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.

Implementation

Mercurial (c68fe15a81fc)

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373
/* -*- 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/. */

#ifndef mozilla_dom_indexeddb_key_h__
#define mozilla_dom_indexeddb_key_h__

#include "mozilla/dom/indexedDB/IDBResult.h"

#include "js/Array.h"  // JS::GetArrayLength
#include "js/RootingAPI.h"
#include "jsapi.h"
#include "mozilla/ErrorResult.h"
#include "nsString.h"

class mozIStorageStatement;
class mozIStorageValueArray;

namespace IPC {

template <typename>
struct ParamTraits;

}  // namespace IPC

namespace mozilla {
namespace dom {
namespace indexedDB {

class Key {
  friend struct IPC::ParamTraits<Key>;

  nsCString mBuffer;

 public:
  enum {
    eTerminator = 0,
    eFloat = 0x10,
    eDate = 0x20,
    eString = 0x30,
    eBinary = 0x40,
    eArray = 0x50,
    eMaxType = eArray
  };

  static const uint8_t kMaxArrayCollapse = uint8_t(3);
  static const uint8_t kMaxRecursionDepth = uint8_t(64);

  Key() { Unset(); }

  explicit Key(nsCString aBuffer) : mBuffer(std::move(aBuffer)) {}

  Key& operator=(int64_t aInt) {
    SetFromInteger(aInt);
    return *this;
  }

  bool operator==(const Key& aOther) const {
    MOZ_ASSERT(!mBuffer.IsVoid());
    MOZ_ASSERT(!aOther.mBuffer.IsVoid());

    return mBuffer.Equals(aOther.mBuffer);
  }

  bool operator!=(const Key& aOther) const {
    MOZ_ASSERT(!mBuffer.IsVoid());
    MOZ_ASSERT(!aOther.mBuffer.IsVoid());

    return !mBuffer.Equals(aOther.mBuffer);
  }

  bool operator<(const Key& aOther) const {
    MOZ_ASSERT(!mBuffer.IsVoid());
    MOZ_ASSERT(!aOther.mBuffer.IsVoid());

    return Compare(mBuffer, aOther.mBuffer) < 0;
  }

  bool operator>(const Key& aOther) const {
    MOZ_ASSERT(!mBuffer.IsVoid());
    MOZ_ASSERT(!aOther.mBuffer.IsVoid());

    return Compare(mBuffer, aOther.mBuffer) > 0;
  }

  bool operator<=(const Key& aOther) const {
    MOZ_ASSERT(!mBuffer.IsVoid());
    MOZ_ASSERT(!aOther.mBuffer.IsVoid());

    return Compare(mBuffer, aOther.mBuffer) <= 0;
  }

  bool operator>=(const Key& aOther) const {
    MOZ_ASSERT(!mBuffer.IsVoid());
    MOZ_ASSERT(!aOther.mBuffer.IsVoid());

    return Compare(mBuffer, aOther.mBuffer) >= 0;
  }

  void Unset() { mBuffer.SetIsVoid(true); }

  bool IsUnset() const { return mBuffer.IsVoid(); }

  bool IsFloat() const { return !IsUnset() && *BufferStart() == eFloat; }

  bool IsDate() const { return !IsUnset() && *BufferStart() == eDate; }

  bool IsString() const { return !IsUnset() && *BufferStart() == eString; }

  bool IsBinary() const { return !IsUnset() && *BufferStart() == eBinary; }

  bool IsArray() const { return !IsUnset() && *BufferStart() >= eArray; }

  double ToFloat() const {
    MOZ_ASSERT(IsFloat());
    const EncodedDataType* pos = BufferStart();
    double res = DecodeNumber(pos, BufferEnd());
    MOZ_ASSERT(pos >= BufferEnd());
    return res;
  }

  double ToDateMsec() const {
    MOZ_ASSERT(IsDate());
    const EncodedDataType* pos = BufferStart();
    double res = DecodeNumber(pos, BufferEnd());
    MOZ_ASSERT(pos >= BufferEnd());
    return res;
  }

  void ToString(nsString& aString) const {
    MOZ_ASSERT(IsString());
    const EncodedDataType* pos = BufferStart();
    DecodeString(pos, BufferEnd(), aString);
    MOZ_ASSERT(pos >= BufferEnd());
  }

  IDBResult<void, IDBSpecialValue::Invalid> SetFromString(
      const nsAString& aString, ErrorResult& aRv);

  void SetFromInteger(int64_t aInt) {
    mBuffer.Truncate();
    EncodeNumber(double(aInt), eFloat);
    TrimBuffer();
  }

