1 files changed, 56 insertions, 0 deletions
diff --git a/raa.h b/raa.h
new file mode 100644
index 0000000..665e728
--- /dev/null
+++ b/raa.h
@@ -0,0 +1,56 @@
+#ifndef NASM_RAA_H
+#define NASM_RAA_H 1
+
+#include "compiler.h"
+
+/*
+ * Routines to manage a dynamic random access array of int64_ts which
+ * may grow in size to be more than the largest single malloc'able
+ * chunk.
+ */
+
+#define RAA_BLKSHIFT	15	/* 2**this many longs allocated at once */
+#define RAA_BLKSIZE	(1 << RAA_BLKSHIFT)
+#define RAA_LAYERSHIFT	15	/* 2**this many _pointers_ allocated */
+#define RAA_LAYERSIZE	(1 << RAA_LAYERSHIFT)
+
+typedef struct RAA RAA;
+typedef union RAA_UNION RAA_UNION;
+typedef struct RAA_LEAF RAA_LEAF;
+typedef struct RAA_BRANCH RAA_BRANCH;
+
+struct RAA {
+    /*
+     * Number of layers below this one to get to the real data. 0
+     * means this structure is a leaf, holding RAA_BLKSIZE real
+     * data items; 1 and above mean it's a branch, holding
+     * RAA_LAYERSIZE pointers to the next level branch or leaf
+     * structures.
+     */
+    int layers;
+
+    /*
+     * Number of real data items spanned by one position in the
+     * `data' array at this level. This number is 0 trivially, for
+     * a leaf (level 0): for a level 1 branch it should be
+     * RAA_BLKSHIFT, and for a level 2 branch it's
+     * RAA_LAYERSHIFT+RAA_BLKSHIFT.
+     */
+    int shift;
+
+    union RAA_UNION {
+        struct RAA_LEAF {
+            int64_t data[RAA_BLKSIZE];
+        } l;
+        struct RAA_BRANCH {
+            struct RAA *data[RAA_LAYERSIZE];
+        } b;
+    } u;
+};
+
+struct RAA *raa_init(void);
+void raa_free(struct RAA *);
+int64_t raa_read(struct RAA *, int32_t);
+struct RAA *raa_write(struct RAA *r, int32_t posn, int64_t value);
+
+#endif /* NASM_RAA_H */