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comparison: storage/src/Variant.h
storage/src/Variant.h
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| -1:000000000000 | 0:ac5ebd6fd564 |
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| 1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- | |
| 2 * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ : | |
| 3 * This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 #ifndef mozilla_storage_Variant_h__ | |
| 8 #define mozilla_storage_Variant_h__ | |
| 9 | |
| 10 #include <utility> | |
| 11 | |
| 12 #include "nsIVariant.h" | |
| 13 #include "nsString.h" | |
| 14 #include "nsTArray.h" | |
| 15 | |
| 16 /** | |
| 17 * This class is used by the storage module whenever an nsIVariant needs to be | |
| 18 * returned. We provide traits for the basic sqlite types to make use easier. | |
| 19 * The following types map to the indicated sqlite type: | |
| 20 * int64_t -> INTEGER (use IntegerVariant) | |
| 21 * double -> FLOAT (use FloatVariant) | |
| 22 * nsString -> TEXT (use TextVariant) | |
| 23 * nsCString -> TEXT (use UTF8TextVariant) | |
| 24 * uint8_t[] -> BLOB (use BlobVariant) | |
| 25 * nullptr -> NULL (use NullVariant) | |
| 26 */ | |
| 27 | |
| 28 namespace mozilla { | |
| 29 namespace storage { | |
| 30 | |
| 31 //////////////////////////////////////////////////////////////////////////////// | |
| 32 //// Base Class | |
| 33 | |
| 34 class Variant_base : public nsIVariant | |
| 35 { | |
| 36 public: | |
| 37 NS_DECL_THREADSAFE_ISUPPORTS | |
| 38 NS_DECL_NSIVARIANT | |
| 39 | |
| 40 protected: | |
| 41 virtual ~Variant_base() { } | |
| 42 }; | |
| 43 | |
| 44 //////////////////////////////////////////////////////////////////////////////// | |
| 45 //// Traits | |
| 46 | |
| 47 /** | |
| 48 * Generics | |
| 49 */ | |
| 50 | |
| 51 template <typename DataType> | |
| 52 struct variant_traits | |
| 53 { | |
| 54 static inline uint16_t type() { return nsIDataType::VTYPE_EMPTY; } | |
| 55 }; | |
| 56 | |
| 57 template <typename DataType, bool Adopting=false> | |
| 58 struct variant_storage_traits | |
| 59 { | |
| 60 typedef DataType ConstructorType; | |
| 61 typedef DataType StorageType; | |
| 62 static inline void storage_conversion(const ConstructorType aData, StorageType* _storage) | |
| 63 { | |
| 64 *_storage = aData; | |
| 65 } | |
| 66 | |
| 67 static inline void destroy(const StorageType& _storage) | |
| 68 { } | |
| 69 }; | |
| 70 | |
| 71 #define NO_CONVERSION return NS_ERROR_CANNOT_CONVERT_DATA; | |
| 72 | |
| 73 template <typename DataType, bool Adopting=false> | |
| 74 struct variant_integer_traits | |
| 75 { | |
| 76 typedef typename variant_storage_traits<DataType, Adopting>::StorageType StorageType; | |
| 77 static inline nsresult asInt32(const StorageType &, int32_t *) { NO_CONVERSION } | |
| 78 static inline nsresult asInt64(const StorageType &, int64_t *) { NO_CONVERSION } | |
| 79 }; | |
| 80 | |
| 81 template <typename DataType, bool Adopting=false> | |
| 82 struct variant_float_traits | |
| 83 { | |
| 84 typedef typename variant_storage_traits<DataType, Adopting>::StorageType StorageType; | |
| 85 static inline nsresult asDouble(const StorageType &, double *) { NO_CONVERSION } | |
| 86 }; | |
| 87 | |
| 88 template <typename DataType, bool Adopting=false> | |
| 89 struct variant_text_traits | |
| 90 { | |
| 91 typedef typename variant_storage_traits<DataType, Adopting>::StorageType StorageType; | |
| 92 static inline nsresult asUTF8String(const StorageType &, nsACString &) { NO_CONVERSION } | |
| 93 static inline nsresult asString(const StorageType &, nsAString &) { NO_CONVERSION } | |
