DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (88db9bea4580)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248
/* -*- 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 "mozilla/Attributes.h"

#include "nsEnumeratorUtils.h"

#include "nsIStringEnumerator.h"
#include "nsSimpleEnumerator.h"

#include "nsCOMPtr.h"
#include "mozilla/RefPtr.h"

class EmptyEnumeratorImpl : public nsSimpleEnumerator,
                            public nsIUTF8StringEnumerator,
                            public nsIStringEnumerator {
 public:
  EmptyEnumeratorImpl() {}

  // nsISupports interface. Not really inherited, but no mRefCnt.
  NS_DECL_ISUPPORTS_INHERITED

  // nsISimpleEnumerator
  NS_DECL_NSISIMPLEENUMERATOR
  NS_DECL_NSIUTF8STRINGENUMERATOR
  NS_DECL_NSISTRINGENUMERATORBASE
  // can't use NS_DECL_NSISTRINGENUMERATOR because they share the
  // HasMore() signature

  NS_IMETHOD GetNext(nsAString& aResult) override;

  static EmptyEnumeratorImpl* GetInstance() {
    static const EmptyEnumeratorImpl kInstance;
    return const_cast<EmptyEnumeratorImpl*>(&kInstance);
  }
};

// nsISupports interface
NS_IMETHODIMP_(MozExternalRefCountType)
EmptyEnumeratorImpl::AddRef(void) { return 2; }

NS_IMETHODIMP_(MozExternalRefCountType)
EmptyEnumeratorImpl::Release(void) { return 1; }

NS_IMPL_QUERY_INTERFACE_INHERITED(EmptyEnumeratorImpl, nsSimpleEnumerator,
                                  nsIUTF8StringEnumerator, nsIStringEnumerator)

// nsISimpleEnumerator interface
NS_IMETHODIMP
EmptyEnumeratorImpl::HasMoreElements(bool* aResult) {
  *aResult = false;
  return NS_OK;
}

NS_IMETHODIMP
EmptyEnumeratorImpl::HasMore(bool* aResult) {
  *aResult = false;
  return NS_OK;
}

NS_IMETHODIMP
EmptyEnumeratorImpl::GetNext(nsISupports** aResult) { return NS_ERROR_FAILURE; }

NS_IMETHODIMP
EmptyEnumeratorImpl::GetNext(nsACString& aResult) {
  return NS_ERROR_UNEXPECTED;
}

NS_IMETHODIMP
EmptyEnumeratorImpl::GetNext(nsAString& aResult) { return NS_ERROR_UNEXPECTED; }

NS_IMETHODIMP
EmptyEnumeratorImpl::StringIterator(nsIJSEnumerator** aRetVal) {
  return NS_ERROR_NOT_IMPLEMENTED;
}

nsresult NS_NewEmptyEnumerator(nsISimpleEnumerator** aResult) {
  *aResult = EmptyEnumeratorImpl::GetInstance();
  return NS_OK;
}

////////////////////////////////////////////////////////////////////////////////

class nsSingletonEnumerator final : public nsSimpleEnumerator {
 public:
  // nsISimpleEnumerator methods
  NS_IMETHOD HasMoreElements(bool* aResult) override;
  NS_IMETHOD GetNext(nsISupports** aResult) override;

  explicit nsSingletonEnumerator(nsISupports* aValue);

 private:
  ~nsSingletonEnumerator() override;

 protected:
  nsCOMPtr<nsISupports> mValue;
  bool mConsumed;
};

nsSingletonEnumerator::nsSingletonEnumerator(nsISupports* aValue)
    : mValue(aValue) {
  mConsumed = (mValue ? false : true);
}

nsSingletonEnumerator::~nsSingletonEnumerator() = default;

NS_IMETHODIMP
nsSingletonEnumerator::HasMoreElements(bool* aResult) {
  MOZ_ASSERT(aResult != 0, "null ptr");
  if (!aResult) {
    return NS_ERROR_NULL_POINTER;
  }

