtils::SetTime(GlobalObject& aGlobal, + const nsAString& aPath, + const Optional<int64_t>& aNewTime, + IOUtils::SetTimeFn aSetTimeFn, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + int64_t newTime = aNewTime.WasPassed() ? aNewTime.Value() + : PR_Now() / PR_USEC_PER_MSEC; + DispatchAndResolve<int64_t>( + state->mEventQueue, promise, + [file = std::move(file), aSetTimeFn, newTime]() { + return SetTimeSync(file, aSetTimeFn, newTime); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::GetChildren( + GlobalObject& aGlobal, const nsAString& aPath, + const GetChildrenOptions& aOptions, ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<nsTArray<nsString>>( + state->mEventQueue, promise, + [file = std::move(file), ignoreAbsent = aOptions.mIgnoreAbsent]() { + return GetChildrenSync(file, ignoreAbsent); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::SetPermissions(GlobalObject& aGlobal, + const nsAString& aPath, + uint32_t aPermissions, + const bool aHonorUmask, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { +#if defined(XP_UNIX) && !defined(ANDROID) + if (aHonorUmask) { + aPermissions &= ~nsSystemInfo::gUserUmask; + } +#endif + + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<Ok>( + state->mEventQueue, promise, + [file = std::move(file), permissions = aPermissions]() { + return SetPermissionsSync(file, permissions); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::Exists(GlobalObject& aGlobal, + const nsAString& aPath, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<bool>( + state->mEventQueue, promise, + [file = std::move(file)]() { return ExistsSync(file); }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::CreateUniqueFile(GlobalObject& aGlobal, + const nsAString& aParent, + const nsAString& aPrefix, + const uint32_t aPermissions, + ErrorResult& aError) { + return CreateUnique(aGlobal, aParent, aPrefix, nsIFile::NORMAL_FILE_TYPE, + aPermissions, aError); +} + +/* static */ +already_AddRefed<Promise> IOUtils::CreateUniqueDirectory( + GlobalObject& aGlobal, const nsAString& aParent, const nsAString& aPrefix, + const uint32_t aPermissions, ErrorResult& aError) { + return CreateUnique(aGlobal, aParent, aPrefix, nsIFile::DIRECTORY_TYPE, + aPermissions, aError); +} + +/* static */ +already_AddRefed<Promise> IOUtils::CreateUnique(GlobalObject& aGlobal, + const nsAString& aParent, + const nsAString& aPrefix, + const uint32_t aFileType, + const uint32_t aPermissions, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aParent, promise); + + if (nsresult rv = file->Append(aPrefix); NS_FAILED(rv)) { + RejectJSPromise(promise, + IOError(rv).WithMessage( + "Could not append prefix `%s' to parent `%s'", + NS_ConvertUTF16toUTF8(aPrefix).get(), + file->HumanReadablePath().get())); + return; + } + + DispatchAndResolve<nsString>( + state->mEventQueue, promise, + [file = std::move(file), aPermissions, aFileType]() { + return CreateUniqueSync(file, aFileType, aPermissions); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::ComputeHexDigest( + GlobalObject& aGlobal, const nsAString& aPath, + const HashAlgorithm aAlgorithm, ErrorResult& aError) { + const bool nssInitialized = EnsureNSSInitializedChromeOrContent(); + + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + if (!nssInitialized) { + RejectJSPromise(promise, + IOError(NS_ERROR_UNEXPECTED) + .WithMessage("Could not initialize NSS")); + return; + } + + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<nsCString>(state->mEventQueue, promise, + [file = std::move(file), aAlgorithm]() { + return ComputeHexDigestSync(file, + aAlgorithm); + }); + }); +} + +#if defined(XP_WIN) + +/* static */ +already_AddRefed<Promise> IOUtils::GetWindowsAttributes(GlobalObject& aGlobal, + const nsAString& aPath, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + RefPtr<StrongWorkerRef> workerRef; + if (!NS_IsMainThread()) { + // We need to manually keep the worker alive until the promise + // returned by Dispatch() resolves or rejects. + workerRef = StrongWorkerRef::CreateForcibly( + GetCurrentThreadWorkerPrivate(), __func__); + } + + state->mEventQueue + ->template Dispatch<uint32_t>([file = std::move(file)]() { + return GetWindowsAttributesSync(file); + }) + ->Then( + GetCurrentSerialEventTarget(), __func__, + [workerRef, promise = RefPtr{promise}](const uint32_t aAttrs) { + WindowsFileAttributes attrs; + + attrs.mReadOnly.Construct(aAttrs & FILE_ATTRIBUTE_READONLY); + attrs.mHidden.Construct(aAttrs & FILE_ATTRIBUTE_HIDDEN); + attrs.mSystem.Construct(aAttrs & FILE_ATTRIBUTE_SYSTEM); + + promise->MaybeResolve(attrs); + }, + [workerRef, promise = RefPtr{promise}](const IOError& aErr) { + RejectJSPromise(promise, aErr); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::SetWindowsAttributes( + GlobalObject& aGlobal, const nsAString& aPath, + const WindowsFileAttributes& aAttrs, ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + uint32_t setAttrs = 0; + uint32_t clearAttrs = 0; + + if (aAttrs.mReadOnly.WasPassed()) { + if (aAttrs.mReadOnly.Value()) { + setAttrs |= FILE_ATTRIBUTE_READONLY; + } else { + clearAttrs |= FILE_ATTRIBUTE_READONLY; + } + } + + if (aAttrs.mHidden.WasPassed()) { + if (aAttrs.mHidden.Value()) { + setAttrs |= FILE_ATTRIBUTE_HIDDEN; + } else { + clearAttrs |= FILE_ATTRIBUTE_HIDDEN; + } + } + + if (aAttrs.mSystem.WasPassed()) { + if (aAttrs.mSystem.Value()) { + setAttrs |= FILE_ATTRIBUTE_SYSTEM; + } else { + clearAttrs |= FILE_ATTRIBUTE_SYSTEM; + } + } + + DispatchAndResolve<Ok>( + state->mEventQueue, promise, + [file = std::move(file), setAttrs, clearAttrs]() { + return SetWindowsAttributesSync(file, setAttrs, clearAttrs); + }); + }); +} + +#elif defined(XP_MACOSX) + +/* static */ +already_AddRefed<Promise> IOUtils::HasMacXAttr(GlobalObject& aGlobal, + const nsAString& aPath, + const nsACString& aAttr, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<bool>( + state->mEventQueue, promise, + [file = std::move(file), attr = nsCString(aAttr)]() { + return HasMacXAttrSync(file, attr); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::GetMacXAttr(GlobalObject& aGlobal, + const nsAString& aPath, + const nsACString& aAttr, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<nsTArray<uint8_t>>( + state->mEventQueue, promise, + [file = std::move(file), attr = nsCString(aAttr)]() { + return GetMacXAttrSync(file, attr); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::SetMacXAttr(GlobalObject& aGlobal, + const nsAString& aPath, + const nsACString& aAttr, + const Uint8Array& aValue, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + aValue.ComputeState(); + nsTArray<uint8_t> value; + + if (!value.AppendElements(aValue.Data(), aValue.Length(), fallible)) { + RejectJSPromise( + promise, + IOError(NS_ERROR_OUT_OF_MEMORY) + .WithMessage( + "Could not allocate buffer to set extended attribute")); + return; + } + + DispatchAndResolve<Ok>(state->mEventQueue, promise, + [file = std::move(file), attr = nsCString(aAttr), + value = std::move(value)] { + return SetMacXAttrSync(file, attr, value); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::DelMacXAttr(GlobalObject& aGlobal, + const nsAString& aPath, + const nsACString& aAttr, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + nsCOMPtr<nsIFile> file = new nsLocalFile(); + REJECT_IF_INIT_PATH_FAILED(file, aPath, promise); + + DispatchAndResolve<Ok>( + state->mEventQueue, promise, + [file = std::move(file), attr = nsCString(aAttr)] { + return DelMacXAttrSync(file, attr); + }); + }); +} + +#endif + +/* static */ +already_AddRefed<Promise> IOUtils::GetFile( + GlobalObject& aGlobal, const Sequence<nsString>& aComponents, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + ErrorResult joinErr; + nsCOMPtr<nsIFile> file = PathUtils::Join(aComponents, joinErr); + if (joinErr.Failed()) { + promise->MaybeReject(std::move(joinErr)); + return; + } + + nsCOMPtr<nsIFile> parent; + if (nsresult rv = file->GetParent(getter_AddRefs(parent)); + NS_FAILED(rv)) { + RejectJSPromise(promise, IOError(rv).WithMessage( + "Could not get parent directory")); + return; + } + + state->mEventQueue + ->template Dispatch<Ok>([parent = std::move(parent)]() { + return MakeDirectorySync(parent, /* aCreateAncestors = */ true, + /* aIgnoreExisting = */ true, 0755); + }) + ->Then( + GetCurrentSerialEventTarget(), __func__, + [file = std::move(file), promise = RefPtr(promise)](const Ok&) { + promise->MaybeResolve(file); + }, + [promise = RefPtr(promise)](const IOError& err) { + RejectJSPromise(promise, err); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::GetDirectory( + GlobalObject& aGlobal, const Sequence<nsString>& aComponents, + ErrorResult& aError) { + return WithPromiseAndState( + aGlobal, aError, [&](Promise* promise, auto& state) { + ErrorResult joinErr; + nsCOMPtr<nsIFile> dir = PathUtils::Join(aComponents, joinErr); + if (joinErr.Failed()) { + promise->MaybeReject(std::move(joinErr)); + return; + } + + state->mEventQueue + ->template Dispatch<Ok>([dir]() { + return MakeDirectorySync(dir, /* aCreateAncestors = */ true, + /* aIgnoreExisting = */ true, 0755); + }) + ->Then( + GetCurrentSerialEventTarget(), __func__, + [dir, promise = RefPtr(promise)](const Ok&) { + promise->MaybeResolve(dir); + }, + [promise = RefPtr(promise)](const IOError& err) { + RejectJSPromise(promise, err); + }); + }); +} + +/* static */ +already_AddRefed<Promise> IOUtils::CreateJSPromise(GlobalObject& aGlobal, + ErrorResult& aError) { + nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports()); + RefPtr<Promise> promise = Promise::Create(global, aError); + if (aError.Failed()) { + return nullptr; + } + MOZ_ASSERT(promise); + return do_AddRef(promise); +} + +/* static */ +Result<IOUtils::JsBuffer, IOUtils::IOError> IOUtils::ReadSync( + nsIFile* aFile, const uint64_t aOffset, const Maybe<uint32_t> aMaxBytes, + const bool aDecompress, IOUtils::BufferKind aBufferKind) { + MOZ_ASSERT(!NS_IsMainThread()); + + if (aMaxBytes.isSome() && aDecompress) { + return Err( + IOError(NS_ERROR_ILLEGAL_INPUT) + .WithMessage( + "The `maxBytes` and `decompress` options are not compatible")); + } + + if (aOffset > static_cast<uint64_t>(INT64_MAX)) { + return Err(IOError(NS_ERROR_ILLEGAL_INPUT) + .WithMessage("Requested offset is too large (%" PRIu64 + " > %" PRId64 ")", + aOffset, INT64_MAX)); + } + + const int64_t offset = static_cast<int64_t>(aOffset); + + RefPtr<nsFileRandomAccessStream> stream = new nsFileRandomAccessStream(); + if (nsresult rv = + stream->Init(aFile, PR_RDONLY | nsIFile::OS_READAHEAD, 0666, 0); + NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage("Could not open the file at %s", + aFile->HumanReadablePath().get())); + } + + uint32_t bufSize = 0; + + if (aMaxBytes.isNothing()) { + // Limitation: We cannot read more than the maximum size of a TypedArray + // (UINT32_MAX bytes). Reject if we have been requested to + // perform too large of a read. + + int64_t rawStreamSize = -1; + if (nsresult rv = stream->GetSize(&rawStreamSize); NS_FAILED(rv)) { + return Err(IOError(NS_ERROR_FILE_ACCESS_DENIED) + .WithMessage("Could not get info for the file at %s", + aFile->HumanReadablePath().get())); + } + MOZ_RELEASE_ASSERT(rawStreamSize >= 0); + + uint64_t streamSize = static_cast<uint64_t>(rawStreamSize); + if (aOffset >= streamSize) { + bufSize = 0; + } else { + if (streamSize - offset > static_cast<int64_t>(UINT32_MAX)) { + return Err(IOError(NS_ERROR_FILE_TOO_BIG) + .WithMessage( + "Could not read the file at %s with offset %" PRIu32 + " because it is too large(size=%" PRIu64 " bytes)", + aFile->HumanReadablePath().get(), offset, + streamSize)); + } + + bufSize = static_cast<uint32_t>(streamSize - offset); + } + } else { + bufSize = aMaxBytes.value(); + } + + if (offset > 0) { + if (nsresult rv = stream->Seek(PR_SEEK_SET, offset); NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Could not seek to position %" PRId64 " in file %s", offset, + aFile->HumanReadablePath().get())); + } + } + + JsBuffer buffer = JsBuffer::CreateEmpty(aBufferKind); + + if (bufSize > 0) { + auto result = JsBuffer::Create(aBufferKind, bufSize); + if (result.isErr()) { + return result.propagateErr(); + } + buffer = result.unwrap(); + Span<char> toRead = buffer.BeginWriting(); + + // Read the file from disk. + uint32_t totalRead = 0; + while (totalRead != bufSize) { + // Read no more than INT32_MAX on each call to stream->Read, otherwise it + // returns an error. + uint32_t bytesToReadThisChunk = + std::min<uint32_t>(bufSize - totalRead, INT32_MAX); + uint32_t bytesRead = 0; + if (nsresult rv = + stream->Read(toRead.Elements(), bytesToReadThisChunk, &bytesRead); + NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Encountered an unexpected error while reading file(%s)", + aFile->HumanReadablePath().get())); + } + if (bytesRead == 0) { + break; + } + totalRead += bytesRead; + toRead = toRead.From(bytesRead); + } + + buffer.SetLength(totalRead); + } + + // Decompress the file contents, if required. + if (aDecompress) { + return MozLZ4::Decompress(AsBytes(buffer.BeginReading()), aBufferKind); + } + + return std::move(buffer); +} + +/* static */ +Result<IOUtils::JsBuffer, IOUtils::IOError> IOUtils::ReadUTF8Sync( + nsIFile* aFile, bool aDecompress) { + auto result = ReadSync(aFile, 0, Nothing{}, aDecompress, BufferKind::String); + if (result.isErr()) { + return result.propagateErr(); + } + + JsBuffer buffer = result.unwrap(); + if (!IsUtf8(buffer.BeginReading())) { + return Err( + IOError(NS_ERROR_FILE_CORRUPTED) + .WithMessage( + "Could not read file(%s) because it is not UTF-8 encoded", + aFile->HumanReadablePath().get())); + } + + return buffer; +} + +/* static */ +Result<uint32_t, IOUtils::IOError> IOUtils::WriteSync( + nsIFile* aFile, const Span<const uint8_t>& aByteArray, + const IOUtils::InternalWriteOpts& aOptions) { + MOZ_ASSERT(!NS_IsMainThread()); + + nsIFile* backupFile = aOptions.mBackupFile; + nsIFile* tempFile = aOptions.mTmpFile; + + bool exists = false; + MOZ_TRY(aFile->Exists(&exists)); + + if (exists && aOptions.mMode == WriteMode::Create) { + return Err(IOError(NS_ERROR_FILE_ALREADY_EXISTS) + .WithMessage("Refusing to overwrite the file at %s\n" + "Specify `mode: \"overwrite\"` to allow " + "overwriting the destination", + aFile->HumanReadablePath().get())); + } + + // If backupFile was specified, perform the backup as a move. + if (exists && backupFile) { + // We copy `destFile` here to a new `nsIFile` because + // `nsIFile::MoveToFollowingLinks` will update the path of the file. If we + // did not do this, we would end up having `destFile` point to the same + // location as `backupFile`. Then, when we went to write to `destFile`, we + // would end up overwriting `backupFile` and never actually write to the + // file we were supposed to. + nsCOMPtr<nsIFile> toMove; + MOZ_ALWAYS_SUCCEEDS(aFile->Clone(getter_AddRefs(toMove))); + + bool noOverwrite = aOptions.mMode == WriteMode::Create; + + if (MoveSync(toMove, backupFile, noOverwrite).isErr()) { + return Err(IOError(NS_ERROR_FILE_COPY_OR_MOVE_FAILED) + .WithMessage("Failed to backup the source file(%s) to %s", + aFile->HumanReadablePath().get(), + backupFile->HumanReadablePath().get())); + } + } + + // If tempFile was specified, we will write to there first, then perform a + // move to ensure the file ends up at the final requested destination. + nsIFile* writeFile; + + if (tempFile) { + writeFile = tempFile; + } else { + writeFile = aFile; + } + + int32_t flags = PR_WRONLY; + + switch (aOptions.mMode) { + case WriteMode::Overwrite: + flags |= PR_TRUNCATE | PR_CREATE_FILE; + break; + + case WriteMode::Append: + flags |= PR_APPEND; + break; + + case WriteMode::AppendOrCreate: + flags |= PR_APPEND | PR_CREATE_FILE; + break; + + case