storage/mozStoragePrivateHelpers.cpp
author Kyle Huey <khuey@kylehuey.com>
Tue, 11 Aug 2015 06:10:46 -0700
changeset 257246 a13c1f26e351dd6251da641fe7a9eb53790fc2d0
parent 252629 91d6e262b662a0b4e47358665e222d3927337af9
child 263912 b30b0dcc562c4fce5802c1ff222d0cd6c7309f53
permissions -rw-r--r--
Bug 1179909: Refactor stable state handling. r=smaug This is motivated by three separate but related problems: 1. Our concept of recursion depth is broken for things that run from AfterProcessNextEvent observers (e.g. Promises). We decrement the recursionDepth counter before firing observers, so a Promise callback running at the lowest event loop depth has a recursion depth of 0 (whereas a regular nsIRunnable would be 1). This is a problem because it's impossible to distinguish a Promise running after a sync XHR's onreadystatechange handler from a top-level event (since the former runs with depth 2 - 1 = 1, and the latter runs with just 1). 2. The nsIThreadObserver mechanism that is used by a lot of code to run "after" the current event is a poor fit for anything that runs script. First, the order the observers fire in is the order they were added, not anything fixed by spec. Additionally, running script can cause the event loop to spin, which is a big source of pain here (bholley has some nasty bug caused by this). 3. We run Promises from different points in the code for workers and main thread. The latter runs from XPConnect's nsIThreadObserver callbacks, while the former runs from a hardcoded call to run Promises in the worker event loop. What workers do is particularly problematic because it means we can't get the right recursion depth no matter what we do to nsThread. The solve this, this patch does the following: 1. Consolidate some handling of microtasks and all handling of stable state from appshell and WorkerPrivate into CycleCollectedJSRuntime. 2. Make the recursionDepth counter only available to CycleCollectedJSRuntime (and its consumers) and remove it from the nsIThreadInternal and nsIThreadObserver APIs. 3. Adjust the recursionDepth counter so that microtasks run with the recursionDepth of the task they are associated with. 4. Introduce the concept of metastable state to replace appshell's RunBeforeNextEvent. Metastable state is reached after every microtask or task is completed. This provides the semantics that bent and I want for IndexedDB, where transactions autocommit at the end of a microtask and do not "spill" from one microtask into a subsequent microtask. This differs from appshell's RunBeforeNextEvent in two ways: a) It fires between microtasks, which was the motivation for starting this. b) It no longer ensures that we're at the same event loop depth in the native event queue. bent decided we don't care about this. 5. Reorder stable state to happen after microtasks such as Promises, per HTML. Right now we call the regular thread observers, including appshell, before the main thread observer (XPConnect), so stable state tasks happen before microtasks.

/* -*- 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 "sqlite3.h"

#include "jsfriendapi.h"

#include "nsPrintfCString.h"
#include "nsString.h"
#include "nsError.h"
#include "mozilla/Mutex.h"
#include "mozilla/CondVar.h"
#include "nsQueryObject.h"
#include "nsThreadUtils.h"
#include "nsJSUtils.h"

#include "Variant.h"
#include "mozStoragePrivateHelpers.h"
#include "mozIStorageStatement.h"
#include "mozIStorageCompletionCallback.h"
#include "mozIStorageBindingParams.h"

#include "mozilla/Logging.h"
extern PRLogModuleInfo* gStorageLog;

namespace mozilla {
namespace storage {

nsresult
convertResultCode(int aSQLiteResultCode)
{
  // Drop off the extended result bits of the result code.
  int rc = aSQLiteResultCode & 0xFF;

