[inspector] use OS independent number to string conversion

src/inspector/string-16.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/inspector/string-16.h"
 
 #include <algorithm>
 #include <cctype>
 #include <cstdlib>
 #include <cstring>
-#include <iomanip>
 #include <limits>
-#include <locale>
-#include <sstream>
 #include <string>
 
 #include "src/base/platform/platform.h"
+#include "src/conversions.h"
 
 namespace v8_inspector {
 
 namespace {
 
 bool isASCII(UChar c) { return !(c & ~0x7F); }
 
 bool isSpaceOrNewLine(UChar c) {
   return isASCII(c) && c <= ' ' && (c == ' ' || (c <= 0xD && c >= 0x9));
 }
@@ skipping 331 matching lines @@
 static inline void putUTF8Triple(char*& buffer, UChar ch) {
   *buffer++ = static_cast<char>(((ch >> 12) & 0x0F) | 0xE0);
   *buffer++ = static_cast<char>(((ch >> 6) & 0x3F) | 0x80);
   *buffer++ = static_cast<char>((ch & 0x3F) | 0x80);
 }
 
 }  // namespace
 
 // static
 String16 String16::fromInteger(int number) {
-  const size_t kBufferSize = 50;
-  char buffer[kBufferSize];
-  v8::base::OS::SNPrintF(buffer, kBufferSize, "%d", number);
-  return String16(buffer);
+  char arr[50];
+  v8::internal::Vector<char> buffer(arr, arraysize(arr));
+  return String16(IntToCString(number, buffer));
 }
 
 // static
 String16 String16::fromInteger(size_t number) {
   const size_t kBufferSize = 50;
   char buffer[kBufferSize];
 #if !defined(_WIN32) && !defined(_WIN64)
   v8::base::OS::SNPrintF(buffer, kBufferSize, "%zu", number);
 #else
   v8::base::OS::SNPrintF(buffer, kBufferSize, "%Iu", number);
 #endif
   return String16(buffer);
 }
 
 // static
 String16 String16::fromDouble(double number) {
-  std::ostringstream s;
-  s.imbue(std::locale("C"));
-  s << std::fixed << std::setprecision(std::numeric_limits<double>::digits10)
-    << number;
-  return String16(s.str().c_str());
+  char arr[50];
+  v8::internal::Vector<char> buffer(arr, arraysize(arr));
+  return String16(DoubleToCString(number, buffer));
 }
 
 // static
 String16 String16::fromDouble(double number, int precision) {
-  std::ostringstream s;
-  s.imbue(std::locale("C"));
-  s << std::fixed << std::setprecision(precision) << number;
-  return String16(s.str().c_str());
+  std::unique_ptr<char[]> str(
+      v8::internal::DoubleToPrecisionCString(number, precision));
+  return String16(str.get());
 }
 
 int String16::toInteger(bool* ok) const {
   return charactersToInteger(characters16(), length(), ok);
 }
 
 String16 String16::stripWhiteSpace() const {
   if (!length()) return String16();
 
   size_t start = 0;
@@ skipping 120 matching lines @@
     // There should be room left, since one UChar hasn't been
     // converted.
     DCHECK((buffer + 3) <= (buffer + bufferVector.size()));
     putUTF8Triple(buffer, *characters);
   }
 
   return std::string(bufferVector.data(), buffer - bufferVector.data());
 }
 
 }  // namespace v8_inspector