From 518fd4c5ababbfbf28e010a9c27098e8f6669e4b Mon Sep 17 00:00:00 2001 From: tsepez Date: Tue, 26 Apr 2016 12:13:16 -0700 Subject: CFX_ByteString::Reserve(), ReleaseBuffer() fixes. Also identical fixes for CFX_WideString. Reserve() on an empty string would not actually reserve a buffer. Currently unused, but there are places where this would really help. ReleaseBuffer() would rarely return memory to the system, since it would short-circuit thinking it could operate in place. Tune the algorithm slightly so that we hold on when the savings is small. Bounds check release buffer args rather than just asserting. Add tests for all of these. Review URL: https://codereview.chromium.org/1916303004 --- core/fxcrt/fx_basic_wstring.cpp | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'core/fxcrt/fx_basic_wstring.cpp') diff --git a/core/fxcrt/fx_basic_wstring.cpp b/core/fxcrt/fx_basic_wstring.cpp index f3b430c7bf..38fd15e13f 100644 --- a/core/fxcrt/fx_basic_wstring.cpp +++ b/core/fxcrt/fx_basic_wstring.cpp @@ -224,20 +224,25 @@ void CFX_WideString::ReleaseBuffer(FX_STRSIZE nNewLength) { if (nNewLength == -1) nNewLength = FXSYS_wcslen(m_pData->m_String); + nNewLength = std::min(nNewLength, m_pData->m_nAllocLength); if (nNewLength == 0) { clear(); return; } - FXSYS_assert(nNewLength <= m_pData->m_nAllocLength); - ReallocBeforeWrite(nNewLength); + FXSYS_assert(m_pData->m_nRefs == 1); m_pData->m_nDataLength = nNewLength; m_pData->m_String[nNewLength] = 0; + if (m_pData->m_nAllocLength - nNewLength >= 32) { + // Over arbitrary threshold, so pay the price to relocate. Force copy to + // always occur by holding a second reference to the string. + CFX_WideString preserve(*this); + ReallocBeforeWrite(nNewLength); + } } void CFX_WideString::Reserve(FX_STRSIZE len) { GetBuffer(len); - ReleaseBuffer(GetLength()); } FX_WCHAR* CFX_WideString::GetBuffer(FX_STRSIZE nMinBufLength) { -- cgit v1.2.3