gecko-dev/dom/quota/QuotaCommon.h
Chris Peterson af64df99e7 Bug 1769778 - Replace deprecated std::result_of_t with std::invoke_result_t. r=janv
std::result_of_t was deprecated in C++17 and removed in C++20.

https://en.cppreference.com/w/cpp/types/result_of

The pattern to replace std::result_of_t with std::invoke_result_t is:

-std::result_of_t<Func(ArgTypes)>
+std::invoke_result_t<Func, ArgTypes>

Differential Revision: https://phabricator.services.mozilla.com/D146593
2022-05-25 06:07:32 +00:00

1651 lines
64 KiB
C++

/* -*- 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/. */
#ifndef mozilla_dom_quota_quotacommon_h__
#define mozilla_dom_quota_quotacommon_h__
#include "mozilla/dom/quota/Config.h"
#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <type_traits>
#include <utility>
#include "mozIStorageStatement.h"
#include "mozilla/Assertions.h"
#include "mozilla/Atomics.h"
#include "mozilla/Attributes.h"
#include "mozilla/Likely.h"
#include "mozilla/MacroArgs.h"
#include "mozilla/Maybe.h"
#include "mozilla/Result.h"
#include "mozilla/ResultExtensions.h"
#if defined(QM_LOG_ERROR_ENABLED) && defined(QM_ERROR_STACKS_ENABLED)
# include "mozilla/Variant.h"
#endif
#include "mozilla/dom/QMResult.h"
#include "mozilla/dom/quota/FirstInitializationAttemptsImpl.h"
#include "mozilla/dom/quota/RemoveParen.h"
#include "mozilla/dom/quota/ScopedLogExtraInfo.h"
#include "mozilla/ipc/ProtocolUtils.h"
#include "nsCOMPtr.h"
#include "nsDebug.h"
#include "nsError.h"
#include "nsIDirectoryEnumerator.h"
#include "nsIEventTarget.h"
#include "nsIFile.h"
#include "nsLiteralString.h"
#include "nsPrintfCString.h"
#include "nsReadableUtils.h"
#include "nsString.h"
#include "nsTArray.h"
#include "nsTLiteralString.h"
namespace mozilla {
template <typename T>
class NotNull;
}
#define MOZ_ADD_ARGS2(...) , ##__VA_ARGS__
#define MOZ_ADD_ARGS(...) MOZ_ADD_ARGS2(__VA_ARGS__)
// Proper use of unique variable names can be tricky (especially if nesting of
// the final macro is required).
// See https://lifecs.likai.org/2016/07/c-preprocessor-hygienic-macros.html
#define MOZ_UNIQUE_VAR(base) MOZ_CONCAT(base, __COUNTER__)
// See https://florianjw.de/en/passing_overloaded_functions.html
// TODO: Add a test for this macro.
#define MOZ_SELECT_OVERLOAD(func) \
[](auto&&... aArgs) -> decltype(auto) { \
return func(std::forward<decltype(aArgs)>(aArgs)...); \
}
#define DSSTORE_FILE_NAME ".DS_Store"
#define DESKTOP_FILE_NAME ".desktop"
#define DESKTOP_INI_FILE_NAME "desktop.ini"
#define THUMBS_DB_FILE_NAME "thumbs.db"
#define QM_WARNING(...) \
do { \
nsPrintfCString str(__VA_ARGS__); \
mozilla::dom::quota::ReportInternalError(__FILE__, __LINE__, str.get()); \
NS_WARNING(str.get()); \
} while (0)
#define QM_LOG_TEST() MOZ_LOG_TEST(GetQuotaManagerLogger(), LogLevel::Info)
#define QM_LOG(_args) MOZ_LOG(GetQuotaManagerLogger(), LogLevel::Info, _args)
#define UNKNOWN_FILE_WARNING(_leafName) \
NS_WARNING( \
nsPrintfCString("Something (%s) in the directory that doesn't belong!", \
NS_ConvertUTF16toUTF8(_leafName).get()) \
.get())
// This macro should be used in directory traversals for files or directories
// that are unknown for given directory traversal. It should only be called
// after all known (directory traversal specific) files or directories have
// been checked and handled.
// XXX Consider renaming the macro to QM_LOG_UNKNOWN_DIR_ENTRY.
#ifdef DEBUG
# define WARN_IF_FILE_IS_UNKNOWN(_file) \
mozilla::dom::quota::WarnIfFileIsUnknown(_file, __FILE__, __LINE__)
#else
# define WARN_IF_FILE_IS_UNKNOWN(_file) Result<bool, nsresult>(false)
#endif
/**
* There are multiple ways to handle unrecoverable conditions (note that the
* patterns are put in reverse chronological order and only the first pattern
* QM_TRY/QM_TRY_UNWRAP/QM_TRY_INSPECT/QM_TRY_RETURN/QM_FAIL should be used in
* new code):
*
* 1. Using QM_TRY/QM_TRY_UNWRAP/QM_TRY_INSPECT/QM_TRY_RETURN/QM_FAIL macros
* (Quota manager specific, defined below)
*
* Typical use cases:
*
* nsresult MyFunc1(nsIFile& aFile) {
* bool exists;
* QM_TRY(aFile.Exists(&exists));
* QM_TRY(OkIf(exists), NS_ERROR_FAILURE);
*
* // The file exists, and data could be read from it here.
*
* return NS_OK;
* }
*
* nsresult MyFunc2(nsIFile& aFile) {
* bool exists;
* QM_TRY(aFile.Exists(&exists), NS_ERROR_UNEXPECTED);
* QM_TRY(OkIf(exists), NS_ERROR_UNEXPECTED);
*
* // The file exists, and data could be read from it here.
*
* return NS_OK;
* }
*
* void MyFunc3(nsIFile& aFile) {
* bool exists;
* QM_TRY(aFile.Exists(&exists), QM_VOID);
* QM_TRY(OkIf(exists), QM_VOID);
*
* // The file exists, and data could be read from it here.
* }
*
* nsresult MyFunc4(nsIFile& aFile) {
* bool exists;
* QM_TRY(storageFile->Exists(&exists), QM_PROPAGATE,
* []() { NS_WARNING("The Exists call failed!"); });
* QM_TRY(OkIf(exists), NS_ERROR_FAILURE,
* []() { NS_WARNING("The file doesn't exist!"); });
*
* // The file exists, and data could be read from it here.
*
* return NS_OK;
* }
*
* nsresult MyFunc5(nsIFile& aFile) {
* bool exists;
* QM_TRY(aFile.Exists(&exists));
* if (exists) {
* // The file exists, and data could be read from it here.
* } else {
* QM_FAIL(NS_ERROR_FAILURE);
* }
*
* return NS_OK;
* }
*
* nsresult MyFunc6(nsIFile& aFile) {
* bool exists;
* QM_TRY(aFile.Exists(&exists));
* if (exists) {
* // The file exists, and data could be read from it here.
* } else {
* QM_FAIL(NS_ERROR_FAILURE,
* []() { NS_WARNING("The file doesn't exist!"); });
* }
*
* return NS_OK;
* }
*
* 2. Using MOZ_TRY/MOZ_TRY_VAR macros
*
* Typical use cases:
*
* nsresult MyFunc1(nsIFile& aFile) {
* // MOZ_TRY can't return a custom return value
*
* return NS_OK;
* }
*
* nsresult MyFunc2(nsIFile& aFile) {
* // MOZ_TRY can't return a custom return value
*
* return NS_OK;
* }
*
* void MyFunc3(nsIFile& aFile) {
* // MOZ_TRY can't return a custom return value, "void" in this case
* }
*
* nsresult MyFunc4(nsIFile& aFile) {
* // MOZ_TRY can't return a custom return value and run an additional
* // cleanup function
*
* return NS_OK;
* }
*
* nsresult MyFunc5(nsIFile& aFile) {
* // There's no MOZ_FAIL, MOZ_TRY can't return a custom return value
*
* return NS_OK;
* }
*
* nsresult MyFunc6(nsIFile& aFile) {
* // There's no MOZ_FAIL, MOZ_TRY can't return a custom return value and run
* // an additional cleanup function
*
* return NS_OK;
* }
*
* 3. Using NS_WARN_IF and NS_WARNING macro with own control flow handling
*
* Typical use cases:
*
* nsresult MyFunc1(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* if (NS_WARN_IF(NS_FAILED(rv)) {
* return rv;
* }
* if (NS_WARN_IF(!exists) {
* return NS_ERROR_FAILURE;
* }
*
* // The file exists, and data could be read from it here.