WriteMode::Create: + flags |= PR_CREATE_FILE | PR_EXCL; + break; + + default: + MOZ_CRASH("IOUtils: unknown write mode"); + } + + if (aOptions.mFlush) { + flags |= PR_SYNC; + } + + // Try to perform the write and ensure that the file is closed before + // continuing. + uint32_t totalWritten = 0; + { + // Compress the byte array if required. + nsTArray<uint8_t> compressed; + Span<const char> bytes; + if (aOptions.mCompress) { + auto rv = MozLZ4::Compress(aByteArray); + if (rv.isErr()) { + return rv.propagateErr(); + } + compressed = rv.unwrap(); + bytes = Span(reinterpret_cast<const char*>(compressed.Elements()), + compressed.Length()); + } else { + bytes = Span(reinterpret_cast<const char*>(aByteArray.Elements()), + aByteArray.Length()); + } + + RefPtr<nsFileOutputStream> stream = new nsFileOutputStream(); + if (nsresult rv = stream->Init(writeFile, flags, 0666, 0); NS_FAILED(rv)) { + // Normalize platform-specific errors for opening a directory to an access + // denied error. + if (rv == nsresult::NS_ERROR_FILE_IS_DIRECTORY) { + rv = NS_ERROR_FILE_ACCESS_DENIED; + } + return Err( + IOError(rv).WithMessage("Could not open the file at %s for writing", + writeFile->HumanReadablePath().get())); + } + + // nsFileRandomAccessStream::Write uses PR_Write under the hood, which + // accepts a *int32_t* for the chunk size. + uint32_t chunkSize = INT32_MAX; + Span<const char> pendingBytes = bytes; + + while (pendingBytes.Length() > 0) { + if (pendingBytes.Length() < chunkSize) { + chunkSize = pendingBytes.Length(); + } + + uint32_t bytesWritten = 0; + if (nsresult rv = + stream->Write(pendingBytes.Elements(), chunkSize, &bytesWritten); + NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Could not write chunk (size = %" PRIu32 + ") to file %s. The file may be corrupt.", + chunkSize, writeFile->HumanReadablePath().get())); + } + pendingBytes = pendingBytes.From(bytesWritten); + totalWritten += bytesWritten; + } + } + + // If tempFile was passed, check destFile against writeFile and, if they + // differ, the operation is finished by performing a move. + if (tempFile) { + nsAutoStringN<256> destPath; + nsAutoStringN<256> writePath; + + MOZ_ALWAYS_SUCCEEDS(aFile->GetPath(destPath)); + MOZ_ALWAYS_SUCCEEDS(writeFile->GetPath(writePath)); + + // nsIFile::MoveToFollowingLinks will only update the path of the file if + // the move succeeds. + if (destPath != writePath) { + if (aOptions.mTmpFile) { + bool isDir = false; + if (nsresult rv = aFile->IsDirectory(&isDir); + NS_FAILED(rv) && !IsFileNotFound(rv)) { + return Err(IOError(rv).WithMessage("Could not stat the file at %s", + aFile->HumanReadablePath().get())); + } + + // If we attempt to write to a directory *without* a temp file, we get a + // permission error. + // + // However, if we are writing to a temp file first, when we copy the + // temp file over the destination file, we actually end up copying it + // inside the directory, which is not what we want. In this case, we are + // just going to bail out early. + if (isDir) { + return Err( + IOError(NS_ERROR_FILE_ACCESS_DENIED) + .WithMessage("Could not open the file at %s for writing", + aFile->HumanReadablePath().get())); + } + } + + if (MoveSync(writeFile, aFile, /* aNoOverwrite = */ false).isErr()) { + return Err( + IOError(NS_ERROR_FILE_COPY_OR_MOVE_FAILED) + .WithMessage( + "Could not move temporary file(%s) to destination(%s)", + writeFile->HumanReadablePath().get(), + aFile->HumanReadablePath().get())); + } + } + } + return totalWritten; +} + +/* static */ +Result<Ok, IOUtils::IOError> IOUtils::MoveSync(nsIFile* aSourceFile, + nsIFile* aDestFile, + bool aNoOverwrite) { + MOZ_ASSERT(!NS_IsMainThread()); + + // Ensure the source file exists before continuing. If it doesn't exist, + // subsequent operations can fail in different ways on different platforms. + bool srcExists = false; + MOZ_TRY(aSourceFile->Exists(&srcExists)); + if (!srcExists) { + return Err( + IOError(NS_ERROR_FILE_NOT_FOUND) + .WithMessage( + "Could not move source file(%s) because it does not exist", + aSourceFile->HumanReadablePath().get())); + } + + return CopyOrMoveSync(&nsIFile::MoveToFollowingLinks, "move", aSourceFile, + aDestFile, aNoOverwrite); +} + +/* static */ +Result<Ok, IOUtils::IOError> IOUtils::CopySync(nsIFile* aSourceFile, + nsIFile* aDestFile, + bool aNoOverwrite, + bool aRecursive) { + MOZ_ASSERT(!NS_IsMainThread()); + + // Ensure the source file exists before continuing. If it doesn't exist, + // subsequent operations can fail in different ways on different platforms. + bool srcExists; + MOZ_TRY(aSourceFile->Exists(&srcExists)); + if (!srcExists) { + return Err( + IOError(NS_ERROR_FILE_NOT_FOUND) + .WithMessage( + "Could not copy source file(%s) because it does not exist", + aSourceFile->HumanReadablePath().get())); + } + + // If source is a directory, fail immediately unless the recursive option is + // true. + bool srcIsDir = false; + MOZ_TRY(aSourceFile->IsDirectory(&srcIsDir)); + if (srcIsDir && !aRecursive) { + return Err( + IOError(NS_ERROR_FILE_COPY_OR_MOVE_FAILED) + .WithMessage( + "Refused to copy source directory(%s) to the destination(%s)\n" + "Specify the `recursive: true` option to allow copying " + "directories", + aSourceFile->HumanReadablePath().get(), + aDestFile->HumanReadablePath().get())); + } + + return CopyOrMoveSync(&nsIFile::CopyToFollowingLinks, "copy", aSourceFile, + aDestFile, aNoOverwrite); +} + +/* static */ +template <typename CopyOrMoveFn> +Result<Ok, IOUtils::IOError> IOUtils::CopyOrMoveSync(CopyOrMoveFn aMethod, + const char* aMethodName, + nsIFile* aSource, + nsIFile* aDest, + bool aNoOverwrite) { + MOZ_ASSERT(!NS_IsMainThread()); + + // Case 1: Destination is an existing directory. Copy/move source into dest. + bool destIsDir = false; + bool destExists = true; + + nsresult rv = aDest->IsDirectory(&destIsDir); + if (NS_SUCCEEDED(rv) && destIsDir) { + rv = (aSource->*aMethod)(aDest, u""_ns); + if (NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Could not %s source file(%s) to destination directory(%s)", + aMethodName, aSource->HumanReadablePath().get(), + aDest->HumanReadablePath().get())); + } + return Ok(); + } + + if (NS_FAILED(rv)) { + if (!IsFileNotFound(rv)) { + // It's ok if the dest file doesn't exist. Case 2 handles this below. + // Bail out early for any other kind of error though. + return Err(IOError(rv)); + } + destExists = false; + } + + // Case 2: Destination is a file which may or may not exist. + // Try to copy or rename the source to the destination. + // If the destination exists and the source is not a regular file, + // then this may fail. + if (aNoOverwrite && destExists) { + return Err( + IOError(NS_ERROR_FILE_ALREADY_EXISTS) + .WithMessage( + "Could not %s source file(%s) to destination(%s) because the " + "destination already exists and overwrites are not allowed\n" + "Specify the `noOverwrite: false` option to mitigate this " + "error", + aMethodName, aSource->HumanReadablePath().get(), + aDest->HumanReadablePath().get())); + } + if (destExists && !destIsDir) { + // If the source file is a directory, but the target is a file, abort early. + // Different implementations of |CopyTo| and |MoveTo| seem to handle this + // error case differently (or not at all), so we explicitly handle it here. + bool srcIsDir = false; + MOZ_TRY(aSource->IsDirectory(&srcIsDir)); + if (srcIsDir) { + return Err(IOError(NS_ERROR_FILE_DESTINATION_NOT_DIR) + .WithMessage("Could not %s the source directory(%s) to " + "the destination(%s) because the destination " + "is not a directory", + aMethodName, + aSource->HumanReadablePath().get(), + aDest->HumanReadablePath().get())); + } + } + + nsCOMPtr<nsIFile> destDir; + nsAutoString destName; + MOZ_TRY(aDest->GetLeafName(destName)); + MOZ_TRY(aDest->GetParent(getter_AddRefs(destDir))); + + // We know `destName` is a file and therefore must have a parent directory. + MOZ_RELEASE_ASSERT(destDir); + + // NB: if destDir doesn't exist, then |CopyToFollowingLinks| or + // |MoveToFollowingLinks| will create it. + rv = (aSource->*aMethod)(destDir, destName); + if (NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Could not %s the source file(%s) to the destination(%s)", aMethodName, + aSource->HumanReadablePath().get(), aDest->HumanReadablePath().get())); + } + return Ok(); +} + +/* static */ +Result<Ok, IOUtils::IOError> IOUtils::RemoveSync(nsIFile* aFile, + bool aIgnoreAbsent, + bool aRecursive, + bool aRetryReadonly) { + MOZ_ASSERT(!NS_IsMainThread()); + + // Prevent an unused variable warning. + (void)aRetryReadonly; + + nsresult rv = aFile->Remove(aRecursive); + if (aIgnoreAbsent && IsFileNotFound(rv)) { + return Ok(); + } + if (NS_FAILED(rv)) { + IOError err(rv); + if (IsFileNotFound(rv)) { + return Err(err.WithMessage( + "Could not remove the file at %s because it does not exist.