Changeset 133726 in webkit

Timestamp:

Nov 6, 2012, 11:13:20 PM (13 years ago)

Author:

msaboff@apple.com

Message:

StringBuilder::append(UChar) with an 8 bit quantity shouldn't change the contents to 16 bits
​https://bugs.webkit.org/show_bug.cgi?id=101421

Reviewed by Anders Carlsson.

If the string builder contains only 8 bit data, check if the character being appended contains
8 bit data. If so, append it to the 8 bit buffer instead of converting the buffer to 16 bits.

• wtf/text/StringBuilder.cpp:

(WTF::StringBuilder::append):

• wtf/text/StringBuilder.h:

(WTF::StringBuilder::append):

Location:

trunk/Source/WTF

Files:

• ChangeLog (modified) (1 diff)
• wtf/text/StringBuilder.cpp (modified) (1 diff)
• wtf/text/StringBuilder.h (modified) (1 diff)

trunk/Source/WTF/ChangeLog

@@ +1 @@
+2012-11-06  Michael Saboff  <msaboff@apple.com>
+
+        StringBuilder::append(UChar) with an 8 bit quantity shouldn't change the contents to 16 bits
+        https://bugs.webkit.org/show_bug.cgi?id=101421
+
+        Reviewed by Anders Carlsson.
+
+        If the string builder contains only 8 bit data, check if the character being appended contains
+        8 bit data.  If so, append it to the 8 bit buffer instead of converting the buffer to 16 bits.
+
+        * wtf/text/StringBuilder.cpp:
+        (WTF::StringBuilder::append):
+        * wtf/text/StringBuilder.h:
+        (WTF::StringBuilder::append):
+
 2012-11-06  Benjamin Poulain  <benjamin@webkit.org>
 

trunk/Source/WTF/wtf/text/StringBuilder.cpp

@@ -244 +244 @@
 
     if (m_is8Bit) {
+        if (length == 1 && !(*characters & ~0xff)) {
+            // Append as 8 bit character
+            LChar lChar = static_cast<LChar>(*characters);
+            append(&lChar, 1);
+            return;
+        }
+
         // Calculate the new size of the builder after appending.
         unsigned requiredLength = length + m_length;

trunk/Source/WTF/wtf/text/StringBuilder.h

@@ -112 +112 @@
     void append(UChar c)
     {
-        if (m_buffer && !m_is8Bit && m_length < m_buffer->length() && m_string.isNull())
-            m_bufferCharacters16[m_length++] = c;
-        else
-            append(&c, 1);
+        if (m_buffer && m_length < m_buffer->length() && m_string.isNull()) {
+            if (!m_is8Bit) {
+                m_bufferCharacters16[m_length++] = c;
+                return;
+            }
+
+            if (!(c & ~0xff)) {
+                m_bufferCharacters8[m_length++] = static_cast<LChar>(c);
+                return;
+            }
+        }
+        append(&c, 1);
     }