*
* return NS_OK;
* }
*
* nsresult MyFunc2(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* if (NS_WARN_IF(NS_FAILED(rv)) {
* return NS_ERROR_UNEXPECTED;
* }
* if (NS_WARN_IF(!exists) {
* return NS_ERROR_UNEXPECTED;
* }
*
* // The file exists, and data could be read from it here.
*
* return NS_OK;
* }
*
* void MyFunc3(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* if (NS_WARN_IF(NS_FAILED(rv)) {
* return;
* }
* if (NS_WARN_IF(!exists) {
* return;
* }
*
* // The file exists, and data could be read from it here.
* }
*
* nsresult MyFunc4(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* if (NS_WARN_IF(NS_FAILED(rv)) {
* NS_WARNING("The Exists call failed!");
* return rv;
* }
* if (NS_WARN_IF(!exists) {
* NS_WARNING("The file doesn't exist!");
* return NS_ERROR_FAILURE;
* }
*
* // The file exists, and data could be read from it here.
*
* return NS_OK;
* }
*
* nsresult MyFunc5(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* if (NS_WARN_IF(NS_FAILED(rv)) {
* return rv;
* }
* if (exists) {
* // The file exists, and data could be read from it here.
* } else {
* return NS_ERROR_FAILURE;
* }
*
* return NS_OK;
* }
*
* nsresult MyFunc6(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* if (NS_WARN_IF(NS_FAILED(rv)) {
* return rv;
* }
* if (exists) {
* // The file exists, and data could be read from it here.
* } else {
* NS_WARNING("The file doesn't exist!");
* return NS_ERROR_FAILURE;
* }
*
* return NS_OK;
* }
*
* 4. Using NS_ENSURE_* macros
*
* Mainly:
* - NS_ENSURE_SUCCESS
* - NS_ENSURE_SUCCESS_VOID
* - NS_ENSURE_TRUE
* - NS_ENSURE_TRUE_VOID
*
* Typical use cases:
*
* nsresult MyFunc1(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* NS_ENSURE_SUCCESS(rv, rv);
* NS_ENSURE_TRUE(exists, NS_ERROR_FAILURE);
*
* // The file exists, and data could be read from it here.
*
* return NS_OK;
* }
*
* nsresult MyFunc2(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* NS_ENSURE_SUCCESS(rv, NS_ERROR_UNEXPECTED);
* NS_ENSURE_TRUE(exists, NS_ERROR_UNEXPECTED);
*
* // The file exists, and data could be read from it here.
*
* return NS_OK;
* }
*
* void MyFunc3(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* NS_ENSURE_SUCCESS_VOID(rv);
* NS_ENSURE_TRUE_VOID(exists);
*
* // The file exists, and data could be read from it here.
* }
*
* nsresult MyFunc4(nsIFile& aFile) {
* // NS_ENSURE_SUCCESS/NS_ENSURE_TRUE can't run an additional cleanup
* // function
*
* return NS_OK;
* }
*
* nsresult MyFunc5(nsIFile& aFile) {
* bool exists;
* nsresult rv = aFile.Exists(&exists);
* NS_ENSURE_SUCCESS(rv, rv);
* if (exists) {
* // The file exists, and data could be read from it here.
* } else {
* NS_ENSURE_TRUE(false, NS_ERROR_FAILURE);
* }
*
* return NS_OK;
* }
*
* nsresult MyFunc6(nsIFile& aFile) {
* // NS_ENSURE_TRUE can't run an additional cleanup function
*
* return NS_OK;
* }
*
* QM_TRY/QM_TRY_UNWRAP/QM_TRY_INSPECT is like MOZ_TRY/MOZ_TRY_VAR but if an
* error occurs it additionally calls a generic function HandleError to handle
* the error and it can be used to return custom return values as well and even
* call an additional cleanup function.
* HandleError currently only warns in debug builds, it will report to the
* browser console and telemetry in the future.
* The other advantage of QM_TRY/QM_TRY_UNWRAP/QM_TRY_INSPECT is that a local
* nsresult is not needed at all in all cases, all calls can be wrapped
* directly. If an error occurs, the warning contains a concrete call instead
* of the rv local variable. For example:
*
* 1. WARNING: NS_ENSURE_SUCCESS(rv, rv) failed with result 0x80004005
* (NS_ERROR_FAILURE): file XYZ, line N
*
* 2. WARNING: 'NS_FAILED(rv)', file XYZ, line N
*
* 3. Nothing (MOZ_TRY doesn't warn)
*
* 4. WARNING: Error: 'aFile.Exists(&exists)', file XYZ, line N
*
* QM_TRY_RETURN is a supplementary macro for cases when the result's success
* value can be directly returned (instead of assigning to a variable as in the
* QM_TRY_UNWRAP/QM_TRY_INSPECT case).
*
* QM_FAIL is a supplementary macro for cases when an error needs to be
* returned without evaluating an expression. It's possible to write
* QM_TRY(OkIf(false), NS_ERROR_FAILURE), but QM_FAIL(NS_ERROR_FAILURE) looks
* more straightforward.
*
* It's highly recommended to use
* QM_TRY/QM_TRY_UNWRAP/QM_TRY_INSPECT/QM_TRY_RETURN/QM_FAIL in new code for
* quota manager and quota clients. Existing code should be incrementally
* converted as needed.
*
* QM_TRY_VOID/QM_TRY_UNWRAP_VOID/QM_TRY_INSPECT_VOID/QM_FAIL_VOID is not
* defined on purpose since it's possible to use
* QM_TRY/QM_TRY_UNWRAP/QM_TRY_INSPECT/QM_FAIL even in void functions.
* However, QM_TRY(Task(), ) would look odd so it's recommended to use a dummy
* define QM_VOID that evaluates to nothing instead: QM_TRY(Task(), QM_VOID)
*/
#define QM_VOID
#define QM_PROPAGATE Err(tryTempError)
#define QM_IPC_FAIL(actor) \
[&_actor = *actor](const char* aFunc, const char* aExpr) { \
return Err( \
mozilla::ipc::IPCResult::Fail(WrapNotNull(&_actor), aFunc, aExpr)); \
}
#ifdef DEBUG
# define QM_ASSERT_UNREACHABLE \
[](const char*, const char*) -> ::mozilla::GenericErrorResult<nsresult> { \
MOZ_CRASH("Should never be reached."); \
}
# define QM_ASSERT_UNREACHABLE_VOID \
[](const char*, const char*) { MOZ_CRASH("Should never be reached."); }
#endif
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
# define QM_DIAGNOSTIC_ASSERT_UNREACHABLE \
[](const char*, const char*) -> ::mozilla::GenericErrorResult<nsresult> { \
MOZ_CRASH("Should never be reached."); \
}
# define QM_DIAGNOSTIC_ASSERT_UNREACHABLE_VOID \
[](const char*, const char*) { MOZ_CRASH("Should never be reached."); }
#endif
// QM_MISSING_ARGS and QM_HANDLE_ERROR macros are implementation details of
// QM_TRY/QM_TRY_UNWRAP/QM_TRY_INSPECT/QM_FAIL and shouldn't be used directly.
#define QM_MISSING_ARGS(...) \
do { \
static_assert(false, "Did you forget arguments?"); \
} while (0)
#ifdef DEBUG
# define QM_HANDLE_ERROR(expr, error, severity) \
HandleError(#expr, error, __FILE__, __LINE__, severity)
#else
# define QM_HANDLE_ERROR(expr, error, severity) \
HandleError("Unavailable", error, __FILE__, __LINE__, severity)
#endif
#ifdef DEBUG
# define QM_HANDLE_ERROR_RETURN_NOTHING(expr, error, severity) \
HandleErrorReturnNothing(#expr, error, __FILE__, __LINE__, severity)
#else
# define QM_HANDLE_ERROR_RETURN_NOTHING(expr, error, severity) \
HandleErrorReturnNothing("Unavailable", error, __FILE__, __LINE__, severity)
#endif
#ifdef DEBUG
# define QM_HANDLE_ERROR_WITH_CLEANUP_RETURN_NOTHING(expr, error, severity, \
cleanup) \
HandleErrorWithCleanupReturnNothing(#expr, error, __FILE__, __LINE__, \
severity, cleanup)
#else
# define QM_HANDLE_ERROR_WITH_CLEANUP_RETURN_NOTHING(expr, error, severity, \
cleanup) \
HandleErrorWithCleanupReturnNothing("Unavailable", error, __FILE__, \
__LINE__, severity, cleanup)
#endif
// Handles the case when QM_VOID is passed as a custom return value.
