storage/mozStorageAsyncStatement.cpp
author Chris H-C <chutten@mozilla.com>
Mon, 04 Jul 2016 11:16:05 -0400
changeset 312997 df28918fe2361f0b54ca9ce4773a29c4c0675d06
parent 309018 babe907f527681f351d62d689230d23e55d6a729
permissions -rw-r--r--
bug 1218576 - Support remote accumulation via JS histograms. r=gfritzsche The JS histograms, too, need to dispatch their accumulations from child to parent. JSHistograms_Add now only supports histograms that are in gHistogramsMap or that were created in the parent process. After bug 1288745, maybe we'll be able to change this to be less convoluted. MozReview-Commit-ID: 3qTH89YKbGP

/* -*- 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/. */

#include <limits.h>
#include <stdio.h>

#include "nsError.h"
#include "nsMemory.h"
#include "nsProxyRelease.h"
#include "nsThreadUtils.h"
#include "nsIClassInfoImpl.h"
#include "Variant.h"

#include "mozIStorageError.h"

#include "mozStorageBindingParams.h"
#include "mozStorageConnection.h"
#include "mozStorageAsyncStatementJSHelper.h"
#include "mozStorageAsyncStatementParams.h"
#include "mozStoragePrivateHelpers.h"
#include "mozStorageStatementRow.h"
#include "mozStorageStatement.h"
#include "nsDOMClassInfo.h"

#include "mozilla/Logging.h"

extern mozilla::LazyLogModule gStorageLog;

namespace mozilla {
namespace storage {

////////////////////////////////////////////////////////////////////////////////
//// nsIClassInfo

NS_IMPL_CI_INTERFACE_GETTER(AsyncStatement,
                            mozIStorageAsyncStatement,
                            mozIStorageBaseStatement,
                            mozIStorageBindingParams,
                            mozilla::storage::StorageBaseStatementInternal)

class AsyncStatementClassInfo : public nsIClassInfo
{
public:
  constexpr AsyncStatementClassInfo() {}

  NS_DECL_ISUPPORTS_INHERITED

  NS_IMETHOD
  GetInterfaces(uint32_t *_count, nsIID ***_array) override
  {
    return NS_CI_INTERFACE_GETTER_NAME(AsyncStatement)(_count, _array);
  }

  NS_IMETHOD
  GetScriptableHelper(nsIXPCScriptable **_helper) override
  {
    static AsyncStatementJSHelper sJSHelper;
    *_helper = &sJSHelper;
    return NS_OK;
  }

  NS_IMETHOD
  GetContractID(char **_contractID) override
  {
    *_contractID = nullptr;
    return NS_OK;
  }

  NS_IMETHOD
  GetClassDescription(char **_desc) override
  {
    *_desc = nullptr;
    return NS_OK;
  }

  NS_IMETHOD
  GetClassID(nsCID **_id) override
  {
    *_id = nullptr;
    return NS_OK;
  }

  NS_IMETHOD
  GetFlags(uint32_t *_flags) override
  {
    *_flags = 0;
    return NS_OK;
  }

  NS_IMETHOD
  GetClassIDNoAlloc(nsCID *_cid) override
  {
    return NS_ERROR_NOT_AVAILABLE;
  }
};

NS_IMETHODIMP_(MozExternalRefCountType) AsyncStatementClassInfo::AddRef() { return 2; }
NS_IMETHODIMP_(MozExternalRefCountType) AsyncStatementClassInfo::Release() { return 1; }
NS_IMPL_QUERY_INTERFACE(AsyncStatementClassInfo, nsIClassInfo)

static AsyncStatementClassInfo sAsyncStatementClassInfo;

////////////////////////////////////////////////////////////////////////////////
//// AsyncStatement

AsyncStatement::AsyncStatement()
: StorageBaseStatementInternal()
, mFinalized(false)
{
}

nsresult
AsyncStatement::initialize(Connection *aDBConnection,
                           sqlite3 *aNativeConnection,
                           const nsACString &aSQLStatement)
{
  MOZ_ASSERT(aDBConnection, "No database connection given!");
  MOZ_ASSERT(!aDBConnection->isClosed(), "Database connection should be valid");
  MOZ_ASSERT(aNativeConnection, "No native connection given!");

  mDBConnection = aDBConnection;
  mNativeConnection = aNativeConnection;
  mSQLString = aSQLStatement;

  MOZ_LOG(gStorageLog, LogLevel::Debug, ("Inited async statement '%s' (0x%p)",
                                      mSQLString.get()));

