[[ Perf ]] Add a variant of MCStringCreateWithNativeCharsAndRelease that is zero-copy

livecodefraser · livecodefraser · commit 4f6e9b725b16 · 2015-10-06T10:53:04.000+01:00
diff --git a/engine/src/exec.cpp b/engine/src/exec.cpp
@@ -98,10 +98,12 @@ bool MCExecContext::ConvertToString(MCValueRef p_value, MCStringRef& r_string)
         t_length = MCU_r8tos(t_buffer, t_buffer_size, MCNumberFetchAsReal((MCNumberRef)p_value), m_nffw, m_nftrailing, m_nfforce);
 
         bool t_success;
-        t_success = MCStringCreateWithNativeChars((char_t *)t_buffer, t_length, r_string) &&
+        t_success = MCStringCreateWithNativeCharBufferAndRelease((char_t *)t_buffer, t_length, t_buffer_size, r_string) &&
                 MCStringSetNumericValue(r_string, MCNumberFetchAsReal((MCNumberRef)p_value));
+        
+        if (!t_success)
+            delete[] t_buffer;
 
-        delete[] t_buffer;
         return t_success;
     }
     break;
diff --git a/libfoundation/include/foundation.h b/libfoundation/include/foundation.h
@@ -1473,6 +1473,7 @@ bool MCStringCreateWithWStringAndRelease(unichar_t *wstring, MCStringRef& r_stri
 // Create an immutable string from the given native char sequence.
 bool MCStringCreateWithNativeChars(const char_t *chars, uindex_t char_count, MCStringRef& r_string);
 bool MCStringCreateWithNativeCharsAndRelease(char_t *chars, uindex_t char_count, MCStringRef& r_string);
+bool MCStringCreateWithNativeCharBufferAndRelease(char_t* buffer, uindex_t char_count, uindex_t buffer_length, MCStringRef& r_string);
 
 // Create an immutable string from the given (native) c-string.
 bool MCStringCreateWithCString(const char *cstring, MCStringRef& r_string);
diff --git a/libfoundation/src/foundation-string.cpp b/libfoundation/src/foundation-string.cpp
@@ -567,6 +567,11 @@ bool MCStringCreateWithNativeChars(const char_t *p_chars, uindex_t p_char_count,
 }
 
 bool MCStringCreateWithNativeCharsAndRelease(char_t *p_chars, uindex_t p_char_count, MCStringRef& r_string)
+{
+    return MCStringCreateWithNativeCharBufferAndRelease(p_chars, p_char_count, p_char_count, r_string);
+}
+
+bool MCStringCreateWithNativeCharBufferAndRelease(char_t* p_chars, uindex_t p_char_count, uindex_t p_buffer_length, MCStringRef& r_string)
 {
     bool t_success;
     t_success = true;
@@ -583,14 +588,19 @@ bool MCStringCreateWithNativeCharsAndRelease(char_t *p_chars, uindex_t p_char_co
     if (t_success)
         t_success = __MCValueCreate(kMCValueTypeCodeString, self);
     
-    if (t_success)
-        t_success = MCMemoryReallocate(p_chars, p_char_count + 1, p_chars);
-    
+    uindex_t t_capacity = p_buffer_length;
+    if (t_success && t_capacity < p_char_count + 1)
+    {
+        t_capacity = p_char_count + 1;
+        t_success = MCMemoryReallocate(p_chars, t_capacity, p_chars);
+    }
+
     if (t_success)
     {
         p_chars[p_char_count] = '\0';
         self -> native_chars = p_chars;
         self -> char_count = p_char_count;
+        self -> capacity = t_capacity;
         r_string = self;
     }
     else
