corysanin/tubestation
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fixes bug 201574 "Many Unaligned access messages when reading XUL.mfasl" r/sr=alecf,brendan

Browse Source
This commit is contained in:
darin@netscape.com
2003-04-15 18:17:54 +00:00
parent 6a4bb1d6db
commit abc91d0640
1 changed files with 22 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
xpcom/io/nsBinaryStream.cpp
View File

@@ -182,6 +182,7 @@ nsBinaryOutputStream::WriteWStringZ(const PRUnichar* aString)
#ifdef IS_BIG_ENDIAN
rv = WriteBytes(NS_REINTERPRET_CAST(const char*, aString), byteCount);
#else
// XXX use WriteSegments here to avoid copy!
PRUnichar *copy, temp[64];
if (length <= 64) {
copy = temp;
@@ -190,6 +191,7 @@ nsBinaryOutputStream::WriteWStringZ(const PRUnichar* aString)
if (!copy)
return NS_ERROR_OUT_OF_MEMORY;
}
NS_ASSERTION((PRUptrdiff(aString) & 0x1) == 0, "aString not properly aligned");
for (PRUint32 i = 0; i < length; i++)
copy[i] = NS_SWAP16(aString[i]);
rv = WriteBytes(NS_REINTERPRET_CAST(const char*, copy), byteCount);
@@ -462,7 +464,7 @@ nsBinaryInputStream::ReadCString(nsACString& aString)
// sometimes, WriteSegmentToString will be handed an odd-number of
// bytes, which means we only have half of the last PRUnichar
struct WriteStringClosure {
nsAString* mString;
PRUnichar *mWriteCursor;
PRPackedBool mHasCarryoverByte;
char mCarryoverByte;
};
@@ -493,9 +495,9 @@ WriteSegmentToString(nsIInputStream* aStream,
{
NS_PRECONDITION(aCount > 0, "Why are we being told to write 0 bytes?");
NS_PRECONDITION(sizeof(PRUnichar) == 2, "We can't handle other sizes!");
WriteStringClosure* closure = NS_STATIC_CAST(WriteStringClosure*,aClosure);
nsAString* outString = closure->mString;
PRUnichar *cursor = closure->mWriteCursor;
// we're always going to consume the whole buffer no matter what
// happens, so take care of that right now.. that allows us to
@@ -506,13 +508,12 @@ WriteSegmentToString(nsIInputStream* aStream,
if (closure->mHasCarryoverByte) {
// re-create the two-byte sequence we want to work with
char bytes[2] = { closure->mCarryoverByte, *aFromSegment };
PRUnichar unichar = *(PRUnichar*)bytes;
*cursor = *(PRUnichar*)bytes;
// Now the little endianness dance
#ifdef IS_LITTLE_ENDIAN
outString->Append(PRUnichar(NS_SWAP16(unichar)));
#else
outString->Append(unichar);
*cursor = (PRUnichar) NS_SWAP16(*cursor);
#endif
++cursor;
// now skip past the first byte of the buffer.. code from here
// can assume normal operations, but should not assume aCount
@@ -523,17 +524,21 @@ WriteSegmentToString(nsIInputStream* aStream,
closure->mHasCarryoverByte = PR_FALSE;
}
// this array is possibly unaligned... be careful how we access it!
const PRUnichar *unicodeSegment =
NS_REINTERPRET_CAST(const PRUnichar*, aFromSegment);
// calculate number of full characters in segment (aCount could be odd!)
PRUint32 segmentLength = aCount / sizeof(PRUnichar);
// this sucks. we have to swap every 2 bytes on some machines
// copy all data into our aligned buffer. byte swap if necessary.
memcpy(cursor, unicodeSegment, segmentLength * sizeof(PRUnichar));
PRUnichar *end = cursor + segmentLength;
#ifdef IS_LITTLE_ENDIAN
for (PRUint32 i = 0; i < segmentLength; i++)
outString->Append(PRUnichar(NS_SWAP16(unicodeSegment[i])));
#else
outString->Append(unicodeSegment, segmentLength);
for (; cursor < end; ++cursor)
*cursor = (PRUnichar) NS_SWAP16(*cursor);
#endif
closure->mWriteCursor = end;
// remember this is the modifed aCount and aFromSegment,
// so that will take into account the fact that we might have
@@ -558,10 +563,13 @@ nsBinaryInputStream::ReadString(nsAString& aString)
rv = Read32(&length);
if (NS_FAILED(rv)) return rv;
aString.Truncate();
// pre-allocate output buffer, and get direct access to buffer...
aString.SetLength(length);
nsAString::iterator start;
aString.BeginWriting(start);
WriteStringClosure closure;
closure.mString = &aString;
closure.mWriteCursor = start.get();
closure.mHasCarryoverByte = PR_FALSE;
rv = ReadSegments(WriteSegmentToString, &closure,