widget/nsTransferable.cpp
author Chris H-C <chutten@mozilla.com>
Mon, 04 Jul 2016 11:16:05 -0400
changeset 312997 df28918fe2361f0b54ca9ce4773a29c4c0675d06
parent 310758 51410d553f6f0c1c260f3e63012b024484dfe67a
child 318173 bd7461a1ed09447f4d38b4911f0e83933f9d875b
permissions -rw-r--r--
bug 1218576 - Support remote accumulation via JS histograms. r=gfritzsche The JS histograms, too, need to dispatch their accumulations from child to parent. JSHistograms_Add now only supports histograms that are in gHistogramsMap or that were created in the parent process. After bug 1288745, maybe we'll be able to change this to be less convoluted. MozReview-Commit-ID: 3qTH89YKbGP

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */

/*
Notes to self:

- at some point, strings will be accessible from JS, so we won't have to wrap
   flavors in an nsISupportsCString. Until then, we're kinda stuck with
   this crappy API of nsISupportsArrays.

*/


#include "nsTransferable.h"
#include "nsString.h"
#include "nsReadableUtils.h"
#include "nsTArray.h"
#include "nsIFormatConverter.h"
#include "nsIContentPolicy.h"
#include "nsIComponentManager.h"
#include "nsCOMPtr.h"
#include "nsXPCOM.h"
#include "nsISupportsPrimitives.h"
#include "nsMemory.h"
#include "nsPrimitiveHelpers.h"
#include "nsXPIDLString.h"
#include "nsDirectoryServiceDefs.h"
#include "nsDirectoryService.h"
#include "nsCRT.h"
#include "nsNetUtil.h"
#include "nsIDOMNode.h"
#include "nsIOutputStream.h"
#include "nsIInputStream.h"
#include "nsIWeakReferenceUtils.h"
#include "nsIFile.h"
#include "nsILoadContext.h"
#include "mozilla/UniquePtr.h"

NS_IMPL_ISUPPORTS(nsTransferable, nsITransferable)

size_t GetDataForFlavor (const nsTArray<DataStruct>& aArray,
                           const char* aDataFlavor)
{
  for (size_t i = 0 ; i < aArray.Length () ; ++i) {
    if (aArray[i].GetFlavor().Equals (aDataFlavor))
      return i;
  }

  return aArray.NoIndex;
}

//-------------------------------------------------------------------------
DataStruct::~DataStruct()
{
  if (mCacheFileName) free(mCacheFileName);
}

//-------------------------------------------------------------------------
void
DataStruct::SetData ( nsISupports* aData, uint32_t aDataLen, bool aIsPrivateData )
{
  // Now, check to see if we consider the data to be "too large"
  // as well as ensuring that private browsing mode is disabled
  if (aDataLen > kLargeDatasetSize && !aIsPrivateData) {
    // if so, cache it to disk instead of memory
    if ( NS_SUCCEEDED(WriteCache(aData, aDataLen)) )
      return;
    else
			NS_WARNING("Oh no, couldn't write data to the cache file");
  }

  mData    = aData;
  mDataLen = aDataLen;
}


//-------------------------------------------------------------------------
void
DataStruct::GetData ( nsISupports** aData, uint32_t *aDataLen )
{
  // check here to see if the data is cached on disk
  if ( !mData && mCacheFileName ) {
    // if so, read it in and pass it back
    // ReadCache creates memory and copies the data into it.
    if ( NS_SUCCEEDED(ReadCache(aData, aDataLen)) )
      return;
    else {
      // oh shit, something went horribly wrong here.
      NS_WARNING("Oh no, couldn't read data in from the cache file");
      *aData = nullptr;
      *aDataLen = 0;
      return;
    }
  }

  *aData = mData;
  if ( mData )
    NS_ADDREF(*aData);
  *aDataLen = mDataLen;
}


//-------------------------------------------------------------------------
already_AddRefed<nsIFile>
DataStruct::GetFileSpec(const char* aFileName)
{
  nsCOMPtr<nsIFile> cacheFile;
  NS_GetSpecialDirectory(NS_OS_TEMP_DIR, getter_AddRefs(cacheFile));

  if (!cacheFile)
    return nullptr;

