dom/indexedDB/KeyPath.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "KeyPath.h"
#include "IDBObjectStore.h"
#include "Key.h"
#include "ReportInternalError.h"

#include "nsCharSeparatedTokenizer.h"
#include "nsJSUtils.h"
#include "xpcpublic.h"

#include "mozilla/dom/BindingDeclarations.h"
#include "mozilla/dom/IDBObjectStoreBinding.h"

namespace mozilla {
namespace dom {
namespace indexedDB {

namespace {

inline
bool
IgnoreWhitespace(char16_t c)
{
  return false;
}

typedef nsCharSeparatedTokenizerTemplate<IgnoreWhitespace> KeyPathTokenizer;

bool
IsValidKeyPathString(const nsAString& aKeyPath)
{
  NS_ASSERTION(!aKeyPath.IsVoid(), "What?");

  KeyPathTokenizer tokenizer(aKeyPath, '.');

  while (tokenizer.hasMoreTokens()) {
    nsString token(tokenizer.nextToken());

    if (!token.Length()) {
      return false;
    }

    if (!JS_IsIdentifier(token.get(), token.Length())) {
      return false;
    }
  }

  // If the very last character was a '.', the tokenizer won't give us an empty
  // token, but the keyPath is still invalid.
  if (!aKeyPath.IsEmpty() &&
      aKeyPath.CharAt(aKeyPath.Length() - 1) == '.') {
    return false;
  }

  return true;
}

enum KeyExtractionOptions {
  DoNotCreateProperties,
  CreateProperties
};

nsresult
GetJSValFromKeyPathString(JSContext* aCx,
                          const JS::Value& aValue,
                          const nsAString& aKeyPathString,
                          JS::Value* aKeyJSVal,
                          KeyExtractionOptions aOptions,
                          KeyPath::ExtractOrCreateKeyCallback aCallback,
                          void* aClosure)
{
  NS_ASSERTION(aCx, "Null pointer!");
  NS_ASSERTION(IsValidKeyPathString(aKeyPathString),
               "This will explode!");
  NS_ASSERTION(!(aCallback || aClosure) || aOptions == CreateProperties,
               "This is not allowed!");
  NS_ASSERTION(aOptions != CreateProperties || aCallback,
               "If properties are created, there must be a callback!");

  nsresult rv = NS_OK;
  *aKeyJSVal = aValue;

  KeyPathTokenizer tokenizer(aKeyPathString, '.');

  nsString targetObjectPropName;
  JS::Rooted<JSObject*> targetObject(aCx, nullptr);
  JS::Rooted<JS::Value> currentVal(aCx, aValue);
  JS::Rooted<JSObject*> obj(aCx);

  while (tokenizer.hasMoreTokens()) {
    const nsDependentSubstring& token = tokenizer.nextToken();

    NS_ASSERTION(!token.IsEmpty(), "Should be a valid keypath");

    const char16_t* keyPathChars = token.BeginReading();
    const size_t keyPathLen = token.Length();

    bool hasProp;
    if (!targetObject) {
      // We're still walking the chain of existing objects
      // http://w3c.github.io/IndexedDB/#dfn-evaluate-a-key-path-on-a-value
      // step 4 substep 1: check for .length on a String value.
      if (currentVal.isString() && !tokenizer.hasMoreTokens() &&
          token.EqualsLiteral("length") && aOptions == DoNotCreateProperties) {
        aKeyJSVal->setNumber(double(JS_GetStringLength(currentVal.toString())));
        break;
      }

      if (!currentVal.isObject()) {
        return NS_ERROR_DOM_INDEXEDDB_DATA_ERR;
      }
      obj = &currentVal.toObject();

      bool ok = JS_HasUCProperty(aCx, obj, keyPathChars, keyPathLen,
                                 &hasProp);
      IDB_ENSURE_TRUE(ok, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);

      if (hasProp) {
        // Get if the property exists...
        JS::Rooted<JS::Value> intermediate(aCx);
        bool ok = JS_GetUCProperty(aCx, obj, keyPathChars, keyPathLen, &intermediate);
        IDB_ENSURE_TRUE(ok, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);

