Initial commit of Hyperscan

src/util/pqueue.h

@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2015, Intel Corporation
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *  * Neither the name of Intel Corporation nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef PQUEUE_H
+#define PQUEUE_H
+
+#include "ue2common.h"
+
+static really_inline u32
+pq_left(u32 i) {
+    return (i << 1) + 1;
+}
+
+static really_inline u32
+pq_right(u32 i) {
+    return (i << 1) + 2;
+}
+
+static really_inline
+u32 pq_parent(u32 i) {
+    return (i - 1) >> 1;
+}
+
+static really_inline
+void pq_sift(PQ_T *items, u32 start, u32 end) {
+    u32 j = start;
+    PQ_T j_temp = items[j];
+
+    while (pq_left(j) < end) {
+        u32 max_child;
+
+        if (pq_right(j) < end && PQ_COMP(items, pq_right(j), pq_left(j))) {
+            max_child = pq_right(j);
+        } else {
+            max_child = pq_left(j);
+        }
+
+        if (PQ_COMP_B(items, max_child, j_temp)) {
+            items[j] = items[max_child];
+            j = max_child;
+        } else {
+            /* j is already less than its children. We know heap property
+             * is already maintained for children we are done */
+            break;
+        }
+    }
+    items[j] = j_temp;
+}
+
+static really_inline
+PQ_T *pq_top(PQ_T *items) {
+    return items;
+}
+
+static really_inline
+void pq_pop(PQ_T *items, u32 item_count) {
+    item_count--;
+    items[0] = items[item_count];
+    pq_sift(items, 0, item_count);
+}
+
+static really_inline
+void pq_insert(PQ_T *items, u32 item_count, PQ_T new_item) {
+    u32 pos = item_count;
+    while (pos) {
+        u32 parent = pq_parent(pos);
+        if (!PQ_COMP_B(items, parent, new_item)) {
+            items[pos] = items[parent];
+            pos = parent;
+        } else {
+            break;
+        }
+    }
+    items[pos] = new_item;
+}
+
+static really_inline
+void pq_replace_top(PQ_T *items, u32 item_count, PQ_T new_item) {
+    items[0] = new_item;
+    pq_sift(items, 0, item_count);
+}
+
+#endif
+