gecko-dev/dom/fs/parent/FileSystemHashSource.cpp

68 строки
2.2 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/. */
#include "FileSystemHashSource.h"
#include "mozilla/dom/FileSystemTypes.h"
#include "mozilla/dom/data_encoding_ffi_generated.h"
#include "mozilla/dom/quota/QuotaCommon.h"
#include "nsComponentManagerUtils.h"
#include "nsICryptoHash.h"
#include "nsNetCID.h"
#include "nsString.h"
#include "nsStringFwd.h"
namespace mozilla::dom::fs::data {
Result<EntryId, QMResult> FileSystemHashSource::GenerateHash(
const EntryId& aParent, const Name& aName) {
auto makeHasher = [](nsresult* aRv) {
return do_CreateInstance(NS_CRYPTO_HASH_CONTRACTID, aRv);
};
QM_TRY_INSPECT(const auto& hasher,
QM_TO_RESULT_TRANSFORM(MOZ_TO_RESULT_GET_TYPED(
nsCOMPtr<nsICryptoHash>, makeHasher)));
QM_TRY(QM_TO_RESULT(hasher->Init(nsICryptoHash::SHA256)));
QM_TRY(QM_TO_RESULT(
hasher->Update(reinterpret_cast<const uint8_t*>(aName.BeginReading()),
sizeof(char16_t) * aName.Length())));
QM_TRY(QM_TO_RESULT(
hasher->Update(reinterpret_cast<const uint8_t*>(aParent.BeginReading()),
aParent.Length())));
EntryId entryId;
QM_TRY(QM_TO_RESULT(hasher->Finish(/* aASCII */ false, entryId)));
MOZ_ASSERT(!entryId.IsEmpty());
return entryId;
}
Result<Name, QMResult> FileSystemHashSource::EncodeHash(
const EntryId& aEntryId) {
MOZ_ASSERT(32u == aEntryId.Length());
nsCString encoded;
base32encode(&aEntryId, &encoded);
// We are stripping last four padding characters because
// it may not be allowed in some file systems.
MOZ_ASSERT(56u == encoded.Length() && '=' == encoded[52u] &&
'=' == encoded[53u] && '=' == encoded[54u] && '=' == encoded[55u]);
encoded.SetLength(52u);
Name result;
QM_TRY(OkIf(result.SetCapacity(encoded.Length(), mozilla::fallible)),
Err(QMResult(NS_ERROR_OUT_OF_MEMORY)));
result.AppendASCII(encoded);
return result;
}
} // namespace mozilla::dom::fs::data