#define QM_HANDLE_CUSTOM_RET_VAL_HELPER0(func, expr)
#define QM_HANDLE_CUSTOM_RET_VAL_HELPER1(func, expr, customRetVal) \
mozilla::dom::quota::HandleCustomRetVal(func, #expr, customRetVal)
#define QM_HANDLE_CUSTOM_RET_VAL_GLUE(a, b) a b
#define QM_HANDLE_CUSTOM_RET_VAL(...) \
QM_HANDLE_CUSTOM_RET_VAL_GLUE( \
MOZ_PASTE_PREFIX_AND_ARG_COUNT(QM_HANDLE_CUSTOM_RET_VAL_HELPER, \
MOZ_ARGS_AFTER_2(__VA_ARGS__)), \
(MOZ_ARG_1(__VA_ARGS__), \
MOZ_ARG_2(__VA_ARGS__) MOZ_ADD_ARGS(MOZ_ARGS_AFTER_2(__VA_ARGS__))))
// QM_TRY_PROPAGATE_ERR, QM_TRY_CUSTOM_RET_VAL,
// QM_TRY_CUSTOM_RET_VAL_WITH_CLEANUP and QM_TRY_GLUE macros are implementation
// details of QM_TRY and shouldn't be used directly.
// Handles the two arguments case when the error is propagated.
#define QM_TRY_PROPAGATE_ERR(tryResult, expr) \
auto tryResult = (expr); \
static_assert(std::is_empty_v<typename decltype(tryResult)::ok_type>); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryResult.inspectErr(), mozilla::dom::quota::Severity::Error); \
return tryResult.propagateErr(); \
}
// Handles the three arguments case when a custom return value needs to be
// returned
#define QM_TRY_CUSTOM_RET_VAL(tryResult, expr, customRetVal) \
auto tryResult = (expr); \
static_assert(std::is_empty_v<typename decltype(tryResult)::ok_type>); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
auto tryTempError MOZ_MAYBE_UNUSED = tryResult.unwrapErr(); \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryTempError, mozilla::dom::quota::Severity::Error); \
constexpr const auto& func MOZ_MAYBE_UNUSED = __func__; \
return QM_HANDLE_CUSTOM_RET_VAL(func, expr, customRetVal); \
}
// Handles the four arguments case when a cleanup function needs to be called
// before a custom return value is returned
#define QM_TRY_CUSTOM_RET_VAL_WITH_CLEANUP(tryResult, expr, customRetVal, \
cleanup) \
auto tryResult = (expr); \
static_assert(std::is_empty_v<typename decltype(tryResult)::ok_type>); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
auto tryTempError = tryResult.unwrapErr(); \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryTempError, mozilla::dom::quota::Severity::Error); \
cleanup(tryTempError); \
constexpr const auto& func MOZ_MAYBE_UNUSED = __func__; \
return QM_HANDLE_CUSTOM_RET_VAL(func, expr, customRetVal); \
}
// Chooses the final implementation macro for given argument count.
// This could use MOZ_PASTE_PREFIX_AND_ARG_COUNT, but explicit named suffxes
// read slightly better than plain numbers.
// See also
// https://stackoverflow.com/questions/3046889/optional-parameters-with-c-macros
#define QM_TRY_META(...) \
{ \
MOZ_ARG_6( \
, ##__VA_ARGS__, QM_TRY_CUSTOM_RET_VAL_WITH_CLEANUP(__VA_ARGS__), \
QM_TRY_CUSTOM_RET_VAL(__VA_ARGS__), QM_TRY_PROPAGATE_ERR(__VA_ARGS__), \
QM_MISSING_ARGS(__VA_ARGS__), QM_MISSING_ARGS(__VA_ARGS__)) \
}
// Generates unique variable name. This extra internal macro (along with
// __COUNTER__) allows nesting of the final macro.
#define QM_TRY_GLUE(...) QM_TRY_META(MOZ_UNIQUE_VAR(tryResult), ##__VA_ARGS__)
/**
* QM_TRY(expr[, customRetVal, cleanup]) is the C++ equivalent of Rust's
* `try!(expr);`. First, it evaluates expr, which must produce a Result value
* with empty ok_type. On Success, it does nothing else. On error, it calls
* HandleError and an additional cleanup function (if the third argument was
* passed) and finally returns an error Result from the enclosing function or a
* custom return value (if the second argument was passed).
*/
#define QM_TRY(...) QM_TRY_GLUE(__VA_ARGS__)
// QM_TRY_ASSIGN_PROPAGATE_ERR, QM_TRY_ASSIGN_CUSTOM_RET_VAL,
// QM_TRY_ASSIGN_CUSTOM_RET_VAL_WITH_CLEANUP and QM_TRY_ASSIGN_GLUE macros are
// implementation details of QM_TRY_UNWRAP/QM_TRY_INSPECT and shouldn't be used
// directly.
// Handles the four arguments case when the error is propagated.
#define QM_TRY_ASSIGN_PROPAGATE_ERR(tryResult, accessFunction, target, expr) \
auto tryResult = (expr); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryResult.inspectErr(), mozilla::dom::quota::Severity::Error); \
return tryResult.propagateErr(); \
} \
MOZ_REMOVE_PAREN(target) = tryResult.accessFunction();
// Handles the five arguments case when a custom return value needs to be
// returned
#define QM_TRY_ASSIGN_CUSTOM_RET_VAL(tryResult, accessFunction, target, expr, \
customRetVal) \
auto tryResult = (expr); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
auto tryTempError MOZ_MAYBE_UNUSED = tryResult.unwrapErr(); \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryTempError, mozilla::dom::quota::Severity::Error); \
constexpr const auto& func MOZ_MAYBE_UNUSED = __func__; \
return QM_HANDLE_CUSTOM_RET_VAL(func, expr, customRetVal); \
} \
MOZ_REMOVE_PAREN(target) = tryResult.accessFunction();
// Handles the six arguments case when a cleanup function needs to be called
// before a custom return value is returned
#define QM_TRY_ASSIGN_CUSTOM_RET_VAL_WITH_CLEANUP( \
tryResult, accessFunction, target, expr, customRetVal, cleanup) \
auto tryResult = (expr); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
auto tryTempError = tryResult.unwrapErr(); \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryTempError, mozilla::dom::quota::Severity::Error); \
cleanup(tryTempError); \
constexpr const auto& func MOZ_MAYBE_UNUSED = __func__; \
return QM_HANDLE_CUSTOM_RET_VAL(func, expr, customRetVal); \
} \
MOZ_REMOVE_PAREN(target) = tryResult.accessFunction();
// Chooses the final implementation macro for given argument count.
// See also the comment for QM_TRY_META.
#define QM_TRY_ASSIGN_META(...) \
MOZ_ARG_8(, ##__VA_ARGS__, \
QM_TRY_ASSIGN_CUSTOM_RET_VAL_WITH_CLEANUP(__VA_ARGS__), \
QM_TRY_ASSIGN_CUSTOM_RET_VAL(__VA_ARGS__), \
QM_TRY_ASSIGN_PROPAGATE_ERR(__VA_ARGS__), \
QM_MISSING_ARGS(__VA_ARGS__), QM_MISSING_ARGS(__VA_ARGS__), \
QM_MISSING_ARGS(__VA_ARGS__), QM_MISSING_ARGS(__VA_ARGS__))
// Generates unique variable name. This extra internal macro (along with
// __COUNTER__) allows nesting of the final macro.
