list.h 20.5 KB
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546
// Copyright (c) 2013, Kenton Varda <temporal@gmail.com>
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef CAPNP_LIST_H_
#define CAPNP_LIST_H_

#include "layout.h"
#include "orphan.h"
#include <initializer_list>

namespace capnp {
namespace _ {  // private

template <typename T>
class TemporaryPointer {
  // This class is a little hack which lets us define operator->() in cases where it needs to
  // return a pointer to a temporary value.  We instead construct a TemporaryPointer and return that
  // (by value).  The compiler then invokes operator->() on the TemporaryPointer, which itself is
  // able to return a real pointer to its member.

public:
  TemporaryPointer(T&& value): value(kj::mv(value)) {}
  TemporaryPointer(const T& value): value(value) {}

  inline T* operator->() { return &value; }
private:
  T value;
};

template <typename Container, typename Element>
class IndexingIterator {
public:
  IndexingIterator() = default;

  inline Element operator*() const { return (*container)[index]; }
  inline TemporaryPointer<Element> operator->() const {
    return TemporaryPointer<Element>((*container)[index]);
  }
  inline Element operator[]( int off) const { return (*container)[index]; }
  inline Element operator[](uint off) const { return (*container)[index]; }

  inline IndexingIterator& operator++() { ++index; return *this; }
  inline IndexingIterator operator++(int) { IndexingIterator other = *this; ++index; return other; }
  inline IndexingIterator& operator--() { --index; return *this; }
  inline IndexingIterator operator--(int) { IndexingIterator other = *this; --index; return other; }

  inline IndexingIterator operator+(uint amount) const { return IndexingIterator(container, index + amount); }
  inline IndexingIterator operator-(uint amount) const { return IndexingIterator(container, index - amount); }
  inline IndexingIterator operator+( int amount) const { return IndexingIterator(container, index + amount); }
  inline IndexingIterator operator-( int amount) const { return IndexingIterator(container, index - amount); }

  inline int operator-(const IndexingIterator& other) const { return index - other.index; }

  inline IndexingIterator& operator+=(uint amount) { index += amount; return *this; }
  inline IndexingIterator& operator-=(uint amount) { index -= amount; return *this; }
  inline IndexingIterator& operator+=( int amount) { index += amount; return *this; }
  inline IndexingIterator& operator-=( int amount) { index -= amount; return *this; }

  // STL says comparing iterators of different containers is not allowed, so we only compare
  // indices here.
  inline bool operator==(const IndexingIterator& other) const { return index == other.index; }
  inline bool operator!=(const IndexingIterator& other) const { return index != other.index; }
  inline bool operator<=(const IndexingIterator& other) const { return index <= other.index; }
  inline bool operator>=(const IndexingIterator& other) const { return index >= other.index; }
  inline bool operator< (const IndexingIterator& other) const { return index <  other.index; }
  inline bool operator> (const IndexingIterator& other) const { return index >  other.index; }

private:
  Container* container;
  uint index;

  friend Container;
  inline IndexingIterator(Container* container, uint index)
      : container(container), index(index) {}
};

}  // namespace _ (private)

template <typename T>
struct List<T, Kind::PRIMITIVE> {
  // List of primitives.

  List() = delete;

  class Reader {
  public:
    typedef List<T> Reads;

    Reader() = default;
    inline explicit Reader(_::ListReader reader): reader(reader) {}

    inline uint size() const { return reader.size() / ELEMENTS; }
    inline T operator[](uint index) const {
      return reader.template getDataElement<T>(index * ELEMENTS);
    }

    typedef _::IndexingIterator<const Reader, T> Iterator;
    inline Iterator begin() const { return Iterator(this, 0); }
    inline Iterator end() const { return Iterator(this, size()); }

  private:
    _::ListReader reader;
    template <typename U, Kind K>
    friend struct _::PointerHelpers;
    template <typename U, Kind K>
    friend struct List;
    friend class Orphanage;
    template <typename U, Kind K>
    friend struct ToDynamic_;
  };

  class Builder {
  public:
    typedef List<T> Builds;

