Start addressing massive arrays on the stack. There is hardly ever...

src/string-stream.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 39 matching lines @@
 
 
 NoAllocationStringAllocator::NoAllocationStringAllocator(char* memory,
                                                          unsigned size) {
   size_ = size;
   space_ = memory;
 }
 
 
 bool StringStream::Put(char c) {
-  if (space() == 0) return false;
-  if (length_ >= capacity_ - 1) {
+  if (full()) return false;
+  ASSERT(length_ < capacity_);
+  // Since the trailing '\0' is not accounted for in length_ fullness is
+  // indicated by a difference of 1 between length_ and capacity_. Thus when
+  // reaching a difference of 2 we need to grow the buffer.
+  if (length_ == capacity_ - 2) {  // 
     unsigned new_capacity = capacity_;
     char* new_buffer = allocator_->grow(&new_capacity);
     if (new_capacity > capacity_) {
       capacity_ = new_capacity;
       buffer_ = new_buffer;
     } else {
-      // Indicate truncation with dots.
-      memset(cursor(), '.', space());
-      length_ = capacity_;
-      buffer_[length_ - 2] = '\n';
-      buffer_[length_ - 1] = '\0';
+      // Reached the end of the available buffer.
+      ASSERT(capacity_ >= 5);
+      length_ = capacity_ - 1;  // Indicate fullness of the stream.
+      buffer_[length_ - 4] = '.';
+      buffer_[length_ - 3] = '.';
+      buffer_[length_ - 2] = '.';
+      buffer_[length_ - 1] = '\n';
+      buffer_[length_] = '\0';
       return false;
     }
   }
   buffer_[length_] = c;
   buffer_[length_ + 1] = '\0';
   length_++;
   return true;
 }
 
 
 // A control character is one that configures a format element.  For
 // instance, in %.5s, .5 are control characters.
 static bool IsControlChar(char c) {
   switch (c) {
   case '0': case '1': case '2': case '3': case '4': case '5':
   case '6': case '7': case '8': case '9': case '.': case '-':
     return true;
   default:
     return false;
   }
 }
 
 
 void StringStream::Add(Vector<const char> format, Vector<FmtElm> elms) {
   // If we already ran out of space then return immediately.
-  if (space() == 0)
-    return;
+  if (full()) return;
   int offset = 0;
   int elm = 0;
   while (offset < format.length()) {
     if (format[offset] != '%' || elm == elms.length()) {
       Put(format[offset]);
       offset++;
       continue;
     }
     // Read this formatting directive into a temporary buffer
     EmbeddedVector<char, 24> temp;
@@ skipping 447 matching lines @@
     return space_;
   }
   memcpy(new_space, space_, *bytes);
   *bytes = new_bytes;
   DeleteArray(space_);
   space_ = new_space;
   return new_space;
 }
 
 
+// Only grow once to the maximum allowable size.
 char* NoAllocationStringAllocator::grow(unsigned* bytes) {
-  unsigned new_bytes = *bytes * 2;
-  if (new_bytes > size_) {
-    new_bytes = size_;
-  }
-  *bytes = new_bytes;
+  ASSERT(size_ >= *bytes);
+  *bytes = size_;
   return space_;
 }
 
 
 } }  // namespace v8::internal