Changeset 51168 in webkit for trunk/JavaScriptCore/runtime/UString.cpp

Timestamp:

Nov 18, 2009, 7:12:50 PM (16 years ago)

Author:

[email protected]

Message:

2009-11-18 Kent Tamura <​[email protected]>

Reviewed by Darin Adler.

Move UString::from(double) implementation to new
WTF::doubleToStringInJavaScriptFormat(), and expose it because WebCore
code will use it.
​https://bugs.webkit.org/show_bug.cgi?id=31330

• Introduce new function createRep(const char*, unsigned) and UString::UString(const char*, unsigned) to reduce 2 calls to strlen().
• Fix a bug that dtoa() doesn't update *rve if the input value is NaN or Infinity.

No new tests because this doesn't change the behavior.

• JavaScriptCore.exp:
• JavaScriptCore.vcproj/JavaScriptCore/JavaScriptCore.def:
• runtime/UString.cpp: (JSC::createRep): (JSC::UString::UString): (JSC::UString::from): Move the code to doubleToStringInJavaScriptFormat().
• runtime/UString.h:
• wtf/dtoa.cpp: (WTF::dtoa): Fix a bug about rve. (WTF::append): A helper for doubleToStringInJavaScriptFormat(). (WTF::doubleToStringInJavaScriptFormat): Move the code from UString::from(double).
• wtf/dtoa.h:

File:

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

trunk/JavaScriptCore/runtime/UString.cpp

@@ -579 +579 @@
 }
 
+static inline PassRefPtr<UString::Rep> createRep(const char* c, int length)
+{
+    if (!c)
+        return &UString::Rep::null();
+
+    if (!length)
+        return &UString::Rep::empty();
+
+    UChar* d;
+    if (!allocChars(length).getValue(d))
+        return &UString::Rep::null();
+
+    for (int i = 0; i < length; i++)
+        d[i] = static_cast<unsigned char>(c[i]); // use unsigned char to zero-extend instead of sign-extend
+    return UString::Rep::create(d, length);
+}
+
 UString::UString(const char* c)
     : m_rep(createRep(c))
+{
+}
+
+UString::UString(const char* c, int length)
+    : m_rep(createRep(c, length))
 {
 }
@@ -1026 +1048 @@
 UString UString::from(double d)
 {
-    // avoid ever printing -NaN, in JS conceptually there is only one NaN value
-    if (isnan(d))
-        return "NaN";
-    if (!d)
-        return "0"; // -0 -> "0"
-
-    char buf[80];
-    int decimalPoint;
-    int sign;
-    
-    char result[80];
-    WTF::dtoa(result, d, 0, &decimalPoint, &sign, NULL);
-    int length = static_cast<int>(strlen(result));
-  
-    int i = 0;
-    if (sign)
-        buf[i++] = '-';
-  
-    if (decimalPoint <= 0 && decimalPoint > -6) {
-        buf[i++] = '0';
-        buf[i++] = '.';
-        for (int j = decimalPoint; j < 0; j++)
-            buf[i++] = '0';
-        strcpy(buf + i, result);
-    } else if (decimalPoint <= 21 && decimalPoint > 0) {
-        if (length <= decimalPoint) {
-            strcpy(buf + i, result);
-            i += length;
-            for (int j = 0; j < decimalPoint - length; j++)
-                buf[i++] = '0';
-            buf[i] = '\0';
-        } else {
-            strncpy(buf + i, result, decimalPoint);
-            i += decimalPoint;
-            buf[i++] = '.';
-            strcpy(buf + i, result + decimalPoint);
-        }
-    } else if (result[0] < '0' || result[0] > '9')
-        strcpy(buf + i, result);
-    else {
-        buf[i++] = result[0];
-        if (length > 1) {
-            buf[i++] = '.';
-            strcpy(buf + i, result + 1);
-            i += length - 1;
-        }
-        
-        buf[i++] = 'e';
-        buf[i++] = (decimalPoint >= 0) ? '+' : '-';
-        // decimalPoint can't be more than 3 digits decimal given the
-        // nature of float representation
-        int exponential = decimalPoint - 1;
-        if (exponential < 0)
-            exponential = -exponential;
-        if (exponential >= 100)
-            buf[i++] = static_cast<char>('0' + exponential / 100);
-        if (exponential >= 10)
-            buf[i++] = static_cast<char>('0' + (exponential % 100) / 10);
-        buf[i++] = static_cast<char>('0' + exponential % 10);
-        buf[i++] = '\0';
-    }
-    
-    return UString(buf);
+    DtoaBuffer buffer;
+    unsigned length;
+    doubleToStringInJavaScriptFormat(d, buffer, &length);
+    return UString(buffer, length);
 }