implement util.Sort

darcs-hash:20040524031340-24bed-5580aee7e80d64880a01fe2e29212746235275b6.gz

diff --git a/src/org/ibex/nestedvm/util/Sort.java b/src/org/ibex/nestedvm/util/Sort.java
index bf5c8dd..a2bba16 100644 (file)
--- a/src/org/ibex/nestedvm/util/Sort.java
+++ b/src/org/ibex/nestedvm/util/Sort.java
@@ -3,11 +3,45 @@ package org.ibex.nestedvm.util;
 public final class Sort {
     private Sort() { }
     
-    public interface Sortable {
-        public int compareTo(Object o);
-    }
+    public interface Comparable { public int compareTo(Object o); }
+    public interface CompareFunc { public int compare(Object a, Object b); }
+    
+    private static final CompareFunc comparableCompareFunc = new CompareFunc() {
+        public int compare(Object a,Object b) { return ((Comparable)a).compareTo(b); }
+    };
+    
+    public static void sort(Comparable[] a) { sort(a,comparableCompareFunc); }
+    public static void sort(Object[] a, CompareFunc c) { sort(a,c,0,a.length-1); }
     
-    public static void sort(Sortable[] a) {
-        throw new Error("FIXME");
+    private static void sort(Object[] a, CompareFunc c, int start, int end) {
+        Object tmp;
+        if(start >= end) return;
+        if(end-start <= 6) {
+            for(int i=start+1;i<=end;i++) {
+                tmp = a[i];
+                int j;
+                for(j=i-1;j>=start;j--) {
+                    if(c.compare(a[j],tmp) <= 0) break;
+                    a[j+1] = a[j];
+                }
+                a[j+1] = tmp;
+            }
+            return;
+        }
+        
+        Object pivot = a[end];
+        int lo = start - 1;
+        int hi = end;
+        
+        do {
+            while((lo < hi) && c.compare(a[++lo],pivot) < 0) { }
+            while((hi > lo) && c.compare(a[--hi],pivot) > 0) { }
+            tmp = a[lo]; a[lo] = a[hi]; a[hi] = tmp;
+        } while(lo < hi);
+        
+        tmp = a[lo]; a[lo] = a[end]; a[end] = tmp;
+        
+        sort(a, c, start, lo-1);
+        sort(a, c, lo+1, end);
     }
 }