From 5a02e98f44e95db2660e1468c5765d924af68534 Mon Sep 17 00:00:00 2001
From: Ralph Ronnquist <ralph.ronnquist@gmail.com>
Date: Mon, 27 Jun 2022 10:24:40 +1000
Subject: [PATCH] restore to the 8-bit level index variant

---
 vector/Makefile |  2 +-
 vector/vector.c | 13 +++++++++++++
 vector/vector.h |  4 +++-
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/vector/Makefile b/vector/Makefile
index f8b05a7..edd309f 100644
--- a/vector/Makefile
+++ b/vector/Makefile
@@ -2,7 +2,7 @@ LIBRARY = libvector.a
 LIBOBJS = vector.o hashvector.o
 
 # This is overridable on command line
-VECTOR_LEVEL_BITS = 4
+VECTOR_LEVEL_BITS = 8
 
 default: $(LIBRARY)
 
diff --git a/vector/vector.c b/vector/vector.c
index feaed9f..c4482a7 100644
--- a/vector/vector.c
+++ b/vector/vector.c
@@ -32,6 +32,19 @@ static int VECTOR_INDEX_PART_INC(vector_index *index,int part) {
     }
     return ++VECTOR_PART_BYTE(index,part).msb;
 }
+#elif VECTOR_LEVEL_BITS == 8
+
+#define VECTOR_LEVEL_MASK ( VECTOR_SLOTS - 1 )
+
+typedef union {
+    vector_index as_whole;
+    unsigned char as_byte[8];
+} vector_indexing;
+
+#define VECTOR_INDEX_PART(i,p) (((vector_indexing*)(i))->as_byte[p])
+
+#define VECTOR_INDEX_PART_INC(i,p) (++VECTOR_INDEX_PART(i,p))
+
 #endif
 
 /**
diff --git a/vector/vector.h b/vector/vector.h
index d84c08c..ccd57f3 100644
--- a/vector/vector.h
+++ b/vector/vector.h
@@ -6,11 +6,13 @@
  * of index pages. The indexing is done using "unsigned long" indexes.
  */
 
+#ifndef VECTOR_LEVEL_BITS
 /*!
  * Macro: VECTOR_LEVEL_BITS
  * This defines the number of bits in the indexing bit field.
  */
-#define VECTOR_LEVEL_BITS 4
+#define VECTOR_LEVEL_BITS 8
+#endif
 
 /*!
  * Type: vector_index
-- 
2.39.2