  switch (rc) {
    case SQLITE_OK:
    case SQLITE_ROW:
    case SQLITE_DONE:
      return NS_OK;
    case SQLITE_CORRUPT:
    case SQLITE_NOTADB:
      return NS_ERROR_FILE_CORRUPTED;
    case SQLITE_PERM:
    case SQLITE_CANTOPEN:
      return NS_ERROR_FILE_ACCESS_DENIED;
    case SQLITE_BUSY:
      return NS_ERROR_STORAGE_BUSY;
    case SQLITE_LOCKED:
      return NS_ERROR_FILE_IS_LOCKED;
    case SQLITE_READONLY:
      return NS_ERROR_FILE_READ_ONLY;
    case SQLITE_IOERR:
      return NS_ERROR_STORAGE_IOERR;
    case SQLITE_FULL:
    case SQLITE_TOOBIG:
      return NS_ERROR_FILE_NO_DEVICE_SPACE;
    case SQLITE_NOMEM:
      return NS_ERROR_OUT_OF_MEMORY;
    case SQLITE_MISUSE:
      return NS_ERROR_UNEXPECTED;
    case SQLITE_ABORT:
    case SQLITE_INTERRUPT:
      return NS_ERROR_ABORT;
    case SQLITE_CONSTRAINT:
      return NS_ERROR_STORAGE_CONSTRAINT;
  }

  // generic error
#ifdef DEBUG
  nsAutoCString message;
  message.AppendLiteral("SQLite returned error code ");
  message.AppendInt(rc);
  message.AppendLiteral(" , Storage will convert it to NS_ERROR_FAILURE");
  NS_WARN_IF_FALSE(rc == SQLITE_ERROR, message.get());
#endif
  return NS_ERROR_FAILURE;
}

void
checkAndLogStatementPerformance(sqlite3_stmt *aStatement)
{
  // Check to see if the query performed sorting operations or not.  If it
  // did, it may need to be optimized!
  int count = ::sqlite3_stmt_status(aStatement, SQLITE_STMTSTATUS_SORT, 1);
  if (count <= 0)
    return;

  const char *sql = ::sqlite3_sql(aStatement);

  // Check to see if this is marked to not warn
  if (::strstr(sql, "/* do not warn (bug "))
    return;

  nsAutoCString message("Suboptimal indexes for the SQL statement ");
#ifdef MOZ_STORAGE_SORTWARNING_SQL_DUMP
  message.Append('`');
  message.Append(sql);
  message.AppendLiteral("` [");
  message.AppendInt(count);
  message.AppendLiteral(" sort operation(s)]");
#else
  nsPrintfCString address("0x%p", aStatement);
  message.Append(address);
#endif
  message.AppendLiteral(" (http://mzl.la/1FuID0j).");
  NS_WARNING(message.get());
}

nsIVariant *
convertJSValToVariant(
  JSContext *aCtx,
  JS::Value aValue)
{
  if (aValue.isInt32())
    return new IntegerVariant(aValue.toInt32());

  if (aValue.isDouble())
    return new FloatVariant(aValue.toDouble());

  if (aValue.isString()) {
    nsAutoJSString value;
    if (!value.init(aCtx, aValue.toString()))
        return nullptr;
    return new TextVariant(value);
  }

  if (aValue.isBoolean())
    return new IntegerVariant(aValue.isTrue() ? 1 : 0);

  if (aValue.isNull())
    return new NullVariant();

  if (aValue.isObject()) {
    JS::Rooted<JSObject*> obj(aCtx, &aValue.toObject());
    // We only support Date instances, all others fail.
    if (!js::DateIsValid(aCtx, obj))
      return nullptr;

    double msecd = js::DateGetMsecSinceEpoch(aCtx, obj);
    msecd *= 1000.0;
    int64_t msec = msecd;

    return new IntegerVariant(msec);
  }

  return nullptr;
}

Variant_base *
convertVariantToStorageVariant(nsIVariant* aVariant)
{
  nsRefPtr<Variant_base> variant = do_QueryObject(aVariant);
  if (variant) {
    // JS helpers already convert the JS representation to a Storage Variant,
    // in such a case there's nothing left to do here, so just pass-through.
    return variant;
  }

  if (!aVariant)
    return new NullVariant();