    Builder() = default;
    inline explicit Builder(_::ListBuilder builder): builder(builder) {}

    inline operator Reader() { return Reader(builder.asReader()); }
    inline Reader asReader() { return Reader(builder.asReader()); }

    inline uint size() const { return builder.size() / ELEMENTS; }
    inline T operator[](uint index) {
      return builder.template getDataElement<T>(index * ELEMENTS);
    }
    inline void set(uint index, T value) {
      // Alas, it is not possible to make operator[] return a reference to which you can assign,
      // since the encoded representation does not necessarily match the compiler's representation
      // of the type.  We can't even return a clever class that implements operator T() and
      // operator=() because it will lead to surprising behavior when using type inference (e.g.
      // calling a template function with inferred argument types, or using "auto" or "decltype").

      builder.template setDataElement<T>(index * ELEMENTS, value);
    }

    typedef _::IndexingIterator<Builder, T> Iterator;
    inline Iterator begin() { return Iterator(this, 0); }
    inline Iterator end() { return Iterator(this, size()); }

  private:
    _::ListBuilder builder;
    friend class Orphanage;
    template <typename U, Kind K>
    friend struct ToDynamic_;
  };

private:
  inline static _::ListBuilder initAsElementOf(
      _::ListBuilder& builder, uint index, uint size) {
    return builder.initListElement(
        index * ELEMENTS, _::ElementSizeForType<T>::value, size * ELEMENTS);
  }
  inline static _::ListBuilder getAsElementOf(
      _::ListBuilder& builder, uint index) {
    return builder.getListElement(index * ELEMENTS, _::ElementSizeForType<T>::value);
  }
  inline static _::ListReader getAsElementOf(
      const _::ListReader& reader, uint index) {
    return reader.getListElement(index * ELEMENTS, _::ElementSizeForType<T>::value);
  }

  inline static _::ListBuilder initAsFieldOf(
      _::StructBuilder& builder, WirePointerCount index, uint size) {
    return builder.initListField(index, _::ElementSizeForType<T>::value, size * ELEMENTS);
  }
  inline static _::ListBuilder getAsFieldOf(
      _::StructBuilder& builder, WirePointerCount index, const word* defaultValue) {
    return builder.getListField(index, _::ElementSizeForType<T>::value, defaultValue);
  }
  inline static _::ListReader getAsFieldOf(
      const _::StructReader& reader, WirePointerCount index, const word* defaultValue) {
    return reader.getListField(index, _::ElementSizeForType<T>::value, defaultValue);
  }

  template <typename U, Kind k>
  friend struct List;
  template <typename U, Kind K>
  friend struct _::PointerHelpers;
};

template <typename T>
struct List<T, Kind::ENUM>: public List<T, Kind::PRIMITIVE> {};

template <typename T>
struct List<T, Kind::STRUCT> {
  // List of structs.

  List() = delete;

  class Reader {
  public:
    typedef List<T> Reads;

    Reader() = default;
    inline explicit Reader(_::ListReader reader): reader(reader) {}

    inline uint size() const { return reader.size() / ELEMENTS; }
    inline typename T::Reader operator[](uint index) const {
      return typename T::Reader(reader.getStructElement(index * ELEMENTS));
    }

    typedef _::IndexingIterator<const Reader, typename T::Reader> Iterator;
    inline Iterator begin() const { return Iterator(this, 0); }
    inline Iterator end() const { return Iterator(this, size()); }

  private:
    _::ListReader reader;
    template <typename U, Kind K>
    friend struct _::PointerHelpers;
    template <typename U, Kind K>
    friend struct List;
    friend class Orphanage;
    template <typename U, Kind K>
    friend struct ToDynamic_;
  };

  class Builder {
  public:
    typedef List<T> Builds;