  // if the param aFileName contains a name we should use that
  // because the file probably already exists
  // otherwise create a unique name
  if (!aFileName) {
    cacheFile->AppendNative(NS_LITERAL_CSTRING("clipboardcache"));
    nsresult rv = cacheFile->CreateUnique(nsIFile::NORMAL_FILE_TYPE, 0600);
    if (NS_FAILED(rv))
      return nullptr;
  } else {
    cacheFile->AppendNative(nsDependentCString(aFileName));
  }

  return cacheFile.forget();
}


//-------------------------------------------------------------------------
nsresult
DataStruct::WriteCache(nsISupports* aData, uint32_t aDataLen)
{
  // Get a new path and file to the temp directory
  nsCOMPtr<nsIFile> cacheFile = GetFileSpec(mCacheFileName);
  if (cacheFile) {
    // remember the file name
    if (!mCacheFileName) {
      nsXPIDLCString fName;
      cacheFile->GetNativeLeafName(fName);
      mCacheFileName = strdup(fName);
    }

    // write out the contents of the clipboard
    // to the file
    //uint32_t bytes;
    nsCOMPtr<nsIOutputStream> outStr;

    NS_NewLocalFileOutputStream(getter_AddRefs(outStr),
                                cacheFile);

    if (!outStr) return NS_ERROR_FAILURE;

    void* buff = nullptr;
    nsPrimitiveHelpers::CreateDataFromPrimitive ( mFlavor.get(), aData, &buff, aDataLen );
    if ( buff ) {
      uint32_t ignored;
      outStr->Write(reinterpret_cast<char*>(buff), aDataLen, &ignored);
      free(buff);
      return NS_OK;
    }
  }
  return NS_ERROR_FAILURE;
}


//-------------------------------------------------------------------------
nsresult
DataStruct::ReadCache(nsISupports** aData, uint32_t* aDataLen)
{
  // if we don't have a cache filename we are out of luck
  if (!mCacheFileName)
    return NS_ERROR_FAILURE;

  // get the path and file name
  nsCOMPtr<nsIFile> cacheFile = GetFileSpec(mCacheFileName);
  bool exists;
  if ( cacheFile && NS_SUCCEEDED(cacheFile->Exists(&exists)) && exists ) {
    // get the size of the file
    int64_t fileSize;
    int64_t max32 = 0xFFFFFFFF;
    cacheFile->GetFileSize(&fileSize);
    if (fileSize > max32)
      return NS_ERROR_OUT_OF_MEMORY;

    uint32_t size = uint32_t(fileSize);
    // create new memory for the large clipboard data
    auto data = mozilla::MakeUnique<char[]>(size);
    if ( !data )
      return NS_ERROR_OUT_OF_MEMORY;

    // now read it all in
    nsCOMPtr<nsIInputStream> inStr;
    NS_NewLocalFileInputStream( getter_AddRefs(inStr),
                                cacheFile);

    if (!cacheFile) return NS_ERROR_FAILURE;

    nsresult rv = inStr->Read(data.get(), fileSize, aDataLen);

    // make sure we got all the data ok
    if (NS_SUCCEEDED(rv) && *aDataLen == size) {
      nsPrimitiveHelpers::CreatePrimitiveForData(mFlavor.get(), data.get(),
                                                 fileSize, aData);
      return *aData ? NS_OK : NS_ERROR_FAILURE;
    }

    // zero the return params
    *aData    = nullptr;
    *aDataLen = 0;
  }

  return NS_ERROR_FAILURE;
}


//-------------------------------------------------------------------------
//
// Transferable constructor
//
//-------------------------------------------------------------------------
nsTransferable::nsTransferable()
  : mPrivateData(false)
  , mContentPolicyType(nsIContentPolicy::TYPE_OTHER)
#ifdef DEBUG
  , mInitialized(false)
#endif
{
}

//-------------------------------------------------------------------------
//
// Transferable destructor
//
//-------------------------------------------------------------------------
nsTransferable::~nsTransferable()
{
}


NS_IMETHODIMP
nsTransferable::Init(nsILoadContext* aContext)
{
  MOZ_ASSERT(!mInitialized);

  if (aContext) {
    mPrivateData = aContext->UsePrivateBrowsing();
  }
#ifdef DEBUG
  mInitialized = true;
#endif
  return NS_OK;
}

