widget/nsPrimitiveHelpers.cpp
author Brindusan Cristian <cbrindusan@mozilla.com>
Tue, 05 Mar 2019 22:42:15 +0200
changeset 520316 be4b780a7783cdf7d3ead37c98917dc0d2e94a1d
parent 505383 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
Backed out 5 changesets (bug 1508976, bug 1522581) for android geckoview bustages at /usr/bin/python2.7. CLOSED TREE Backed out changeset 7a6be593b0be (bug 1522581) Backed out changeset c47b37ac1775 (bug 1522581) Backed out changeset 91c31d2a7706 (bug 1508976) Backed out changeset da57df805c56 (bug 1508976) Backed out changeset 4e5d97c93515 (bug 1508976)

/* -*- 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/. */

//
// Part of the reason these routines are all in once place is so that as new
// data flavors are added that are known to be one-byte or two-byte strings, or
// even raw binary data, then we just have to go to one place to change how the
// data moves into/out of the primitives and native line endings.
//
// If you add new flavors that have special consideration (binary data or
// one-byte char* strings), please update all the helper classes in this file.
//
// For now, this is the assumption that we are making:
//  - text/plain is always a char*
//  - anything else is a char16_t*
//

#include "nsPrimitiveHelpers.h"

#include "mozilla/UniquePtr.h"
#include "nsCOMPtr.h"
#include "nsXPCOM.h"
#include "nsISupportsPrimitives.h"
#include "nsITransferable.h"
#include "nsIComponentManager.h"
#include "nsLinebreakConverter.h"
#include "nsReadableUtils.h"

//
// CreatePrimitiveForData
//
// Given some data and the flavor it corresponds to, creates the appropriate
// nsISupports* wrapper for passing across IDL boundaries. Right now, everything
// creates a two-byte |nsISupportsString|, except for "text/plain" and native
// platform HTML (CF_HTML on win32)
//
void nsPrimitiveHelpers ::CreatePrimitiveForData(const nsACString& aFlavor,
                                                 const void* aDataBuff,
                                                 uint32_t aDataLen,
                                                 nsISupports** aPrimitive) {
  if (!aPrimitive) return;

  if (aFlavor.EqualsLiteral(kTextMime) ||
      aFlavor.EqualsLiteral(kNativeHTMLMime) ||
      aFlavor.EqualsLiteral(kRTFMime) ||
      aFlavor.EqualsLiteral(kCustomTypesMime)) {
    nsCOMPtr<nsISupportsCString> primitive =
        do_CreateInstance(NS_SUPPORTS_CSTRING_CONTRACTID);
    if (primitive) {
      const char* start = reinterpret_cast<const char*>(aDataBuff);
      primitive->SetData(Substring(start, start + aDataLen));
      NS_ADDREF(*aPrimitive = primitive);
    }
  } else {
    nsCOMPtr<nsISupportsString> primitive =
        do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID);
    if (primitive) {
      if (aDataLen % 2) {
        auto buffer = mozilla::MakeUnique<char[]>(aDataLen + 1);
        if (!MOZ_LIKELY(buffer)) return;

        memcpy(buffer.get(), aDataBuff, aDataLen);
        buffer[aDataLen] = 0;
        const char16_t* start = reinterpret_cast<const char16_t*>(buffer.get());
        // recall that length takes length as characters, not bytes
        primitive->SetData(Substring(start, start + (aDataLen + 1) / 2));
      } else {
        const char16_t* start = reinterpret_cast<const char16_t*>(aDataBuff);
        // recall that length takes length as characters, not bytes
        primitive->SetData(Substring(start, start + (aDataLen / 2)));
      }
      NS_ADDREF(*aPrimitive = primitive);
    }
  }

}  // CreatePrimitiveForData

//
// CreatePrimitiveForCFHTML
//
// Platform specific CreatePrimitive, windows CF_HTML.
//
void nsPrimitiveHelpers ::CreatePrimitiveForCFHTML(const void* aDataBuff,
                                                   uint32_t* aDataLen,
                                                   nsISupports** aPrimitive) {
  if (!aPrimitive) return;

  nsCOMPtr<nsISupportsString> primitive =
      do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID);
  if (!primitive) return;