    Builder() = default;
    inline explicit Builder(_::ListBuilder builder): builder(builder) {}

    inline operator Reader() { return Reader(builder.asReader()); }
    inline Reader asReader() { return Reader(builder.asReader()); }

    inline uint size() const { return builder.size() / ELEMENTS; }
    inline typename T::Builder operator[](uint index) {
      return typename T::Builder(builder.getStructElement(index * ELEMENTS));
    }

    inline void adoptWithCaveats(uint index, Orphan<T>&& orphan) {
      // Mostly behaves like you'd expect `adopt` to behave, but with two caveats originating from
      // the fact that structs in a struct list are allocated inline rather than by pointer:
      // * This actually performs a shallow copy, effectively adopting each of the orphan's
      //   children rather than adopting the orphan itself.  The orphan ends up being discarded,
      //   possibly wasting space in the message object.
      // * If the orphan is larger than the target struct -- say, because the orphan was built
      //   using a newer version of the schema that has additional fields -- it will be truncated,
      //   losing data.

      // We pass a zero-valued StructSize to asStruct() because we do not want the struct to be
      // expanded under any circumstances.  We're just going to throw it away anyway, and
      // transferContentFrom() already carefully compares the struct sizes before transferring.
      builder.getStructElement(index * ELEMENTS).transferContentFrom(
          orphan.builder.asStruct(_::StructSize(
              0 * WORDS, 0 * POINTERS, _::FieldSize::VOID)));
    }
    inline void setWithCaveats(uint index, const typename T::Reader& reader) {
      // Mostly behaves like you'd expect `set` to behave, but with a caveat originating from
      // the fact that structs in a struct list are allocated inline rather than by pointer:
      // If the source struct is larger than the target struct -- say, because the source was built
      // using a newer version of the schema that has additional fields -- it will be truncated,
      // losing data.

      builder.getStructElement(index * ELEMENTS).copyContentFrom(reader._reader);
    }

    // There are no init(), set(), adopt(), or disown() methods for lists of structs because the
    // elements of the list are inlined and are initialized when the list is initialized.  This
    // means that init() would be redundant, and set() would risk data loss if the input struct
    // were from a newer version of the protocol.

    typedef _::IndexingIterator<Builder, typename T::Builder> Iterator;
    inline Iterator begin() { return Iterator(this, 0); }
    inline Iterator end() { return Iterator(this, size()); }

  private:
    _::ListBuilder builder;
    friend class Orphanage;
    template <typename U, Kind K>
    friend struct ToDynamic_;
  };

private:
  inline static _::ListBuilder initAsElementOf(
      _::ListBuilder& builder, uint index, uint size) {
    return builder.initStructListElement(
        index * ELEMENTS, size * ELEMENTS, _::structSize<T>());
  }
  inline static _::ListBuilder getAsElementOf(
      _::ListBuilder& builder, uint index) {
    return builder.getStructListElement(index * ELEMENTS, _::structSize<T>());
  }
  inline static _::ListReader getAsElementOf(
      const _::ListReader& reader, uint index) {
    return reader.getListElement(index * ELEMENTS, _::FieldSize::INLINE_COMPOSITE);
  }

  inline static _::ListBuilder initAsFieldOf(
      _::StructBuilder& builder, WirePointerCount index, uint size) {
    return builder.initStructListField(index, size * ELEMENTS, _::structSize<T>());
  }
  inline static _::ListBuilder getAsFieldOf(
      _::StructBuilder& builder, WirePointerCount index, const word* defaultValue) {
    return builder.getStructListField(index, _::structSize<T>(), defaultValue);
  }
  inline static _::ListReader getAsFieldOf(
      const _::StructReader& reader, WirePointerCount index, const word* defaultValue) {
    return reader.getListField(index, _::FieldSize::INLINE_COMPOSITE, defaultValue);
  }

  template <typename U, Kind k>
  friend struct List;
  template <typename U, Kind K>
  friend struct _::PointerHelpers;
};

template <typename T>
struct List<List<T>, Kind::LIST> {
  // List of lists.