//
// GetTransferDataFlavors
//
// Returns a copy of the internal list of flavors. This does NOT take into
// account any converter that may be registered. This list consists of
// nsISupportsCString objects so that the flavor list can be accessed from JS.
//
nsresult
nsTransferable::GetTransferDataFlavors(nsISupportsArray ** aDataFlavorList)
{
  MOZ_ASSERT(mInitialized);

  nsresult rv = NS_NewISupportsArray ( aDataFlavorList );
  if (NS_FAILED(rv)) return rv;

  for (size_t i = 0; i < mDataArray.Length(); ++i) {
    DataStruct& data = mDataArray.ElementAt(i);
    nsCOMPtr<nsISupportsCString> flavorWrapper = do_CreateInstance(NS_SUPPORTS_CSTRING_CONTRACTID);
    if ( flavorWrapper ) {
      flavorWrapper->SetData ( data.GetFlavor() );
      nsCOMPtr<nsISupports> genericWrapper ( do_QueryInterface(flavorWrapper) );
      (*aDataFlavorList)->AppendElement( genericWrapper );
    }
  }

  return NS_OK;
}


//
// GetTransferData
//
// Returns the data of the requested flavor, obtained from either having the data on hand or
// using a converter to get it. The data is wrapped in a nsISupports primitive so that it is
// accessible from JS.
//
NS_IMETHODIMP
nsTransferable::GetTransferData(const char *aFlavor, nsISupports **aData, uint32_t *aDataLen)
{
  MOZ_ASSERT(mInitialized);

  NS_ENSURE_ARG_POINTER(aFlavor && aData && aDataLen);

  nsresult rv = NS_OK;
  nsCOMPtr<nsISupports> savedData;

  // first look and see if the data is present in one of the intrinsic flavors
  for (size_t i = 0; i < mDataArray.Length(); ++i) {
    DataStruct& data = mDataArray.ElementAt(i);
    if ( data.GetFlavor().Equals(aFlavor) ) {
      nsCOMPtr<nsISupports> dataBytes;
      uint32_t len;
      data.GetData(getter_AddRefs(dataBytes), &len);
      if (len == kFlavorHasDataProvider && dataBytes) {
        // do we have a data provider?
        nsCOMPtr<nsIFlavorDataProvider> dataProvider = do_QueryInterface(dataBytes);
        if (dataProvider) {
          rv = dataProvider->GetFlavorData(this, aFlavor,
                                           getter_AddRefs(dataBytes), &len);
          if (NS_FAILED(rv))
            break;    // the provider failed. fall into the converter code below.
        }
      }
      if (dataBytes && len > 0) { // XXXmats why is zero length not ok?
        *aDataLen = len;
        dataBytes.forget(aData);
        return NS_OK;
      }
      savedData = dataBytes;  // return this if format converter fails
      break;
    }
  }

  bool found = false;

  // if not, try using a format converter to get the requested flavor
  if ( mFormatConv ) {
    for (size_t i = 0; i < mDataArray.Length(); ++i) {
      DataStruct& data = mDataArray.ElementAt(i);
      bool canConvert = false;
      mFormatConv->CanConvert(data.GetFlavor().get(), aFlavor, &canConvert);
      if ( canConvert ) {
        nsCOMPtr<nsISupports> dataBytes;
        uint32_t len;
        data.GetData(getter_AddRefs(dataBytes), &len);
        if (len == kFlavorHasDataProvider && dataBytes) {
          // do we have a data provider?
          nsCOMPtr<nsIFlavorDataProvider> dataProvider = do_QueryInterface(dataBytes);
          if (dataProvider) {
            rv = dataProvider->GetFlavorData(this, aFlavor,
                                             getter_AddRefs(dataBytes), &len);
            if (NS_FAILED(rv))
              break;  // give up
          }
        }
        mFormatConv->Convert(data.GetFlavor().get(), dataBytes, len, aFlavor, aData, aDataLen);
        found = true;
        break;
      }
    }
  }

  // for backward compatibility
  if (!found) {
    savedData.forget(aData);
    *aDataLen = 0;
  }

  return found ? NS_OK : NS_ERROR_FAILURE;
}


//
// GetAnyTransferData
//
// Returns the data of the first flavor found. Caller is responsible for deleting the
// flavor string.
//
NS_IMETHODIMP
nsTransferable::GetAnyTransferData(char **aFlavor, nsISupports **aData, uint32_t *aDataLen)
{
  MOZ_ASSERT(mInitialized);