\n" + "Specify the `ignoreAbsent: true` option to mitigate this error", + aFile->HumanReadablePath().get())); + } + if (rv == NS_ERROR_FILE_DIR_NOT_EMPTY) { + return Err(err.WithMessage( + "Could not remove the non-empty directory at %s.\n" + "Specify the `recursive: true` option to mitigate this error", + aFile->HumanReadablePath().get())); + } + +#ifdef XP_WIN + + if (rv == NS_ERROR_FILE_ACCESS_DENIED && aRetryReadonly) { + MOZ_TRY(SetWindowsAttributesSync(aFile, 0, FILE_ATTRIBUTE_READONLY)); + return RemoveSync(aFile, aIgnoreAbsent, aRecursive, + /* aRetryReadonly = */ false); + } + +#endif + + return Err(err.WithMessage("Could not remove the file at %s", + aFile->HumanReadablePath().get())); + } + return Ok(); +} + +/* static */ +Result<Ok, IOUtils::IOError> IOUtils::MakeDirectorySync(nsIFile* aFile, + bool aCreateAncestors, + bool aIgnoreExisting, + int32_t aMode) { + MOZ_ASSERT(!NS_IsMainThread()); + + nsCOMPtr<nsIFile> parent; + MOZ_TRY(aFile->GetParent(getter_AddRefs(parent))); + if (!parent) { + // If we don't have a parent directory, we were called with a + // root directory. If the directory doesn't already exist (e.g., asking + // for a drive on Windows that does not exist), we will not be able to + // create it. + // + // Calling `nsLocalFile::Create()` on Windows can fail with + // `NS_ERROR_ACCESS_DENIED` trying to create a root directory, but we + // would rather the call succeed, so return early if the directory exists. + // + // Otherwise, we fall through to `nsiFile::Create()` and let it fail there + // instead. + bool exists = false; + MOZ_TRY(aFile->Exists(&exists)); + if (exists) { + return Ok(); + } + } + + nsresult rv = + aFile->Create(nsIFile::DIRECTORY_TYPE, aMode, !aCreateAncestors); + if (NS_FAILED(rv)) { + if (rv == NS_ERROR_FILE_ALREADY_EXISTS) { + // NB: We may report a success only if the target is an existing + // directory. We don't want to silence errors that occur if the target is + // an existing file, since trying to create a directory where a regular + // file exists may be indicative of a logic error. + bool isDirectory; + MOZ_TRY(aFile->IsDirectory(&isDirectory)); + if (!isDirectory) { + return Err(IOError(NS_ERROR_FILE_NOT_DIRECTORY) + .WithMessage("Could not create directory because the " + "target file(%s) exists " + "and is not a directory", + aFile->HumanReadablePath().get())); + } + // The directory exists. + // The caller may suppress this error. + if (aIgnoreExisting) { + return Ok(); + } + // Otherwise, forward it. + return Err(IOError(rv).WithMessage( + "Could not create directory because it already exists at %s\n" + "Specify the `ignoreExisting: true` option to mitigate this " + "error", + aFile->HumanReadablePath().get())); + } + return Err(IOError(rv).WithMessage("Could not create directory at %s", + aFile->HumanReadablePath().get())); + } + return Ok(); +} + +Result<IOUtils::InternalFileInfo, IOUtils::IOError> IOUtils::StatSync( + nsIFile* aFile) { + MOZ_ASSERT(!NS_IsMainThread()); + + InternalFileInfo info; + MOZ_ALWAYS_SUCCEEDS(aFile->GetPath(info.mPath)); + + bool isRegular = false; + // IsFile will stat and cache info in the file object. If the file doesn't + // exist, or there is an access error, we'll discover it here. + // Any subsequent errors are unexpected and will just be forwarded. + nsresult rv = aFile->IsFile(&isRegular); + if (NS_FAILED(rv)) { + IOError err(rv); + if (IsFileNotFound(rv)) { + return Err( + err.WithMessage("Could not stat file(%s) because it does not exist", + aFile->HumanReadablePath().get())); + } + return Err(err); + } + + // Now we can populate the info object by querying the file. + info.mType = FileType::Regular; + if (!isRegular) { + bool isDir = false; + MOZ_TRY(aFile->IsDirectory(&isDir)); + info.mType = isDir ? FileType::Directory : FileType::Other; + } + + int64_t size = -1; + if (info.mType == FileType::Regular) { + MOZ_TRY(aFile->GetFileSize(&size)); + } + info.mSize = size; + + PRTime creationTime = 0; + if (nsresult rv = aFile->GetCreationTime(&creationTime); NS_SUCCEEDED(rv)) { + info.mCreationTime.emplace(static_cast<int64_t>(creationTime)); + } else if (NS_FAILED(rv) && rv != NS_ERROR_NOT_IMPLEMENTED) { + // This field is only supported on some platforms. + return Err(IOError(rv)); + } + + PRTime lastAccessed = 0; + MOZ_TRY(aFile->GetLastAccessedTime(&lastAccessed)); + info.mLastAccessed = static_cast<int64_t>(lastAccessed); + + PRTime lastModified = 0; + MOZ_TRY(aFile->GetLastModifiedTime(&lastModified)); + info.mLastModified = static_cast<int64_t>(lastModified); + + MOZ_TRY(aFile->GetPermissions(&info.mPermissions)); + + return info; +} + +/* static */ +Result<int64_t, IOUtils::IOError> IOUtils::SetTimeSync( + nsIFile* aFile, IOUtils::SetTimeFn aSetTimeFn, int64_t aNewTime) { + MOZ_ASSERT(!NS_IsMainThread()); + + // nsIFile::SetLastModifiedTime will *not* do what is expected when passed 0 + // as an argument. Rather than setting the time to 0, it will recalculate the + // system time and set it to that value instead. We explicit forbid this, + // because this side effect is surprising. + // + // If it ever becomes possible to set a file time to 0, this check should be + // removed, though this use case seems rare. + if (aNewTime == 0) { + return Err( + IOError(NS_ERROR_ILLEGAL_VALUE) + .WithMessage( + "Refusing to set the modification time of file(%s) to 0.\n" + "To use the current system time, call `setModificationTime` " + "with no arguments", + aFile->HumanReadablePath().get())); + } + + nsresult rv = (aFile->*aSetTimeFn)(aNewTime); + + if (NS_FAILED(rv)) { + IOError err(rv); + if (IsFileNotFound(rv)) { + return Err( + err.WithMessage("Could not set modification time of file(%s) " + "because it does not exist", + aFile->HumanReadablePath().get())); + } + return Err(err); + } + return aNewTime; +} + +/* static */ +Result<nsTArray<nsString>, IOUtils::IOError> IOUtils::GetChildrenSync( + nsIFile* aFile, bool aIgnoreAbsent) { + MOZ_ASSERT(!NS_IsMainThread()); + + nsTArray<nsString> children; + nsCOMPtr<nsIDirectoryEnumerator> iter; + nsresult rv = aFile->GetDirectoryEntries(getter_AddRefs(iter)); + if (aIgnoreAbsent && IsFileNotFound(rv)) { + return children; + } + if (NS_FAILED(rv)) { + IOError err(rv); + if (IsFileNotFound(rv)) { + return Err(err.WithMessage( + "Could not get children of file(%s) because it does not exist", + aFile->HumanReadablePath().get())); + } + if (IsNotDirectory(rv)) { + return Err(err.WithMessage( + "Could not get children of file(%s) because it is not a directory", + aFile->HumanReadablePath().get())); + } + return Err(err); + } + + bool hasMoreElements = false; + MOZ_TRY(iter->HasMoreElements(&hasMoreElements)); + while (hasMoreElements) { + nsCOMPtr<nsIFile> child; + MOZ_TRY(iter->GetNextFile(getter_AddRefs(child))); + if (child) { + nsString