Performance optimisations - mimimise calls to malloc and avoid method despatch

overhead on deaalloc.


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@7925 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -1,3 +1,11 @@
+2000-10-29  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/GSString.m: New inline string classes added to avoid calls
+	to malloc in some cases.  Changed all deallocation methods to call
+	NSDeallocateObject() directy for efficiency.
+	* Source/NSString.m: Use new inline string classes for creation of
+	strings where we know the length of the data in advaance.
+
 2000-10-28  Mirko Viviani  <mirko.viviani@rccr.cremona.it>
 
 	* Headers/gnustep/base/NSBundle.h: added ivar.

Source/GSString.m

@@ -58,7 +58,16 @@
 @end
 
 /*
- * GSCSubString - concrete subclass of GSCString, that relys on the
+ * GSCInlineString - concrete subclass of GSCString, that expects the
+ * characterData to appear in memory immediately after the object itsself.
+ */
+@interface GSCInlineString : GSCString
+{
+}
+@end
+
+/*
+ * GSCSubString - concrete subclass of GSCString, that relies on the
  * data stored in a GSCString object.
  */
 @interface GSCSubString : GSCString
@@ -76,6 +85,15 @@
 }
 @end
 
+/*
+ * GSUInlineString - concrete subclass of GSUString, that expects the
+ * characterData to appear in memory immediately after the object itsself.
+ */
+@interface GSUInlineString : GSUString
+{
+}
+@end
+
 /*
  * GSUSubString - concrete subclass of GSUString, that relys on the
  * data stored in a GSUString object.
@@ -160,9 +178,11 @@ static Class NSDataClass = 0;
 static Class NSStringClass = 0;
 static Class GSStringClass = 0;
 static Class GSCStringClass = 0;
+static Class GSCInlineStringClass = 0;
 static Class GSCSubStringClass = 0;
 static Class GSUStringClass = 0;
 static Class GSUSubStringClass = 0;
+static Class GSUInlineStringClass = 0;
 static Class GSMStringClass = 0;
 static Class NXConstantStringClass = 0;
 
@@ -193,6 +213,8 @@ setup()
       GSStringClass = [GSString class];
       GSCStringClass = [GSCString class];
       GSUStringClass = [GSUString class];
+      GSCInlineStringClass = [GSCInlineString class];
+      GSUInlineStringClass = [GSUInlineString class];
       GSCSubStringClass = [GSCSubString class];
       GSUSubStringClass = [GSUSubString class];
       GSMStringClass = [GSMString class];
@@ -1204,7 +1226,7 @@ transmute(ivars self, NSString *aString)
       NSZoneFree(NSZoneFromPointer(_contents.c), _contents.c);
       _contents.c = 0;
     }
-  [super dealloc];
+  NSDeallocateObject(self);
 }
 
 - (id) initWithCharactersNoCopy: (unichar*)chars
@@ -1300,17 +1322,10 @@ transmute(ivars self, NSString *aString)
 {
   if (NSShouldRetainWithZone(self, z) == NO)
     {
-      GSCString	*obj;
+      NSString	*obj;
 
-      obj = (GSCString*)NSCopyObject(self, 0, z);
+      obj = (NSString*)NSAllocateObject(GSCInlineStringClass, _count, z);
-      if (_contents.c != 0)
+      obj = [obj initWithCString: _contents.c length: _count];
-	{
-	  unsigned char	*tmp;
-
-	  tmp = NSZoneMalloc(z, _count);
-	  memcpy(tmp, _contents.c, _count);
-	  obj->_contents.c = tmp;
-	}
       return obj;
     }
   else 
@@ -1483,11 +1498,26 @@ transmute(ivars self, NSString *aString)
 
 
 
+@implementation	GSCInlineString
+- (id) initWithCString: (const char*)chars length: (unsigned)length
+{
+  _count = length;
+  _contents.c = (unsigned char*)&self[1];
+  memcpy(_contents.c, chars, length);
+  _flags.wide = 0;
+  return self;
+}
+- (void) dealloc
+{
+  NSDeallocateObject(self);
+}
+@end
+
 @implementation	GSCSubString
 - (void) dealloc
 {
   RELEASE(_parent);
-  [super dealloc];
+  NSDeallocateObject(self);
 }
 @end
 
@@ -1559,17 +1589,10 @@ transmute(ivars self, NSString *aString)
 {
   if (NSShouldRetainWithZone(self, z) == NO)
     {
-      GSUString	*obj;
+      NSString	*obj;
 
-      obj = (GSUString*)NSCopyObject(self, 0, z);
+      obj = (NSString*)NSAllocateObject(GSUInlineStringClass, _count*2, z);
-      if (_contents.u != 0)
+      obj = [obj initWithCharacters: _contents.u length: _count];
-	{
-	  unichar	*tmp;
-
-	  tmp = NSZoneMalloc(z, _count*sizeof(unichar));
-	  memcpy(tmp, _contents.u, _count*sizeof(unichar));
-	  obj->_contents.u = tmp;
-	}
       return obj;
     }
   else 
@@ -1751,11 +1774,26 @@ transmute(ivars self, NSString *aString)
 
 
 