| 94 }; | |
| 95 | |
| 96 template <typename DataType, bool Adopting=false> | |
| 97 struct variant_blob_traits | |
| 98 { | |
| 99 typedef typename variant_storage_traits<DataType, Adopting>::StorageType StorageType; | |
| 100 static inline nsresult asArray(const StorageType &, uint16_t *, uint32_t *, void **) | |
| 101 { NO_CONVERSION } | |
| 102 }; | |
| 103 | |
| 104 #undef NO_CONVERSION | |
| 105 | |
| 106 /** | |
| 107 * INTEGER types | |
| 108 */ | |
| 109 | |
| 110 template < > | |
| 111 struct variant_traits<int64_t> | |
| 112 { | |
| 113 static inline uint16_t type() { return nsIDataType::VTYPE_INT64; } | |
| 114 }; | |
| 115 template < > | |
| 116 struct variant_integer_traits<int64_t> | |
| 117 { | |
| 118 static inline nsresult asInt32(int64_t aValue, | |
| 119 int32_t *_result) | |
| 120 { | |
| 121 if (aValue > INT32_MAX || aValue < INT32_MIN) | |
| 122 return NS_ERROR_CANNOT_CONVERT_DATA; | |
| 123 | |
| 124 *_result = static_cast<int32_t>(aValue); | |
| 125 return NS_OK; | |
| 126 } | |
| 127 static inline nsresult asInt64(int64_t aValue, | |
| 128 int64_t *_result) | |
| 129 { | |
| 130 *_result = aValue; | |
| 131 return NS_OK; | |
| 132 } | |
| 133 }; | |
| 134 // xpcvariant just calls get double for integers... | |
| 135 template < > | |
| 136 struct variant_float_traits<int64_t> | |
| 137 { | |
| 138 static inline nsresult asDouble(int64_t aValue, | |
| 139 double *_result) | |
| 140 { | |
| 141 *_result = double(aValue); | |
| 142 return NS_OK; | |
| 143 } | |
| 144 }; | |
| 145 | |
| 146 /** | |
| 147 * FLOAT types | |
| 148 */ | |
| 149 | |
| 150 template < > | |
| 151 struct variant_traits<double> | |
| 152 { | |
| 153 static inline uint16_t type() { return nsIDataType::VTYPE_DOUBLE; } | |
| 154 }; | |
| 155 template < > | |
| 156 struct variant_float_traits<double> | |
| 157 { | |
| 158 static inline nsresult asDouble(double aValue, | |
| 159 double *_result) | |
| 160 { | |
| 161 *_result = aValue; | |
| 162 return NS_OK; | |
| 163 } | |
| 164 }; | |
| 165 | |
| 166 /** | |
| 167 * TEXT types | |
| 168 */ | |
| 169 | |
| 170 template < > | |
| 171 struct variant_traits<nsString> | |
| 172 { | |
| 173 static inline uint16_t type() { return nsIDataType::VTYPE_ASTRING; } | |
| 174 }; | |
| 175 template < > | |
| 176 struct variant_storage_traits<nsString> | |
| 177 { | |
| 178 typedef const nsAString & ConstructorType; | |
| 179 typedef nsString StorageType; | |
| 180 static inline void storage_conversion(ConstructorType aText, StorageType* _outData) | |
| 181 { | |
| 182 *_outData = aText; | |
| 183 } | |
| 184 static inline void destroy(const StorageType& _outData) | |
| 185 { } | |
| 186 }; | |
| 187 template < > | |
| 188 struct variant_text_traits<nsString> | |
| 189 { | |
| 190 static inline nsresult asUTF8String(const nsString &aValue, | |
| 191 nsACString &_result) | |
| 192 { | |
| 193 CopyUTF16toUTF8(aValue, _result); | |
| 194 return NS_OK; | |
| 195 } | |
| 196 static inline nsresult asString(const nsString &aValue, | |
| 197 nsAString &_result) | |
| 198 { | |
| 199 _result = aValue; | |
| 200 return NS_OK; | |
| 201 } | |
| 202 }; | |
| 203 | |
| 204 template < > | |
| 205 struct variant_traits<nsCString> | |
| 206 { | |
| 207 static inline uint16_t type() { return nsIDataType::VTYPE_UTF8STRING; } | |
| 208 }; | |
| 209 template < > | |
| 210 struct variant_storage_traits<nsCString> | |
| 211 { | |
| 212 typedef const nsACString & ConstructorType; | |
| 213 typedef nsCString StorageType; | |
| 214 static inline void storage_conversion(ConstructorType aText, StorageType* _outData) | |