path; + MOZ_TRY(child->GetPath(path)); + children.AppendElement(path); + } + MOZ_TRY(iter->HasMoreElements(&hasMoreElements)); + } + + return children; +} + +/* static */ +Result<Ok, IOUtils::IOError> IOUtils::SetPermissionsSync( + nsIFile* aFile, const uint32_t aPermissions) { + MOZ_ASSERT(!NS_IsMainThread()); + + MOZ_TRY(aFile->SetPermissions(aPermissions)); + return Ok{}; +} + +/* static */ +Result<bool, IOUtils::IOError> IOUtils::ExistsSync(nsIFile* aFile) { + MOZ_ASSERT(!NS_IsMainThread()); + + bool exists = false; + MOZ_TRY(aFile->Exists(&exists)); + + return exists; +} + +/* static */ +Result<nsString, IOUtils::IOError> IOUtils::CreateUniqueSync( + nsIFile* aFile, const uint32_t aFileType, const uint32_t aPermissions) { + MOZ_ASSERT(!NS_IsMainThread()); + + if (nsresult rv = aFile->CreateUnique(aFileType, aPermissions); + NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage("Could not create unique path")); + } + + nsString path; + MOZ_ALWAYS_SUCCEEDS(aFile->GetPath(path)); + + return path; +} + +/* static */ +Result<nsCString, IOUtils::IOError> IOUtils::ComputeHexDigestSync( + nsIFile* aFile, const HashAlgorithm aAlgorithm) { + static constexpr size_t BUFFER_SIZE = 8192; + + SECOidTag alg; + switch (aAlgorithm) { + case HashAlgorithm::Sha1: + alg = SEC_OID_SHA1; + break; + + case HashAlgorithm::Sha256: + alg = SEC_OID_SHA256; + break; + + case HashAlgorithm::Sha384: + alg = SEC_OID_SHA384; + break; + + case HashAlgorithm::Sha512: + alg = SEC_OID_SHA512; + break; + + default: + MOZ_RELEASE_ASSERT(false, "Unexpected HashAlgorithm"); + } + + Digest digest; + if (nsresult rv = digest.Begin(alg); NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage("Could not hash file at %s", + aFile->HumanReadablePath().get())); + } + + RefPtr<nsIInputStream> stream; + if (nsresult rv = NS_NewLocalFileInputStream(getter_AddRefs(stream), aFile); + NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage("Could not open the file at %s", + aFile->HumanReadablePath().get())); + } + + char buffer[BUFFER_SIZE]; + uint32_t read = 0; + for (;;) { + if (nsresult rv = stream->Read(buffer, BUFFER_SIZE, &read); NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Encountered an unexpected error while reading file(%s)", + aFile->HumanReadablePath().get())); + } + if (read == 0) { + break; + } + + if (nsresult rv = + digest.Update(reinterpret_cast<unsigned char*>(buffer), read); + NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage("Could not hash file at %s", + aFile->HumanReadablePath().get())); + } + } + + AutoTArray<uint8_t, SHA512_LENGTH> rawDigest; + if (nsresult rv = digest.End(rawDigest); NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage("Could not hash file at %s", + aFile->HumanReadablePath().get())); + } + + nsCString hexDigest; + if (!hexDigest.SetCapacity(2 * rawDigest.Length(), fallible)) { + return Err(IOError(NS_ERROR_OUT_OF_MEMORY)); + } + + const char HEX[] = "0123456789abcdef"; + for (uint8_t b : rawDigest) { + hexDigest.Append(HEX[(b >> 4) & 0xF]); + hexDigest.Append(HEX[b & 0xF]); + } + + return hexDigest; +} + +#if defined(XP_WIN) + +Result<uint32_t, IOUtils::IOError> IOUtils::GetWindowsAttributesSync( + nsIFile* aFile) { + MOZ_ASSERT(!NS_IsMainThread()); + + uint32_t attrs = 0; + + nsCOMPtr<nsILocalFileWin> file = do_QueryInterface(aFile); + MOZ_ASSERT(file); + + if (nsresult rv = file->GetWindowsFileAttributes(&attrs); NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Could not get Windows file attributes for the file at `%s'", + aFile->HumanReadablePath().get())); + } + return attrs; +} + +Result<Ok, IOUtils::IOError> IOUtils::SetWindowsAttributesSync( + nsIFile* aFile, const uint32_t aSetAttrs, const uint32_t aClearAttrs) { + MOZ_ASSERT(!NS_IsMainThread()); + + nsCOMPtr<nsILocalFileWin> file = do_QueryInterface(aFile); + MOZ_ASSERT(file); + + if (nsresult rv = file->SetWindowsFileAttributes(aSetAttrs, aClearAttrs); + NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Could not set Windows file attributes for the file at `%s'", + aFile->HumanReadablePath().get())); + } + + return Ok{}; +} + +#elif defined(XP_MACOSX) + +/* static */ +Result<bool, IOUtils::IOError> IOUtils::HasMacXAttrSync( + nsIFile* aFile, const nsCString& aAttr) { + MOZ_ASSERT(!NS_IsMainThread()); + + nsCOMPtr<nsILocalFileMac> file = do_QueryInterface(aFile); + MOZ_ASSERT(file); + + bool hasAttr = false; + if (nsresult rv = file->HasXAttr(aAttr, &hasAttr); NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Could not read the extended attribute `%s' from the file `%s'", + aAttr.get(), aFile->HumanReadablePath().get())); + } + + return hasAttr; +} + +/* static */ +Result<nsTArray<uint8_t>, IOUtils::IOError> IOUtils::GetMacXAttrSync( + nsIFile* aFile, const nsCString& aAttr) { + MOZ_ASSERT(!NS_IsMainThread()); + + nsCOMPtr<nsILocalFileMac> file = do_QueryInterface(aFile); + MOZ_ASSERT(file); + + nsTArray<uint8_t> value; + if (nsresult rv = file->GetXAttr(aAttr, value); NS_FAILED(rv)) { + auto err = IOError(rv); + + if (rv == NS_ERROR_NOT_AVAILABLE) { + return Err(err.WithMessage( + "The file `%s' does not have an extended attribute `%s'", + aFile->HumanReadablePath().get(), aAttr.get())); + } + + return Err(err.WithMessage( + "Could not read the extended attribute `%s' from the file `%s'", + aAttr.get(), aFile->HumanReadablePath().get())); + } + + return value; +} + +/* static */ +Result<Ok, IOUtils::IOError> IOUtils::SetMacXAttrSync( + nsIFile* aFile, const nsCString& aAttr, const nsTArray<uint8_t>& aValue) { + MOZ_ASSERT(!NS_IsMainThread()); + + nsCOMPtr<nsILocalFileMac> file = do_QueryInterface(aFile); + MOZ_ASSERT(file); + + if (nsresult rv = file->SetXAttr(aAttr, aValue); NS_FAILED(rv)) { + return Err(IOError(rv).WithMessage( + "Could not set extended attribute `%s' on file `%s'", aAttr.get(), + aFile->HumanReadablePath().get())); + } + + return Ok{}; +} + +/* static */ +Result<Ok, IOUtils::IOError> IOUtils::DelMacXAttrSync(nsIFile* aFile, + const nsCString& aAttr) { + MOZ_ASSERT(!NS_IsMainThread()); + + nsCOMPtr<nsILocalFileMac> file = do_QueryInterface(aFile); + MOZ_ASSERT(file); + + if (nsresult rv = file->DelXAttr(aAttr); NS_FAILED(rv)) { + auto err = IOError(rv); + + if (rv == NS_ERROR_NOT_AVAILABLE) { + return Err(err.WithMessage( + "The file `%s' does not have an extended attribute `%s'", + aFile->HumanReadablePath().get(), aAttr.get())); + } + + return Err(IOError(rv).WithMessage( + "Could not delete extended attribute `%s' on file `%s'", aAttr.get(), + aFile->HumanReadablePath().get())); + } + + return Ok{}; +} + +#endif + +/* static */ +void IOUtils::GetProfileBeforeChange(GlobalObject& aGlobal, + JS::MutableHandle<JS::Value> aClient, + ErrorResult& aRv) { + return GetShutdownClient(aGlobal, aClient, aRv, + ShutdownPhase::ProfileBeforeChange); +} + +/* static */ +void IOUtils::GetSendTelemetry(GlobalObject& aGlobal, + JS::MutableHandle<JS::Value> aClient, + ErrorResult& aRv) { + return GetShutdownClient(aGlobal, aClient, aRv, ShutdownPhase::SendTelemetry); +} + +/** + * Assert that the given phase has a shutdown client exposed by IOUtils + * + * There is no shutdown client exposed for XpcomWillShutdown. + */ +static void AssertHasShutdownClient(const IOUtils::ShutdownPhase aPhase) { + MOZ_RELEASE_ASSERT(aPhase >= IOUtils::ShutdownPhase::ProfileBeforeChange && + aPhase < IOUtils::ShutdownPhase::XpcomWillShutdown); +} + +/* static */ +void IOUtils::GetShutdownClient(GlobalObject& aGlobal, + JS::MutableHandle<JS::Value> aClient, + ErrorResult& aRv, + const IOUtils::ShutdownPhase aPhase) { + MOZ_RELEASE_ASSERT(XRE_IsParentProcess()); + MOZ_RELEASE_ASSERT(NS_IsMainThread()); + AssertHasShutdownClient(aPhase); + + if (auto state = GetState()) { + MOZ_RELEASE_ASSERT(state.ref()->mBlockerStatus != + ShutdownBlockerStatus::Uninitialized); + + if (state.ref()->mBlockerStatus == ShutdownBlockerStatus::Failed) { + aRv.ThrowAbortError("IOUtils: could not register shutdown blockers"); + return; + } + + MOZ_RELEASE_ASSERT(state.ref()->mBlockerStatus == + ShutdownBlockerStatus::Initialized); + auto result = state.ref()->mEventQueue->GetShutdownClient(aPhase); + if (result.isErr()) { + aRv.ThrowAbortError("IOUtils: could not get shutdown client"); + return; + } + + RefPtr<nsIAsyncShutdownClient> client = result.unwrap(); + MOZ_RELEASE_ASSERT(client); + if (nsresult rv = client->GetJsclient(aClient); NS_FAILED(rv)) { + aRv.ThrowAbortError("IOUtils: Could not get shutdown jsclient"); + } + return; + } + + aRv.ThrowAbortError( + "IOUtils: profileBeforeChange phase has already finished"); +} + +/* sstatic */ +Maybe<IOUtils::StateMutex::AutoLock> IOUtils::GetState() { + auto state = sState.Lock(); + if (state->mQueueStatus == EventQueueStatus::Shutdown) { + return Nothing{}; + } + + if (state->mQueueStatus == EventQueueStatus::Uninitialized) { + MOZ_RELEASE_ASSERT(!state->mEventQueue); + state->mEventQueue = new EventQueue(); + state->mQueueStatus = EventQueueStatus::Initialized; + + MOZ_RELEASE_ASSERT(state->mBlockerStatus == + ShutdownBlockerStatus::Uninitialized); + } + + if (NS_IsMainThread() && + state->mBlockerStatus == ShutdownBlockerStatus::Uninitialized) { + state->SetShutdownHooks(); + } + + return Some(std::move(state)); +} + +IOUtils::EventQueue::EventQueue() { + MOZ_ALWAYS_SUCCEEDS(NS_CreateBackgroundTaskQueue( + "IOUtils::EventQueue", getter_AddRefs(mBackgroundEventTarget))); + + MOZ_RELEASE_ASSERT(mBackgroundEventTarget); +} + +void IOUtils::State::SetShutdownHooks() { + if (mBlockerStatus != ShutdownBlockerStatus::Uninitialized) { + return; + } + + if (NS_WARN_IF(NS_FAILED(mEventQueue->SetShutdownHooks()))) { + mBlockerStatus = ShutdownBlockerStatus::Failed; + } else { + mBlockerStatus = ShutdownBlockerStatus::Initialized; + } + + if (mBlockerStatus != ShutdownBlockerStatus::Initialized) { + NS_WARNING("IOUtils: could not register shutdown blockers."); + } +} + +nsresult IOUtils::EventQueue::SetShutdownHooks() { + MOZ_RELEASE_ASSERT(NS_IsMainThread()); + + constexpr static auto STACK = u"IOUtils::EventQueue::SetShutdownHooks"_ns; + constexpr static auto FILE = NS_LITERAL_STRING_FROM_CSTRING(__FILE__); + + nsCOMPtr<nsIAsyncShutdownService> svc = services::GetAsyncShutdownService(); + if (!svc) { + return NS_ERROR_NOT_AVAILABLE; + } + + nsCOMPtr<nsIAsyncShutdownBlocker> profileBeforeChangeBlocker; + + // Create a shutdown blocker for the profile-before-change phase. + { + profileBeforeChangeBlocker = + new IOUtilsShutdownBlocker(ShutdownPhase::ProfileBeforeChange); + + nsCOMPtr<nsIAsyncShutdownClient> globalClient; + MOZ_TRY(svc->GetProfileBeforeChange(getter_AddRefs(globalClient))); + MOZ_RELEASE_ASSERT(globalClient); + + MOZ_TRY(globalClient->AddBlocker(profileBeforeChangeBlocker, FILE, __LINE__, + STACK)); + } + + // Create the shutdown barrier for profile-before-change so that consumers can + // register shutdown blockers. + // + // The blocker we just created will wait for all clients registered on this + // barrier to finish. + { + nsCOMPtr<nsIAsyncShutdownBarrier> barrier; + + // It is okay for this to fail. The created shutdown blocker won't await + // anything and shutdown will proceed. + MOZ_TRY(svc->MakeBarrier( + u"IOUtils: waiting for profileBeforeChange IO to complete"_ns, + getter_AddRefs(barrier))); + MOZ_RELEASE_ASSERT(barrier); + + mBarriers[ShutdownPhase::ProfileBeforeChange] = std::move(barrier); + } + + // Create a shutdown blocker for the profile-before-change-telemetry phase. + nsCOMPtr<nsIAsyncShutdownBlocker> sendTelemetryBlocker; + { + sendTelemetryBlocker = + new IOUtilsShutdownBlocker(ShutdownPhase::SendTelemetry); + + nsCOMPtr<nsIAsyncShutdownClient> globalClient; + MOZ_TRY(svc->GetSendTelemetry(getter_AddRefs(globalClient))); + MOZ_RELEASE_ASSERT(globalClient); + + MOZ_TRY( + globalClient->AddBlocker(sendTelemetryBlocker, FILE, __LINE__, STACK)); + } + + // Create the shutdown barrier for profile-before-change-telemetry so that + // consumers can register shutdown blockers. + // + // The blocker we just created will wait for all clients registered on this + // barrier to finish. + { + nsCOMPtr<nsIAsyncShutdownBarrier> barrier; + + MOZ_TRY(svc->MakeBarrier( + u"IOUtils: waiting for sendTelemetry IO to complete"_ns, + getter_AddRefs(barrier))); + MOZ_RELEASE_ASSERT(barrier); + + // Add a blocker on the previous shutdown phase. + nsCOMPtr<nsIAsyncShutdownClient> client; + MOZ_TRY(barrier->GetClient(getter_AddRefs(client))); + + MOZ_TRY( + client->AddBlocker(profileBeforeChangeBlocker, FILE, __LINE__, STACK)); + + mBarriers[ShutdownPhase::SendTelemetry] = std::move(barrier); + } + + // Create a shutdown blocker for the xpcom-will-shutdown phase. + { + nsCOMPtr<nsIAsyncShutdownClient> globalClient; + MOZ_TRY(svc->GetXpcomWillShutdown(getter_AddRefs(globalClient))); + MOZ_RELEASE_ASSERT(globalClient); + + nsCOMPtr<nsIAsyncShutdownBlocker> blocker = + new IOUtilsShutdownBlocker(ShutdownPhase::XpcomWillShutdown); + MOZ_TRY(globalClient->AddBlocker( + blocker, FILE, __LINE__, u"IOUtils::EventQueue::SetShutdownHooks"_ns)); + } + + // Create a shutdown barrier for the xpcom-will-shutdown phase. + // + // The blocker we just created will wait for all clients registered on this + // barrier to finish. + // + // The only client registered on this barrier should be a blocker for the + // previous phase. This is to ensure that all shutdown IO happens when + // shutdown phases do not happen (e.g., in xpcshell tests where + // profile-before-change does not occur). + { + nsCOMPtr<nsIAsyncShutdownBarrier> barrier; + + MOZ_TRY(svc->MakeBarrier( + u"IOUtils: waiting for xpcomWillShutdown IO to complete"_ns, + getter_AddRefs(barrier))); + MOZ_RELEASE_ASSERT(barrier); + + // Add a blocker on the previous shutdown phase. + nsCOMPtr<nsIAsyncShutdownClient> client; + MOZ_TRY(barrier->GetClient(getter_AddRefs(client))); + + client->AddBlocker(sendTelemetryBlocker, FILE, __LINE__, + u"IOUtils::EventQueue::SetShutdownHooks"_ns); + + mBarriers[ShutdownPhase::XpcomWillShutdown] = std::move(barrier); + } + + return NS_OK; +} + +template <typename OkT, typename Fn> +RefPtr<IOUtils::IOPromise<OkT>> IOUtils::EventQueue::Dispatch(Fn aFunc) { + MOZ_RELEASE_ASSERT(mBackgroundEventTarget); + + auto promise = + MakeRefPtr<typename IOUtils::IOPromise<OkT>::Private>(__func__); + mBackgroundEventTarget->Dispatch( + NS_NewRunnableFunction("IOUtils::EventQueue::Dispatch", + [promise, func = std::move(aFunc)] { + Result<OkT, IOError> result = func(); + if (result.isErr()) { + promise->Reject(result.unwrapErr(), __func__); + } else { + promise->Resolve(result.unwrap(), __func__); + } + }), + NS_DISPATCH_EVENT_MAY_BLOCK); + return promise; +}; + +Result<already_AddRefed<nsIAsyncShutdownBarrier>, nsresult> +IOUtils::EventQueue::GetShutdownBarrier(const IOUtils::ShutdownPhase aPhase) { + if (!mBarriers[aPhase]) { + return Err(NS_ERROR_NOT_AVAILABLE); + } + + return do_AddRef(mBarriers[aPhase]); +} + +Result<already_AddRefed<nsIAsyncShutdownClient>, nsresult> +IOUtils::EventQueue::GetShutdownClient(const IOUtils::ShutdownPhase aPhase) { + AssertHasShutdownClient(aPhase); + + if (!mBarriers[aPhase]) { + return Err(NS_ERROR_NOT_AVAILABLE); + } + + nsCOMPtr<nsIAsyncShutdownClient> client; + MOZ_TRY(mBarriers[aPhase]->GetClient(getter_AddRefs(client))); + + return do_AddRef(client); +} + +/* static */ +Result<nsTArray<uint8_t>, IOUtils::IOError> IOUtils::MozLZ4::Compress( + Span<const uint8_t> aUncompressed) { + nsTArray<uint8_t> result; + size_t worstCaseSize = + Compression::LZ4::maxCompressedSize(aUncompressed.Length()) + HEADER_SIZE; + if (!result.SetCapacity(worstCaseSize, fallible)) { + return Err(IOError(NS_ERROR_OUT_OF_MEMORY) + .WithMessage("Could not allocate buffer to compress