        // Treat explicitly undefined as an error.
        if (intermediate.isUndefined()) {
          return NS_ERROR_DOM_INDEXEDDB_DATA_ERR;
        }
        if (tokenizer.hasMoreTokens()) {
          // ...and walk to it if there are more steps...
          currentVal = intermediate;
        }
        else {
          // ...otherwise use it as key
          *aKeyJSVal = intermediate;
        }
      }
      else {
        // If the property doesn't exist, fall into below path of starting
        // to define properties, if allowed.
        if (aOptions == DoNotCreateProperties) {
          return NS_ERROR_DOM_INDEXEDDB_DATA_ERR;
        }

        targetObject = obj;
        targetObjectPropName = token;
      }
    }

    if (targetObject) {
      // We have started inserting new objects or are about to just insert
      // the first one.

      aKeyJSVal->setUndefined();

      if (tokenizer.hasMoreTokens()) {
        // If we're not at the end, we need to add a dummy object to the
        // chain.
        JS::Rooted<JSObject*> dummy(aCx, JS_NewPlainObject(aCx));
        if (!dummy) {
          IDB_REPORT_INTERNAL_ERR();
          rv = NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
          break;
        }

        if (!JS_DefineUCProperty(aCx, obj, token.BeginReading(),
                                 token.Length(), dummy, JSPROP_ENUMERATE)) {
          IDB_REPORT_INTERNAL_ERR();
          rv = NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
          break;
        }

        obj = dummy;
      }
      else {
        JS::Rooted<JSObject*> dummy(aCx,
          JS_NewObject(aCx, IDBObjectStore::DummyPropClass()));
        if (!dummy) {
          IDB_REPORT_INTERNAL_ERR();
          rv = NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
          break;
        }

        if (!JS_DefineUCProperty(aCx, obj, token.BeginReading(),
                                 token.Length(), dummy, JSPROP_ENUMERATE)) {
          IDB_REPORT_INTERNAL_ERR();
          rv = NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
          break;
        }

        obj = dummy;
      }
    }
  }

  // We guard on rv being a success because we need to run the property
  // deletion code below even if we should not be running the callback.
  if (NS_SUCCEEDED(rv) && aCallback) {
    rv = (*aCallback)(aCx, aClosure);
  }

  if (targetObject) {
    // If this fails, we lose, and the web page sees a magical property
    // appear on the object :-(
    JS::ObjectOpResult succeeded;
    if (!JS_DeleteUCProperty(aCx, targetObject,
                             targetObjectPropName.get(),
                             targetObjectPropName.Length(),
                             succeeded)) {
      IDB_REPORT_INTERNAL_ERR();
      return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
    }
    IDB_ENSURE_TRUE(succeeded, NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
  }

  NS_ENSURE_SUCCESS(rv, rv);
  return rv;
}

} // namespace

// static
nsresult
KeyPath::Parse(const nsAString& aString, KeyPath* aKeyPath)
{
  KeyPath keyPath(0);
  keyPath.SetType(STRING);

  if (!keyPath.AppendStringWithValidation(aString)) {
    return NS_ERROR_FAILURE;
  }

  *aKeyPath = keyPath;
  return NS_OK;
}

//static
nsresult
KeyPath::Parse(const Sequence<nsString>& aStrings, KeyPath* aKeyPath)
{
  KeyPath keyPath(0);
  keyPath.SetType(ARRAY);

  for (uint32_t i = 0; i < aStrings.Length(); ++i) {
    if (!keyPath.AppendStringWithValidation(aStrings[i])) {
      return NS_ERROR_FAILURE;
    }
  }