#ifdef DEBUG
  // We want to try and test for LIKE and that consumers are using
  // escapeStringForLIKE instead of just trusting user input.  The idea to
  // check to see if they are binding a parameter after like instead of just
  // using a string.  We only do this in debug builds because it's expensive!
  const nsCaseInsensitiveCStringComparator c;
  nsACString::const_iterator start, end, e;
  aSQLStatement.BeginReading(start);
  aSQLStatement.EndReading(end);
  e = end;
  while (::FindInReadable(NS_LITERAL_CSTRING(" LIKE"), start, e, c)) {
    // We have a LIKE in here, so we perform our tests
    // FindInReadable moves the iterator, so we have to get a new one for
    // each test we perform.
    nsACString::const_iterator s1, s2, s3;
    s1 = s2 = s3 = start;

    if (!(::FindInReadable(NS_LITERAL_CSTRING(" LIKE ?"), s1, end, c) ||
          ::FindInReadable(NS_LITERAL_CSTRING(" LIKE :"), s2, end, c) ||
          ::FindInReadable(NS_LITERAL_CSTRING(" LIKE @"), s3, end, c))) {
      // At this point, we didn't find a LIKE statement followed by ?, :,
      // or @, all of which are valid characters for binding a parameter.
      // We will warn the consumer that they may not be safely using LIKE.
      NS_WARNING("Unsafe use of LIKE detected!  Please ensure that you "
                 "are using mozIStorageAsyncStatement::escapeStringForLIKE "
                 "and that you are binding that result to the statement "
                 "to prevent SQL injection attacks.");
    }

    // resetting start and e
    start = e;
    e = end;
  }
#endif

  return NS_OK;
}

mozIStorageBindingParams *
AsyncStatement::getParams()
{
  nsresult rv;

  // If we do not have an array object yet, make it.
  if (!mParamsArray) {
    nsCOMPtr<mozIStorageBindingParamsArray> array;
    rv = NewBindingParamsArray(getter_AddRefs(array));
    NS_ENSURE_SUCCESS(rv, nullptr);

    mParamsArray = static_cast<BindingParamsArray *>(array.get());
  }

  // If there isn't already any rows added, we'll have to add one to use.
  if (mParamsArray->length() == 0) {
    RefPtr<AsyncBindingParams> params(new AsyncBindingParams(mParamsArray));
    NS_ENSURE_TRUE(params, nullptr);

    rv = mParamsArray->AddParams(params);
    NS_ENSURE_SUCCESS(rv, nullptr);

    // We have to unlock our params because AddParams locks them.  This is safe
    // because no reference to the params object was, or ever will be given out.
    params->unlock(nullptr);

    // We also want to lock our array at this point - we don't want anything to
    // be added to it.
    mParamsArray->lock();
  }

  return *mParamsArray->begin();
}

/**
 * If we are here then we know there are no pending async executions relying on
 * us (StatementData holds a reference to us; this also goes for our own
 * AsyncStatementFinalizer which proxies its release to the calling thread) and
 * so it is always safe to destroy our sqlite3_stmt if one exists.  We can be
 * destroyed on the caller thread by garbage-collection/reference counting or on
 * the async thread by the last execution of a statement that already lost its
 * main-thread refs.
 */
AsyncStatement::~AsyncStatement()
{
  destructorAsyncFinalize();

  // If we are getting destroyed on the wrong thread, proxy the connection
  // release to the right thread.  I'm not sure why we do this.
  bool onCallingThread = false;
  (void)mDBConnection->threadOpenedOn->IsOnCurrentThread(&onCallingThread);
  if (!onCallingThread) {
    // NS_ProxyRelase only magic forgets for us if mDBConnection is an
    // nsCOMPtr.  Which it is not; it's an nsRefPtr.
    nsCOMPtr<nsIThread> targetThread(mDBConnection->threadOpenedOn);
    NS_ProxyRelease(targetThread, mDBConnection.forget());
  }
}

////////////////////////////////////////////////////////////////////////////////
//// nsISupports

NS_IMPL_ADDREF(AsyncStatement)
NS_IMPL_RELEASE(AsyncStatement)

