Bommels05/Mozilla
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix nsSharableString::SetLength to correctly handle having a shared buffer. Override GetWritableFragment on nsSharableString (perhaps temporarily) to allow use of writing iterators on nsSharableString. b=114438 r=jag sr=jst

Browse Source 
git-svn-id: svn://10.0.0.236/trunk@110214 18797224-902f-48f8-a5cc-f745e15eee43
This commit is contained in:
dbaron%fas.harvard.edu
2001-12-11 03:33:09 +00:00
parent 280aca881c
commit 3855c146ac
6 changed files with 120 additions and 42 deletions
Download Patch File Download Diff File Expand all files Collapse all files

66
mozilla/string/src/nsSharableString.cpp
View File

@@ -56,11 +56,11 @@ nsSharableString::SetCapacity( size_type aNewCapacity )
// therefore *unconditionally* truncate the current length of
// the string to the requested capacity.
if ( mBuffer->IsShared() )
if ( !mBuffer->IsMutable() )
{
if ( aNewCapacity > Length() )
if ( aNewCapacity > mBuffer->DataLength() )
mBuffer = NS_AllocateContiguousHandleWithData(mBuffer.get(),
*this, PRUint32(aNewCapacity - Length() + 1));
*this, PRUint32(aNewCapacity - mBuffer->DataLength() + 1));
else
mBuffer = NS_AllocateContiguousHandleWithData(mBuffer.get(),
Substring(*this, 0, aNewCapacity), PRUint32(1));
@@ -78,10 +78,10 @@ nsSharableString::SetCapacity( size_type aNewCapacity )
aNewCapacity = doubledCapacity;
// XXX We should be able to use |realloc| under certain
// conditions (contiguous buffer handle, kIsShared
// (,etc.)?)
// conditions (contiguous buffer handle, not
// kIsImmutable (,etc.)?)
mBuffer = NS_AllocateContiguousHandleWithData(mBuffer.get(),
*this, PRUint32(aNewCapacity - Length() + 1));
*this, PRUint32(aNewCapacity - mBuffer->DataLength() + 1));
}
else if ( aNewCapacity < mBuffer->DataLength() )
{
@@ -100,7 +100,7 @@ nsSharableString::SetCapacity( size_type aNewCapacity )
void
nsSharableString::SetLength( size_type aNewLength )
{
if ( aNewLength > mBuffer->DataLength() )
if ( !mBuffer->IsMutable() || aNewLength > mBuffer->DataLength() )
{
SetCapacity(aNewLength);
mBuffer->DataEnd( mBuffer->DataStart() + aNewLength );
@@ -128,7 +128,7 @@ nsSharableString::do_AssignFromReadable( const abstract_string_type& aReadable )
{
// null-check |mBuffer.get()| here only for the constructor
// taking |const abstract_string_type&|
if ( mBuffer.get() && !mBuffer->IsShared() &&
if ( mBuffer.get() && mBuffer->IsMutable() &&
mBuffer->StorageLength() > aReadable.Length() &&
!aReadable.IsDependentOn(*this) )
{
@@ -175,6 +175,22 @@ nsSharableString::GetSharedEmptyBufferHandle()
return sBufferHandle;
}
// The need to override GetWritableFragment may be temporary, depending
// on the protocol we choose for callers who want to mutate strings
// using iterators. See
// <URL: http://bugzilla.mozilla.org/show_bug.cgi?id=114140 >
nsSharableString::char_type*
nsSharableString::GetWritableFragment( fragment_type& aFragment, nsFragmentRequest aRequest, PRUint32 aOffset )
{
// This makes writing iterators safe to use, but it imposes a
// double-malloc performance penalty on users who intend to modify
// the length of the string but call |BeginWriting| before they call
// |SetLength|.
if ( mBuffer->IsMutable() )
SetCapacity( mBuffer->DataLength() );
return nsAFlatString::GetWritableFragment( aFragment, aRequest, aOffset );
