gecko-dev/widget/nsPrimitiveHelpers.cpp
Nicholas Nethercote ac5efebb4b Bug 1486690 - Remove unnecessary checks after moz_xmalloc() calls. r=glandium
There are surprisingly many of them.

(Plus a couple of unnecessary checks after `new` calls that were nearby.)

--HG--
extra : rebase_source : 47b6d5d7c5c99b1b50b396daf7a3b67abfd74fc1
2018-08-28 15:56:01 +10:00

211 lines
7.3 KiB
C++

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