From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 21:33:14 +0200 Subject: Adding upstream version 115.7.0esr. Signed-off-by: Daniel Baumann --- storage/StatementCache.h | 129 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 storage/StatementCache.h (limited to 'storage/StatementCache.h') diff --git a/storage/StatementCache.h b/storage/StatementCache.h new file mode 100644 index 0000000000..3d07c4ef57 --- /dev/null +++ b/storage/StatementCache.h @@ -0,0 +1,129 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ : + * 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_storage_StatementCache_h +#define mozilla_storage_StatementCache_h + +#include "mozIStorageConnection.h" +#include "mozIStorageStatement.h" +#include "mozIStorageAsyncStatement.h" + +#include "nsHashKeys.h" +#include "nsInterfaceHashtable.h" + +namespace mozilla { +namespace storage { + +/** + * Class used to cache statements (mozIStorageStatement or + * mozIStorageAsyncStatement). + */ +template +class StatementCache { + public: + /** + * Constructor for the cache. + * + * @note a connection can have more than one cache. + * + * @param aConnection + * A reference to the nsCOMPtr for the connection this cache is to be + * used for. This nsCOMPtr must at least live as long as this class, + * otherwise crashes will happen. + */ + explicit StatementCache(nsCOMPtr& aConnection) + : mConnection(aConnection) {} + + /** + * Obtains a cached statement. If this statement is not yet created, it will + * be created and stored for later use. + * + * @param aQuery + * The SQL string (either a const char [] or nsACString) to get a + * cached query for. + * @return the cached statement, or null upon error. + */ + inline already_AddRefed GetCachedStatement( + const nsACString& aQuery) { + nsCOMPtr stmt; + if (!mCachedStatements.Get(aQuery, getter_AddRefs(stmt))) { + stmt = CreateStatement(aQuery); + NS_ENSURE_TRUE(stmt, nullptr); + + mCachedStatements.InsertOrUpdate(aQuery, stmt); + } + return stmt.forget(); + } + + template + MOZ_ALWAYS_INLINE already_AddRefed GetCachedStatement( + const char (&aQuery)[N]) { + nsDependentCString query(aQuery, N - 1); + return GetCachedStatement(query); + } + + /** + * Finalizes all cached statements so the database can be safely closed. The + * behavior of this cache is unspecified after this method is called. + */ + inline void FinalizeStatements() { + for (const auto& data : mCachedStatements.Values()) { + (void)data->Finalize(); + } + + // Clear the cache at this time too! + (void)mCachedStatements.Clear(); + } + + private: + inline already_AddRefed CreateStatement( + const nsACString& aQuery); + + nsInterfaceHashtable mCachedStatements; + nsCOMPtr& mConnection; +}; + +template <> +inline already_AddRefed +StatementCache::CreateStatement( + const nsACString& aQuery) { + NS_ENSURE_TRUE(mConnection, nullptr); + + nsCOMPtr stmt; + nsresult rv = mConnection->CreateStatement(aQuery, getter_AddRefs(stmt)); + if (NS_FAILED(rv)) { + nsCString error; + error.AppendLiteral("The statement '"); + error.Append(aQuery); + error.AppendLiteral("' failed to compile with the error message '"); + nsCString msg; + (void)mConnection->GetLastErrorString(msg); + error.Append(msg); + error.AppendLiteral("'."); + NS_ERROR(error.get()); + } + NS_ENSURE_SUCCESS(rv, nullptr); + + return stmt.forget(); +} + +template <> +inline already_AddRefed +StatementCache::CreateStatement( + const nsACString& aQuery) { + NS_ENSURE_TRUE(mConnection, nullptr); + + nsCOMPtr stmt; + nsresult rv = mConnection->CreateAsyncStatement(aQuery, getter_AddRefs(stmt)); + NS_ENSURE_SUCCESS(rv, nullptr); + + return stmt.forget(); +} + +} // namespace storage +} // namespace mozilla + +#endif // mozilla_storage_StatementCache_h -- cgit v1.2.3