widget/nsTransferable.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /*
   7 Notes to self:
   8
   9 - at some point, strings will be accessible from JS, so we won't have to wrap
  10    flavors in an nsISupportsCString. Until then, we're kinda stuck with
  11    this crappy API of nsIArrays.
  12
  13 */
  14
  15 #include "nsTransferable.h"
  16 #include "nsAnonymousTemporaryFile.h"
  17 #include "nsArray.h"
  18 #include "nsArrayUtils.h"
  19 #include "nsString.h"
  20 #include "nsReadableUtils.h"
  21 #include "nsTArray.h"
  22 #include "nsIFormatConverter.h"
  23 #include "nsIContentPolicy.h"
  24 #include "nsCOMPtr.h"
  25 #include "nsXPCOM.h"
  26 #include "nsISupportsPrimitives.h"
  27 #include "nsMemory.h"
  28 #include "nsPrimitiveHelpers.h"
  29 #include "nsDirectoryServiceDefs.h"
  30 #include "nsDirectoryService.h"
  31 #include "nsCRT.h"
  32 #include "nsNetUtil.h"
  33 #include "nsILoadContext.h"
  34 #include "nsXULAppAPI.h"
  35 #include "mozilla/UniquePtr.h"
  36
  37 using namespace mozilla;
  38
  39 NS_IMPL_ISUPPORTS(nsTransferable, nsITransferable)
  40
  41 DataStruct::DataStruct(DataStruct&& aRHS)
  42     : mData(aRHS.mData.forget()),
  43       mCacheFD(aRHS.mCacheFD),
  44       mFlavor(aRHS.mFlavor) {
  45   aRHS.mCacheFD = nullptr;
  46 }
  47
  48 //-------------------------------------------------------------------------
  49 DataStruct::~DataStruct() {
  50   if (mCacheFD) {
  51     PR_Close(mCacheFD);
  52   }
  53 }
  54
  55 //-------------------------------------------------------------------------
  56
  57 void DataStruct::SetData(nsISupports* aData, bool aIsPrivateData) {
  58   // Now, check to see if we consider the data to be "too large"
  59   // as well as ensuring that private browsing mode is disabled.
  60   // File IO is not allowed in content processes.
  61   if (!aIsPrivateData && XRE_IsParentProcess()) {
  62     void* data = nullptr;
  63     uint32_t dataLen = 0;
  64     nsPrimitiveHelpers::CreateDataFromPrimitive(mFlavor, aData, &data,
  65                                                 &dataLen);
  66
  67     if (dataLen > kLargeDatasetSize) {
  68       // Too large, cache it to disk instead of memory.
  69       if (NS_SUCCEEDED(WriteCache(data, dataLen))) {
  70         free(data);
  71         // Clear previously set small data.
  72         mData = nullptr;
  73         return;
  74       }
  75
  76       NS_WARNING("Oh no, couldn't write data to the cache file");
  77     }
  78
  79     free(data);
  80   }
  81
  82   if (mCacheFD) {
  83     // Clear previously set big data.
  84     PR_Close(mCacheFD);
  85     mCacheFD = nullptr;
  86   }
  87
  88   mData = aData;
  89 }
  90
  91 //-------------------------------------------------------------------------
  92 void DataStruct::GetData(nsISupports** aData) {
  93   // check here to see if the data is cached on disk
  94   if (mCacheFD) {
  95     // if so, read it in and pass it back
  96     // ReadCache creates memory and copies the data into it.
  97     if (NS_SUCCEEDED(ReadCache(aData))) {
  98       return;
  99     }
 100
 101     // oh shit, something went horribly wrong here.
 102     NS_WARNING("Oh no, couldn't read data in from the cache file");
 103     *aData = nullptr;
 104     PR_Close(mCacheFD);
 105     mCacheFD = nullptr;
 106     return;
 107   }
 108
 109   nsCOMPtr<nsISupports> data = mData;
 110   data.forget(aData);
 111 }
 112
 113 //-------------------------------------------------------------------------
 114 nsresult DataStruct::WriteCache(void* aData, uint32_t aDataLen) {
 115   MOZ_ASSERT(aData && aDataLen);
 116   MOZ_ASSERT(aDataLen <= uint32_t(std::numeric_limits<int32_t>::max()),
 117              "too large size for PR_Write");
 118
 119   nsresult rv;
 120   if (!mCacheFD) {
 121     rv = NS_OpenAnonymousTemporaryFile(&mCacheFD);
 122     if (NS_FAILED(rv)) {
 123       return NS_ERROR_FAILURE;
 124     }
 125   } else if (PR_Seek64(mCacheFD, 0, PR_SEEK_SET) == -1) {
 126     return NS_ERROR_FAILURE;
 127   }
 128
 129   // Write out the contents of the clipboard to the file.
