Changeset 37056 in webkit

Timestamp:

Sep 29, 2008 1:20:37 AM (16 years ago)

Author:

mrowe@apple.com

Message:

Apply the ASCII fast path optimization from StringImpl::lower to StringImpl::upper.
In the few places that we call .upper() in WebCore the strings represent things like
tag and attribute names, which are nearly always going to be ASCII.

Reviewed by Sam Weinig.

• platform/text/StringImpl.cpp:

(WebCore::StringImpl::lower): If we have to resize the buffer, be sure to pass the new length
in to Unicode::toLower the second time.
(WebCore::StringImpl::upper):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/text/StringImpl.cpp (modified) (2 diffs)

trunk/WebCore/ChangeLog

@@ +1 @@
+2008-09-29  Mark Rowe  <mrowe@apple.com>
+
+        Reviewed by Sam Weinig.
+
+        Apply the ASCII fast path optimization from StringImpl::lower to StringImpl::upper.
+        In the few places that we call .upper() in WebCore the strings represent things like
+        tag and attribute names, which are nearly always going to be ASCII.
+
+        * platform/text/StringImpl.cpp:
+        (WebCore::StringImpl::lower): If we have to resize the buffer, be sure to pass the new length
+        in to Unicode::toLower the second time.
+        (WebCore::StringImpl::upper):
+
 2008-09-28  Mark Rowe  <mrowe@apple.com>
 

trunk/WebCore/platform/text/StringImpl.cpp

@@ -362 +362 @@
         return adopt(data);
     data.resize(realLength);
-    Unicode::toLower(data.characters(), length, m_data, m_length, &error);
+    Unicode::toLower(data.characters(), realLength, m_data, m_length, &error);
     if (error)
         return this;
@@ -370 +370 @@
 PassRefPtr<StringImpl> StringImpl::upper()
 {
+    StringBuffer data(m_length);
+    int32_t length = m_length;
+
+    // Do a faster loop for the case where all the characters are ASCII.
+    UChar ored = 0;
+    for (int i = 0; i < length; i++) {
+        UChar c = m_data[i];
+        ored |= c;
+        data[i] = toASCIIUpper(c);
+    }
+    if (!(ored & ~0x7F))
+        return adopt(data);
+
+    // Do a slower implementation for cases that include non-ASCII characters.
     bool error;
-    int32_t length = Unicode::toUpper(0, 0, m_data, m_length, &error);
-    StringBuffer data(length);
-    Unicode::toUpper(data.characters(), length, m_data, m_length, &error);
+    int32_t realLength = Unicode::toUpper(data.characters(), length, m_data, m_length, &error);
+    if (!error && realLength == length)
+        return adopt(data);
+    data.resize(realLength);
+    Unicode::toUpper(data.characters(), realLength, m_data, m_length, &error);
     if (error)
         return this;