1 files changed, 95 insertions, 0 deletions
diff --git a/lib/port-array.h b/lib/port-array.h
new file mode 100644
index 000000000..e9b3cf11c
--- /dev/null
+++ b/lib/port-array.h
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2008, 2009 Nicira Networks.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef PORT_ARRAY_H
+#define PORT_ARRAY_H 1
+
+#include <assert.h>
+#include "openflow/openflow.h"
+#include "util.h"
+
+static inline uint16_t
+port_array_extract_bits__(uint16_t data, int start, int count)
+{
+    return (data >> start) & ((1u << count) - 1);
+}
+
+/* Level 1: most-significant bits. */
+#define PORT_ARRAY_L1_BITS 5
+#define PORT_ARRAY_L1_SHIFT (PORT_ARRAY_L3_BITS + PORT_ARRAY_L2_BITS)
+#define PORT_ARRAY_L1_SIZE (1u << PORT_ARRAY_L1_BITS)
+#define PORT_ARRAY_L1(IDX) \
+    port_array_extract_bits__(IDX, PORT_ARRAY_L1_SHIFT, PORT_ARRAY_L1_BITS)
+
+/* Level 2: middle bits. */
+#define PORT_ARRAY_L2_BITS 5
+#define PORT_ARRAY_L2_SHIFT PORT_ARRAY_L3_BITS
+#define PORT_ARRAY_L2_SIZE (1u << PORT_ARRAY_L2_BITS)
+#define PORT_ARRAY_L2(IDX) \
+    port_array_extract_bits__(IDX, PORT_ARRAY_L2_SHIFT, PORT_ARRAY_L2_BITS)
+
+/* Level 3: least-significant bits. */
+#define PORT_ARRAY_L3_BITS 6
+#define PORT_ARRAY_L3_SHIFT 0
+#define PORT_ARRAY_L3_SIZE (1u << PORT_ARRAY_L3_BITS)
+#define PORT_ARRAY_L3(IDX) \
+    port_array_extract_bits__(IDX, PORT_ARRAY_L3_SHIFT, PORT_ARRAY_L3_BITS)
+
+#define PORT_ARRAY_SIZE (1u << (PORT_ARRAY_L1_BITS      \
+                                + PORT_ARRAY_L2_BITS    \
+                                + PORT_ARRAY_L3_BITS))
+
+BUILD_ASSERT_DECL(PORT_ARRAY_SIZE > 0xffff);
+
+/* A "sparse array" of up to 65536 elements (numbered 0...65535), implemented
+ * as a 3-level trie.  Most efficient when the elements are clustered
+ * together. */
+struct port_array {
+    struct port_array_l2 *l1[1u << PORT_ARRAY_L1_BITS];
+};
+
+struct port_array_l2 {
+    struct port_array_l3 *l2[1u << PORT_ARRAY_L2_BITS];
+};
+
+struct port_array_l3 {
+    void *l3[1u << PORT_ARRAY_L3_BITS];
+};
+
+/* Returns the value of the element numbered 'idx' in 'pa', or a null pointer
+ * if no element numbered 'idx' has been set. */
+static inline void *
+port_array_get(const struct port_array *pa, uint16_t idx)
+{
+    unsigned int l1_idx = PORT_ARRAY_L1(idx);
+    unsigned int l2_idx = PORT_ARRAY_L2(idx);
+    unsigned int l3_idx = PORT_ARRAY_L3(idx);
+    return pa->l1[l1_idx]->l2[l2_idx]->l3[l3_idx];
+}
+
+void port_array_init(struct port_array *);
+void port_array_destroy(struct port_array *);
+void port_array_clear(struct port_array *);
+void port_array_set(struct port_array *, uint16_t idx, void *);
+void *port_array_first(const struct port_array *, unsigned int *);
+void *port_array_next(const struct port_array *, unsigned int *);
+unsigned int port_array_count(const struct port_array *);
+
+#define PORT_ARRAY_FOR_EACH(DATA, ARRAY, PORT_NO)                       \
+    for ((DATA) = port_array_first(ARRAY, &(PORT_NO)); (DATA) != NULL;  \
+         (DATA) = port_array_next(ARRAY, &(PORT_NO)))
+
+#endif /* port-array.h */