 130   int32_t written = PR_Write(mCacheFD, aData, aDataLen);
 131   if (written == int32_t(aDataLen)) {
 132     return NS_OK;
 133   }
 134
 135   PR_Close(mCacheFD);
 136   mCacheFD = nullptr;
 137   return NS_ERROR_FAILURE;
 138 }
 139
 140 //-------------------------------------------------------------------------
 141 nsresult DataStruct::ReadCache(nsISupports** aData) {
 142   if (!mCacheFD) {
 143     return NS_ERROR_FAILURE;
 144   }
 145
 146   PRFileInfo fileInfo;
 147   if (PR_GetOpenFileInfo(mCacheFD, &fileInfo) != PR_SUCCESS) {
 148     return NS_ERROR_FAILURE;
 149   }
 150   if (PR_Seek64(mCacheFD, 0, PR_SEEK_SET) == -1) {
 151     return NS_ERROR_FAILURE;
 152   }
 153   uint32_t fileSize = fileInfo.size;
 154
 155   auto data = MakeUnique<char[]>(fileSize);
 156   if (!data) {
 157     return NS_ERROR_OUT_OF_MEMORY;
 158   }
 159
 160   uint32_t actual = PR_Read(mCacheFD, data.get(), fileSize);
 161   if (actual != fileSize) {
 162     return NS_ERROR_FAILURE;
 163   }
 164
 165   nsPrimitiveHelpers::CreatePrimitiveForData(mFlavor, data.get(), fileSize,
 166                                              aData);
 167   return NS_OK;
 168 }
 169
 170 //-------------------------------------------------------------------------
 171 //
 172 // Transferable constructor
 173 //
 174 //-------------------------------------------------------------------------
 175 nsTransferable::nsTransferable()
 176     : mPrivateData(false),
 177       mContentPolicyType(nsIContentPolicy::TYPE_OTHER)
 178 #ifdef DEBUG
 179       ,
 180       mInitialized(false)
 181 #endif
 182 {
 183 }
 184
 185 //-------------------------------------------------------------------------
 186 //
 187 // Transferable destructor
 188 //
 189 //-------------------------------------------------------------------------
 190 nsTransferable::~nsTransferable() = default;
 191
 192 NS_IMETHODIMP
 193 nsTransferable::Init(nsILoadContext* aContext) {
 194   MOZ_ASSERT(!mInitialized);
 195
 196   if (aContext) {
 197     mPrivateData = aContext->UsePrivateBrowsing();
 198   }
 199 #ifdef DEBUG
 200   mInitialized = true;
 201 #endif
 202   return NS_OK;
 203 }
 204
 205 //
 206 // GetTransferDataFlavors
 207 //
 208 // Returns a copy of the internal list of flavors. This does NOT take into
 209 // account any converter that may be registered.
 210 //
 211 void nsTransferable::GetTransferDataFlavors(nsTArray<nsCString>& aFlavors) {
 212   MOZ_ASSERT(mInitialized);
 213
 214   for (size_t i = 0; i < mDataArray.Length(); ++i) {
 215     DataStruct& data = mDataArray.ElementAt(i);
 216     aFlavors.AppendElement(data.GetFlavor());
 217   }
 218 }
 219
 220 Maybe<size_t> nsTransferable::FindDataFlavor(const char* aFlavor) {
 221   nsDependentCString flavor(aFlavor);
 222
 223   for (size_t i = 0; i < mDataArray.Length(); ++i) {
 224     if (mDataArray[i].GetFlavor().Equals(flavor)) {
 225       return Some(i);
 226     }
 227   }
 228
 229   return Nothing();
 230 }
 231
 232 //
 233 // GetTransferData
 234 //
 235 // Returns the data of the requested flavor, obtained from either having the
 236 // data on hand or using a converter to get it. The data is wrapped in a
 237 // nsISupports primitive so that it is accessible from JS.
 238 //
 239 NS_IMETHODIMP
 240 nsTransferable::GetTransferData(const char* aFlavor, nsISupports** aData) {
 241   MOZ_ASSERT(mInitialized);
 242
 243   *aData = nullptr;
 244
 245   nsresult rv = NS_OK;
 246
 247   // First look and see if the data is present in one of the intrinsic flavors.
 248   if (Maybe<size_t> index = FindDataFlavor(aFlavor)) {
 249     nsCOMPtr<nsISupports> dataBytes;
 250     mDataArray[index.value()].GetData(getter_AddRefs(dataBytes));
 251
 252     // Do we have a (lazy) data provider?
 253     if (nsCOMPtr<nsIFlavorDataProvider> dataProvider =
 254             do_QueryInterface(dataBytes)) {
 255       rv =
 256           dataProvider->GetFlavorData(this, aFlavor, getter_AddRefs(dataBytes));
 257       if (NS_FAILED(rv)) {
 258         dataBytes = nullptr;
 259         // The provider failed, fall into the converter code below.
