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
diff --git a/core/fxcrt/fx_basic_bstring.cpp b/core/fxcrt/fx_basic_bstring.cpp
index 1622c4b..e098d8f 100644
--- a/core/fxcrt/fx_basic_bstring.cpp
+++ b/core/fxcrt/fx_basic_bstring.cpp
@@ -276,20 +276,25 @@
if (nNewLength == -1)
nNewLength = FXSYS_strlen(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_ByteString preserve(*this);
+ ReallocBeforeWrite(nNewLength);
+ }
}
void CFX_ByteString::Reserve(FX_STRSIZE len) {
GetBuffer(len);
- ReleaseBuffer(GetLength());
}
FX_CHAR* CFX_ByteString::GetBuffer(FX_STRSIZE nMinBufLength) {
diff --git a/core/fxcrt/fx_basic_bstring_unittest.cpp b/core/fxcrt/fx_basic_bstring_unittest.cpp
index ea7e17f..087c264 100644
--- a/core/fxcrt/fx_basic_bstring_unittest.cpp
+++ b/core/fxcrt/fx_basic_bstring_unittest.cpp
@@ -624,6 +624,83 @@
}
}
+TEST(fxcrt, ByteStringReserve) {
+ {
+ CFX_ByteString str;
+ str.Reserve(6);
+ const FX_CHAR* old_buffer = str.c_str();
+ str += "ABCDEF";
+ EXPECT_EQ(old_buffer, str.c_str());
+ str += "Blah Blah Blah Blah Blah Blah";
+ EXPECT_NE(old_buffer, str.c_str());
+ }
+ {
+ CFX_ByteString str("A");
+ str.Reserve(6);
+ const FX_CHAR* old_buffer = str.c_str();
+ str += "BCDEF";
+ EXPECT_EQ(old_buffer, str.c_str());
+ str += "Blah Blah Blah Blah Blah Blah";
+ EXPECT_NE(old_buffer, str.c_str());
+ }
+}
+
+TEST(fxcrt, ByteStringGetBuffer) {
+ {
+ CFX_ByteString str;
+ FX_CHAR* buffer = str.GetBuffer(12);
+ strcpy(buffer, "clams");
+ str.ReleaseBuffer();
+ EXPECT_EQ("clams", str);
+ }
+ {
+ CFX_ByteString str("cl");
+ FX_CHAR* buffer = str.GetBuffer(12);
+ strcpy(buffer + 2, "ams");
+ str.ReleaseBuffer();
+ EXPECT_EQ("clams", str);
+ }
+}
+
+TEST(fxcrt, ByteStringReleaseBuffer) {
+ {
+ CFX_ByteString str;
+ str.Reserve(12);
+ str += "clams";
+ const FX_CHAR* old_buffer = str.c_str();
+ str.ReleaseBuffer(4);
+ EXPECT_EQ(old_buffer, str.c_str());
+ EXPECT_EQ("clam", str);
+ }
+ {
+ CFX_ByteString str("c");
+ str.Reserve(12);
+ str += "lams";
+ const FX_CHAR* old_buffer = str.c_str();
+ str.ReleaseBuffer(4);
+ EXPECT_EQ(old_buffer, str.c_str());
+ EXPECT_EQ("clam", str);
+ }
+ {
+ CFX_ByteString str;
+ str.Reserve(200);
+ str += "clams";
+ const FX_CHAR* old_buffer = str.c_str();
+ str.ReleaseBuffer(4);
+ EXPECT_NE(old_buffer, str.c_str());
+ EXPECT_EQ("clam", str);
+ }
+ {
+ CFX_ByteString str("c");
+ str.Reserve(200);
+ str += "lams";
+ const FX_CHAR* old_buffer = str.c_str();
+ str.ReleaseBuffer(4);
+ EXPECT_NE(old_buffer, str.c_str());
+ EXPECT_EQ("clam", str);
+ }
+}
+
TEST(fxcrt, ByteStringCNotNull) {
CFX_ByteStringC string3("abc");
CFX_ByteStringC string6("abcdef");
diff --git a/core/fxcrt/fx_basic_wstring.cpp b/core/fxcrt/fx_basic_wstring.cpp
index f3b430c..38fd15e 100644
--- a/core/fxcrt/fx_basic_wstring.cpp
+++ b/core/fxcrt/fx_basic_wstring.cpp
@@ -224,20 +224,25 @@
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) {
diff --git a/core/fxcrt/fx_basic_wstring_unittest.cpp b/core/fxcrt/fx_basic_wstring_unittest.cpp
index 708556a..02281af 100644
--- a/core/fxcrt/fx_basic_wstring_unittest.cpp
+++ b/core/fxcrt/fx_basic_wstring_unittest.cpp
@@ -591,6 +591,83 @@
}
}
+TEST(fxcrt, WideStringReserve) {
+ {
+ CFX_WideString str;
+ str.Reserve(6);
+ const FX_WCHAR* old_buffer = str.c_str();
+ str += L"ABCDEF";
+ EXPECT_EQ(old_buffer, str.c_str());
+ str += L"Blah Blah Blah Blah Blah Blah";
+ EXPECT_NE(old_buffer, str.c_str());
+ }
+ {
+ CFX_WideString str(L"A");
+ str.Reserve(6);
+ const FX_WCHAR* old_buffer = str.c_str();
+ str += L"BCDEF";
+ EXPECT_EQ(old_buffer, str.c_str());
+ str += L"Blah Blah Blah Blah Blah Blah";
+ EXPECT_NE(old_buffer, str.c_str());
+ }
+}
+
+TEST(fxcrt, WideStringGetBuffer) {
+ {
+ CFX_WideString str;
+ FX_WCHAR* buffer = str.GetBuffer(12);
+ wcscpy(buffer, L"clams");
+ str.ReleaseBuffer();
+ EXPECT_EQ(L"clams", str);
+ }
+ {
+ CFX_WideString str(L"cl");
+ FX_WCHAR* buffer = str.GetBuffer(12);
+ wcscpy(buffer + 2, L"ams");
+ str.ReleaseBuffer();
+ EXPECT_EQ(L"clams", str);
+ }
+}
+
+TEST(fxcrt, WideStringReleaseBuffer) {
+ {
+ CFX_WideString str;
+ str.Reserve(12);
+ str += L"clams";
+ const FX_WCHAR* old_buffer = str.c_str();
+ str.ReleaseBuffer(4);
+ EXPECT_EQ(old_buffer, str.c_str());
+ EXPECT_EQ(L"clam", str);
+ }
+ {
+ CFX_WideString str(L"c");
+ str.Reserve(12);
+ str += L"lams";
+ const FX_WCHAR* old_buffer = str.c_str();
+ str.ReleaseBuffer(4);
+ EXPECT_EQ(old_buffer, str.c_str());
+ EXPECT_EQ(L"clam", str);
+ }
+ {
+ CFX_WideString str;
+ str.Reserve(200);
+ str += L"clams";
+ const FX_WCHAR* old_buffer = str.c_str();
+ str.ReleaseBuffer(4);
+ EXPECT_NE(old_buffer, str.c_str());
+ EXPECT_EQ(L"clam", str);
+ }
+ {
+ CFX_WideString str(L"c");
+ str.Reserve(200);
+ str += L"lams";
+ const FX_WCHAR* old_buffer = str.c_str();
+ str.ReleaseBuffer(4);
+ EXPECT_NE(old_buffer, str.c_str());
+ EXPECT_EQ(L"clam", str);
+ }
+}
+
TEST(fxcrt, WideStringUTF16LE_Encode) {
struct UTF16LEEncodeCase {
CFX_WideString ws;