  // We need to duplicate the input buffer, since the removal of linebreaks
  // might reallocte it.
  void* utf8 = moz_xmalloc(*aDataLen);
  memcpy(utf8, aDataBuff, *aDataLen);
  int32_t signedLen = static_cast<int32_t>(*aDataLen);
  nsLinebreakHelpers::ConvertPlatformToDOMLinebreaks(
      nsDependentCString(kTextMime), &utf8, &signedLen);
  *aDataLen = signedLen;

  nsAutoString str(
      NS_ConvertUTF8toUTF16(reinterpret_cast<const char*>(utf8), *aDataLen));
  free(utf8);
  *aDataLen = str.Length() * sizeof(char16_t);
  primitive->SetData(str);
  NS_ADDREF(*aPrimitive = primitive);
}

//
// CreateDataFromPrimitive
//
// Given a nsISupports* primitive and the flavor it represents, creates a new
// data buffer with the data in it. This data will be null terminated, but the
// length parameter does not reflect that.
//
void nsPrimitiveHelpers::CreateDataFromPrimitive(const nsACString& aFlavor,
                                                 nsISupports* aPrimitive,
                                                 void** aDataBuff,
                                                 uint32_t* aDataLen) {
  if (!aDataBuff) return;

  *aDataBuff = nullptr;
  *aDataLen = 0;

  if (aFlavor.EqualsLiteral(kTextMime) ||
      aFlavor.EqualsLiteral(kCustomTypesMime)) {
    nsCOMPtr<nsISupportsCString> plainText(do_QueryInterface(aPrimitive));
    if (plainText) {
      nsAutoCString data;
      plainText->GetData(data);
      *aDataBuff = ToNewCString(data);
      *aDataLen = data.Length() * sizeof(char);
    }
  } else {
    nsCOMPtr<nsISupportsString> doubleByteText(do_QueryInterface(aPrimitive));
    if (doubleByteText) {
      nsAutoString data;
      doubleByteText->GetData(data);
      *aDataBuff = ToNewUnicode(data);
      *aDataLen = data.Length() * sizeof(char16_t);
    }
  }
}

//
// ConvertPlatformToDOMLinebreaks
//
// Given some data, convert from the platform linebreaks into the LF expected by
// the DOM. This will attempt to convert the data in place, but the buffer may
// still need to be reallocated regardless (disposing the old buffer is taken
// care of internally, see the note below).
//
// NOTE: this assumes that it can use 'free' to dispose of the old buffer.
//
nsresult nsLinebreakHelpers ::ConvertPlatformToDOMLinebreaks(
    const nsACString& inFlavor, void** ioData, int32_t* ioLengthInBytes) {
  NS_ASSERTION(ioData && *ioData && ioLengthInBytes, "Bad Params");
  if (!(ioData && *ioData && ioLengthInBytes)) return NS_ERROR_INVALID_ARG;

  nsresult retVal = NS_OK;

  if (inFlavor.EqualsLiteral(kTextMime) || inFlavor.EqualsLiteral(kRTFMime)) {
    char* buffAsChars = reinterpret_cast<char*>(*ioData);
    char* oldBuffer = buffAsChars;
    retVal = nsLinebreakConverter::ConvertLineBreaksInSitu(
        &buffAsChars, nsLinebreakConverter::eLinebreakAny,
        nsLinebreakConverter::eLinebreakContent, *ioLengthInBytes,
        ioLengthInBytes);
    if (NS_SUCCEEDED(retVal)) {
      if (buffAsChars != oldBuffer)  // check if buffer was reallocated
        free(oldBuffer);
      *ioData = buffAsChars;
    }
  } else if (inFlavor.EqualsLiteral("image/jpeg")) {
    // I'd assume we don't want to do anything for binary data....
  } else {
    char16_t* buffAsUnichar = reinterpret_cast<char16_t*>(*ioData);
    char16_t* oldBuffer = buffAsUnichar;
    int32_t newLengthInChars;
    retVal = nsLinebreakConverter::ConvertUnicharLineBreaksInSitu(
        &buffAsUnichar, nsLinebreakConverter::eLinebreakAny,
        nsLinebreakConverter::eLinebreakContent,
        *ioLengthInBytes / sizeof(char16_t), &newLengthInChars);
    if (NS_SUCCEEDED(retVal)) {
      if (buffAsUnichar != oldBuffer)  // check if buffer was reallocated
        free(oldBuffer);
      *ioData = buffAsUnichar;
      *ioLengthInBytes = newLengthInChars * sizeof(char16_t);
    }
  }

  return retVal;

}  // ConvertPlatformToDOMLinebreaks