tenfourfox/storage/StorageBaseStatementInternal.cpp
Cameron Kaiser c9b2922b70 hello FPR
2017-04-19 00:56:45 -07:00

225 lines
7.0 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=2 sts=2 expandtab
* 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 "StorageBaseStatementInternal.h"
#include "nsProxyRelease.h"
#include "mozStorageBindingParamsArray.h"
#include "mozStorageStatementData.h"
#include "mozStorageAsyncStatementExecution.h"
namespace mozilla {
namespace storage {
////////////////////////////////////////////////////////////////////////////////
//// Local Classes
/**
* Used to finalize an asynchronous statement on the background thread.
*/
class AsyncStatementFinalizer : public nsRunnable
{
public:
/**
* Constructor for the event.
*
* @param aStatement
* We need the AsyncStatement to be able to get at the sqlite3_stmt;
* we only access/create it on the async thread.
* @param aConnection
* We need the connection to know what thread to release the statement
* on. We release the statement on that thread since releasing the
* statement might end up releasing the connection too.
*/
AsyncStatementFinalizer(StorageBaseStatementInternal *aStatement,
Connection *aConnection)
: mStatement(aStatement)
, mConnection(aConnection)
{
}
NS_IMETHOD Run()
{
if (mStatement->mAsyncStatement) {
(void)::sqlite3_finalize(mStatement->mAsyncStatement);
mStatement->mAsyncStatement = nullptr;
}
(void)::NS_ProxyRelease(mConnection->threadOpenedOn, mStatement);
return NS_OK;
}
private:
RefPtr<StorageBaseStatementInternal> mStatement;
RefPtr<Connection> mConnection;
};
/**
* Finalize a sqlite3_stmt on the background thread for a statement whose
* destructor was invoked and the statement was non-null.
*/
class LastDitchSqliteStatementFinalizer : public nsRunnable
{
public:
/**
* Event constructor.
*
* @param aConnection
* Used to keep the connection alive. If we failed to do this, it
* is possible that the statement going out of scope invoking us
* might have the last reference to the connection and so trigger
* an attempt to close the connection which is doomed to fail
* (because the asynchronous execution thread must exist which will
* trigger the failure case).
* @param aStatement
* The sqlite3_stmt to finalize. This object takes ownership /
* responsibility for the instance and all other references to it
* should be forgotten.
*/
LastDitchSqliteStatementFinalizer(RefPtr<Connection> &aConnection,
sqlite3_stmt *aStatement)
: mConnection(aConnection)
, mAsyncStatement(aStatement)
{
NS_PRECONDITION(aConnection, "You must provide a Connection");
}
NS_IMETHOD Run()
{
(void)::sqlite3_finalize(mAsyncStatement);
mAsyncStatement = nullptr;
// Because of our ambiguous nsISupports we cannot use the NS_ProxyRelease
// template helpers.
Connection *rawConnection = nullptr;
mConnection.swap(rawConnection);
(void)::NS_ProxyRelease(
rawConnection->threadOpenedOn,
NS_ISUPPORTS_CAST(mozIStorageConnection *, rawConnection));
return NS_OK;
}
private:
RefPtr<Connection> mConnection;
sqlite3_stmt *mAsyncStatement;
};
////////////////////////////////////////////////////////////////////////////////
//// StorageBaseStatementInternal
StorageBaseStatementInternal::StorageBaseStatementInternal()
: mAsyncStatement(nullptr)
{
}
void
StorageBaseStatementInternal::asyncFinalize()
{
nsIEventTarget *target = mDBConnection->getAsyncExecutionTarget();
if (target) {
// Attempt to finalize asynchronously
nsCOMPtr<nsIRunnable> event =
new AsyncStatementFinalizer(this, mDBConnection);
// Dispatch. Note that dispatching can fail, typically if
// we have a race condition with asyncClose(). It's ok,
// let asyncClose() win.
(void)target->Dispatch(event, NS_DISPATCH_NORMAL);
}
// If we cannot get the background thread,
// mozStorageConnection::AsyncClose() has already been called and
// the statement either has been or will be cleaned up by
// internalClose().
}
void
StorageBaseStatementInternal::destructorAsyncFinalize()
{
if (!mAsyncStatement)
return;
// If we reach this point, our owner has not finalized this
// statement, yet we are being destructed. If possible, we want to
// auto-finalize it early, to release the resources early.
nsIEventTarget *target = mDBConnection->getAsyncExecutionTarget();
if (target) {
// If we can get the async execution target, we can indeed finalize
// the statement, as the connection is still open.
bool isAsyncThread = false;
(void)target->IsOnCurrentThread(&isAsyncThread);
nsCOMPtr<nsIRunnable> event =
new LastDitchSqliteStatementFinalizer(mDBConnection, mAsyncStatement);
if (isAsyncThread) {
(void)event->Run();
} else {
(void)target->Dispatch(event, NS_DISPATCH_NORMAL);
}
}
// We might not be able to dispatch to the background thread,
// presumably because it is being shutdown. Since said shutdown will
// finalize the statement, we just need to clean-up around here.
mAsyncStatement = nullptr;
}
NS_IMETHODIMP
StorageBaseStatementInternal::NewBindingParamsArray(
mozIStorageBindingParamsArray **_array
)
{
nsCOMPtr<mozIStorageBindingParamsArray> array = new BindingParamsArray(this);
NS_ENSURE_TRUE(array, NS_ERROR_OUT_OF_MEMORY);
array.forget(_array);
return NS_OK;
}
NS_IMETHODIMP
StorageBaseStatementInternal::ExecuteAsync(
mozIStorageStatementCallback *aCallback,
mozIStoragePendingStatement **_stmt
)
{
// We used to call Connection::ExecuteAsync but it takes a
// mozIStorageBaseStatement signature because it is also a public API. Since
// our 'this' has no static concept of mozIStorageBaseStatement and Connection
// would just QI it back across to a StorageBaseStatementInternal and the
// actual logic is very simple, we now roll our own.
nsTArray<StatementData> stmts(1);
StatementData data;
nsresult rv = getAsynchronousStatementData(data);
NS_ENSURE_SUCCESS(rv, rv);
NS_ENSURE_TRUE(stmts.AppendElement(data), NS_ERROR_OUT_OF_MEMORY);
// Dispatch to the background
return AsyncExecuteStatements::execute(stmts, mDBConnection,
mNativeConnection, aCallback, _stmt);
}
NS_IMETHODIMP
StorageBaseStatementInternal::EscapeStringForLIKE(
const nsAString &aValue,
const char16_t aEscapeChar,
nsAString &_escapedString
)
{
const char16_t MATCH_ALL('%');
const char16_t MATCH_ONE('_');
_escapedString.Truncate(0);
for (uint32_t i = 0; i < aValue.Length(); i++) {
if (aValue[i] == aEscapeChar || aValue[i] == MATCH_ALL ||
aValue[i] == MATCH_ONE) {
_escapedString += aEscapeChar;
}
_escapedString += aValue[i];
}
return NS_OK;
}
} // namespace storage
} // namespace mozilla