| 215 { | |
| 216 *_outData = aText; | |
| 217 } | |
| 218 static inline void destroy(const StorageType &aData) | |
| 219 { } | |
| 220 }; | |
| 221 template < > | |
| 222 struct variant_text_traits<nsCString> | |
| 223 { | |
| 224 static inline nsresult asUTF8String(const nsCString &aValue, | |
| 225 nsACString &_result) | |
| 226 { | |
| 227 _result = aValue; | |
| 228 return NS_OK; | |
| 229 } | |
| 230 static inline nsresult asString(const nsCString &aValue, | |
| 231 nsAString &_result) | |
| 232 { | |
| 233 CopyUTF8toUTF16(aValue, _result); | |
| 234 return NS_OK; | |
| 235 } | |
| 236 }; | |
| 237 | |
| 238 /** | |
| 239 * BLOB types | |
| 240 */ | |
| 241 | |
| 242 template < > | |
| 243 struct variant_traits<uint8_t[]> | |
| 244 { | |
| 245 static inline uint16_t type() { return nsIDataType::VTYPE_ARRAY; } | |
| 246 }; | |
| 247 template < > | |
| 248 struct variant_storage_traits<uint8_t[], false> | |
| 249 { | |
| 250 typedef std::pair<const void *, int> ConstructorType; | |
| 251 typedef FallibleTArray<uint8_t> StorageType; | |
| 252 static inline void storage_conversion(ConstructorType aBlob, StorageType* _outData) | |
| 253 { | |
| 254 _outData->Clear(); | |
| 255 _outData->SetCapacity(aBlob.second); | |
| 256 (void)_outData->AppendElements(static_cast<const uint8_t *>(aBlob.first), | |
| 257 aBlob.second); | |
| 258 } | |
| 259 static inline void destroy(const StorageType& _outData) | |
| 260 { } | |
| 261 }; | |
| 262 template < > | |
| 263 struct variant_storage_traits<uint8_t[], true> | |
| 264 { | |
| 265 typedef std::pair<uint8_t *, int> ConstructorType; | |
| 266 typedef std::pair<uint8_t *, int> StorageType; | |
| 267 static inline void storage_conversion(ConstructorType aBlob, StorageType* _outData) | |
| 268 { | |
| 269 *_outData = aBlob; | |
| 270 } | |
| 271 static inline void destroy(StorageType &aData) | |
| 272 { | |
| 273 if (aData.first) { | |
| 274 NS_Free(aData.first); | |
| 275 aData.first = nullptr; | |
| 276 } | |
| 277 } | |
| 278 }; | |
| 279 template < > | |
| 280 struct variant_blob_traits<uint8_t[], false> | |
| 281 { | |
| 282 static inline nsresult asArray(FallibleTArray<uint8_t> &aData, | |
| 283 uint16_t *_type, | |
| 284 uint32_t *_size, | |
| 285 void **_result) | |
| 286 { | |
| 287 // For empty blobs, we return nullptr. | |
| 288 if (aData.Length() == 0) { | |
| 289 *_result = nullptr; | |
| 290 *_type = nsIDataType::VTYPE_UINT8; | |
| 291 *_size = 0; | |
| 292 return NS_OK; | |
| 293 } | |
| 294 | |
| 295 // Otherwise, we copy the array. | |
| 296 *_result = nsMemory::Clone(aData.Elements(), aData.Length() * sizeof(uint8_t)); | |
| 297 NS_ENSURE_TRUE(*_result, NS_ERROR_OUT_OF_MEMORY); | |
| 298 | |
| 299 // Set type and size | |
| 300 *_type = nsIDataType::VTYPE_UINT8; | |
| 301 *_size = aData.Length(); | |
| 302 return NS_OK; | |
| 303 } | |
| 304 }; | |
| 305 | |
| 306 template < > | |
| 307 struct variant_blob_traits<uint8_t[], true> | |
| 308 { | |
| 309 static inline nsresult asArray(std::pair<uint8_t *, int> &aData, | |
| 310 uint16_t *_type, | |
| 311 uint32_t *_size, | |
| 312 void **_result) | |
| 313 { | |
| 314 // For empty blobs, we return nullptr. | |
| 315 if (aData.second == 0) { | |
| 316 *_result = nullptr; | |
| 317 *_type = nsIDataType::VTYPE_UINT8; | |
| 318 *_size = 0; | |
| 319 return NS_OK; | |
| 320 } | |
| 321 | |
| 322 // Otherwise, transfer the data out. | |
| 323 *_result = aData.first; | |
| 324 aData.first = nullptr; | |
| 325 MOZ_ASSERT(*_result); // We asked for it twice, better not use adopting! | |
| 326 | |