 260       }
 261     }
 262
 263     if (dataBytes) {
 264       dataBytes.forget(aData);
 265       return NS_OK;
 266     }
 267
 268     // Empty data
 269   }
 270
 271   // If not, try using a format converter to get the requested flavor.
 272   if (mFormatConv) {
 273     for (size_t i = 0; i < mDataArray.Length(); ++i) {
 274       DataStruct& data = mDataArray.ElementAt(i);
 275       bool canConvert = false;
 276       mFormatConv->CanConvert(data.GetFlavor().get(), aFlavor, &canConvert);
 277       if (canConvert) {
 278         nsCOMPtr<nsISupports> dataBytes;
 279         data.GetData(getter_AddRefs(dataBytes));
 280
 281         // Do we have a (lazy) data provider?
 282         if (nsCOMPtr<nsIFlavorDataProvider> dataProvider =
 283                 do_QueryInterface(dataBytes)) {
 284           rv = dataProvider->GetFlavorData(this, aFlavor,
 285                                            getter_AddRefs(dataBytes));
 286           if (NS_FAILED(rv)) {
 287             // Give up.
 288             return rv;
 289           }
 290         }
 291
 292         return mFormatConv->Convert(data.GetFlavor().get(), dataBytes, aFlavor,
 293                                     aData);
 294       }
 295     }
 296   }
 297
 298   return NS_ERROR_FAILURE;
 299 }
 300
 301 //
 302 // GetAnyTransferData
 303 //
 304 // Returns the data of the first flavor found. Caller is responsible for
 305 // deleting the flavor string.
 306 //
 307 NS_IMETHODIMP
 308 nsTransferable::GetAnyTransferData(nsACString& aFlavor, nsISupports** aData) {
 309   MOZ_ASSERT(mInitialized);
 310
 311   for (size_t i = 0; i < mDataArray.Length(); ++i) {
 312     DataStruct& data = mDataArray.ElementAt(i);
 313     if (data.IsDataAvailable()) {
 314       aFlavor.Assign(data.GetFlavor());
 315       data.GetData(aData);
 316       return NS_OK;
 317     }
 318   }
 319
 320   return NS_ERROR_FAILURE;
 321 }
 322
 323 //
 324 // SetTransferData
 325 //
 326 //
 327 //
 328 NS_IMETHODIMP
 329 nsTransferable::SetTransferData(const char* aFlavor, nsISupports* aData) {
 330   MOZ_ASSERT(mInitialized);
 331
 332   // first check our intrinsic flavors to see if one has been registered.
 333   if (Maybe<size_t> index = FindDataFlavor(aFlavor)) {
 334     DataStruct& data = mDataArray.ElementAt(index.value());
 335     data.SetData(aData, mPrivateData);
 336     return NS_OK;
 337   }
 338
 339   // if not, try using a format converter to find a flavor to put the data in
 340   if (mFormatConv) {
 341     for (size_t i = 0; i < mDataArray.Length(); ++i) {
 342       DataStruct& data = mDataArray.ElementAt(i);
 343       bool canConvert = false;
 344       mFormatConv->CanConvert(aFlavor, data.GetFlavor().get(), &canConvert);
 345
 346       if (canConvert) {
 347         nsCOMPtr<nsISupports> ConvertedData;
 348         mFormatConv->Convert(aFlavor, aData, data.GetFlavor().get(),
 349                              getter_AddRefs(ConvertedData));
 350         data.SetData(ConvertedData, mPrivateData);
 351         return NS_OK;
 352       }
 353     }
 354   }
 355
 356   // Can't set data neither directly nor through converter. Just add this flavor
 357   // and try again
 358   if (NS_SUCCEEDED(AddDataFlavor(aFlavor))) {
 359     return SetTransferData(aFlavor, aData);
 360   }
 361
 362   return NS_ERROR_FAILURE;
 363 }
 364
 365 //
 366 // AddDataFlavor
 367 //
 368 // Adds a data flavor to our list with no data. Error if it already exists.
 369 //
 370 NS_IMETHODIMP
 371 nsTransferable::AddDataFlavor(const char* aDataFlavor) {
 372   MOZ_ASSERT(mInitialized);
 373
 374   if (FindDataFlavor(aDataFlavor).isSome()) {
 375     return NS_ERROR_FAILURE;
 376   }
 377
 378   // Create a new "slot" for the data
 379   mDataArray.AppendElement(DataStruct(aDataFlavor));
 380   return NS_OK;
 381 }
 382
 383 //
 384 // RemoveDataFlavor
 385 //
 386 // Removes a data flavor (and causes the data to be destroyed). Error if
 387 // the requested flavor is not present.
