Sort algorithms should always be built, and be selectable at runtime

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@39998 72102866-910b-0410-8b05-ffd578937521

Source/GSQuickSort.m

@@ -35,7 +35,6 @@
  * Sorts the provided object array's sortRange according to sortDescriptor.
  */
 // Quicksort algorithm copied from Wikipedia :-).
-#if GS_USE_QUICKSORT
 
 static inline void
 SwapObjects(id * o1, id * o2)
@@ -84,12 +83,12 @@ _GSQuickSort(id *objects,
 }
 
 @interface GSQuickSortPlaceHolder : NSObject
++ (void) setUnstable;
 @end
 
 @implementation GSQuickSortPlaceHolder
-+ (void) load
++ (void) setUnstable
 {
   _GSSortUnstable = _GSQuickSort;
 }
 @end
-#endif

Source/GSShellSort.m

@@ -30,7 +30,6 @@
 #import "Foundation/NSObjCRuntime.h"
 #import "GSSorting.h"
 
-#if GS_USE_SHELLSORT
 void
 _GSShellSort(id *objects,
   NSRange sortRange,
@@ -114,13 +113,13 @@ _GSShellSort(id *objects,
 
 
 @interface GSShellSortPlaceHolder : NSObject
-
++ (void) setUnstable;
 @end
 
 @implementation GSShellSortPlaceHolder
-+ (void) load
++ (void) setUnstable
 {
   _GSSortUnstable = _GSShellSort;
 }
 @end
-#endif
+

Source/GSSorting.h

@@ -30,7 +30,7 @@
 
 enum
 {
-  GSComparisonTypeSortDescriptor = 0, /** Comparison using an NSSortDescriptor */
+  GSComparisonTypeSortDescriptor = 0, /** Comparison using NSSortDescriptor */
   GSComparisonTypeComparatorBlock, /** Comparison using an NSComparator */
   GSComparisonTypeFunction, /** Comparison using a comparison function of type
   * NSInteger(*)(id,id,void*) */
@@ -130,7 +130,7 @@ GSRightInsertionPointForKeyInSortedRange(id key, id *buffer,
  * This function is provided using the implementation of the timsort algorithm.
  */
 NSUInteger
-GSLeftInsertionPointForKeyInSortedRange(id key, id* buffer,
+GSLeftInsertionPointForKeyInSortedRange(id key, id *buffer,
   NSRange range, NSComparator comparator);
 
 /**
@@ -139,7 +139,7 @@ GSLeftInsertionPointForKeyInSortedRange(id key, id* buffer,
  */
 static inline NSComparisonResult
 GSCompareUsingDescriptorOrComparator(id first, id second, id descOrComp,
-  GSComparisonType cmprType, void* context)
+  GSComparisonType cmprType, void *context)
 {
 
   switch (cmprType)

Source/GSTimSort.m

@@ -295,8 +295,6 @@ NSRange range, NSComparator cmptr)
     GSComparisonTypeComparatorBlock, NULL);
 }
 
-#if GS_USE_TIMSORT
-
 static inline void
 reverseRange(id *buffer, NSRange r)
 {
@@ -476,7 +474,7 @@ static IMP mergeLowImp;
 static IMP mergeHighImp;
 static IMP ensureCapImp;
 
-@interface GSTimSortDescriptor : NSObject
+@interface GSTimSortPlaceHolder : NSObject
 {
   id *objects;
   NSRange sortRange;
@@ -511,7 +509,7 @@ _GSTimSort(id *objects,
   GSComparisonType comparisonType,
   void *context);
 
-@implementation GSTimSortDescriptor
+@implementation GSTimSortPlaceHolder
 + (void) load
 {
   _GSSortStable = _GSTimSort;
@@ -519,7 +517,7 @@ _GSTimSort(id *objects,
 
 + (void) initialize
 {
-  if ([GSTimSortDescriptor class] == [self class])
+  if ([GSTimSortPlaceHolder class] == [self class])
     {
       // We need to be fast, so we cache a lot of IMPs
       pushRunImp =
@@ -539,6 +537,11 @@ _GSTimSort(id *objects,
     }
 }
 