  *aKeyPath = keyPath;
  return NS_OK;
}

// static
nsresult
KeyPath::Parse(const Nullable<OwningStringOrStringSequence>& aValue, KeyPath* aKeyPath)
{
  KeyPath keyPath(0);

  aKeyPath->SetType(NONEXISTENT);

  if (aValue.IsNull()) {
    *aKeyPath = keyPath;
    return NS_OK;
  }

  if (aValue.Value().IsString()) {
    return Parse(aValue.Value().GetAsString(), aKeyPath);
  }

  MOZ_ASSERT(aValue.Value().IsStringSequence());

  const Sequence<nsString>& seq = aValue.Value().GetAsStringSequence();
  if (seq.Length() == 0) {
    return NS_ERROR_FAILURE;
  }
  return Parse(seq, aKeyPath);
}

void
KeyPath::SetType(KeyPathType aType)
{
  mType = aType;
  mStrings.Clear();
}

bool
KeyPath::AppendStringWithValidation(const nsAString& aString)
{
  if (!IsValidKeyPathString(aString)) {
    return false;
  }

  if (IsString()) {
    NS_ASSERTION(mStrings.Length() == 0, "Too many strings!");
    mStrings.AppendElement(aString);
    return true;
  }

  if (IsArray()) {
    mStrings.AppendElement(aString);
    return true;
  }

  NS_NOTREACHED("What?!");
  return false;
}

nsresult
KeyPath::ExtractKey(JSContext* aCx, const JS::Value& aValue, Key& aKey) const
{
  uint32_t len = mStrings.Length();
  JS::Rooted<JS::Value> value(aCx);

  aKey.Unset();

  for (uint32_t i = 0; i < len; ++i) {
    nsresult rv = GetJSValFromKeyPathString(aCx, aValue, mStrings[i],
                                            value.address(),
                                            DoNotCreateProperties, nullptr,
                                            nullptr);
    if (NS_FAILED(rv)) {
      return rv;
    }

    if (NS_FAILED(aKey.AppendItem(aCx, IsArray() && i == 0, value))) {
      NS_ASSERTION(aKey.IsUnset(), "Encoding error should unset");
      return NS_ERROR_DOM_INDEXEDDB_DATA_ERR;
    }
  }

  aKey.FinishArray();

  return NS_OK;
}

nsresult
KeyPath::ExtractKeyAsJSVal(JSContext* aCx, const JS::Value& aValue,
                           JS::Value* aOutVal) const
{
  NS_ASSERTION(IsValid(), "This doesn't make sense!");

  if (IsString()) {
    return GetJSValFromKeyPathString(aCx, aValue, mStrings[0], aOutVal,
                                     DoNotCreateProperties, nullptr, nullptr);
  }

  const uint32_t len = mStrings.Length();
  JS::Rooted<JSObject*> arrayObj(aCx, JS_NewArrayObject(aCx, len));
  if (!arrayObj) {
    return NS_ERROR_OUT_OF_MEMORY;
  }

  JS::Rooted<JS::Value> value(aCx);
  for (uint32_t i = 0; i < len; ++i) {
    nsresult rv = GetJSValFromKeyPathString(aCx, aValue, mStrings[i],
                                            value.address(),
                                            DoNotCreateProperties, nullptr,
                                            nullptr);
    if (NS_FAILED(rv)) {
      return rv;
    }

    if (!JS_DefineElement(aCx, arrayObj, i, value, JSPROP_ENUMERATE)) {
      IDB_REPORT_INTERNAL_ERR();
      return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
    }
  }

  aOutVal->setObject(*arrayObj);
  return NS_OK;
}

nsresult
KeyPath::ExtractOrCreateKey(JSContext* aCx, const JS::Value& aValue,
                            Key& aKey, ExtractOrCreateKeyCallback aCallback,
                            void* aClosure) const
{
  NS_ASSERTION(IsString(), "This doesn't make sense!");