}
void
nsSharableCString::SetCapacity( size_type aNewCapacity )
@@ -205,11 +221,11 @@ nsSharableCString::SetCapacity( size_type aNewCapacity )
// therefore *unconditionally* truncate the current length of
// the string to the requested capacity.
if ( mBuffer->IsShared() )
if ( !mBuffer->IsMutable() )
{
if ( aNewCapacity > Length() )
if ( aNewCapacity > mBuffer->DataLength() )
mBuffer = NS_AllocateContiguousHandleWithData(mBuffer.get(),
*this, PRUint32(aNewCapacity - Length() + 1));
*this, PRUint32(aNewCapacity - mBuffer->DataLength() + 1));
else
mBuffer = NS_AllocateContiguousHandleWithData(mBuffer.get(),
Substring(*this, 0, aNewCapacity), PRUint32(1));
@@ -227,10 +243,10 @@ nsSharableCString::SetCapacity( size_type aNewCapacity )
aNewCapacity = doubledCapacity;
// XXX We should be able to use |realloc| under certain
// conditions (contiguous buffer handle, kIsShared
// (,etc.)?)
// conditions (contiguous buffer handle, not
// kIsImmutable (,etc.)?)
mBuffer = NS_AllocateContiguousHandleWithData(mBuffer.get(),
*this, PRUint32(aNewCapacity - Length() + 1));
*this, PRUint32(aNewCapacity - mBuffer->DataLength() + 1));
}
else if ( aNewCapacity < mBuffer->DataLength() )
{
@@ -249,7 +265,7 @@ nsSharableCString::SetCapacity( size_type aNewCapacity )
void
nsSharableCString::SetLength( size_type aNewLength )
{
if ( aNewLength > mBuffer->DataLength() )
if ( !mBuffer->IsMutable() || aNewLength > mBuffer->DataLength() )
{
SetCapacity(aNewLength);
mBuffer->DataEnd( mBuffer->DataStart() + aNewLength );
@@ -261,7 +277,7 @@ nsSharableCString::SetLength( size_type aNewLength )
// This is needed for |Truncate| callers and also for some callers
// (such as nsACString::do_AppendFromReadable) that are manipulating
// the internals of the string. It also makes sense to do this
// since this class implements |nsAFlatString|, so the buffer must
// since this class implements |nsAFlatCString|, so the buffer must
// always be null-terminated at its length. Callers using writing
// iterators can't be expected to null-terminate themselves since
// they don't know if they're dealing with a string that has a
@@ -277,7 +293,7 @@ nsSharableCString::do_AssignFromReadable( const abstract_string_type& aReadable
{
// null-check |mBuffer.get()| here only for the constructor
// taking |const abstract_string_type&|
if ( mBuffer.get() && !mBuffer->IsShared() &&
if ( mBuffer.get() && mBuffer->IsMutable() &&
mBuffer->StorageLength() > aReadable.Length() &&
!aReadable.IsDependentOn(*this) )
{
@@ -324,3 +340,19 @@ nsSharableCString::GetSharedEmptyBufferHandle()
return sBufferHandle;
}
// The need to override GetWritableFragment may be temporary, depending
// on the protocol we choose for callers who want to mutate strings
// using iterators. See
// <URL: http://bugzilla.mozilla.org/show_bug.cgi?id=114140 >
nsSharableCString::char_type*
nsSharableCString::GetWritableFragment( fragment_type& aFragment, nsFragmentRequest aRequest, PRUint32 aOffset )
{
// This makes writing iterators safe to use, but it imposes a
// double-malloc performance penalty on users who intend to modify
// the length of the string but call |BeginWriting| before they call
// |SetLength|.
if ( mBuffer->IsMutable() )
SetCapacity( mBuffer->DataLength() );
return nsAFlatCString::GetWritableFragment( aFragment, aRequest, aOffset );
}