#define QM_TRY_ASSIGN_GLUE(accessFunction, ...) \
QM_TRY_ASSIGN_META(MOZ_UNIQUE_VAR(tryResult), accessFunction, ##__VA_ARGS__)
/**
* QM_TRY_UNWRAP(target, expr[, customRetVal, cleanup]) is the C++ equivalent of
* Rust's `target = try!(expr);`. First, it evaluates expr, which must produce
* a Result value. On success, the result's success value is unwrapped and
* assigned to target. On error, it calls HandleError and an additional cleanup
* function (if the fourth argument was passed) and finally returns the error
* result or a custom return value (if the third argument was passed). |target|
* must be an lvalue.
*/
#define QM_TRY_UNWRAP(...) QM_TRY_ASSIGN_GLUE(unwrap, __VA_ARGS__)
/**
* QM_TRY_INSPECT is similar to QM_TRY_UNWRAP, but it does not unwrap a success
* value, but inspects it and binds it to the target. It can therefore only be
* used when the target declares a const&. In general,
*
* QM_TRY_INSPECT(const auto &target, DoSomething())
*
* should be preferred over
*
* QM_TRY_UNWRAP(const auto target, DoSomething())
*
* as it avoids unnecessary moves/copies.
*/
#define QM_TRY_INSPECT(...) QM_TRY_ASSIGN_GLUE(inspect, __VA_ARGS__)
// QM_TRY_RETURN_PROPAGATE_ERR, QM_TRY_RETURN_CUSTOM_RET_VAL,
// QM_TRY_RETURN_CUSTOM_RET_VAL_WITH_CLEANUP and QM_TRY_RETURN_GLUE macros are
// implementation details of QM_TRY_RETURN and shouldn't be used directly.
// Handles the two arguments case when the error is (also) propagated.
// Note that this deliberately uses a single return statement without going
// through unwrap/unwrapErr/propagateErr, so that this does not prevent NRVO or
// tail call optimizations when possible.
#define QM_TRY_RETURN_PROPAGATE_ERR(tryResult, expr) \
auto tryResult = (expr); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryResult.inspectErr(), mozilla::dom::quota::Severity::Error); \
} \
return tryResult;
// Handles the three arguments case when a custom return value needs to be
// returned
#define QM_TRY_RETURN_CUSTOM_RET_VAL(tryResult, expr, customRetVal) \
auto tryResult = (expr); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
auto tryTempError MOZ_MAYBE_UNUSED = tryResult.unwrapErr(); \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryResult.inspectErr(), mozilla::dom::quota::Severity::Error); \
constexpr const auto& func MOZ_MAYBE_UNUSED = __func__; \
return QM_HANDLE_CUSTOM_RET_VAL(func, expr, customRetVal); \
} \
return tryResult.unwrap();
// Handles the four arguments case when a cleanup function needs to be called
// before a custom return value is returned
#define QM_TRY_RETURN_CUSTOM_RET_VAL_WITH_CLEANUP(tryResult, expr, \
customRetVal, cleanup) \
auto tryResult = (expr); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
auto tryTempError = tryResult.unwrapErr(); \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryTempError, mozilla::dom::quota::Severity::Error); \
cleanup(tryTempError); \
constexpr const auto& func MOZ_MAYBE_UNUSED = __func__; \
return QM_HANDLE_CUSTOM_RET_VAL(func, expr, customRetVal); \
} \
return tryResult.unwrap();
// Chooses the final implementation macro for given argument count.
// See also the comment for QM_TRY_META.
#define QM_TRY_RETURN_META(...) \
{ \
MOZ_ARG_6(, ##__VA_ARGS__, \
QM_TRY_RETURN_CUSTOM_RET_VAL_WITH_CLEANUP(__VA_ARGS__), \
QM_TRY_RETURN_CUSTOM_RET_VAL(__VA_ARGS__), \
QM_TRY_RETURN_PROPAGATE_ERR(__VA_ARGS__), \
QM_MISSING_ARGS(__VA_ARGS__), QM_MISSING_ARGS(__VA_ARGS__)) \
}
// Generates unique variable name. This extra internal macro (along with
// __COUNTER__) allows nesting of the final macro.
#define QM_TRY_RETURN_GLUE(...) \
QM_TRY_RETURN_META(MOZ_UNIQUE_VAR(tryResult), ##__VA_ARGS__)
/**
* QM_TRY_RETURN(expr[, customRetVal, cleanup]) evaluates expr, which must
* produce a Result value. On success, the result's success value is returned.
* On error, it calls HandleError and an additional cleanup function (if the
* third argument was passed) and finally returns the error result or a custom
* return value (if the second argument was passed).
*/
#define QM_TRY_RETURN(...) QM_TRY_RETURN_GLUE(__VA_ARGS__)
// QM_FAIL_RET_VAL and QM_FAIL_RET_VAL_WITH_CLEANUP macros are implementation
// details of QM_FAIL and shouldn't be used directly.
// Handles the one argument case when just an error is returned
#define QM_FAIL_RET_VAL(retVal) \
mozilla::dom::quota::QM_HANDLE_ERROR(Failure, 0, \
mozilla::dom::quota::Severity::Error); \
return retVal;
// Handles the two arguments case when a cleanup function needs to be called
// before a return value is returned
#define QM_FAIL_RET_VAL_WITH_CLEANUP(retVal, cleanup) \
mozilla::dom::quota::QM_HANDLE_ERROR(Failure, 0, \
mozilla::dom::quota::Severity::Error); \
cleanup(); \
return retVal;
// Chooses the final implementation macro for given argument count.
// See also the comment for QM_TRY_META.
#define QM_FAIL_META(...) \
MOZ_ARG_4(, ##__VA_ARGS__, QM_FAIL_RET_VAL_WITH_CLEANUP(__VA_ARGS__), \
QM_FAIL_RET_VAL(__VA_ARGS__), QM_MISSING_ARGS(__VA_ARGS__))
// This extra internal macro allows nesting of the final macro.
#define QM_FAIL_GLUE(...) QM_FAIL_META(__VA_ARGS__)
/**
* QM_FAIL(retVal[, cleanup]) calls HandleError and an additional cleanup
* function (if the second argument was passed) and returns a return value.
*/
#define QM_FAIL(...) QM_FAIL_GLUE(__VA_ARGS__)
// QM_REPORTONLY_TRY, QM_REPORTONLY_TRY_WITH_CLEANUP, QM_REPORTONLY_TRY_GLUE
// macros are implementation details of QM_WARNONLY_TRY/QM_INFOONLY_TRY and
// shouldn't be used directly.
// Handles the three arguments case when only a warning/info is reported.
#define QM_REPORTONLY_TRY(tryResult, severity, expr) \
auto tryResult = (expr); \
static_assert(std::is_empty_v<typename decltype(tryResult)::ok_type>); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryResult.unwrapErr(), mozilla::dom::quota::Severity::severity); \
}
// Handles the four arguments case when a cleanup function needs to be called
#define QM_REPORTONLY_TRY_WITH_CLEANUP(tryResult, severity, expr, cleanup) \
auto tryResult = (expr); \
static_assert(std::is_empty_v<typename decltype(tryResult)::ok_type>); \
if (MOZ_UNLIKELY(tryResult.isErr())) { \
auto tryTempError = tryResult.unwrapErr(); \
mozilla::dom::quota::QM_HANDLE_ERROR( \
expr, tryTempError, mozilla::dom::quota::Severity::severity); \
cleanup(tryTempError); \
}
// Chooses the final implementation macro for given argument count.
// See also the comment for QM_TRY_META.
#define QM_REPORTONLY_TRY_META(...) \
{ \
MOZ_ARG_6(, ##__VA_ARGS__, QM_REPORTONLY_TRY_WITH_CLEANUP(__VA_ARGS__), \
QM_REPORTONLY_TRY(__VA_ARGS__), QM_MISSING_ARGS(__VA_ARGS__), \
QM_MISSING_ARGS(__VA_ARGS__), QM_MISSING_ARGS(__VA_ARGS__)) \
}
// Generates unique variable name. This extra internal macro (along with
// __COUNTER__) allows nesting of the final macro.
#define QM_REPORTONLY_TRY_GLUE(severity, ...) \
QM_REPORTONLY_TRY_META(MOZ_UNIQUE_VAR(tryResult), severity, ##__VA_ARGS__)
/**
* QM_WARNONLY_TRY(expr[, cleanup]) evaluates expr, which must produce a
* Result value with empty ok_type. On Success, it does nothing else. On error,
* it calls HandleError and an additional cleanup function (if the second
* argument was passed). This macro never returns and failures are always
* reported using a lower level of severity relative to failures reported by
* QM_TRY. The macro is intended for failures that should not be propagated.