  JS::Rooted<JS::Value> value(aCx);

  aKey.Unset();

  nsresult rv = GetJSValFromKeyPathString(aCx, aValue, mStrings[0],
                                          value.address(),
                                          CreateProperties, aCallback,
                                          aClosure);
  if (NS_FAILED(rv)) {
    return rv;
  }

  if (NS_FAILED(aKey.AppendItem(aCx, false, value))) {
    NS_ASSERTION(aKey.IsUnset(), "Should be unset");
    return value.isUndefined() ? NS_OK : NS_ERROR_DOM_INDEXEDDB_DATA_ERR;
  }

  aKey.FinishArray();

  return NS_OK;
}

void
KeyPath::SerializeToString(nsAString& aString) const
{
  NS_ASSERTION(IsValid(), "Check to see if I'm valid first!");

  if (IsString()) {
    aString = mStrings[0];
    return;
  }

  if (IsArray()) {
    // We use a comma in the beginning to indicate that it's an array of
    // key paths. This is to be able to tell a string-keypath from an
    // array-keypath which contains only one item.
    // It also makes serializing easier :-)
    uint32_t len = mStrings.Length();
    for (uint32_t i = 0; i < len; ++i) {
      aString.Append(',');
      aString.Append(mStrings[i]);
    }

    return;
  }

  NS_NOTREACHED("What?");
}

// static
KeyPath
KeyPath::DeserializeFromString(const nsAString& aString)
{
  KeyPath keyPath(0);

  if (!aString.IsEmpty() && aString.First() == ',') {
    keyPath.SetType(ARRAY);

    // We use a comma in the beginning to indicate that it's an array of
    // key paths. This is to be able to tell a string-keypath from an
    // array-keypath which contains only one item.
    nsCharSeparatedTokenizerTemplate<IgnoreWhitespace> tokenizer(aString, ',');
    tokenizer.nextToken();
    while (tokenizer.hasMoreTokens()) {
      keyPath.mStrings.AppendElement(tokenizer.nextToken());
    }

    return keyPath;
  }

  keyPath.SetType(STRING);
  keyPath.mStrings.AppendElement(aString);

  return keyPath;
}

nsresult
KeyPath::ToJSVal(JSContext* aCx, JS::MutableHandle<JS::Value> aValue) const
{
  if (IsArray()) {
    uint32_t len = mStrings.Length();
    JS::Rooted<JSObject*> array(aCx, JS_NewArrayObject(aCx, len));
    if (!array) {
      IDB_WARNING("Failed to make array!");
      return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
    }

    for (uint32_t i = 0; i < len; ++i) {
      JS::Rooted<JS::Value> val(aCx);
      nsString tmp(mStrings[i]);
      if (!xpc::StringToJsval(aCx, tmp, &val)) {
        IDB_REPORT_INTERNAL_ERR();
        return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
      }

      if (!JS_DefineElement(aCx, array, i, val, JSPROP_ENUMERATE)) {
        IDB_REPORT_INTERNAL_ERR();
        return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
      }
    }

    aValue.setObject(*array);
    return NS_OK;
  }

  if (IsString()) {
    nsString tmp(mStrings[0]);
    if (!xpc::StringToJsval(aCx, tmp, aValue)) {
      IDB_REPORT_INTERNAL_ERR();
      return NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR;
    }
    return NS_OK;
  }

  aValue.setNull();
  return NS_OK;
}

nsresult
KeyPath::ToJSVal(JSContext* aCx, JS::Heap<JS::Value>& aValue) const
{
  JS::Rooted<JS::Value> value(aCx);
  nsresult rv = ToJSVal(aCx, &value);
  if (NS_SUCCEEDED(rv)) {
    aValue = value;
  }
  return rv;
}

bool
KeyPath::IsAllowedForObjectStore(bool aAutoIncrement) const
{
  // Any keypath that passed validation is allowed for non-autoIncrement
  // objectStores.
  if (!aAutoIncrement) {
    return true;
  }

  // Array keypaths are not allowed for autoIncrement objectStores.
  if (IsArray()) {
    return false;
  }

  // Neither are empty strings.
  if (IsEmpty()) {
    return false;
  }

  // Everything else is ok.
  return true;
}

} // namespace indexedDB
} // namespace dom
} // namespace mozilla