  *aResult = !mConsumed;
  return NS_OK;
}

NS_IMETHODIMP
nsSingletonEnumerator::GetNext(nsISupports** aResult) {
  MOZ_ASSERT(aResult != 0, "null ptr");
  if (!aResult) {
    return NS_ERROR_NULL_POINTER;
  }

  if (mConsumed) {
    return NS_ERROR_FAILURE;
  }

  mConsumed = true;

  *aResult = mValue;
  NS_ADDREF(*aResult);
  return NS_OK;
}

nsresult NS_NewSingletonEnumerator(nsISimpleEnumerator** aResult,
                                   nsISupports* aSingleton) {
  RefPtr<nsSingletonEnumerator> enumer = new nsSingletonEnumerator(aSingleton);
  enumer.forget(aResult);
  return NS_OK;
}

////////////////////////////////////////////////////////////////////////////////

class nsUnionEnumerator final : public nsSimpleEnumerator {
 public:
  // nsISimpleEnumerator methods
  NS_IMETHOD HasMoreElements(bool* aResult) override;
  NS_IMETHOD GetNext(nsISupports** aResult) override;

  nsUnionEnumerator(nsISimpleEnumerator* aFirstEnumerator,
                    nsISimpleEnumerator* aSecondEnumerator);

 private:
  ~nsUnionEnumerator() override;

 protected:
  nsCOMPtr<nsISimpleEnumerator> mFirstEnumerator, mSecondEnumerator;
  bool mConsumed;
  bool mAtSecond;
};

nsUnionEnumerator::nsUnionEnumerator(nsISimpleEnumerator* aFirstEnumerator,
                                     nsISimpleEnumerator* aSecondEnumerator)
    : mFirstEnumerator(aFirstEnumerator),
      mSecondEnumerator(aSecondEnumerator),
      mConsumed(false),
      mAtSecond(false) {}

nsUnionEnumerator::~nsUnionEnumerator() = default;

NS_IMETHODIMP
nsUnionEnumerator::HasMoreElements(bool* aResult) {
  MOZ_ASSERT(aResult != 0, "null ptr");
  if (!aResult) {
    return NS_ERROR_NULL_POINTER;
  }

  nsresult rv;

  if (mConsumed) {
    *aResult = false;
    return NS_OK;
  }

  if (!mAtSecond) {
    rv = mFirstEnumerator->HasMoreElements(aResult);
    if (NS_FAILED(rv)) {
      return rv;
    }

    if (*aResult) {
      return NS_OK;
    }

    mAtSecond = true;
  }

  rv = mSecondEnumerator->HasMoreElements(aResult);
  if (NS_FAILED(rv)) {
    return rv;
  }

  if (*aResult) {
    return NS_OK;
  }

  *aResult = false;
  mConsumed = true;
  return NS_OK;
}

NS_IMETHODIMP
nsUnionEnumerator::GetNext(nsISupports** aResult) {
  MOZ_ASSERT(aResult != 0, "null ptr");
  if (!aResult) {
    return NS_ERROR_NULL_POINTER;
  }

  if (mConsumed) {
    return NS_ERROR_FAILURE;
  }

  if (!mAtSecond) {
    return mFirstEnumerator->GetNext(aResult);
  }

  return mSecondEnumerator->GetNext(aResult);
}

nsresult NS_NewUnionEnumerator(nsISimpleEnumerator** aResult,
                               nsISimpleEnumerator* aFirstEnumerator,
                               nsISimpleEnumerator* aSecondEnumerator) {
  *aResult = nullptr;
  if (!aFirstEnumerator) {
    *aResult = aSecondEnumerator;
  } else if (!aSecondEnumerator) {
    *aResult = aFirstEnumerator;
  } else {
    auto* enumer = new nsUnionEnumerator(aFirstEnumerator, aSecondEnumerator);
    *aResult = enumer;
  }
  NS_ADDREF(*aResult);
  return NS_OK;
}