*/
#define QM_WARNONLY_TRY(...) QM_REPORTONLY_TRY_GLUE(Warning, __VA_ARGS__)
/**
* QM_INFOONLY_TRY is like QM_WARNONLY_TRY. The only difference is that
* failures are reported using a lower level of severity relative to failures
* reported by QM_WARNONLY_TRY.
*/
#define QM_INFOONLY_TRY(...) QM_REPORTONLY_TRY_GLUE(Info, __VA_ARGS__)
// QM_REPORTONLY_TRY_ASSIGN, QM_REPORTONLY_TRY_ASSIGN_WITH_CLEANUP,
// QM_REPORTONLY_TRY_ASSIGN_GLUE macros are implementation details of
// QM_WARNONLY_TRY_UNWRAP/QM_INFOONLY_TRY_UNWRAP and shouldn't be used
// directly.
// Handles the four arguments case when only a warning/info is reported.
#define QM_REPORTONLY_TRY_ASSIGN(tryResult, severity, target, expr) \
auto tryResult = (expr); \
MOZ_REMOVE_PAREN(target) = \
MOZ_LIKELY(tryResult.isOk()) \
? Some(tryResult.unwrap()) \
: mozilla::dom::quota::QM_HANDLE_ERROR_RETURN_NOTHING( \
expr, tryResult.unwrapErr(), \
mozilla::dom::quota::Severity::severity);
// Handles the five arguments case when a cleanup function needs to be called
#define QM_REPORTONLY_TRY_ASSIGN_WITH_CLEANUP(tryResult, severity, target, \
expr, cleanup) \
auto tryResult = (expr); \
MOZ_REMOVE_PAREN(target) = \
MOZ_LIKELY(tryResult.isOk()) \
? Some(tryResult.unwrap()) \
: mozilla::dom::quota::QM_HANDLE_ERROR_WITH_CLEANUP_RETURN_NOTHING( \
expr, tryResult.unwrapErr(), \
mozilla::dom::quota::Severity::severity, cleanup);
// Chooses the final implementation macro for given argument count.
// See also the comment for QM_TRY_META.
#define QM_REPORTONLY_TRY_ASSIGN_META(...) \
MOZ_ARG_7(, ##__VA_ARGS__, \
QM_REPORTONLY_TRY_ASSIGN_WITH_CLEANUP(__VA_ARGS__), \
QM_REPORTONLY_TRY_ASSIGN(__VA_ARGS__), \
QM_MISSING_ARGS(__VA_ARGS__), QM_MISSING_ARGS(__VA_ARGS__), \
QM_MISSING_ARGS(__VA_ARGS__), QM_MISSING_ARGS(__VA_ARGS__))
// Generates unique variable name. This extra internal macro (along with
// __COUNTER__) allows nesting of the final macro.
#define QM_REPORTONLY_TRY_ASSIGN_GLUE(severity, ...) \
QM_REPORTONLY_TRY_ASSIGN_META(MOZ_UNIQUE_VAR(tryResult), severity, \
##__VA_ARGS__)
/**
* QM_WARNONLY_TRY_UNWRAP(target, expr[, cleanup]) evaluates expr, which must
* produce a Result value. On success, the result's success value is first
* unwrapped from the Result, then wrapped in a Maybe and finally assigned to
* target. On error, it calls HandleError and an additional cleanup
* function (if the third argument was passed) and finally assigns Nothing to
* target. |target| must be an lvalue. This macro never returns and failures
* are always reported using a lower level of severity relative to failures
* reported by QM_TRY_UNWRAP/QM_TRY_INSPECT. The macro is intended for failures
* that should not be propagated.
*/
#define QM_WARNONLY_TRY_UNWRAP(...) \
QM_REPORTONLY_TRY_ASSIGN_GLUE(Warning, __VA_ARGS__)
// QM_WARNONLY_TRY_INSPECT doesn't make sense.
/**
* QM_INFOONLY_TRY_UNWRAP is like QM_WARNONLY_TRY_UNWRAP. The only difference is
* that failures are reported using a lower level of severity relative to
* failures reported by QM_WARNONLY_TRY_UNWRAP.
*/
#define QM_INFOONLY_TRY_UNWRAP(...) \
QM_REPORTONLY_TRY_ASSIGN_GLUE(Info, __VA_ARGS__)
// QM_INFOONLY_TRY_INSPECT doesn't make sense.
// QM_OR_ELSE_REPORT macro is an implementation detail of
// QM_OR_ELSE_WARN/QM_OR_ELSE_INFO/QM_OR_ELSE_LOG_VERBOSE and shouldn't be used
// directly.
#define QM_OR_ELSE_REPORT(severity, expr, fallback) \
(expr).orElse([&](const auto& firstRes) { \
mozilla::dom::quota::QM_HANDLE_ERROR( \
#expr, firstRes, mozilla::dom::quota::Severity::severity); \
return fallback(firstRes); \
})
/*
* QM_OR_ELSE_WARN(expr, fallback) evaluates expr, which must produce a Result
* value. On Success, it just moves the success over. On error, it calls
* HandleError (with the Warning severity) and a fallback function (passed as
* the second argument) which produces a new result. Failed expr is always
* reported as a warning (the macro essentially wraps the fallback function
* with a warning). QM_OR_ELSE_WARN is a sub macro and is intended to be used
* along with one of the main macros such as QM_TRY.
*/
#define QM_OR_ELSE_WARN(...) QM_OR_ELSE_REPORT(Warning, __VA_ARGS__)
/**
* QM_OR_ELSE_INFO is like QM_OR_ELSE_WARN. The only difference is that
* failures are reported using a lower level of severity relative to failures
* reported by QM_OR_ELSE_WARN.
*/
#define QM_OR_ELSE_INFO(...) QM_OR_ELSE_REPORT(Info, __VA_ARGS__)
/**
* QM_OR_ELSE_LOG_VERBOSE is like QM_OR_ELSE_WARN. The only difference is that
* failures are reported using the lowest severity which is currently ignored
* in LogError, so nothing goes to the console, browser console and telemetry.
* Since nothing goes to the telemetry, the macro can't signal the end of the
* underlying error stack or change the type of the error stack in the
* telemetry. For that reason, the expression shouldn't contain nested QM_TRY
* macro uses.
*/
#define QM_OR_ELSE_LOG_VERBOSE(...) QM_OR_ELSE_REPORT(Log, __VA_ARGS__)
namespace mozilla::dom::quota {
// XXX Support orElseIf directly in mozilla::Result
template <typename V, typename E, typename P, typename F>
auto OrElseIf(Result<V, E>&& aResult, P&& aPred, F&& aFunc) -> Result<V, E> {
return MOZ_UNLIKELY(aResult.isErr())
? (std::forward<P>(aPred)(aResult.inspectErr()))
? std::forward<F>(aFunc)(aResult.unwrapErr())
: aResult.propagateErr()
: aResult.unwrap();
}
} // namespace mozilla::dom::quota
// QM_OR_ELSE_REPORT_IF macro is an implementation detail of
// QM_OR_ELSE_WARN_IF/QM_OR_ELSE_INFO_IF/QM_OR_ELSE_LOG_VERBOSE_IF and
// shouldn't be used directly.
#define QM_OR_ELSE_REPORT_IF(severity, expr, predicate, fallback) \
mozilla::dom::quota::OrElseIf( \
(expr), \
[&](const auto& firstRes) { \
bool res = predicate(firstRes); \
mozilla::dom::quota::QM_HANDLE_ERROR( \
#expr, firstRes, \
res ? mozilla::dom::quota::Severity::severity \
: mozilla::dom::quota::Severity::Error); \
return res; \
}, \
fallback)
/*
* QM_OR_ELSE_WARN_IF(expr, predicate, fallback) evaluates expr first, which
* must produce a Result value. On Success, it just moves the success over.
* On error, it calls a predicate function (passed as the second argument) and
* then it either calls HandleError (with the Warning severity) and a fallback
* function (passed as the third argument) which produces a new result if the
* predicate returned true. Or it calls HandleError (with the Error severity)
* and propagates the error result if the predicate returned false. So failed
* expr can be reported as a warning or as an error depending on the predicate.