+@implementation	GSUInlineString
+- (id) initWithCharacters: (const unichar*)chars length: (unsigned)length
+{
+  _count = length;
+  _contents.u = (unichar*)&self[1];
+  memcpy(_contents.u, chars, length*sizeof(unichar));
+  _flags.wide = 1;
+  return self;
+}
+- (void) dealloc
+{
+  NSDeallocateObject(self);
+}
+@end
+
 @implementation	GSUSubString
 - (void) dealloc
 {
   RELEASE(_parent);
-  [super dealloc];
+  NSDeallocateObject(self);
 }
 @end
 
@@ -1835,12 +1873,13 @@ transmute(ivars self, NSString *aString)
 
   if (_flags.wide == 1)
     {
-      copy = [GSUStringClass allocWithZone: z];
+      copy = (NSString*)NSAllocateObject(GSUInlineStringClass,
+	_count*sizeof(unichar), z);
       copy = [copy initWithCharacters: _contents.u length: _count];
     }
   else
     {
-      copy = [GSCStringClass allocWithZone: z];
+      copy = (NSString*)NSAllocateObject(GSCInlineStringClass, _count, z);
       copy = [copy initWithCString: _contents.c length: _count];
     }
   return copy;
@@ -1879,7 +1918,7 @@ transmute(ivars self, NSString *aString)
       self->_contents.c = 0;
       self->_zone = 0;
     }
-  [super dealloc];
+  NSDeallocateObject(self);
 }
 
 - (void) deleteCharactersInRange: (NSRange)range

Source/NSString.m

@@ -8,7 +8,7 @@
    Date: February 1997
 
    Optimisations by Richard Frith-Macdonald <richard@brainstorm.co.uk>
-   Date: October 1998
+   Date: October 1998 - 2000
 
    This file is part of the GNUstep Base Library.
 
@@ -75,6 +75,8 @@
 @class	GSString;
 @class	GSMString;
 @class	GSUString;
+@class	GSCInlineString;
+@class	GSUInlineString;
 @class	NSGMutableArray;
 @class	NSGMutableDictionary;
 
@@ -89,6 +91,8 @@ static Class	NSMutableStringClass;
 static Class	GSStringClass;
 static Class	GSMStringClass;
 static Class	GSUStringClass;
+static Class	GSCInlineStringClass;
+static Class	GSUInlineStringClass;
 
 static Class	plArray;
 static id	(*plAdd)(id, SEL, id) = 0;
@@ -281,6 +285,8 @@ handle_printf_atsign (FILE *stream,
       GSStringClass = [GSString class];
       GSMStringClass = [GSMString class];
       GSUStringClass = [GSUString class];
+      GSCInlineStringClass = [GSCInlineString class];
+      GSUInlineStringClass = [GSUInlineString class];
 
 #if HAVE_REGISTER_PRINTF_FUNCTION
       if (register_printf_function ('@', 
@@ -324,21 +330,34 @@ handle_printf_atsign (FILE *stream,
 + (id) stringWithCharacters: (const unichar*)chars
 		     length: (unsigned)length
 {
-  return AUTORELEASE([[self allocWithZone: NSDefaultMallocZone()]
+  NSString	*obj;
-    initWithCharacters: chars length: length]);
+
+  obj = (NSString*)NSAllocateObject(GSUInlineStringClass, length*2,
+    NSDefaultMallocZone());
+  obj = [obj initWithCharacters: chars length: length];
+  return AUTORELEASE(obj);
 }
 
 + (id) stringWithCString: (const char*) byteString
 {
-  return AUTORELEASE([[self allocWithZone: NSDefaultMallocZone()]
+  NSString	*obj;
-    initWithCString: byteString]);
+  unsigned	length = strlen(byteString);
+
+  obj = (NSString*)NSAllocateObject(GSCInlineStringClass, length,
+    NSDefaultMallocZone());
+  obj = [obj initWithCString: byteString length: length];
+  return AUTORELEASE(obj);
 }
 
 + (id) stringWithCString: (const char*)byteString
 		  length: (unsigned)length
 {
-  return AUTORELEASE([[self allocWithZone: NSDefaultMallocZone()]
+  NSString	*obj;
-    initWithCString: byteString length: length]);
+
+  obj = (NSString*)NSAllocateObject(GSCInlineStringClass, length,
+    NSDefaultMallocZone());
+  obj = [obj initWithCString: byteString length: length];
+  return AUTORELEASE(obj);
 }
 
 + (id) stringWithUTF8String: (const char *)bytes
@@ -1410,7 +1429,7 @@ handle_printf_atsign (FILE *stream,
 	      prefix_len++;
 	    }
 	}
-      return [NSString stringWithCharacters: u length: prefix_len];
+      return [NSStringClass stringWithCharacters: u length: prefix_len];
     }
   else
     {
@@ -2450,7 +2469,7 @@ handle_printf_atsign (FILE *stream,
       if (lstat(&new_buf[8], &st) == 0)
 	strcpy(new_buf, &new_buf[8]);
     }
-  return [NSString stringWithCString: new_buf];
+  return [NSStringClass stringWithCString: new_buf];
 #endif  /* (__MINGW__) */  
 }