  uint16_t dataType;
  nsresult rv = aVariant->GetDataType(&dataType);
  NS_ENSURE_SUCCESS(rv, nullptr);

  switch (dataType) {
    case nsIDataType::VTYPE_BOOL:
    case nsIDataType::VTYPE_INT8:
    case nsIDataType::VTYPE_INT16:
    case nsIDataType::VTYPE_INT32:
    case nsIDataType::VTYPE_UINT8:
    case nsIDataType::VTYPE_UINT16:
    case nsIDataType::VTYPE_UINT32:
    case nsIDataType::VTYPE_INT64:
    case nsIDataType::VTYPE_UINT64: {
      int64_t v;
      rv = aVariant->GetAsInt64(&v);
      NS_ENSURE_SUCCESS(rv, nullptr);
      return new IntegerVariant(v);
    }
    case nsIDataType::VTYPE_FLOAT:
    case nsIDataType::VTYPE_DOUBLE: {
      double v;
      rv = aVariant->GetAsDouble(&v);
      NS_ENSURE_SUCCESS(rv, nullptr);
      return new FloatVariant(v);
    }
    case nsIDataType::VTYPE_CHAR:
    case nsIDataType::VTYPE_CHAR_STR:
    case nsIDataType::VTYPE_STRING_SIZE_IS:
    case nsIDataType::VTYPE_UTF8STRING:
    case nsIDataType::VTYPE_CSTRING: {
      nsCString v;
      rv = aVariant->GetAsAUTF8String(v);
      NS_ENSURE_SUCCESS(rv, nullptr);
      return new UTF8TextVariant(v);
    }
    case nsIDataType::VTYPE_WCHAR:
    case nsIDataType::VTYPE_DOMSTRING:
    case nsIDataType::VTYPE_WCHAR_STR:
    case nsIDataType::VTYPE_WSTRING_SIZE_IS:
    case nsIDataType::VTYPE_ASTRING: {
      nsString v;
      rv = aVariant->GetAsAString(v);
      NS_ENSURE_SUCCESS(rv, nullptr);
      return new TextVariant(v);
    }
    case nsIDataType::VTYPE_ARRAY: {
      uint16_t type;
      nsIID iid;
      uint32_t len;
      void *rawArray;
      // Note this copies the array data.
      rv = aVariant->GetAsArray(&type, &iid, &len, &rawArray);
      NS_ENSURE_SUCCESS(rv, nullptr);
      if (type == nsIDataType::VTYPE_UINT8) {
        std::pair<uint8_t *, int> v(static_cast<uint8_t *>(rawArray), len);
        // Take ownership of the data avoiding a further copy.
        return new AdoptedBlobVariant(v);
      }
    }
    case nsIDataType::VTYPE_EMPTY:
    case nsIDataType::VTYPE_EMPTY_ARRAY:
    case nsIDataType::VTYPE_VOID:
      return new NullVariant();
    case nsIDataType::VTYPE_ID:
    case nsIDataType::VTYPE_INTERFACE:
    case nsIDataType::VTYPE_INTERFACE_IS:
    default:
      NS_WARNING("Unsupported variant type");
      return nullptr;
  }

  return nullptr;

}

namespace {
class CallbackEvent : public nsRunnable
{
public:
  explicit CallbackEvent(mozIStorageCompletionCallback *aCallback)
  : mCallback(aCallback)
  {
  }

  NS_IMETHOD Run()
  {
    (void)mCallback->Complete(NS_OK, nullptr);
    return NS_OK;
  }
private:
  nsCOMPtr<mozIStorageCompletionCallback> mCallback;
};
} // namespace
already_AddRefed<nsIRunnable>
newCompletionEvent(mozIStorageCompletionCallback *aCallback)
{
  NS_ASSERTION(aCallback, "Passing a null callback is a no-no!");
  nsCOMPtr<nsIRunnable> event = new CallbackEvent(aCallback);
  return event.forget();
}



} // namespace storage
} // namespace mozilla