  List() = delete;

  class Reader {
  public:
    typedef List<List<T>> Reads;

    Reader() = default;
    inline explicit Reader(_::ListReader reader): reader(reader) {}

    inline uint size() const { return reader.size() / ELEMENTS; }
    inline typename List<T>::Reader operator[](uint index) const {
      return typename List<T>::Reader(List<T>::getAsElementOf(reader, index));
    }

    typedef _::IndexingIterator<const Reader, typename List<T>::Reader> Iterator;
    inline Iterator begin() const { return Iterator(this, 0); }
    inline Iterator end() const { return Iterator(this, size()); }

  private:
    _::ListReader reader;
    template <typename U, Kind K>
    friend struct _::PointerHelpers;
    template <typename U, Kind K>
    friend struct List;
    friend class Orphanage;
    template <typename U, Kind K>
    friend struct ToDynamic_;
  };

  class Builder {
  public:
    typedef List<List<T>> Builds;

    Builder() = default;
    inline explicit Builder(_::ListBuilder builder): builder(builder) {}

    inline operator Reader() { return Reader(builder.asReader()); }
    inline Reader asReader() { return Reader(builder.asReader()); }

    inline uint size() const { return builder.size() / ELEMENTS; }
    inline typename List<T>::Builder operator[](uint index) {
      return typename List<T>::Builder(List<T>::getAsElementOf(builder, index));
    }
    inline typename List<T>::Builder init(uint index, uint size) {
      return typename List<T>::Builder(List<T>::initAsElementOf(builder, index, size));
    }
    inline void set(uint index, typename List<T>::Reader value) {
      builder.setListElement(index * ELEMENTS, value.reader);
    }
    void set(uint index, std::initializer_list<ReaderFor<T>> value) {
      auto l = init(index, value.size());
      uint i = 0;
      for (auto& element: value) {
        l.set(i++, element);
      }
    }
    inline void adopt(uint index, Orphan<T>&& value) {
      builder.adopt(index * ELEMENTS, kj::mv(value));
    }
    inline Orphan<T> disown(uint index) {
      return Orphan<T>(builder.disown(index * ELEMENTS));
    }

    typedef _::IndexingIterator<Builder, typename List<T>::Builder> Iterator;
    inline Iterator begin() { return Iterator(this, 0); }
    inline Iterator end() { return Iterator(this, size()); }

  private:
    _::ListBuilder builder;
    friend class Orphanage;
    template <typename U, Kind K>
    friend struct ToDynamic_;
  };

private:
  inline static _::ListBuilder initAsElementOf(
      _::ListBuilder& builder, uint index, uint size) {
    return builder.initListElement(
        index * ELEMENTS, _::FieldSize::POINTER, size * ELEMENTS);
  }
  inline static _::ListBuilder getAsElementOf(
      _::ListBuilder& builder, uint index) {
    return builder.getListElement(index * ELEMENTS, _::FieldSize::POINTER);
  }
  inline static _::ListReader getAsElementOf(
      const _::ListReader& reader, uint index) {
    return reader.getListElement(index * ELEMENTS, _::FieldSize::POINTER);
  }

  inline static _::ListBuilder initAsFieldOf(
      _::StructBuilder& builder, WirePointerCount index, uint size) {
    return builder.initListField(index, _::FieldSize::POINTER, size * ELEMENTS);
  }
  inline static _::ListBuilder getAsFieldOf(
      _::StructBuilder& builder, WirePointerCount index, const word* defaultValue) {
    return builder.getListField(index, _::FieldSize::POINTER, defaultValue);
  }
  inline static _::ListReader getAsFieldOf(
      const _::StructReader& reader, WirePointerCount index, const word* defaultValue) {
    return reader.getListField(index, _::FieldSize::POINTER, defaultValue);
  }

  template <typename U, Kind k>
  friend struct List;
  template <typename U, Kind K>
  friend struct _::PointerHelpers;
};

template <typename T>
struct List<T, Kind::BLOB> {
  List() = delete;

  class Reader {
  public:
    typedef List<T> Reads;

