dom/commandhandler/nsCommandParams.cpp
author Emilio Cobos Álvarez <emilio@crisal.io>
Tue, 02 Jul 2019 18:50:04 +0000
changeset 480995 6525ac41c35455512bc1b681df331a5b74cb75cc
parent 448947 6f3709b3878117466168c40affa7bca0b60cf75b
child 513549 3d27ad6aefe3499a58e0e3762082becad8df52ec
permissions -rw-r--r--
Bug 1562789 - SmallPointerArray should support moves, and have an IsEmpty() helper. r=froydnj This also implicitly deletes its copy-assignment operator and copy-constructor, which is great since it's a huge footgun. Differential Revision: https://phabricator.services.mozilla.com/D36549

/* -*- 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 "xpcom-config.h"
#include <new>
#include "nscore.h"
#include "nsCRT.h"

#include "nsCommandParams.h"
#include "mozilla/HashFunctions.h"

using namespace mozilla;

const PLDHashTableOps nsCommandParams::sHashOps = {
    HashKey, HashMatchEntry, HashMoveEntry, HashClearEntry};

NS_IMPL_ISUPPORTS(nsCommandParams, nsICommandParams)

nsCommandParams::nsCommandParams()
    : mValuesHash(&sHashOps, sizeof(HashEntry), 2) {}

nsCommandParams::~nsCommandParams() {}

NS_IMETHODIMP
nsCommandParams::GetValueType(const char* aName, int16_t* aRetVal) {
  NS_ENSURE_ARG_POINTER(aRetVal);

  HashEntry* foundEntry = GetNamedEntry(aName);
  if (foundEntry) {
    *aRetVal = foundEntry->mEntryType;
    return NS_OK;
  }
  *aRetVal = eNoType;
  return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
nsCommandParams::GetBooleanValue(const char* aName, bool* aRetVal) {
  NS_ENSURE_ARG_POINTER(aRetVal);

  ErrorResult error;
  *aRetVal = GetBool(aName, error);
  return error.StealNSResult();
}

bool nsCommandParams::GetBool(const char* aName, ErrorResult& aRv) const {
  MOZ_ASSERT(!aRv.Failed());

  HashEntry* foundEntry = GetNamedEntry(aName);
  if (foundEntry && foundEntry->mEntryType == eBooleanType) {
    return foundEntry->mData.mBoolean;
  }
  aRv.Throw(NS_ERROR_FAILURE);
  return false;
}

NS_IMETHODIMP
nsCommandParams::GetLongValue(const char* aName, int32_t* aRetVal) {
  NS_ENSURE_ARG_POINTER(aRetVal);

  ErrorResult error;
  *aRetVal = GetInt(aName, error);
  return error.StealNSResult();
}

int32_t nsCommandParams::GetInt(const char* aName, ErrorResult& aRv) const {
  MOZ_ASSERT(!aRv.Failed());

  HashEntry* foundEntry = GetNamedEntry(aName);
  if (foundEntry && foundEntry->mEntryType == eLongType) {
    return foundEntry->mData.mLong;
  }
  aRv.Throw(NS_ERROR_FAILURE);
  return 0;
}

NS_IMETHODIMP
nsCommandParams::GetDoubleValue(const char* aName, double* aRetVal) {
  NS_ENSURE_ARG_POINTER(aRetVal);

  ErrorResult error;
  *aRetVal = GetDouble(aName, error);
  return error.StealNSResult();
}

double nsCommandParams::GetDouble(const char* aName, ErrorResult& aRv) const {
  MOZ_ASSERT(!aRv.Failed());

  HashEntry* foundEntry = GetNamedEntry(aName);
  if (foundEntry && foundEntry->mEntryType == eDoubleType) {
    return foundEntry->mData.mDouble;
  }
  aRv.Throw(NS_ERROR_FAILURE);
  return 0.0;
}

NS_IMETHODIMP
nsCommandParams::GetStringValue(const char* aName, nsAString& aRetVal) {
  return GetString(aName, aRetVal);
}

nsresult nsCommandParams::GetString(const char* aName,
                                    nsAString& aRetVal) const {
  HashEntry* foundEntry = GetNamedEntry(aName);
  if (foundEntry && foundEntry->mEntryType == eWStringType) {
    NS_ASSERTION(foundEntry->mData.mString, "Null string");
    aRetVal.Assign(*foundEntry->mData.mString);
    return NS_OK;
  }
  aRetVal.Truncate();
  return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
nsCommandParams::GetCStringValue(const char* aName, nsACString& aRetVal) {
  return GetCString(aName, aRetVal);
}

nsresult nsCommandParams::GetCString(const char* aName,
                                     nsACString& aRetVal) const {
  HashEntry* foundEntry = GetNamedEntry(aName);
  if (foundEntry && foundEntry->mEntryType == eStringType) {
    NS_ASSERTION(foundEntry->mData.mCString, "Null string");
    aRetVal.Assign(*foundEntry->mData.mCString);
    return NS_OK;
  }
  aRetVal.Truncate();
  return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
nsCommandParams::GetISupportsValue(const char* aName, nsISupports** aRetVal) {
  NS_ENSURE_ARG_POINTER(aRetVal);

  ErrorResult error;
  nsCOMPtr<nsISupports> result = GetISupports(aName, error);
  if (result) {
    result.forget(aRetVal);
  } else {
    *aRetVal = nullptr;
  }
  return error.StealNSResult();
}

already_AddRefed<nsISupports> nsCommandParams::GetISupports(
    const char* aName, ErrorResult& aRv) const {
  MOZ_ASSERT(!aRv.Failed());