  // This function implements the standard algorithm "convert a value to a key".
  // A key return value is indicated by returning `true` whereas `false` means
  // either invalid (if `aRv.Failed()` is `false`) or an exception (otherwise).
  IDBResult<void, IDBSpecialValue::Invalid> SetFromJSVal(
      JSContext* aCx, JS::Handle<JS::Value> aVal, ErrorResult& aRv);

  nsresult ToJSVal(JSContext* aCx, JS::MutableHandle<JS::Value> aVal) const;

  nsresult ToJSVal(JSContext* aCx, JS::Heap<JS::Value>& aVal) const;

  // See SetFromJSVal() for the meaning of values returned by this function.
  IDBResult<void, IDBSpecialValue::Invalid> AppendItem(
      JSContext* aCx, bool aFirstOfArray, JS::Handle<JS::Value> aVal,
      ErrorResult& aRv);

  IDBResult<void, IDBSpecialValue::Invalid> ToLocaleAwareKey(
      Key& aTarget, const nsCString& aLocale, ErrorResult& aRv) const;

  void FinishArray() { TrimBuffer(); }

  const nsCString& GetBuffer() const { return mBuffer; }

  nsresult BindToStatement(mozIStorageStatement* aStatement,
                           const nsACString& aParamName) const;

  nsresult SetFromStatement(mozIStorageStatement* aStatement, uint32_t aIndex);

  nsresult SetFromValueArray(mozIStorageValueArray* aValues, uint32_t aIndex);

  static int16_t CompareKeys(const Key& aFirst, const Key& aSecond) {
    int32_t result = Compare(aFirst.mBuffer, aSecond.mBuffer);

    if (result < 0) {
      return -1;
    }

    if (result > 0) {
      return 1;
    }

    return 0;
  }

  // Implementation of the array branch of step 3 of
  // https://w3c.github.io/IndexedDB/#convert-value-to-key
  template <typename ArrayConversionPolicy>
  static IDBResult<void, IDBSpecialValue::Invalid> ConvertArrayValueToKey(
      JSContext* const aCx, JS::HandleObject aObject,
      ArrayConversionPolicy&& aPolicy, ErrorResult& aRv) {
    // 1. Let `len` be ? ToLength( ? Get(`input`, "length")).
    uint32_t len;
    if (!JS::GetArrayLength(aCx, aObject, &len)) {
      aRv.Throw(NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
      return Exception;
    }

    // 2. Add `input` to `seen`.
    aPolicy.AddToSeenSet(aCx, aObject);

    // 3. Let `keys` be a new empty list.
    aPolicy.BeginSubkeyList();

    // 4. Let `index` be 0.
    uint32_t index = 0;

    // 5. While `index` is less than `len`:
    while (index < len) {
      JS::RootedId indexId(aCx);
      if (!JS_IndexToId(aCx, index, &indexId)) {
        aRv.Throw(NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
        return Exception;
      }

      // 1. Let `hop` be ? HasOwnProperty(`input`, `index`).
      bool hop;
      if (!JS_HasOwnPropertyById(aCx, aObject, indexId, &hop)) {
        aRv.Throw(NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
        return Exception;
      }

      // 2. If `hop` is false, return invalid.
      if (!hop) {
        return Invalid;
      }

      // 3. Let `entry` be ? Get(`input`, `index`).
      JS::RootedValue entry(aCx);
      if (!JS_GetPropertyById(aCx, aObject, indexId, &entry)) {
        aRv.Throw(NS_ERROR_DOM_INDEXEDDB_UNKNOWN_ERR);
        return Exception;
      }

      // 4. Let `key` be the result of running the steps to convert a value to a
      //    key with arguments `entry` and `seen`.
      // 5. ReturnIfAbrupt(`key`).
      // 6. If `key` is invalid abort these steps and return invalid.
      // 7. Append `key` to `keys`.
      auto result = aPolicy.ConvertSubkey(aCx, entry, index, aRv);
      if (!result.Is(Ok, aRv)) {
        return result;
      }

      // 8. Increase `index` by 1.
      index += 1;
    }

    // 6. Return a new array key with value `keys`.
    aPolicy.EndSubkeyList();
    return Ok();
  }

 private:
  class MOZ_STACK_CLASS ArrayValueEncoder;

  using EncodedDataType = unsigned char;

  const EncodedDataType* BufferStart() const {
    // TODO it would be nicer if mBuffer was also using EncodedDataType
    return reinterpret_cast<const EncodedDataType*>(mBuffer.BeginReading());
  }

  const EncodedDataType* BufferEnd() const {
    return reinterpret_cast<const EncodedDataType*>(mBuffer.EndReading());
  }