  NS_ENSURE_ARG_POINTER(aFlavor && aData && aDataLen);

  for (size_t i = 0; i < mDataArray.Length(); ++i) {
    DataStruct& data = mDataArray.ElementAt(i);
    if (data.IsDataAvailable()) {
      *aFlavor = ToNewCString(data.GetFlavor());
      data.GetData(aData, aDataLen);
      return NS_OK;
    }
  }

  return NS_ERROR_FAILURE;
}


//
// SetTransferData
//
//
//
NS_IMETHODIMP
nsTransferable::SetTransferData(const char *aFlavor, nsISupports *aData, uint32_t aDataLen)
{
  MOZ_ASSERT(mInitialized);

  NS_ENSURE_ARG(aFlavor);

  // first check our intrinsic flavors to see if one has been registered.
  for (size_t i = 0; i < mDataArray.Length(); ++i) {
    DataStruct& data = mDataArray.ElementAt(i);
    if ( data.GetFlavor().Equals(aFlavor) ) {
      data.SetData ( aData, aDataLen, mPrivateData );
      return NS_OK;
    }
  }

  // if not, try using a format converter to find a flavor to put the data in
  if ( mFormatConv ) {
    for (size_t i = 0; i < mDataArray.Length(); ++i) {
      DataStruct& data = mDataArray.ElementAt(i);
      bool canConvert = false;
      mFormatConv->CanConvert(aFlavor, data.GetFlavor().get(), &canConvert);

      if ( canConvert ) {
        nsCOMPtr<nsISupports> ConvertedData;
        uint32_t ConvertedLen;
        mFormatConv->Convert(aFlavor, aData, aDataLen, data.GetFlavor().get(), getter_AddRefs(ConvertedData), &ConvertedLen);
        data.SetData(ConvertedData, ConvertedLen, mPrivateData);
        return NS_OK;
      }
    }
  }

  // Can't set data neither directly nor through converter. Just add this flavor and try again
  nsresult result = NS_ERROR_FAILURE;
  if ( NS_SUCCEEDED(AddDataFlavor(aFlavor)) )
    result = SetTransferData (aFlavor, aData, aDataLen);

  return result;
}


//
// AddDataFlavor
//
// Adds a data flavor to our list with no data. Error if it already exists.
//
NS_IMETHODIMP
nsTransferable::AddDataFlavor(const char *aDataFlavor)
{
  MOZ_ASSERT(mInitialized);

  if (GetDataForFlavor (mDataArray, aDataFlavor) != mDataArray.NoIndex)
    return NS_ERROR_FAILURE;

  // Create a new "slot" for the data
  mDataArray.AppendElement(DataStruct ( aDataFlavor ));

  return NS_OK;
}


//
// RemoveDataFlavor
//
// Removes a data flavor (and causes the data to be destroyed). Error if
// the requested flavor is not present.
//
NS_IMETHODIMP
nsTransferable::RemoveDataFlavor(const char *aDataFlavor)
{
  MOZ_ASSERT(mInitialized);

  size_t idx = GetDataForFlavor(mDataArray, aDataFlavor);
  if (idx != mDataArray.NoIndex) {
    mDataArray.RemoveElementAt (idx);
    return NS_OK;
  }
  return NS_ERROR_FAILURE;
}


/**
  *
  *
  */
NS_IMETHODIMP
nsTransferable::IsLargeDataSet(bool *_retval)
{
  MOZ_ASSERT(mInitialized);

  NS_ENSURE_ARG_POINTER(_retval);
  *_retval = false;
  return NS_OK;
}


/**
  *
  *
  */
NS_IMETHODIMP nsTransferable::SetConverter(nsIFormatConverter * aConverter)
{
  MOZ_ASSERT(mInitialized);

  mFormatConv = aConverter;
  return NS_OK;
}


/**
  *
  *
  */
NS_IMETHODIMP nsTransferable::GetConverter(nsIFormatConverter * *aConverter)
{
  MOZ_ASSERT(mInitialized);

  NS_ENSURE_ARG_POINTER(aConverter);
  *aConverter = mFormatConv;
  NS_IF_ADDREF(*aConverter);
  return NS_OK;
}


//
// FlavorsTransferableCanImport
//
// Computes a list of flavors that the transferable can accept into it, either through
// intrinsic knowledge or input data converters.
//
NS_IMETHODIMP
nsTransferable::FlavorsTransferableCanImport(nsISupportsArray **_retval)
{
  MOZ_ASSERT(mInitialized);

  NS_ENSURE_ARG_POINTER(_retval);