++ (void) setUnstable
+{
+  _GSSortUnstable = _GSTimSort; // Use for unstable even though we are stable
+}
+
 - (id) initWithObjects: (id*)theObjects
              sortRange: (NSRange)theSortRange
 descriptorOrComparator: (id)descriptorOrComparator
@@ -552,7 +555,7 @@ descriptorOrComparator: (id)descriptorOrComparator
     {
       return nil;
     }
-  /* GSTimSortDescriptors are ephemeral objects that just track state, so we
+  /* GSTimSortPlaceHolders are ephemeral objects that just track state, so we
    * don't bother making sure that the objects don't go away.
    */
   objects = theObjects;
@@ -1107,7 +1110,7 @@ _GSTimSort(id *objects,
   NSUInteger sortEnd = NSMaxRange(sortRange);
   NSUInteger sortLen = sortRange.length;
   NSUInteger minimalRunLen = 0;
-  GSTimSortDescriptor *desc = nil;
+  GSTimSortPlaceHolder *desc = nil;
   if (sortLen < 2)
     {
       // Don't sort anything that doesn't contain at least two elements.
@@ -1116,16 +1119,17 @@ _GSTimSort(id *objects,
 
   if (sortLen < GS_MIN_MERGE)
     {
-      miniTimSort(objects, sortRange, sortDescriptorOrComparator, comparisonType, context);
+      miniTimSort(objects, sortRange,
+        sortDescriptorOrComparator, comparisonType, context);
       return;
     }
 
   // Now we need a timsort descriptor for state-tracking.
-  desc = [[GSTimSortDescriptor alloc] initWithObjects: objects
-                                            sortRange: sortRange
-                               descriptorOrComparator: sortDescriptorOrComparator
-                                       comparisonType: comparisonType
-                                      functionContext: context];
+  desc = [[GSTimSortPlaceHolder alloc] initWithObjects: objects
+    sortRange: sortRange
+    descriptorOrComparator: sortDescriptorOrComparator
+    comparisonType: comparisonType
+    functionContext: context];
 
   NS_DURING
     {
@@ -1172,4 +1176,3 @@ _GSTimSort(id *objects,
   [desc release];
 }
 
-#endif

Source/NSSortDescriptor.m

@@ -30,6 +30,8 @@
 #import "Foundation/NSCoder.h"
 #import "Foundation/NSException.h"
 #import "Foundation/NSKeyValueCoding.h"
+#import "Foundation/NSNotification.h"
+#import "Foundation/NSUserDefaults.h"
 
 #import "GNUstepBase/GSObjCRuntime.h"
 #import "GSPrivate.h"
@@ -41,34 +43,61 @@ static BOOL     initialized = NO;
 #pragma clang diagnostic ignored "-Wreceiver-forward-class"
 #endif
 
-#if     GS_USE_TIMSORT
-@interface GSTimSortDescriptor : NSObject
+@interface GSTimSortPlaceHolder : NSObject
++ (void) setUnstable;
 @end
-#endif
-#if     GS_USE_QUICKSORT
 @interface GSQuickSortPlaceHolder : NSObject
++ (void) setUnstable;
 @end
-#endif
-#if     GS_USE_SHELLSORT
 @interface GSShellSortPlaceHolder : NSObject
++ (void) setUnstable;
 @end
-#endif
 
 @implementation NSSortDescriptor
 
++ (void) defaultsChanged: (NSNotification*)n
+{
+  NSUserDefaults        *defs = (NSUserDefaults*)[n object];
+  NSString              *algorithm;
+
+  algorithm = [defs stringForKey: @"GSSortAlgorithm"];
+  if ([algorithm isEqual: @"QuickSort"])
+    {
+      [GSQuickSortPlaceHolder setUnstable];
+    }
+  else if ([algorithm isEqual: @"ShellSort"])
+    {
+      [GSShellSortPlaceHolder setUnstable];
+    }
+  else if ([algorithm isEqual: @"TimSort"])
+    {
+      [GSTimSortPlaceHolder setUnstable];
+    }
+  else
+    {
+      [GSTimSortPlaceHolder setUnstable];
+      if (nil != algorithm)
+        {
+          NSLog(@"GSSortAlgorithm default unknown value (%@)", algorithm);
+        }
+    }
+}
+
 + (void) initialize
 {
   if (NO == initialized)
     {
-#if     GS_USE_TIMSORT
-      [GSTimSortDescriptor class];
-#endif
-#if     GS_USE_QUICKSORT
-      [GSQuickSortPlaceHolder class];
-#endif
-#if     GS_USE_SHELLSORT
-      [GSShellSortPlaceHolder class];
-#endif
+      NSNotificationCenter      *nc;
+      NSUserDefaults            *defs;
+
+      [GSTimSortPlaceHolder class];     // default stable sort
+      nc = [NSNotificationCenter defaultCenter];
+      defs = [NSUserDefaults standardUserDefaults];
+      [nc addObserver: self
+             selector: @selector(defaultsChanged:)
+                 name: NSUserDefaultsDidChangeNotification
+               object: defs];
+      [self defaultsChanged: nil];      // set unstable sort
       initialized = YES;
     }
 }