data")); + } + result.AppendElements(Span(MAGIC_NUMBER.data(), MAGIC_NUMBER.size())); + std::array<uint8_t, sizeof(uint32_t)> contentSizeBytes{}; + LittleEndian::writeUint32(contentSizeBytes.data(), aUncompressed.Length()); + result.AppendElements(Span(contentSizeBytes.data(), contentSizeBytes.size())); + + if (aUncompressed.Length() == 0) { + // Don't try to compress an empty buffer. + // Just return the correctly formed header. + result.SetLength(HEADER_SIZE); + return result; + } + + size_t compressed = Compression::LZ4::compress( + reinterpret_cast<const char*>(aUncompressed.Elements()), + aUncompressed.Length(), + reinterpret_cast<char*>(result.Elements()) + HEADER_SIZE); + if (!compressed) { + return Err( + IOError(NS_ERROR_UNEXPECTED).WithMessage("Could not compress data")); + } + result.SetLength(HEADER_SIZE + compressed); + return result; +} + +/* static */ +Result<IOUtils::JsBuffer, IOUtils::IOError> IOUtils::MozLZ4::Decompress( + Span<const uint8_t> aFileContents, IOUtils::BufferKind aBufferKind) { + if (aFileContents.LengthBytes() < HEADER_SIZE) { + return Err( + IOError(NS_ERROR_FILE_CORRUPTED) + .WithMessage( + "Could not decompress file because the buffer is too short")); + } + auto header = aFileContents.To(HEADER_SIZE); + if (!std::equal(std::begin(MAGIC_NUMBER), std::end(MAGIC_NUMBER), + std::begin(header))) { + nsCString magicStr; + uint32_t i = 0; + for (; i < header.Length() - 1; ++i) { + magicStr.AppendPrintf("%02X ", header.at(i)); + } + magicStr.AppendPrintf("%02X", header.at(i)); + + return Err(IOError(NS_ERROR_FILE_CORRUPTED) + .WithMessage("Could not decompress file because it has an " + "invalid LZ4 header (wrong magic number: '%s')", + magicStr.get())); + } + size_t numBytes = sizeof(uint32_t); + Span<const uint8_t> sizeBytes = header.Last(numBytes); + uint32_t expectedDecompressedSize = + LittleEndian::readUint32(sizeBytes.data()); + if (expectedDecompressedSize == 0) { + return JsBuffer::CreateEmpty(aBufferKind); + } + auto contents = aFileContents.From(HEADER_SIZE); + auto result = JsBuffer::Create(aBufferKind, expectedDecompressedSize); + if (result.isErr()) { + return result.propagateErr(); + } + + JsBuffer decompressed = result.unwrap(); + size_t actualSize = 0; + if (!Compression::LZ4::decompress( + reinterpret_cast<const char*>(contents.Elements()), contents.Length(), + reinterpret_cast<char*>(decompressed.Elements()), + expectedDecompressedSize, &actualSize)) { + return Err( + IOError(NS_ERROR_FILE_CORRUPTED) + .WithMessage( + "Could not decompress file contents, the file may be corrupt")); + } + decompressed.SetLength(actualSize); + return decompressed; +} + +NS_IMPL_ISUPPORTS(IOUtilsShutdownBlocker, nsIAsyncShutdownBlocker, + nsIAsyncShutdownCompletionCallback); + +NS_IMETHODIMP IOUtilsShutdownBlocker::GetName(nsAString& aName) { + aName = u"IOUtils Blocker ("_ns; + aName.Append(PHASE_NAMES[mPhase]); + aName.Append(')'); + + return NS_OK; +} + +NS_IMETHODIMP IOUtilsShutdownBlocker::BlockShutdown( + nsIAsyncShutdownClient* aBarrierClient) { + using EventQueueStatus = IOUtils::EventQueueStatus; + using ShutdownPhase = IOUtils::ShutdownPhase; + + MOZ_RELEASE_ASSERT(NS_IsMainThread()); + + nsCOMPtr<nsIAsyncShutdownBarrier> barrier; + + { + auto state = IOUtils::sState.Lock(); + if (state->mQueueStatus == EventQueueStatus::Shutdown) { + // If the previous blockers have already run, then the event queue is + // already torn down and we have nothing to do. + + MOZ_RELEASE_ASSERT(mPhase == ShutdownPhase::XpcomWillShutdown); + MOZ_RELEASE_ASSERT(!state->mEventQueue); + + Unused << NS_WARN_IF(NS_FAILED(aBarrierClient->RemoveBlocker(this))); + mParentClient = nullptr; + + return NS_OK; + } + + MOZ_RELEASE_ASSERT(state->mEventQueue); + + mParentClient = aBarrierClient; + + barrier = state->mEventQueue->GetShutdownBarrier(mPhase).unwrapOr(nullptr); + } + + // We cannot barrier->Wait() while holding the mutex because it will lead to + // deadlock. + if (!barrier || NS_WARN_IF(NS_FAILED(barrier->Wait(this)))) { + // If we don't have a barrier, we still need to flush the IOUtils event + // queue and disable task submission. + // + // Likewise, if waiting on the barrier failed, we are going to make our best + // attempt to clean up. + Unused << Done(); + } + + return NS_OK; +} + +NS_IMETHODIMP IOUtilsShutdownBlocker::Done() { + using EventQueueStatus = IOUtils::EventQueueStatus; + using ShutdownPhase = IOUtils::ShutdownPhase; + + MOZ_RELEASE_ASSERT(NS_IsMainThread()); + + bool didFlush = false; + + { + auto state = IOUtils::sState.Lock(); + + if (state->mEventQueue) { + MOZ_RELEASE_ASSERT(state->mQueueStatus == EventQueueStatus::Initialized); + + // This method is called once we have served all shutdown clients. Now we + // flush the remaining IO queue. This ensures any straggling IO that was + // not part of the shutdown blocker finishes before we move to the next + // phase. + state->mEventQueue->Dispatch<Ok>([]() { return Ok{}; }) + ->Then(GetMainThreadSerialEventTarget(), __func__, + [self = RefPtr(this)]() { self->OnFlush(); }); + + // And if we're the last shutdown phase to allow IO, disable the event + // queue to disallow further IO requests. + if (mPhase >= LAST_IO_PHASE) { + state->mQueueStatus = EventQueueStatus::Shutdown; + } + + didFlush = true; + } + } + + // If we have already shut down the event loop, then call OnFlush to stop + // blocking our parent shutdown client. + if (!didFlush) { + MOZ_RELEASE_ASSERT(mPhase == ShutdownPhase::XpcomWillShutdown); + OnFlush(); + } + + return NS_OK; +} + +void IOUtilsShutdownBlocker::OnFlush() { + if (mParentClient) { + (void)NS_WARN_IF(NS_FAILED(mParentClient->RemoveBlocker(this))); + mParentClient = nullptr; + + // If we are past the last shutdown phase that allows IO, + // we can shutdown the event queue here because no additional IO requests + // will be allowed (see |Done()|). + if (mPhase >= LAST_IO_PHASE) { + auto state = IOUtils::sState.Lock(); + if (state->mEventQueue) { + state->mEventQueue = nullptr; + } + } + } +} + +NS_IMETHODIMP IOUtilsShutdownBlocker::GetState(nsIPropertyBag** aState) { + return NS_OK; +} + +Result<IOUtils::InternalWriteOpts, IOUtils::IOError> +IOUtils::InternalWriteOpts::FromBinding(const WriteOptions& aOptions) { + InternalWriteOpts opts; + opts.mFlush = aOptions.mFlush; + opts.mMode = aOptions.mMode; + + if (aOptions.mBackupFile.WasPassed()) { + opts.mBackupFile = new nsLocalFile(); + if (nsresult rv = PathUtils::InitFileWithPath(opts.mBackupFile, + aOptions.mBackupFile.Value()); + NS_FAILED(rv)) { + return Err(IOUtils::IOError(rv).WithMessage( + "Could not parse path of backupFile (%s)", + NS_ConvertUTF16toUTF8(aOptions.mBackupFile.Value()).get())); + } + } + + if (aOptions.mTmpPath.WasPassed()) { + opts.mTmpFile = new nsLocalFile(); + if (nsresult rv = PathUtils::InitFileWithPath(opts.mTmpFile, + aOptions.mTmpPath.Value()); + NS_FAILED(rv)) { + return Err(IOUtils::IOError(rv).WithMessage( + "Could not parse path of temp file (%s)", + NS_ConvertUTF16toUTF8(aOptions.mTmpPath.Value()).get())); + } + } + + opts.mCompress = aOptions.mCompress; + return opts; +} + +/* static */ +Result<IOUtils::JsBuffer, IOUtils::IOError> IOUtils::JsBuffer::Create( + IOUtils::BufferKind aBufferKind, size_t aCapacity) { + JsBuffer buffer(aBufferKind, aCapacity); + if (aCapacity != 0 && !buffer.mBuffer) { + return Err(IOError(NS_ERROR_OUT_OF_MEMORY) + .WithMessage("Could not allocate buffer")); + } + return buffer; +} + +/* static */ +IOUtils::JsBuffer IOUtils::JsBuffer::CreateEmpty( + IOUtils::BufferKind aBufferKind) { + JsBuffer buffer(aBufferKind, 0); + MOZ_RELEASE_ASSERT(buffer.mBuffer == nullptr); + return buffer; +} + +IOUtils::JsBuffer::JsBuffer(IOUtils::BufferKind aBufferKind, size_t aCapacity) + : mBufferKind(aBufferKind), mCapacity(aCapacity), mLength(0) { + if (mCapacity) { + if (aBufferKind == BufferKind::String) { + mBuffer = JS::UniqueChars( + js_pod_arena_malloc<char>(js::StringBufferArena, mCapacity)); + } else { + MOZ_RELEASE_ASSERT(aBufferKind == BufferKind::Uint8Array); + mBuffer = JS::UniqueChars( + js_pod_arena_malloc<char>(js::ArrayBufferContentsArena, mCapacity)); + } + } +} + +IOUtils::JsBuffer::JsBuffer(IOUtils::JsBuffer&& aOther) noexcept + : mBufferKind(aOther.mBufferKind), + mCapacity(aOther.mCapacity), + mLength(aOther.mLength), + mBuffer(std::move(aOther.mBuffer)) { + aOther.mCapacity = 0; + aOther.mLength = 0; +} + +IOUtils::JsBuffer& IOUtils::JsBuffer::operator=( + IOUtils::JsBuffer&& aOther) noexcept { + mBufferKind = aOther.mBufferKind; + mCapacity = aOther.mCapacity; + mLength = aOther.mLength; + mBuffer = std::move(aOther.mBuffer); + + // Invalidate aOther. + aOther.mCapacity = 0; + aOther.mLength = 0; + + return *this; +} + +/* static */ +JSString* IOUtils::JsBuffer::IntoString(JSContext* aCx, JsBuffer aBuffer) { + MOZ_RELEASE_ASSERT(aBuffer.mBufferKind == IOUtils::BufferKind::String); + + if (!aBuffer.mCapacity) { + return JS_GetEmptyString(aCx); + } + + if (IsAscii(aBuffer.BeginReading())) { + // If the string is just plain ASCII, then we can hand the buffer off to + // JavaScript as a Latin1 string (since ASCII is a subset of Latin1). + JS::UniqueLatin1Chars asLatin1( + reinterpret_cast<JS::Latin1Char*>(aBuffer.mBuffer.release())); + return JS_NewLatin1String(aCx, std::move(asLatin1), aBuffer.mLength); + } + + // If the string is encodable as Latin1, we need to deflate the string to a + // Latin1 string to accoutn for UTF-8 characters that are encoded as more than + // a single byte. + // + // Otherwise, the string contains characters outside Latin1 so we have to + // inflate to UTF-16. + return JS_NewStringCopyUTF8N( + aCx, JS::UTF8Chars(aBuffer.mBuffer.get(), aBuffer.mLength)); +} + +/* static */ +JSObject* IOUtils::JsBuffer::IntoUint8Array(JSContext* aCx, JsBuffer aBuffer) { + MOZ_RELEASE_ASSERT(aBuffer.mBufferKind == IOUtils::BufferKind::Uint8Array); + + if (!aBuffer.mCapacity) { + return JS_NewUint8Array(aCx, 0); + } + + char* rawBuffer = aBuffer.mBuffer.release(); + MOZ_RELEASE_ASSERT(rawBuffer); + JS::Rooted<JSObject*> arrayBuffer( + aCx, JS::NewArrayBufferWithContents(aCx, aBuffer.mLength, + reinterpret_cast<void*>(rawBuffer))); + + if (!arrayBuffer) { + // The array buffer does not take ownership of the data pointer unless + // creation succeeds. We are still on the hook to free it. + // + // aBuffer will be destructed at end of scope, but its destructor does not + // take into account |mCapacity| or |mLength|, so it is OK for them to be + // non-zero here with a null |mBuffer|. + js_free(rawBuffer); + return nullptr; + } + + return JS_NewUint8ArrayWithBuffer(aCx, arrayBuffer, 0, aBuffer.mLength); +} + +[[nodiscard]] bool ToJSValue(JSContext* aCx, IOUtils::JsBuffer&& aBuffer, + JS::MutableHandle<JS::Value> aValue) { + if (aBuffer.mBufferKind == IOUtils::BufferKind::String) { + JSString* str = IOUtils::JsBuffer::IntoString(aCx, std::move(aBuffer)); + if (!str) { + return false; + } + + aValue.setString(str); + return true; + } + + JSObject* array = IOUtils::JsBuffer::IntoUint8Array(aCx, std::move(aBuffer)); + if (!array) { + return false; + } + + aValue.setObject(*array); + return true; +} + +// SyncReadFile + +NS_IMPL_CYCLE_COLLECTING_ADDREF(SyncReadFile) +NS_IMPL_CYCLE_COLLECTING_RELEASE(SyncReadFile) + +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(SyncReadFile) + NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY + NS_INTERFACE_MAP_ENTRY(nsISupports) +NS_INTERFACE_MAP_END + +NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(SyncReadFile, mParent) + +SyncReadFile::SyncReadFile(nsISupports* aParent, + RefPtr<nsFileRandomAccessStream>&& aStream, + int64_t aSize) + : mParent(aParent), mStream(std::move(aStream)), mSize(aSize) { + MOZ_RELEASE_ASSERT(mSize >= 0); +} + +SyncReadFile::~SyncReadFile() = default; + +JSObject* SyncReadFile::WrapObject(JSContext* aCx, + JS::Handle<JSObject*> aGivenProto) { + return SyncReadFile_Binding::Wrap(aCx, this, aGivenProto); +} + +void SyncReadFile::ReadBytesInto(const Uint8Array& aDestArray, + const int64_t aOffset, ErrorResult& aRv) { + if (!mStream) { + return aRv.ThrowOperationError("SyncReadFile is closed"); + } + + aDestArray.ComputeState(); + + auto rangeEnd = CheckedInt64(aOffset) + aDestArray.Length(); + if (!rangeEnd.isValid()) { + return aRv.ThrowOperationError("Requested range overflows i64"); + } + + if (rangeEnd.value() > mSize) { + return aRv.ThrowOperationError( + "Requested range overflows SyncReadFile size"); + } + + uint32_t readLen{aDestArray.Length()}; + if (readLen == 0) { + return; + } + + if (nsresult rv = mStream->Seek(PR_SEEK_SET, aOffset); NS_FAILED(rv)) { + return aRv.ThrowOperationError( + FormatErrorMessage(rv, "Could not seek to position %lld", aOffset)); + } + + Span<char> toRead(reinterpret_cast<char*>(aDestArray.Data()), readLen); + + uint32_t totalRead = 0; + while (totalRead != readLen) { + // Read no more than INT32_MAX on each call to mStream->Read, otherwise it + // returns an error. + uint32_t bytesToReadThisChunk = + std::min<uint32_t>(readLen - totalRead, INT32_MAX); + + uint32_t bytesRead = 0; + if (nsresult rv = + mStream->Read(toRead.Elements(), bytesToReadThisChunk, &bytesRead); + NS_FAILED(rv)) { + return aRv.ThrowOperationError(FormatErrorMessage( + rv, "Encountered an unexpected error while reading file stream")); + } + if (bytesRead == 0) { + return aRv.ThrowOperationError( + "Reading stopped before the entire array was filled"); + } + totalRead += bytesRead; + toRead = toRead.From(bytesRead); + } +} + +void SyncReadFile::Close() { mStream = nullptr; } + +#ifdef XP_UNIX +namespace { + +static nsCString FromUnixString(const IOUtils::UnixString& aString) { + if (aString.IsUTF8String()) { + return aString.GetAsUTF8String(); + } + if (aString.IsUint8Array()) { + const auto& u8a = aString.GetAsUint8Array(); + u8a.ComputeState(); + // Cast to deal with char signedness + return nsCString(reinterpret_cast<const char*>(u8a.Data()), u8a.Length()); + } + MOZ_CRASH("unreachable"); +} + +} // namespace + +// static +uint32_t IOUtils::LaunchProcess(GlobalObject& aGlobal, + const Sequence<UnixString>& aArgv, + const LaunchOptions& aOptions, + ErrorResult& aRv) { + // The binding is worker-only, so should always be off-main-thread. + MOZ_ASSERT(!NS_IsMainThread()); + + // This generally won't work in child processes due to sandboxing. + AssertParentProcessWithCallerLocation(aGlobal); + + std::vector<std::string> argv; + base::LaunchOptions options; + + for (const auto& arg : aArgv) { + argv.push_back(FromUnixString(arg).get()); + } + + size_t envLen = aOptions.mEnvironment.Length(); + base::EnvironmentArray envp(new char*[envLen + 1]); + for (size_t i = 0; i < envLen; ++i) { + // EnvironmentArray is a UniquePtr instance which will `free` + // these strings. + envp[i] = strdup(FromUnixString(aOptions.mEnvironment[i]).get()); + } + envp[envLen] = nullptr; + options.full_env = std::move(envp); + + if (aOptions.mWorkdir.WasPassed()) { + options.workdir = FromUnixString(aOptions.mWorkdir.Value()).get(); + } + + if (aOptions.mFdMap.WasPassed()) { + for (const auto& fdItem : aOptions.mFdMap.Value()) { + options.fds_to_remap.push_back({fdItem.mSrc, fdItem.mDst}); + } + } + +# ifdef XP_MACOSX + options.disclaim = aOptions.mDisclaim; +# endif + + base::ProcessHandle pid; + static_assert(sizeof(pid) <= sizeof(uint32_t), + "WebIDL long should be large enough for a pid"); + Result<Ok, mozilla::ipc::LaunchError> err = + base::LaunchApp(argv, options, &pid); + if (err.isErr()) { + aRv.Throw(NS_ERROR_FAILURE); + return 0; + } + + MOZ_ASSERT(pid >= 0); + return static_cast<uint32_t>(pid); +} +#endif // XP_UNIX + +} // namespace mozilla::dom + +#undef REJECT_IF_INIT_PATH_FAILED |