  // Get the flavor list, and on to the end of it, append the list of flavors we
  // can also get to through a converter. This is so that we can just walk the list
  // in one go, looking for the desired flavor.
  GetTransferDataFlavors(_retval);                        // addrefs
  nsCOMPtr<nsIFormatConverter> converter;
  GetConverter(getter_AddRefs(converter));
  if ( converter ) {
    nsCOMPtr<nsISupportsArray> convertedList;
    converter->GetInputDataFlavors(getter_AddRefs(convertedList));

    if ( convertedList ) {
      uint32_t importListLen;
      convertedList->Count(&importListLen);

      for (uint32_t i = 0; i < importListLen; ++i ) {
        nsCOMPtr<nsISupports> genericFlavor;
        convertedList->GetElementAt ( i, getter_AddRefs(genericFlavor) );

        nsCOMPtr<nsISupportsCString> flavorWrapper ( do_QueryInterface (genericFlavor) );
        nsAutoCString flavorStr;
        flavorWrapper->GetData( flavorStr );

        if (GetDataForFlavor (mDataArray, flavorStr.get())
            == mDataArray.NoIndex) // Don't append if already in intrinsic list
          (*_retval)->AppendElement (genericFlavor);
      } // foreach flavor that can be converted to
    }
  } // if a converter exists

  return NS_OK;
} // FlavorsTransferableCanImport


//
// FlavorsTransferableCanExport
//
// Computes a list of flavors that the transferable can export, either through
// intrinsic knowledge or output data converters.
//
NS_IMETHODIMP
nsTransferable::FlavorsTransferableCanExport(nsISupportsArray **_retval)
{
  MOZ_ASSERT(mInitialized);

  NS_ENSURE_ARG_POINTER(_retval);

  // Get the flavor list, and on to the end of it, append the list of flavors we
  // can also get to through a converter. This is so that we can just walk the list
  // in one go, looking for the desired flavor.
  GetTransferDataFlavors(_retval);  // addrefs
  nsCOMPtr<nsIFormatConverter> converter;
  GetConverter(getter_AddRefs(converter));
  if ( converter ) {
    nsCOMPtr<nsISupportsArray> convertedList;
    converter->GetOutputDataFlavors(getter_AddRefs(convertedList));

    if ( convertedList ) {
      uint32_t importListLen;
      convertedList->Count(&importListLen);

      for ( uint32_t i=0; i < importListLen; ++i ) {
        nsCOMPtr<nsISupports> genericFlavor;
        convertedList->GetElementAt ( i, getter_AddRefs(genericFlavor) );

        nsCOMPtr<nsISupportsCString> flavorWrapper ( do_QueryInterface (genericFlavor) );
        nsAutoCString flavorStr;
        flavorWrapper->GetData( flavorStr );

        if (GetDataForFlavor (mDataArray, flavorStr.get())
            == mDataArray.NoIndex) // Don't append if already in intrinsic list
          (*_retval)->AppendElement (genericFlavor);
      } // foreach flavor that can be converted to
    }
  } // if a converter exists

  return NS_OK;
} // FlavorsTransferableCanExport

NS_IMETHODIMP
nsTransferable::GetIsPrivateData(bool *aIsPrivateData)
{
  MOZ_ASSERT(mInitialized);

  NS_ENSURE_ARG_POINTER(aIsPrivateData);

  *aIsPrivateData = mPrivateData;

  return NS_OK;
}

NS_IMETHODIMP
nsTransferable::SetIsPrivateData(bool aIsPrivateData)
{
  MOZ_ASSERT(mInitialized);

  mPrivateData = aIsPrivateData;

  return NS_OK;
}

NS_IMETHODIMP
nsTransferable::GetRequestingPrincipal(nsIPrincipal** outRequestingPrincipal)
{
  NS_IF_ADDREF(*outRequestingPrincipal = mRequestingPrincipal);
  return NS_OK;
}

NS_IMETHODIMP
nsTransferable::SetRequestingPrincipal(nsIPrincipal* aRequestingPrincipal)
{
  mRequestingPrincipal = aRequestingPrincipal;
  return NS_OK;
}

NS_IMETHODIMP
nsTransferable::GetContentPolicyType(nsContentPolicyType* outContentPolicyType)
{
  NS_ENSURE_ARG_POINTER(outContentPolicyType);
  *outContentPolicyType = mContentPolicyType;
  return NS_OK;
}

NS_IMETHODIMP
nsTransferable::SetContentPolicyType(nsContentPolicyType aContentPolicyType)
{
  mContentPolicyType = aContentPolicyType;
  return NS_OK;
}