 388 //
 389 NS_IMETHODIMP
 390 nsTransferable::RemoveDataFlavor(const char* aDataFlavor) {
 391   MOZ_ASSERT(mInitialized);
 392
 393   if (Maybe<size_t> index = FindDataFlavor(aDataFlavor)) {
 394     mDataArray.RemoveElementAt(index.value());
 395     return NS_OK;
 396   }
 397
 398   return NS_ERROR_FAILURE;
 399 }
 400
 401 NS_IMETHODIMP
 402 nsTransferable::SetConverter(nsIFormatConverter* aConverter) {
 403   MOZ_ASSERT(mInitialized);
 404
 405   mFormatConv = aConverter;
 406   return NS_OK;
 407 }
 408
 409 NS_IMETHODIMP
 410 nsTransferable::GetConverter(nsIFormatConverter** aConverter) {
 411   MOZ_ASSERT(mInitialized);
 412
 413   nsCOMPtr<nsIFormatConverter> converter = mFormatConv;
 414   converter.forget(aConverter);
 415   return NS_OK;
 416 }
 417
 418 //
 419 // FlavorsTransferableCanImport
 420 //
 421 // Computes a list of flavors that the transferable can accept into it, either
 422 // through intrinsic knowledge or input data converters.
 423 //
 424 NS_IMETHODIMP
 425 nsTransferable::FlavorsTransferableCanImport(nsTArray<nsCString>& aFlavors) {
 426   MOZ_ASSERT(mInitialized);
 427
 428   // Get the flavor list, and on to the end of it, append the list of flavors we
 429   // can also get to through a converter. This is so that we can just walk the
 430   // list in one go, looking for the desired flavor.
 431   GetTransferDataFlavors(aFlavors);
 432
 433   if (mFormatConv) {
 434     nsTArray<nsCString> convertedList;
 435     mFormatConv->GetInputDataFlavors(convertedList);
 436
 437     for (uint32_t i = 0; i < convertedList.Length(); ++i) {
 438       nsCString& flavorStr = convertedList[i];
 439
 440       // Don't append if already in intrinsic list
 441       if (!aFlavors.Contains(flavorStr)) {
 442         aFlavors.AppendElement(flavorStr);
 443       }
 444     }
 445   }
 446
 447   return NS_OK;
 448 }
 449
 450 //
 451 // FlavorsTransferableCanExport
 452 //
 453 // Computes a list of flavors that the transferable can export, either through
 454 // intrinsic knowledge or output data converters.
 455 //
 456 NS_IMETHODIMP
 457 nsTransferable::FlavorsTransferableCanExport(nsTArray<nsCString>& aFlavors) {
 458   MOZ_ASSERT(mInitialized);
 459
 460   // Get the flavor list, and on to the end of it, append the list of flavors we
 461   // can also get to through a converter. This is so that we can just walk the
 462   // list in one go, looking for the desired flavor.
 463   GetTransferDataFlavors(aFlavors);
 464
 465   if (mFormatConv) {
 466     nsTArray<nsCString> convertedList;
 467     mFormatConv->GetOutputDataFlavors(convertedList);
 468
 469     for (uint32_t i = 0; i < convertedList.Length(); ++i) {
 470       nsCString& flavorStr = convertedList[i];
 471
 472       // Don't append if already in intrinsic list
 473       if (!aFlavors.Contains(flavorStr)) {
 474         aFlavors.AppendElement(flavorStr);
 475       }
 476     }
 477   }
 478
 479   return NS_OK;
 480 }
 481
 482 bool nsTransferable::GetIsPrivateData() {
 483   MOZ_ASSERT(mInitialized);
 484
 485   return mPrivateData;
 486 }
 487
 488 void nsTransferable::SetIsPrivateData(bool aIsPrivateData) {
 489   MOZ_ASSERT(mInitialized);
 490
 491   mPrivateData = aIsPrivateData;
 492 }
 493
 494 nsIPrincipal* nsTransferable::GetRequestingPrincipal() {
 495   MOZ_ASSERT(mInitialized);
 496
 497   return mRequestingPrincipal;
 498 }
 499
 500 void nsTransferable::SetRequestingPrincipal(
 501     nsIPrincipal* aRequestingPrincipal) {
 502   MOZ_ASSERT(mInitialized);
 503
 504   mRequestingPrincipal = aRequestingPrincipal;
 505 }
 506
 507 nsContentPolicyType nsTransferable::GetContentPolicyType() {
 508   MOZ_ASSERT(mInitialized);
 509
 510   return mContentPolicyType;
 511 }
 512
 513 void nsTransferable::SetContentPolicyType(
 514     nsContentPolicyType aContentPolicyType) {
 515   MOZ_ASSERT(mInitialized);
 516
 517   mContentPolicyType = aContentPolicyType;
 518 }