trim: Use custom skiplist for required list (instead of std::set<unsigned>)

[apitrace] / cli / trim_callset.cpp

diff --git a/cli/trim_callset.cpp b/cli/trim_callset.cpp
new file mode 100644 (file)
index 0000000..236880a
--- /dev/null
+++ b/cli/trim_callset.cpp
@@ -0,0 +1,187 @@
+/*********************************************************************
+ *
+ * Copyright 2006 Keith Packard and Carl Worth
+ * Copyright 2012 Intel Corporation
+ * Copyright 2012 VMware, Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ *********************************************************************/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits>
+
+#include "trim_callset.hpp"
+
+using namespace trim;
+
+#define MAX_LEVEL 16
+
+CallRange::CallRange(CallNo call_no, int level)
+{
+    first = call_no;
+    last = call_no;
+    this->level = level;
+
+    next = new CallRange*[level];
+}
+
+bool
+CallRange::contains(CallNo call_no)
+{
+    return (first <= call_no && last >= call_no);
+}
+
+CallSet::CallSet(): head(0, MAX_LEVEL)
+{
+    head.first = std::numeric_limits<CallNo>::max();
+    head.last = std::numeric_limits<CallNo>::min();
+
+    for (int i = 0; i < MAX_LEVEL; i++)
+        head.next[i] = NULL;
+
+    max_level = 0;
+}
+
+/*
+ * Generate a random level number, distributed
+ * so that each level is 1/4 as likely as the one before
+ *
+ * Note that level numbers run 1 <= level < MAX_LEVEL
+ */
+static int
+random_level (void)
+{
+    /* tricky bit -- each bit is '1' 75% of the time */
+    long int bits = random() | random();
+    int        level = 1;
+
+    while (level < MAX_LEVEL)
+    {
+       if (bits & 1)
+           break;
+        level++;
+       bits >>= 1;
+    }
+
+    return level;
+}
+
+void
+CallSet::add(CallNo call_no)
+{
+    CallRange **update[MAX_LEVEL];
+    CallRange *node;
+    int i, level;
+
+    /* Find node immediately before insertion point. */
+    node = &head;
+    for (i = max_level - 1; i >= 0; i--) {
+        while (node->next[i] && call_no > node->next[i]->last) {
+            node = node->next[i];
+        }
+        update[i] = &node->next[i];
+    }
+
+    /* Can we contain call_no by expanding tail of current range by 1? */
+    if (node != &head && node->last == call_no - 1) {
+
+        CallRange *next = node->next[0];
+
+        node->last = call_no;
+
+        /* Also merge with next node as needed. */
+        if (next && next->first == call_no + 1) {
+            node->last = next->last;
+
+            /* Delete node 'next' */
+            for (i = 0; i < node->level && i < next->level; i++) {
+                node->next[i] = next->next[i];
+            }
+
+            for (; i < next->level; i++) {
+                *update[i] = next->next[i];
+            }
+
+            delete next;
+        }
+
+        return;
+    }
+
+    /* Current range could not contain call_no, look at next. */
+    node = node->next[0];
+
+    if (node) {
+        /* Do nothing if call_no is already contained. */
+        if (node->first <= call_no) {
+            return;
+        }
+
+        /* Can we exand head of range by 1? */
+        if (node->first == call_no + 1) {
+            node->first = call_no;
+            return;
+        }
+    }
+
+    /* Not possible to expand any existing node, so create new one. */
+
+    level = random_level();
+
+    /* Handle first node of this level. */
+    if (level > max_level) {
+        level = max_level + 1;
+        update[max_level] = &head.next[max_level];
+        max_level = level;
+    }
+
+    node = new CallRange(call_no, level);
+
+    /* Perform insertion into all lists. */
+    for (i = 0; i < level; i++) {
+        node->next[i] = *update[i];
+        *update[i] = node;
+    }
+}
+
+bool
+CallSet::contains(CallNo call_no)
+{
+    CallRange *node;
+    int i;
+
+    node = &head;
+    for (i = max_level - 1; i >= 0; i--) {
+        while (node->next[i] && call_no > node->next[i]->last) {
+            node = node->next[i];
+        }
+    }
+
+    node = node->next[0];
+
+    if (node == NULL)
+        return false;
+
+    return node->contains(call_no);
+}