Changeset 52028 in webkit for trunk/JavaScriptCore/runtime/DateConversion.cpp

Timestamp:

Dec 11, 2009, 3:34:10 PM (15 years ago)

Author:

[email protected]

Message:

​https://bugs.webkit.org/show_bug.cgi?id=32454
Refactor construction of simple strings to avoid string concatenation.

Reviewed by Oliver Hunt.

Building strings through concatenation has a memory and performance cost -
a memory cost since we must over-allocate the buffer to leave space to append
into, and performance in that the string may still require reallocation (and
thus copying during construction). Instead move the full construction to
within a single function call (makeString), so that the arguments' lengths
can be calculated and an appropriate sized buffer allocated before copying
any characters.

~No performance change (~2% progression on date tests).

• bytecode/CodeBlock.cpp:

(JSC::escapeQuotes):
(JSC::valueToSourceString):
(JSC::constantName):
(JSC::idName):
(JSC::CodeBlock::registerName):
(JSC::regexpToSourceString):
(JSC::regexpName):

• bytecompiler/NodesCodegen.cpp:

(JSC::substitute):

• profiler/Profiler.cpp:

(JSC::Profiler::createCallIdentifier):

• runtime/DateConstructor.cpp:

(JSC::callDate):

• runtime/DateConversion.cpp:

(JSC::formatDate):
(JSC::formatDateUTCVariant):
(JSC::formatTime):
(JSC::formatTimeUTC):

• runtime/DateConversion.h:

(JSC::):

• runtime/DatePrototype.cpp:

(JSC::dateProtoFuncToString):
(JSC::dateProtoFuncToUTCString):
(JSC::dateProtoFuncToDateString):
(JSC::dateProtoFuncToTimeString):
(JSC::dateProtoFuncToGMTString):

• runtime/ErrorPrototype.cpp:

(JSC::errorProtoFuncToString):

• runtime/ExceptionHelpers.cpp:

(JSC::createUndefinedVariableError):
(JSC::createErrorMessage):
(JSC::createInvalidParamError):

• runtime/FunctionPrototype.cpp:

(JSC::insertSemicolonIfNeeded):
(JSC::functionProtoFuncToString):

• runtime/ObjectPrototype.cpp:

(JSC::objectProtoFuncToString):

• runtime/RegExpConstructor.cpp:

(JSC::constructRegExp):

• runtime/RegExpObject.cpp:

(JSC::RegExpObject::match):

• runtime/RegExpPrototype.cpp:

(JSC::regExpProtoFuncCompile):
(JSC::regExpProtoFuncToString):

• runtime/StringPrototype.cpp:

(JSC::stringProtoFuncBig):
(JSC::stringProtoFuncSmall):
(JSC::stringProtoFuncBlink):
(JSC::stringProtoFuncBold):
(JSC::stringProtoFuncFixed):
(JSC::stringProtoFuncItalics):
(JSC::stringProtoFuncStrike):
(JSC::stringProtoFuncSub):
(JSC::stringProtoFuncSup):
(JSC::stringProtoFuncFontcolor):
(JSC::stringProtoFuncFontsize):
(JSC::stringProtoFuncAnchor):

• runtime/UString.h:

(JSC::):
(JSC::makeString):

File:

• trunk/JavaScriptCore/runtime/DateConversion.cpp (modified) (2 diffs)

trunk/JavaScriptCore/runtime/DateConversion.cpp

@@ -63 +63 @@
 }
 
-UString formatDate(const GregorianDateTime &t)
+void formatDate(const GregorianDateTime &t, DateConversionBuffer& buffer)
 {
-    char buffer[100];
-    snprintf(buffer, sizeof(buffer), "%s %s %02d %04d",
+    snprintf(buffer, DateConversionBufferSize, "%s %s %02d %04d",
         weekdayName[(t.weekDay + 6) % 7],
         monthName[t.month], t.monthDay, t.year + 1900);
-    return buffer;
 }
 
-UString formatDateUTCVariant(const GregorianDateTime &t)
+void formatDateUTCVariant(const GregorianDateTime &t, DateConversionBuffer& buffer)
 {
-    char buffer[100];
-    snprintf(buffer, sizeof(buffer), "%s, %02d %s %04d",
+    snprintf(buffer, DateConversionBufferSize, "%s, %02d %s %04d",
         weekdayName[(t.weekDay + 6) % 7],
         t.monthDay, monthName[t.month], t.year + 1900);
-    return buffer;
 }
 
-UString formatTime(const GregorianDateTime &t)
+void formatTime(const GregorianDateTime &t, DateConversionBuffer& buffer)
 {
-    char buffer[100];
     int offset = abs(gmtoffset(t));
     char timeZoneName[70];
@@ -90 +85 @@
 
     if (timeZoneName[0]) {
-        snprintf(buffer, sizeof(buffer), "%02d:%02d:%02d GMT%c%02d%02d (%s)",
+        snprintf(buffer, DateConversionBufferSize, "%02d:%02d:%02d GMT%c%02d%02d (%s)",
             t.hour, t.minute, t.second,
             gmtoffset(t) < 0 ? '-' : '+', offset / (60*60), (offset / 60) % 60, timeZoneName);
     } else {
-        snprintf(buffer, sizeof(buffer), "%02d:%02d:%02d GMT%c%02d%02d",
+        snprintf(buffer, DateConversionBufferSize, "%02d:%02d:%02d GMT%c%02d%02d",
             t.hour, t.minute, t.second,
             gmtoffset(t) < 0 ? '-' : '+', offset / (60*60), (offset / 60) % 60);
     }
-    return UString(buffer);
 }
 
-UString formatTimeUTC(const GregorianDateTime &t)
+void formatTimeUTC(const GregorianDateTime &t, DateConversionBuffer& buffer)
 {
-    char buffer[100];
-    snprintf(buffer, sizeof(buffer), "%02d:%02d:%02d GMT", t.hour, t.minute, t.second);
-    return UString(buffer);
+    snprintf(buffer, DateConversionBufferSize, "%02d:%02d:%02d GMT", t.hour, t.minute, t.second);
 }