* QM_OR_ELSE_WARN_IF is a sub macro and is intended to be used along with one
* of the main macros such as QM_TRY.
*/
#define QM_OR_ELSE_WARN_IF(...) QM_OR_ELSE_REPORT_IF(Warning, __VA_ARGS__)
/**
* QM_OR_ELSE_INFO_IF is like QM_OR_ELSE_WARN_IF. The only difference is that
* failures are reported using a lower level of severity relative to failures
* reported by QM_OR_ELSE_WARN_IF.
*/
#define QM_OR_ELSE_INFO_IF(...) QM_OR_ELSE_REPORT_IF(Info, __VA_ARGS__)
/**
* QM_OR_ELSE_LOG_VERBOSE_IF is like QM_OR_ELSE_WARN_IF. The only difference is
* that failures are reported using the lowest severity which is currently
* ignored in LogError, so nothing goes to the console, browser console and
* telemetry. Since nothing goes to the telemetry, the macro can't signal the
* end of the underlying error stack or change the type of the error stack in
* the telemetry. For that reason, the expression shouldn't contain nested
* QM_TRY macro uses.
*/
#define QM_OR_ELSE_LOG_VERBOSE_IF(...) \
QM_OR_ELSE_REPORT_IF(Verbose, __VA_ARGS__)
// Telemetry probes to collect number of failure during the initialization.
#ifdef NIGHTLY_BUILD
# define RECORD_IN_NIGHTLY(_recorder, _status) \
do { \
if (NS_SUCCEEDED(_recorder)) { \
_recorder = _status; \
} \
} while (0)
# define OK_IN_NIGHTLY_PROPAGATE_IN_OTHERS \
Ok {}
# define RETURN_STATUS_OR_RESULT(_status, _rv) \
return Err(NS_FAILED(_status) ? (_status) : (_rv))
#else
# define RECORD_IN_NIGHTLY(_dummy, _status) \
{}
# define OK_IN_NIGHTLY_PROPAGATE_IN_OTHERS QM_PROPAGATE
# define RETURN_STATUS_OR_RESULT(_status, _rv) return Err(_rv)
#endif
class mozIStorageConnection;
class mozIStorageStatement;
class nsIFile;
namespace mozilla {
class LogModule;
struct CreateIfNonExistent {};
struct NotOk {};
// Allow MOZ_TRY/QM_TRY to handle `bool` values by wrapping them with OkIf.
// TODO: Maybe move this to mfbt/ResultExtensions.h
inline Result<Ok, NotOk> OkIf(bool aValue) {
if (aValue) {
return Ok();
}
return Err(NotOk());
}
// TODO: Maybe move this to mfbt/ResultExtensions.h
template <auto SuccessValue>
auto OkToOk(Ok) -> Result<decltype(SuccessValue), nsresult> {
return SuccessValue;
}
template <nsresult ErrorValue, auto SuccessValue,
typename V = decltype(SuccessValue)>
auto ErrToOkOrErr(nsresult aValue) -> Result<V, nsresult> {
if (aValue == ErrorValue) {
return V{SuccessValue};
}
return Err(aValue);
}
template <nsresult ErrorValue, typename V = mozilla::Ok>
auto ErrToDefaultOkOrErr(nsresult aValue) -> Result<V, nsresult> {
if (aValue == ErrorValue) {
return V{};
}
return Err(aValue);
}
// Helper template function so that QM_TRY predicates checking for a specific
// error can be concisely written as IsSpecificError<NS_SOME_ERROR> instead of
// as a more verbose lambda.
template <nsresult ErrorValue>
bool IsSpecificError(const nsresult aValue) {
return aValue == ErrorValue;
}
// Helper template function so that QM_TRY fallback functions that are
// converting errors into specific in-band success values can be concisely
// written as ErrToOk<SuccessValueToReturn> (with the return type inferred).
// For example, many file-related APIs that access information about a file may
// return an nsresult error code if the file does not exist. From an
// application perspective, the file not existing is not actually exceptional
// and can instead be handled by the success case.
template <auto SuccessValue, typename V = decltype(SuccessValue)>
auto ErrToOk(const nsresult aValue) -> Result<V, nsresult> {
return V{SuccessValue};
}
// Helper template function so that QM_TRY fallback functions that are
// suppressing errors by converting them into (generic) success can be
// concisely written as ErrToDefaultOk<>.
template <typename V = mozilla::Ok>
auto ErrToDefaultOk(const nsresult aValue) -> Result<V, nsresult> {
return V{};
}
// Like Rust's collect with a step function, not a generic iterator/range.
//
// Cond must be a function type with a return type to Result<V, E>, where
// V is convertible to bool
// - success converts to true indicates that collection shall continue
// - success converts to false indicates that collection is completed
// - error indicates that collection shall stop, propagating the error
//
// Body must a function type accepting a V xvalue with a return type convertible
// to Result<empty, E>.
template <typename Step, typename Body>
auto CollectEach(Step aStep, const Body& aBody)
-> Result<mozilla::Ok, typename std::invoke_result_t<Step>::err_type> {
using StepResultType = typename std::invoke_result_t<Step>::ok_type;
static_assert(
std::is_empty_v<
typename std::invoke_result_t<Body, StepResultType&&>::ok_type>);
while (true) {
StepResultType element;
MOZ_TRY_VAR(element, aStep());
if (!static_cast<bool>(element)) {
break;
}
MOZ_TRY(aBody(std::move(element)));
}
return mozilla::Ok{};
}
// This is like std::reduce with a to-be-defined execution policy (we don't want
// to std::terminate on an error, but probably it's fine to just propagate any
// error that occurred), operating not on a pair of iterators but rather a
// generator function.
template <typename InputGenerator, typename T, typename BinaryOp>
auto ReduceEach(InputGenerator aInputGenerator, T aInit,
const BinaryOp& aBinaryOp)
-> Result<T, typename std::invoke_result_t<InputGenerator>::err_type> {
T res = std::move(aInit);
// XXX This can be done in parallel!
MOZ_TRY(CollectEach(
std::move(aInputGenerator),
[&res, &aBinaryOp](const auto& element)
-> Result<Ok,
typename std::invoke_result_t<InputGenerator>::err_type> {
MOZ_TRY_VAR(res, aBinaryOp(std::move(res), element));
return Ok{};
}));
return std::move(res);
}
// This is like std::reduce with a to-be-defined execution policy (we don't want
// to std::terminate on an error, but probably it's fine to just propagate any
// error that occurred).
template <typename Range, typename T, typename BinaryOp>
auto Reduce(Range&& aRange, T aInit, const BinaryOp& aBinaryOp) {
using std::begin;
using std::end;
return ReduceEach(
[it = begin(aRange), end = end(aRange)]() mutable {
auto res = ToMaybeRef(it != end ? &*it++ : nullptr);
return Result<decltype(res), typename std::invoke_result_t<
BinaryOp, T, decltype(res)>::err_type>(
res);
},
aInit, aBinaryOp);
}
template <typename Range, typename Body>
auto CollectEachInRange(Range&& aRange, const Body& aBody)
-> Result<mozilla::Ok, nsresult> {
for (auto&& element : aRange) {
MOZ_TRY(aBody(element));
}
return mozilla::Ok{};
}
// Like Rust's collect with a while loop, not a generic iterator/range.
//
// Cond must be a function type accepting no parameters with a return type
// convertible to Result<bool, E>, where
// - success true indicates that collection shall continue
// - success false indicates that collection is completed
// - error indicates that collection shall stop, propagating the error
//
// Body must a function type accepting no parameters with a return type
// convertible to Result<empty, E>.
template <typename Cond, typename Body>
auto CollectWhile(const Cond& aCond, const Body& aBody)
-> Result<mozilla::Ok, typename std::invoke_result_t<Cond>::err_type> {
return CollectEach(aCond, [&aBody](bool) { return aBody(); });
}
template <>
class [[nodiscard]] GenericErrorResult<mozilla::ipc::IPCResult> {
mozilla::ipc::IPCResult mErrorValue;
template <typename V, typename E2>
friend class Result;
public:
explicit GenericErrorResult(mozilla::ipc::IPCResult aErrorValue)
: mErrorValue(aErrorValue) {
MOZ_ASSERT(!aErrorValue);
}
GenericErrorResult(mozilla::ipc::IPCResult aErrorValue,
const ErrorPropagationTag&)
: GenericErrorResult(aErrorValue) {}
operator mozilla::ipc::IPCResult() const { return mErrorValue; }
};
namespace dom::quota {
extern const char kQuotaGenericDelimiter;
// Telemetry keys to indicate types of errors.