  HashEntry* foundEntry = GetNamedEntry(aName);
  if (foundEntry && foundEntry->mEntryType == eISupportsType) {
    nsCOMPtr<nsISupports> result = foundEntry->mISupports;
    return result.forget();
  }
  aRv.Throw(NS_ERROR_FAILURE);
  return nullptr;
}

NS_IMETHODIMP
nsCommandParams::SetBooleanValue(const char* aName, bool aValue) {
  return SetBool(aName, aValue);
}

nsresult nsCommandParams::SetBool(const char* aName, bool aValue) {
  HashEntry* foundEntry = GetOrMakeEntry(aName, eBooleanType);
  if (!foundEntry) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  foundEntry->mData.mBoolean = aValue;
  return NS_OK;
}

NS_IMETHODIMP
nsCommandParams::SetLongValue(const char* aName, int32_t aValue) {
  return SetInt(aName, aValue);
}

nsresult nsCommandParams::SetInt(const char* aName, int32_t aValue) {
  HashEntry* foundEntry = GetOrMakeEntry(aName, eLongType);
  if (!foundEntry) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  foundEntry->mData.mLong = aValue;
  return NS_OK;
}

NS_IMETHODIMP
nsCommandParams::SetDoubleValue(const char* aName, double aValue) {
  return SetDouble(aName, aValue);
}

nsresult nsCommandParams::SetDouble(const char* aName, double aValue) {
  HashEntry* foundEntry = GetOrMakeEntry(aName, eDoubleType);
  if (!foundEntry) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  foundEntry->mData.mDouble = aValue;
  return NS_OK;
}

NS_IMETHODIMP
nsCommandParams::SetStringValue(const char* aName, const nsAString& aValue) {
  return SetString(aName, aValue);
}

nsresult nsCommandParams::SetString(const char* aName,
                                    const nsAString& aValue) {
  HashEntry* foundEntry = GetOrMakeEntry(aName, eWStringType);
  if (!foundEntry) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  foundEntry->mData.mString = new nsString(aValue);
  return NS_OK;
}

NS_IMETHODIMP
nsCommandParams::SetCStringValue(const char* aName, const nsACString& aValue) {
  return SetCString(aName, aValue);
}

nsresult nsCommandParams::SetCString(const char* aName,
                                     const nsACString& aValue) {
  HashEntry* foundEntry = GetOrMakeEntry(aName, eStringType);
  if (!foundEntry) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  foundEntry->mData.mCString = new nsCString(aValue);
  return NS_OK;
}

NS_IMETHODIMP
nsCommandParams::SetISupportsValue(const char* aName, nsISupports* aValue) {
  return SetISupports(aName, aValue);
}

nsresult nsCommandParams::SetISupports(const char* aName, nsISupports* aValue) {
  HashEntry* foundEntry = GetOrMakeEntry(aName, eISupportsType);
  if (!foundEntry) {
    return NS_ERROR_OUT_OF_MEMORY;
  }
  foundEntry->mISupports = aValue;  // addrefs
  return NS_OK;
}

NS_IMETHODIMP
nsCommandParams::RemoveValue(const char* aName) {
  mValuesHash.Remove((void*)aName);
  return NS_OK;
}

nsCommandParams::HashEntry* nsCommandParams::GetNamedEntry(
    const char* aName) const {
  return static_cast<HashEntry*>(mValuesHash.Search((void*)aName));
}

nsCommandParams::HashEntry* nsCommandParams::GetOrMakeEntry(
    const char* aName, uint8_t aEntryType) {
  auto foundEntry = static_cast<HashEntry*>(mValuesHash.Search((void*)aName));
  if (foundEntry) {  // reuse existing entry
    foundEntry->Reset(aEntryType);
    return foundEntry;
  }

  foundEntry = static_cast<HashEntry*>(mValuesHash.Add((void*)aName, fallible));
  if (!foundEntry) {
    return nullptr;
  }

  // Use placement new. Our ctor does not clobber keyHash, which is important.
  new (foundEntry) HashEntry(aEntryType, aName);
  return foundEntry;
}

PLDHashNumber nsCommandParams::HashKey(const void* aKey) {
  return HashString((const char*)aKey);
}

bool nsCommandParams::HashMatchEntry(const PLDHashEntryHdr* aEntry,
                                     const void* aKey) {
  const char* keyString = (const char*)aKey;
  const HashEntry* thisEntry = static_cast<const HashEntry*>(aEntry);
  return thisEntry->mEntryName.Equals(keyString);
}

void nsCommandParams::HashMoveEntry(PLDHashTable* aTable,
                                    const PLDHashEntryHdr* aFrom,
                                    PLDHashEntryHdr* aTo) {
  auto* fromEntry =
      const_cast<HashEntry*>(static_cast<const HashEntry*>(aFrom));
  HashEntry* toEntry = static_cast<HashEntry*>(aTo);

  new (KnownNotNull, toEntry) HashEntry(std::move(*fromEntry));

  fromEntry->~HashEntry();
}

void nsCommandParams::HashClearEntry(PLDHashTable* aTable,
                                     PLDHashEntryHdr* aEntry) {
  HashEntry* thisEntry = static_cast<HashEntry*>(aEntry);
  thisEntry->~HashEntry();
}