    Reader() = default;
    inline explicit Reader(_::ListReader reader): reader(reader) {}

    inline uint size() const { return reader.size() / ELEMENTS; }
    inline typename T::Reader operator[](uint index) const {
      return reader.getBlobElement<T>(index * ELEMENTS);
    }

    typedef _::IndexingIterator<const Reader, typename T::Reader> Iterator;
    inline Iterator begin() const { return Iterator(this, 0); }
    inline Iterator end() const { return Iterator(this, size()); }

  private:
    _::ListReader reader;
    template <typename U, Kind K>
    friend struct _::PointerHelpers;
    template <typename U, Kind K>
    friend struct List;
    friend class Orphanage;
    template <typename U, Kind K>
    friend struct ToDynamic_;
  };

  class Builder {
  public:
    typedef List<T> Builds;

    Builder() = default;
    inline explicit Builder(_::ListBuilder builder): builder(builder) {}

    inline operator Reader() { return Reader(builder.asReader()); }
    inline Reader asReader() { return Reader(builder.asReader()); }

    inline uint size() const { return builder.size() / ELEMENTS; }
    inline typename T::Builder operator[](uint index) {
      return builder.getBlobElement<T>(index * ELEMENTS);
    }
    inline void set(uint index, typename T::Reader value) {
      builder.setBlobElement<T>(index * ELEMENTS, value);
    }
    inline typename T::Builder init(uint index, uint size) {
      return builder.initBlobElement<T>(index * ELEMENTS, size * BYTES);
    }
    inline void adopt(uint index, Orphan<T>&& value) {
      builder.adopt(index * ELEMENTS, kj::mv(value));
    }
    inline Orphan<T> disown(uint index) {
      return Orphan<T>(builder.disown(index * ELEMENTS));
    }

    typedef _::IndexingIterator<Builder, typename T::Builder> Iterator;
    inline Iterator begin() { return Iterator(this, 0); }
    inline Iterator end() { return Iterator(this, size()); }

  private:
    _::ListBuilder builder;
    friend class Orphanage;
    template <typename U, Kind K>
    friend struct ToDynamic_;
  };

private:
  inline static _::ListBuilder initAsElementOf(
      _::ListBuilder& builder, uint index, uint size) {
    return builder.initListElement(
        index * ELEMENTS, _::FieldSize::POINTER, size * ELEMENTS);
  }
  inline static _::ListBuilder getAsElementOf(
      _::ListBuilder& builder, uint index) {
    return builder.getListElement(index * ELEMENTS, _::FieldSize::POINTER);
  }
  inline static _::ListReader getAsElementOf(
      const _::ListReader& reader, uint index) {
    return reader.getListElement(index * ELEMENTS, _::FieldSize::POINTER);
  }

  inline static _::ListBuilder initAsFieldOf(
      _::StructBuilder& builder, WirePointerCount index, uint size) {
    return builder.initListField(index, _::FieldSize::POINTER, size * ELEMENTS);
  }
  inline static _::ListBuilder getAsFieldOf(
      _::StructBuilder& builder, WirePointerCount index, const word* defaultValue) {
    return builder.getListField(index, _::FieldSize::POINTER, defaultValue);
  }
  inline static _::ListReader getAsFieldOf(
      const _::StructReader& reader, WirePointerCount index, const word* defaultValue) {
    return reader.getListField(index, _::FieldSize::POINTER, defaultValue);
  }

  template <typename U, Kind k>
  friend struct List;
  template <typename U, Kind K>
  friend struct _::PointerHelpers;
};

}  // namespace capnp

#endif  // CAPNP_LIST_H_