#ifdef NIGHTLY_BUILD
extern const nsLiteralCString kQuotaInternalError;
extern const nsLiteralCString kQuotaExternalError;
#else
// No need for these when we're not collecting telemetry.
# define kQuotaInternalError
# define kQuotaExternalError
#endif
class BackgroundThreadObject {
protected:
nsCOMPtr<nsIEventTarget> mOwningThread;
public:
void AssertIsOnOwningThread() const
#ifdef DEBUG
;
#else
{
}
#endif
nsIEventTarget* OwningThread() const;
protected:
BackgroundThreadObject();
explicit BackgroundThreadObject(nsIEventTarget* aOwningThread);
};
void AssertIsOnIOThread();
void AssertCurrentThreadOwnsQuotaMutex();
bool IsOnIOThread();
MOZ_COLD void ReportInternalError(const char* aFile, uint32_t aLine,
const char* aStr);
LogModule* GetQuotaManagerLogger();
void AnonymizeCString(nsACString& aCString);
inline auto AnonymizedCString(const nsACString& aCString) {
nsAutoCString result{aCString};
AnonymizeCString(result);
return result;
}
void AnonymizeOriginString(nsACString& aOriginString);
inline auto AnonymizedOriginString(const nsACString& aOriginString) {
nsAutoCString result{aOriginString};
AnonymizeOriginString(result);
return result;
}
#ifdef XP_WIN
void CacheUseDOSDevicePathSyntaxPrefValue();
#endif
Result<nsCOMPtr<nsIFile>, nsresult> QM_NewLocalFile(const nsAString& aPath);
nsDependentCSubstring GetLeafName(const nsACString& aPath);
Result<nsCOMPtr<nsIFile>, nsresult> CloneFileAndAppend(
nsIFile& aDirectory, const nsAString& aPathElement);
enum class nsIFileKind {
ExistsAsDirectory,
ExistsAsFile,
DoesNotExist,
};
// XXX We can use this outside of QM and its clients as well, probably. Maybe it
// could be moved to xpcom/io?
Result<nsIFileKind, nsresult> GetDirEntryKind(nsIFile& aFile);
Result<nsCOMPtr<mozIStorageStatement>, nsresult> CreateStatement(
mozIStorageConnection& aConnection, const nsACString& aStatementString);
enum class SingleStepResult { AssertHasResult, ReturnNullIfNoResult };
template <SingleStepResult ResultHandling>
using SingleStepSuccessType =
std::conditional_t<ResultHandling == SingleStepResult::AssertHasResult,
NotNull<nsCOMPtr<mozIStorageStatement>>,
nsCOMPtr<mozIStorageStatement>>;
template <SingleStepResult ResultHandling>
Result<SingleStepSuccessType<ResultHandling>, nsresult> ExecuteSingleStep(
nsCOMPtr<mozIStorageStatement>&& aStatement);
// Creates a statement with the specified aStatementString, executes a single
// step, and returns the statement.
// Depending on the value ResultHandling,
// - it is asserted that there is a result (default resp.
// SingleStepResult::AssertHasResult), and the success type is
// MovingNotNull<nsCOMPtr<mozIStorageStatement>>
// - it is asserted that there is no result, and the success type is Ok
// - in case there is no result, nullptr is returned, and the success type is
// nsCOMPtr<mozIStorageStatement>
// Any other errors are always propagated.
template <SingleStepResult ResultHandling = SingleStepResult::AssertHasResult>
Result<SingleStepSuccessType<ResultHandling>, nsresult>
CreateAndExecuteSingleStepStatement(mozIStorageConnection& aConnection,
const nsACString& aStatementString);
namespace detail {
// Determine the absolute path of the root of our built source tree so we can
// derive source-relative paths for non-exported header files in
// MakeSourceFileRelativePath. Exported header files end up in the objdir and
// we have GetObjdirDistIncludeTreeBase for that.
nsDependentCSubstring GetSourceTreeBase();
// Determine the absolute path of the root of our built OBJDIR/dist/include
// directory. The aQuotaCommonHPath argument cleverly defaults to __FILE__
// initialized in our exported header; no argument should ever be provided to
// this method. GetSourceTreeBase handles identifying the root of the source
// tree.
nsDependentCSubstring GetObjdirDistIncludeTreeBase(
const nsLiteralCString& aQuotaCommonHPath = nsLiteralCString(__FILE__));
nsDependentCSubstring MakeSourceFileRelativePath(
const nsACString& aSourceFilePath);
} // namespace detail
enum class Severity {
Error,
Warning,
Info,
Verbose,
};
#ifdef QM_LOG_ERROR_ENABLED
# ifdef QM_ERROR_STACKS_ENABLED
using ResultType = Variant<QMResult, nsresult, Nothing>;
void LogError(const nsACString& aExpr, const ResultType& aResult,
const nsACString& aSourceFilePath, int32_t aSourceFileLine,
Severity aSeverity)
# else
void LogError(const nsACString& aExpr, Maybe<nsresult> aMaybeRv,
const nsACString& aSourceFilePath, int32_t aSourceFileLine,
Severity aSeverity)
# endif
;
#endif
#ifdef DEBUG
Result<bool, nsresult> WarnIfFileIsUnknown(nsIFile& aFile,
const char* aSourceFilePath,
int32_t aSourceFileLine);
#endif
// As HandleError is a function that will only be called in error cases, it is
// marked with MOZ_COLD to avoid bloating the code of calling functions, if it's
// not empty.
//
// For the same reason, the string-ish parameters are of type const char* rather
// than any ns*String type, to minimize the code at each call site. This
// deliberately de-optimizes runtime performance, which is uncritical during
// error handling.
//
// This functions are not intended to be called
// directly, they should only be called from the QM_* macros.
