X-Git-Url: https://git.rrq.au/?a=blobdiff_plain;f=vector%2Fvector.c;h=129ba02990e8e01d03ec6364b1092ac418e654d9;hb=d8c1ccad095640b40192055bff9ad37e98216970;hp=8dadf00a440873ad7ee4e4962ee50c822b75db29;hpb=9e0cc3c3727ec7069e7f6f6ae252895308753b5a;p=rrq%2Frrqmisc.git

diff --git a/vector/vector.c b/vector/vector.c
index 8dadf00..129ba02 100644
--- a/vector/vector.c
+++ b/vector/vector.c
@@ -7,6 +7,31 @@
  * void*, and an index is "unsigned long" (64 bits).
  */
 
+#if VECTOR_LEVEL_BITS == 4
+typedef union {
+    vector_index as_whole;
+    struct {
+	unsigned int msb:4; unsigned int lsb:4;
+    } __attribute__ ((__packed__)) as_byte[8];
+} vector_indexing;
+
+#define VECTOR_PART_BYTE(i,p) ((vector_indexing*)(i))->as_byte[ (p)/2 ]
+
+static int VECTOR_INDEX_PART(vector_index *index,int part) {
+    if ( part & 1 ) {
+	return VECTOR_PART_BYTE(index,part).lsb;
+    }
+    return VECTOR_PART_BYTE(index,part).msb;
+}
+
+static int VECTOR_INDEX_PART_INC(vector_index *index,int part) {
+    if ( part & 1 ) {
+	return ++VECTOR_PART_BYTE(index,part).lsb;
+    }
+    return ++VECTOR_PART_BYTE(index,part).msb;
+}
+#endif
+
 /**
  * Advances a vector index to the next used slot at or below the
  * given level, starting from the indexed entry (inclusive) and up.
@@ -35,7 +60,7 @@ static void **vector_level_next_used(
 		*p = 0;
 	    }
 	}
-	if ( ++VECTOR_INDEX_PART( index, level ) == 0 ) {
+	if ( VECTOR_INDEX_PART_INC( index, level ) == 0 ) {
 	    break; // cycling this level => nothing found
 	}
     }
@@ -149,15 +174,21 @@ int vector_resize(
 	vector_page *entries;
 	vector_page **pp = &pv->entries;
 	while ( level.old-- > level.new ) {
-	    pp = (vector_page **)(*pp)[0];
+	    if ( pp ) {
+		pp = (vector_page **)(*pp)[0];
+	    }
 	}
 	if ( pp != &pv->entries ) {
 	    entries = pv->entries;
-	    pv->entries = *pp;
-	    *pp = 0;
+	    if ( pp ) {
+		pv->entries = *pp;
+		*pp = 0; // Detach subtree
+	    } else {
+		pv->entries = 0;
+	    }
 	    vector_reclaim( entries, level.old );
 	}
-	if ( new_size == 0 ) {
+	if ( new_size == 0 && pv->entries ) {
 	    free( pv->entries );
 	    pv->entries = 0;
 	}