+ struct flow masks;
+};
+
+void flow_wildcards_init_catchall(struct flow_wildcards *);
+void flow_wildcards_init_exact(struct flow_wildcards *);
+
+bool flow_wildcards_is_catchall(const struct flow_wildcards *);
+
+void flow_wildcards_set_reg_mask(struct flow_wildcards *,
+ int idx, uint32_t mask);
+
+void flow_wildcards_and(struct flow_wildcards *dst,
+ const struct flow_wildcards *src1,
+ const struct flow_wildcards *src2);
+void flow_wildcards_or(struct flow_wildcards *dst,
+ const struct flow_wildcards *src1,
+ const struct flow_wildcards *src2);
+bool flow_wildcards_has_extra(const struct flow_wildcards *,
+ const struct flow_wildcards *);
+
+void flow_wildcards_fold_minimask(struct flow_wildcards *,
+ const struct minimask *);
+
+uint32_t flow_wildcards_hash(const struct flow_wildcards *, uint32_t basis);
+bool flow_wildcards_equal(const struct flow_wildcards *,
+ const struct flow_wildcards *);
+uint32_t flow_hash_symmetric_l4(const struct flow *flow, uint32_t basis);
+
+void flow_mask_hash_fields(struct flow_wildcards *, enum nx_hash_fields);
+uint32_t flow_hash_fields(const struct flow *, enum nx_hash_fields,
+ uint16_t basis);
+const char *flow_hash_fields_to_str(enum nx_hash_fields);
+bool flow_hash_fields_valid(enum nx_hash_fields);
+
+uint32_t flow_hash_in_wildcards(const struct flow *,
+ const struct flow_wildcards *,
+ uint32_t basis);
+
+bool flow_equal_except(const struct flow *a, const struct flow *b,
+ const struct flow_wildcards *);
+\f
+/* Compressed flow. */
+
+#define MINI_N_INLINE (sizeof(void *) == 4 ? 7 : 8)
+#define MINI_N_MAPS DIV_ROUND_UP(FLOW_U32S, 32)
+
+/* A sparse representation of a "struct flow".
+ *
+ * A "struct flow" is fairly large and tends to be mostly zeros. Sparse
+ * representation has two advantages. First, it saves memory. Second, it
+ * saves time when the goal is to iterate over only the nonzero parts of the
+ * struct.
+ *
+ * The 'map' member holds one bit for each uint32_t in a "struct flow". Each
+ * 0-bit indicates that the corresponding uint32_t is zero, each 1-bit that it
+ * is nonzero.
+ *
+ * 'values' points to the start of an array that has one element for each 1-bit
+ * in 'map'. The least-numbered 1-bit is in values[0], the next 1-bit is in
+ * values[1], and so on.
+ *
+ * 'values' may point to a few different locations:
+ *
+ * - If 'map' has MINI_N_INLINE or fewer 1-bits, it may point to
+ * 'inline_values'. One hopes that this is the common case.
+ *
+ * - If 'map' has more than MINI_N_INLINE 1-bits, it may point to memory
+ * allocated with malloc().
+ *
+ * - The caller could provide storage on the stack for situations where
+ * that makes sense. So far that's only proved useful for
+ * minimask_combine(), but the principle works elsewhere.
+ *
+ * The implementation maintains and depends on the invariant that every element
+ * in 'values' is nonzero; that is, wherever a 1-bit appears in 'map', the
+ * corresponding element of 'values' must be nonzero.
+ */
+struct miniflow {
+ uint32_t *values;
+ uint32_t inline_values[MINI_N_INLINE];
+ uint32_t map[MINI_N_MAPS];
+};
+
+void miniflow_init(struct miniflow *, const struct flow *);
+void miniflow_clone(struct miniflow *, const struct miniflow *);
+void miniflow_destroy(struct miniflow *);
+
+void miniflow_expand(const struct miniflow *, struct flow *);
+
+uint32_t miniflow_get(const struct miniflow *, unsigned int u32_ofs);
+uint16_t miniflow_get_vid(const struct miniflow *);
+
+bool miniflow_equal(const struct miniflow *a, const struct miniflow *b);
+bool miniflow_equal_in_minimask(const struct miniflow *a,
+ const struct miniflow *b,
+ const struct minimask *);
+bool miniflow_equal_flow_in_minimask(const struct miniflow *a,
+ const struct flow *b,
+ const struct minimask *);
+uint32_t miniflow_hash(const struct miniflow *, uint32_t basis);
+uint32_t miniflow_hash_in_minimask(const struct miniflow *,
+ const struct minimask *, uint32_t basis);
+\f
+/* Compressed flow wildcards. */
+
+/* A sparse representation of a "struct flow_wildcards".
+ *
+ * See the large comment on struct miniflow for details. */
+struct minimask {
+ struct miniflow masks;