#ifdef QM_LOG_ERROR_ENABLED
template <typename T>
MOZ_COLD MOZ_NEVER_INLINE void HandleError(const char* aExpr, const T& aRv,
const char* aSourceFilePath,
int32_t aSourceFileLine,
const Severity aSeverity) {
# ifdef QM_ERROR_STACKS_ENABLED
if constexpr (std::is_same_v<T, QMResult> || std::is_same_v<T, nsresult>) {
mozilla::dom::quota::LogError(nsDependentCString(aExpr), ResultType(aRv),
nsDependentCString(aSourceFilePath),
aSourceFileLine, aSeverity);
} else {
mozilla::dom::quota::LogError(
nsDependentCString(aExpr), ResultType(Nothing{}),
nsDependentCString(aSourceFilePath), aSourceFileLine, aSeverity);
}
# else
if constexpr (std::is_same_v<T, nsresult>) {
mozilla::dom::quota::LogError(nsDependentCString(aExpr), Some(aRv),
nsDependentCString(aSourceFilePath),
aSourceFileLine, aSeverity);
} else {
mozilla::dom::quota::LogError(nsDependentCString(aExpr), Nothing{},
nsDependentCString(aSourceFilePath),
aSourceFileLine, aSeverity);
}
# endif
}
#else
template <typename T>
MOZ_ALWAYS_INLINE constexpr void HandleError(const char* aExpr, const T& aRv,
const char* aSourceFilePath,
int32_t aSourceFileLine,
const Severity aSeverity) {}
#endif
template <typename T>
Nothing HandleErrorReturnNothing(const char* aExpr, const T& aRv,
const char* aSourceFilePath,
int32_t aSourceFileLine,
const Severity aSeverity) {
HandleError(aExpr, aRv, aSourceFilePath, aSourceFileLine, aSeverity);
return Nothing();
}
template <typename T, typename CleanupFunc>
Nothing HandleErrorWithCleanupReturnNothing(const char* aExpr, const T& aRv,
const char* aSourceFilePath,
int32_t aSourceFileLine,
const Severity aSeverity,
CleanupFunc&& aCleanupFunc) {
HandleError(aExpr, aRv, aSourceFilePath, aSourceFileLine, aSeverity);
std::forward<CleanupFunc>(aCleanupFunc)(aRv);
return Nothing();
}
template <typename CustomRetVal>
auto HandleCustomRetVal(const char* aFunc, const char* aExpr,
CustomRetVal&& aCustomRetVal) {
if constexpr (std::is_invocable<CustomRetVal, const char*,
const char*>::value) {
return aCustomRetVal(aFunc, aExpr);
} else {
return std::forward<CustomRetVal>(aCustomRetVal);
}
}
template <SingleStepResult ResultHandling = SingleStepResult::AssertHasResult,
typename BindFunctor>
Result<SingleStepSuccessType<ResultHandling>, nsresult>
CreateAndExecuteSingleStepStatement(mozIStorageConnection& aConnection,
const nsACString& aStatementString,
BindFunctor aBindFunctor) {
QM_TRY_UNWRAP(auto stmt, CreateStatement(aConnection, aStatementString));
QM_TRY(aBindFunctor(*stmt));
return ExecuteSingleStep<ResultHandling>(std::move(stmt));
}
template <typename StepFunc>
Result<Ok, nsresult> CollectWhileHasResult(mozIStorageStatement& aStmt,
StepFunc&& aStepFunc) {
return CollectWhile(
[&aStmt] {
QM_TRY_RETURN(MOZ_TO_RESULT_INVOKE_MEMBER(aStmt, ExecuteStep));
},
[&aStmt, &aStepFunc] { return aStepFunc(aStmt); });
}
template <typename StepFunc,
typename ArrayType = nsTArray<typename std::invoke_result_t<
StepFunc, mozIStorageStatement&>::ok_type>>
auto CollectElementsWhileHasResult(mozIStorageStatement& aStmt,
StepFunc&& aStepFunc)
-> Result<ArrayType, nsresult> {
ArrayType res;
QM_TRY(CollectWhileHasResult(
aStmt, [&aStepFunc, &res](auto& stmt) -> Result<Ok, nsresult> {
QM_TRY_UNWRAP(auto element, aStepFunc(stmt));
res.AppendElement(std::move(element));
return Ok{};
}));
return std::move(res);
}
template <typename ArrayType, typename StepFunc>
auto CollectElementsWhileHasResultTyped(mozIStorageStatement& aStmt,
StepFunc&& aStepFunc) {
return CollectElementsWhileHasResult<StepFunc, ArrayType>(
aStmt, std::forward<StepFunc>(aStepFunc));
}
namespace detail {
template <typename Cancel, typename Body>
Result<mozilla::Ok, nsresult> CollectEachFile(nsIFile& aDirectory,
const Cancel& aCancel,
const Body& aBody) {
QM_TRY_INSPECT(const auto& entries, MOZ_TO_RESULT_INVOKE_MEMBER_TYPED(
nsCOMPtr<nsIDirectoryEnumerator>,
aDirectory, GetDirectoryEntries));
return CollectEach(
[&entries, &aCancel]() -> Result<nsCOMPtr<nsIFile>, nsresult> {
if (aCancel()) {
return nsCOMPtr<nsIFile>{};
}
QM_TRY_RETURN(MOZ_TO_RESULT_INVOKE_MEMBER_TYPED(nsCOMPtr<nsIFile>,
entries, GetNextFile));
},
aBody);
}
} // namespace detail
template <typename Body>
Result<mozilla::Ok, nsresult> CollectEachFile(nsIFile& aDirectory,
const Body& aBody) {
return detail::CollectEachFile(
aDirectory, [] { return false; }, aBody);
}
template <typename Body>
Result<mozilla::Ok, nsresult> CollectEachFileAtomicCancelable(
nsIFile& aDirectory, const Atomic<bool>& aCanceled, const Body& aBody) {
return detail::CollectEachFile(
aDirectory, [&aCanceled] { return static_cast<bool>(aCanceled); }, aBody);
}
template <typename T, typename Body>
auto ReduceEachFileAtomicCancelable(nsIFile& aDirectory,
const Atomic<bool>& aCanceled, T aInit,
const Body& aBody) -> Result<T, nsresult> {
QM_TRY_INSPECT(const auto& entries, MOZ_TO_RESULT_INVOKE_MEMBER_TYPED(
nsCOMPtr<nsIDirectoryEnumerator>,
aDirectory, GetDirectoryEntries));
return ReduceEach(
[&entries, &aCanceled]() -> Result<nsCOMPtr<nsIFile>, nsresult> {
if (aCanceled) {
return nsCOMPtr<nsIFile>{};
}
QM_TRY_RETURN(MOZ_TO_RESULT_INVOKE_MEMBER_TYPED(nsCOMPtr<nsIFile>,
entries, GetNextFile));
},
std::move(aInit), aBody);
}
constexpr bool IsDatabaseCorruptionError(const nsresult aRv) {
return aRv == NS_ERROR_FILE_CORRUPTED || aRv == NS_ERROR_STORAGE_IOERR;
}
template <typename Func>
auto CallWithDelayedRetriesIfAccessDenied(Func&& aFunc, uint32_t aMaxRetries,
uint32_t aDelayMs)
-> Result<typename std::invoke_result_t<Func>::ok_type, nsresult> {
uint32_t retries = 0;
while (true) {
auto result = std::forward<Func>(aFunc)();
if (result.isOk()) {
return result;
}
if (result.inspectErr() != NS_ERROR_FILE_IS_LOCKED &&
result.inspectErr() != NS_ERROR_FILE_ACCESS_DENIED) {
return result;
}
if (retries++ >= aMaxRetries) {
return result;
}
PR_Sleep(PR_MillisecondsToInterval(aDelayMs));
}
}
namespace detail {
template <bool flag = false>
void UnsupportedReturnType() {
static_assert(flag, "Unsupported return type!");
}
} // namespace detail
template <typename Initialization, typename StringGenerator, typename Func>
auto ExecuteInitialization(
FirstInitializationAttempts<Initialization, StringGenerator>&
aFirstInitializationAttempts,
const Initialization aInitialization, Func&& aFunc)
-> std::invoke_result_t<Func, const FirstInitializationAttempt<
Initialization, StringGenerator>&> {
return aFirstInitializationAttempts.WithFirstInitializationAttempt(
aInitialization, [&aFunc](auto&& firstInitializationAttempt) {
auto res = std::forward<Func>(aFunc)(firstInitializationAttempt);
const auto rv = [&res]() -> nsresult {
using RetType =
std::invoke_result_t<Func, const FirstInitializationAttempt<
Initialization, StringGenerator>&>;
if constexpr (std::is_same_v<RetType, nsresult>) {
return res;
} else if constexpr (mozilla::detail::IsResult<RetType>::value &&
std::is_same_v<typename RetType::err_type,
nsresult>) {
return res.isOk() ? NS_OK : res.inspectErr();
} else {
detail::UnsupportedReturnType();
}
}();
// NS_ERROR_ABORT signals a non-fatal, recoverable problem during
// initialization. We do not want these kind of failures to count
// against our overall first initialization attempt telemetry. Thus we
// just ignore this kind of failure and keep
// aFirstInitializationAttempts unflagged to stay ready to record a real
// success or failure on the next attempt.
if (rv == NS_ERROR_ABORT) {
return res;
}
if (!firstInitializationAttempt.Recorded()) {
firstInitializationAttempt.Record(rv);
}
return res;
});
}
template <typename Initialization, typename StringGenerator, typename Func>
auto ExecuteInitialization(
FirstInitializationAttempts<Initialization, StringGenerator>&
aFirstInitializationAttempts,
const Initialization aInitialization, const nsACString& aContext,
Func&& aFunc)
-> std::invoke_result_t<Func, const FirstInitializationAttempt<
Initialization, StringGenerator>&> {
return ExecuteInitialization(
aFirstInitializationAttempts, aInitialization,
[&](const auto& firstInitializationAttempt) -> decltype(auto) {
#ifdef QM_SCOPED_LOG_EXTRA_INFO_ENABLED
const auto maybeScopedLogExtraInfo =
firstInitializationAttempt.Recorded()
? Nothing{}
: Some(ScopedLogExtraInfo{ScopedLogExtraInfo::kTagContext,
aContext});
#endif
return std::forward<Func>(aFunc)(firstInitializationAttempt);
});
}
} // namespace dom::quota
} // namespace mozilla
#endif // mozilla_dom_quota_quotacommon_h__