| 327 // Set type and size | |
| 328 *_type = nsIDataType::VTYPE_UINT8; | |
| 329 *_size = aData.second; | |
| 330 return NS_OK; | |
| 331 } | |
| 332 }; | |
| 333 | |
| 334 /** | |
| 335 * nullptr type | |
| 336 */ | |
| 337 | |
| 338 class NullVariant : public Variant_base | |
| 339 { | |
| 340 public: | |
| 341 NS_IMETHOD GetDataType(uint16_t *_type) | |
| 342 { | |
| 343 NS_ENSURE_ARG_POINTER(_type); | |
| 344 *_type = nsIDataType::VTYPE_EMPTY; | |
| 345 return NS_OK; | |
| 346 } | |
| 347 | |
| 348 NS_IMETHOD GetAsAUTF8String(nsACString &_str) | |
| 349 { | |
| 350 // Return a void string. | |
| 351 _str.Truncate(0); | |
| 352 _str.SetIsVoid(true); | |
| 353 return NS_OK; | |
| 354 } | |
| 355 | |
| 356 NS_IMETHOD GetAsAString(nsAString &_str) | |
| 357 { | |
| 358 // Return a void string. | |
| 359 _str.Truncate(0); | |
| 360 _str.SetIsVoid(true); | |
| 361 return NS_OK; | |
| 362 } | |
| 363 }; | |
| 364 | |
| 365 //////////////////////////////////////////////////////////////////////////////// | |
| 366 //// Template Implementation | |
| 367 | |
| 368 template <typename DataType, bool Adopting=false> | |
| 369 class Variant : public Variant_base | |
| 370 { | |
| 371 ~Variant() | |
| 372 { | |
| 373 variant_storage_traits<DataType, Adopting>::destroy(mData); | |
| 374 } | |
| 375 | |
| 376 public: | |
| 377 Variant(const typename variant_storage_traits<DataType, Adopting>::ConstructorType aData) | |
| 378 { | |
| 379 variant_storage_traits<DataType, Adopting>::storage_conversion(aData, &mData); | |
| 380 } | |
| 381 | |
| 382 NS_IMETHOD GetDataType(uint16_t *_type) | |
| 383 { | |
| 384 *_type = variant_traits<DataType>::type(); | |
| 385 return NS_OK; | |
| 386 } | |
| 387 NS_IMETHOD GetAsInt32(int32_t *_integer) | |
| 388 { | |
| 389 return variant_integer_traits<DataType, Adopting>::asInt32(mData, _integer); | |
| 390 } | |
| 391 | |
| 392 NS_IMETHOD GetAsInt64(int64_t *_integer) | |
| 393 { | |
| 394 return variant_integer_traits<DataType, Adopting>::asInt64(mData, _integer); | |
| 395 } | |
| 396 | |
| 397 NS_IMETHOD GetAsDouble(double *_double) | |
| 398 { | |
| 399 return variant_float_traits<DataType, Adopting>::asDouble(mData, _double); | |
| 400 } | |
| 401 | |
| 402 NS_IMETHOD GetAsAUTF8String(nsACString &_str) | |
| 403 { | |
| 404 return variant_text_traits<DataType, Adopting>::asUTF8String(mData, _str); | |
| 405 } | |
| 406 | |
| 407 NS_IMETHOD GetAsAString(nsAString &_str) | |
| 408 { | |
| 409 return variant_text_traits<DataType, Adopting>::asString(mData, _str); | |
| 410 } | |
| 411 | |
| 412 NS_IMETHOD GetAsArray(uint16_t *_type, | |
| 413 nsIID *, | |
| 414 uint32_t *_size, | |
| 415 void **_data) | |
| 416 { | |
| 417 return variant_blob_traits<DataType, Adopting>::asArray(mData, _type, _size, _data); | |
| 418 } | |
| 419 | |
| 420 private: | |
| 421 typename variant_storage_traits<DataType, Adopting>::StorageType mData; | |
| 422 }; | |
| 423 | |
| 424 //////////////////////////////////////////////////////////////////////////////// | |
| 425 //// Handy typedefs! Use these for the right mapping. | |
| 426 | |
| 427 typedef Variant<int64_t> IntegerVariant; | |
| 428 typedef Variant<double> FloatVariant; | |
| 429 typedef Variant<nsString> TextVariant; | |
| 430 typedef Variant<nsCString> UTF8TextVariant; | |
| 431 typedef Variant<uint8_t[], false> BlobVariant; | |
| 432 typedef Variant<uint8_t[], true> AdoptedBlobVariant; | |
| 433 | |
| 434 } // namespace storage | |
| 435 } // namespace mozilla | |
| 436 | |
| 437 #include "Variant_inl.h" | |
| 438 | |
| 439 #endif // mozilla_storage_Variant_h__ |