NS_INTERFACE_MAP_BEGIN(AsyncStatement)
  NS_INTERFACE_MAP_ENTRY(mozIStorageAsyncStatement)
  NS_INTERFACE_MAP_ENTRY(mozIStorageBaseStatement)
  NS_INTERFACE_MAP_ENTRY(mozIStorageBindingParams)
  NS_INTERFACE_MAP_ENTRY(mozilla::storage::StorageBaseStatementInternal)
  if (aIID.Equals(NS_GET_IID(nsIClassInfo))) {
    foundInterface = static_cast<nsIClassInfo *>(&sAsyncStatementClassInfo);
  }
  else
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, mozIStorageAsyncStatement)
NS_INTERFACE_MAP_END


////////////////////////////////////////////////////////////////////////////////
//// StorageBaseStatementInternal

Connection *
AsyncStatement::getOwner()
{
  return mDBConnection;
}

int
AsyncStatement::getAsyncStatement(sqlite3_stmt **_stmt)
{
#ifdef DEBUG
  // Make sure we are never called on the connection's owning thread.
  bool onOpenedThread = false;
  (void)mDBConnection->threadOpenedOn->IsOnCurrentThread(&onOpenedThread);
  NS_ASSERTION(!onOpenedThread,
               "We should only be called on the async thread!");
#endif

  if (!mAsyncStatement) {
    int rc = mDBConnection->prepareStatement(mNativeConnection, mSQLString,
                                             &mAsyncStatement);
    if (rc != SQLITE_OK) {
      MOZ_LOG(gStorageLog, LogLevel::Error,
             ("Sqlite statement prepare error: %d '%s'", rc,
              ::sqlite3_errmsg(mNativeConnection)));
      MOZ_LOG(gStorageLog, LogLevel::Error,
             ("Statement was: '%s'", mSQLString.get()));
      *_stmt = nullptr;
      return rc;
    }
    MOZ_LOG(gStorageLog, LogLevel::Debug, ("Initialized statement '%s' (0x%p)",
                                        mSQLString.get(),
                                        mAsyncStatement));
  }

  *_stmt = mAsyncStatement;
  return SQLITE_OK;
}

nsresult
AsyncStatement::getAsynchronousStatementData(StatementData &_data)
{
  if (mFinalized)
    return NS_ERROR_UNEXPECTED;

  // Pass null for the sqlite3_stmt; it will be requested on demand from the
  // async thread.
  _data = StatementData(nullptr, bindingParamsArray(), this);

  return NS_OK;
}

already_AddRefed<mozIStorageBindingParams>
AsyncStatement::newBindingParams(mozIStorageBindingParamsArray *aOwner)
{
  if (mFinalized)
    return nullptr;

  nsCOMPtr<mozIStorageBindingParams> params(new AsyncBindingParams(aOwner));
  return params.forget();
}


////////////////////////////////////////////////////////////////////////////////
//// mozIStorageAsyncStatement

// (nothing is specific to mozIStorageAsyncStatement)

////////////////////////////////////////////////////////////////////////////////
//// StorageBaseStatementInternal

// proxy to StorageBaseStatementInternal using its define helper.
MIXIN_IMPL_STORAGEBASESTATEMENTINTERNAL(
  AsyncStatement,
  if (mFinalized) return NS_ERROR_UNEXPECTED;)

NS_IMETHODIMP
AsyncStatement::Finalize()
{
  if (mFinalized)
    return NS_OK;

  mFinalized = true;

  MOZ_LOG(gStorageLog, LogLevel::Debug, ("Finalizing statement '%s'",
                                      mSQLString.get()));

  asyncFinalize();

  // Release the params holder, so it can release the reference to us.
  mStatementParamsHolder = nullptr;

  return NS_OK;
}

NS_IMETHODIMP
AsyncStatement::BindParameters(mozIStorageBindingParamsArray *aParameters)
{
  if (mFinalized)
    return NS_ERROR_UNEXPECTED;

  BindingParamsArray *array = static_cast<BindingParamsArray *>(aParameters);
  if (array->getOwner() != this)
    return NS_ERROR_UNEXPECTED;

  if (array->length() == 0)
    return NS_ERROR_UNEXPECTED;

  mParamsArray = array;
  mParamsArray->lock();

  return NS_OK;
}

NS_IMETHODIMP
AsyncStatement::GetState(int32_t *_state)
{
  if (mFinalized)
    *_state = MOZ_STORAGE_STATEMENT_INVALID;
  else
    *_state = MOZ_STORAGE_STATEMENT_READY;

  return NS_OK;
}

////////////////////////////////////////////////////////////////////////////////
//// mozIStorageBindingParams

BOILERPLATE_BIND_PROXIES(
  AsyncStatement, 
  if (mFinalized) return NS_ERROR_UNEXPECTED;
)

} // namespace storage
} // namespace mozilla