  // Encoding helper. Trims trailing zeros off of mBuffer as a post-processing
  // step.
  void TrimBuffer() {
    const char* end = mBuffer.EndReading() - 1;
    while (!*end) {
      --end;
    }

    mBuffer.Truncate(end + 1 - mBuffer.BeginReading());
  }

  // Encoding functions. These append the encoded value to the end of mBuffer
  IDBResult<void, IDBSpecialValue::Invalid> EncodeJSVal(
      JSContext* aCx, JS::Handle<JS::Value> aVal, uint8_t aTypeOffset,
      ErrorResult& aRv);

  IDBResult<void, IDBSpecialValue::Invalid> EncodeString(
      const nsAString& aString, uint8_t aTypeOffset, ErrorResult& aRv);

  template <typename T>
  IDBResult<void, IDBSpecialValue::Invalid> EncodeString(const T* aStart,
                                                         const T* aEnd,
                                                         uint8_t aTypeOffset,
                                                         ErrorResult& aRv);

  template <typename T>
  IDBResult<void, IDBSpecialValue::Invalid> EncodeAsString(const T* aStart,
                                                           const T* aEnd,
                                                           uint8_t aType,
                                                           ErrorResult& aRv);

  IDBResult<void, IDBSpecialValue::Invalid> EncodeLocaleString(
      const nsDependentString& aString, uint8_t aTypeOffset,
      const nsCString& aLocale, ErrorResult& aRv);

  void EncodeNumber(double aFloat, uint8_t aType);

  IDBResult<void, IDBSpecialValue::Invalid> EncodeBinary(JSObject* aObject,
                                                         bool aIsViewObject,
                                                         uint8_t aTypeOffset,
                                                         ErrorResult& aRv);

  // Decoding functions. aPos points into mBuffer and is adjusted to point
  // past the consumed value. (Note: this may be beyond aEnd).
  static nsresult DecodeJSVal(const EncodedDataType*& aPos,
                              const EncodedDataType* aEnd, JSContext* aCx,
                              JS::MutableHandle<JS::Value> aVal);

  static void DecodeString(const EncodedDataType*& aPos,
                           const EncodedDataType* aEnd, nsString& aString);

  static double DecodeNumber(const EncodedDataType*& aPos,
                             const EncodedDataType* aEnd);

  static JSObject* DecodeBinary(const EncodedDataType*& aPos,
                                const EncodedDataType* aEnd, JSContext* aCx);

  // Returns the size of the decoded data for stringy (string or binary),
  // excluding a null terminator.
  // On return, aOutSectionEnd points to the last byte behind the current
  // encoded section, i.e. either aEnd, or the eTerminator.
  // T is the base type for the decoded data.
  template <typename T>
  static uint32_t CalcDecodedStringySize(
      const EncodedDataType* aBegin, const EncodedDataType* aEnd,
      const EncodedDataType** aOutEncodedSectionEnd);

  static uint32_t LengthOfEncodedBinary(const EncodedDataType* aPos,
                                        const EncodedDataType* aEnd);

  template <typename T>
  static void DecodeAsStringy(const EncodedDataType* aEncodedSectionBegin,
                              const EncodedDataType* aEncodedSectionEnd,
                              uint32_t aDecodedLength, T* aOut);

  template <EncodedDataType TypeMask, typename T, typename AcquireBuffer,
            typename AcquireEmpty>
  static void DecodeStringy(const EncodedDataType*& aPos,
                            const EncodedDataType* aEnd,
                            const AcquireBuffer& acquireBuffer,
                            const AcquireEmpty& acquireEmpty);

  IDBResult<void, IDBSpecialValue::Invalid> EncodeJSValInternal(
      JSContext* aCx, JS::Handle<JS::Value> aVal, uint8_t aTypeOffset,
      uint16_t aRecursionDepth, ErrorResult& aRv);

  static nsresult DecodeJSValInternal(const EncodedDataType*& aPos,
                                      const EncodedDataType* aEnd,
                                      JSContext* aCx, uint8_t aTypeOffset,
                                      JS::MutableHandle<JS::Value> aVal,
                                      uint16_t aRecursionDepth);

  template <typename T>
  nsresult SetFromSource(T* aSource, uint32_t aIndex);
};

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

#endif  // mozilla_dom_indexeddb_key_h__