mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-24 13:21:05 +00:00
130 lines
3.8 KiB
C++
130 lines
3.8 KiB
C++
/* -*- 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 <typename StatementType>
|
|
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<mozIStorageConnection>& 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<StatementType> GetCachedStatement(
|
|
const nsACString& aQuery) {
|
|
nsCOMPtr<StatementType> stmt;
|
|
if (!mCachedStatements.Get(aQuery, getter_AddRefs(stmt))) {
|
|
stmt = CreateStatement(aQuery);
|
|
NS_ENSURE_TRUE(stmt, nullptr);
|
|
|
|
mCachedStatements.InsertOrUpdate(aQuery, stmt);
|
|
}
|
|
return stmt.forget();
|
|
}
|
|
|
|
template <int N>
|
|
MOZ_ALWAYS_INLINE already_AddRefed<StatementType> 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<StatementType> CreateStatement(
|
|
const nsACString& aQuery);
|
|
|
|
nsInterfaceHashtable<nsCStringHashKey, StatementType> mCachedStatements;
|
|
nsCOMPtr<mozIStorageConnection>& mConnection;
|
|
};
|
|
|
|
template <>
|
|
inline already_AddRefed<mozIStorageStatement>
|
|
StatementCache<mozIStorageStatement>::CreateStatement(
|
|
const nsACString& aQuery) {
|
|
NS_ENSURE_TRUE(mConnection, nullptr);
|
|
|
|
nsCOMPtr<mozIStorageStatement> 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<mozIStorageAsyncStatement>
|
|
StatementCache<mozIStorageAsyncStatement>::CreateStatement(
|
|
const nsACString& aQuery) {
|
|
NS_ENSURE_TRUE(mConnection, nullptr);
|
|
|
|
nsCOMPtr<mozIStorageAsyncStatement> 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
|