TS-4295: Add Priority Queue in lib/ts/

.gitignore

@@ -77,6 +77,7 @@ lib/ts/test_Map
 lib/ts/test_Vec
 lib/ts/test_geometry
 lib/ts/test_Regex
+lib/ts/test_PriorityQueue
 lib/ts/test_X509HostnameValidator
 lib/perl/lib/Apache/TS.pm
 

lib/ts/Makefile.am

@@ -21,7 +21,7 @@ library_includedir=$(includedir)/ts
 library_include_HEADERS = apidefs.h
 
 noinst_PROGRAMS = mkdfa CompileParseRules
-check_PROGRAMS = test_arena test_atomic test_freelist test_geometry test_List test_Map test_Regex test_Vec test_X509HostnameValidator
+check_PROGRAMS = test_arena test_atomic test_freelist test_geometry test_List test_Map test_Regex test_PriorityQueue test_Vec test_X509HostnameValidator
 TESTS = $(check_PROGRAMS)
 
 AM_CPPFLAGS = -I$(top_srcdir)/lib
@@ -84,6 +84,7 @@ libtsutil_la_SOURCES = \
   MatcherUtils.h \
   ParseRules.cc \
   ParseRules.h \
+  PriorityQueue.h \
   Ptr.h \
   RawHashTable.cc \
   RawHashTable.h \
@@ -216,6 +217,10 @@ test_Regex_SOURCES = test_Regex.cc
 test_Regex_LDADD = libtsutil.la @LIBTCL@ @LIBPCRE@
 test_Regex_LDFLAGS = @EXTRA_CXX_LDFLAGS@ @LIBTOOL_LINK_FLAGS@
 
+test_PriorityQueue_SOURCES = test_PriorityQueue.cc
+test_PriorityQueue_LDADD = libtsutil.la @LIBTCL@ @LIBPCRE@
+test_PriorityQueue_LDFLAGS = @EXTRA_CXX_LDFLAGS@ @LIBTOOL_LINK_FLAGS@
+
 test_Vec_SOURCES = test_Vec.cc
 test_Vec_LDADD = libtsutil.la @LIBTCL@ @LIBPCRE@
 test_Vec_LDFLAGS = @EXTRA_CXX_LDFLAGS@ @LIBTOOL_LINK_FLAGS@

lib/ts/PriorityQueue.h

@@ -0,0 +1,214 @@
+/** @file
+
+  Priority Queue Implementation using Binary Heap.
+
+  @section license License
+
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership.  The ASF licenses this file
+  to you under the Apache License, Version 2.0 (the
+  "License"); you may not use this file except in compliance
+  with the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+ */
+
+#ifndef __PRIORITY_QUEUE_H__
+#define __PRIORITY_QUEUE_H__
+
+#include "ts/ink_assert.h"
+#include "ts/Vec.h"
+
+template <typename T> struct PriorityQueueEntry {
+  PriorityQueueEntry(T n) : index(0), node(n) {}
+
+  uint32_t index;
+  T node;
+};
+
+template <typename T> struct PriorityQueueLess {
+  bool operator()(const T &a, const T &b) { return *a < *b; }
+};
+
+template <typename T, class Comp = PriorityQueueLess<T> > class PriorityQueue
+{
+public:
+  PriorityQueue() {}
+  ~PriorityQueue() {}
+
+  const bool empty();
+  PriorityQueueEntry<T> *top();
+  void pop();
+  void push(PriorityQueueEntry<T> *);
+  void update(PriorityQueueEntry<T> *);
+  void update(PriorityQueueEntry<T> *, bool);
+  const Vec<PriorityQueueEntry<T> *> &dump() const;
+
+private:
+  Vec<PriorityQueueEntry<T> *> _v;
+
+  void _swap(uint32_t, uint32_t);
+  void _bubble_up(uint32_t);
+  void _bubble_down(uint32_t);
+};
+
+template <typename T, typename Comp>
+const Vec<PriorityQueueEntry<T> *> &
+PriorityQueue<T, Comp>::dump() const
+{
+  return _v;
+}
+
+template <typename T, typename Comp>
+const bool
+PriorityQueue<T, Comp>::empty()
+{
+  return _v.length() == 0;
+}
+
+template <typename T, typename Comp>
+void
+PriorityQueue<T, Comp>::push(PriorityQueueEntry<T> *entry)
+{
+  ink_release_assert(entry != NULL);
+
+  int len = _v.length();
+  _v.push_back(entry);
+  entry->index = len;
+
+  _bubble_up(len);
+}
+
+template <typename T, typename Comp>
+PriorityQueueEntry<T> *
+PriorityQueue<T, Comp>::top()
+{
+  if (empty()) {
+    return NULL;
+  } else {
+    return _v[0];
+  }
+}
+
+template <typename T, typename Comp>
+void
+PriorityQueue<T, Comp>::pop()
+{
+  if (empty()) {
+    return;
+  }
+
+  _v[0] = _v[_v.length() - 1];
+  _v.pop();
+  _bubble_down(0);
+}
+
+template <typename T, typename Comp>
+void
+PriorityQueue<T, Comp>::update(PriorityQueueEntry<T> *entry)
+{
+  ink_release_assert(entry != NULL);
+
+  if (empty()) {
+    return;
+  }
+
+  // One of them will works whether weight is increased or decreased
+  _bubble_down(entry->index);
+  _bubble_up(entry->index);
+}
+
+template <typename T, typename Comp>
+void
+PriorityQueue<T, Comp>::update(PriorityQueueEntry<T> *entry, bool increased)
+{
+  ink_release_assert(entry != NULL);
+
+  if (empty()) {
+    return;
+  }
+
+  if (increased) {
+    _bubble_down(entry->index);
+  } else {
+    _bubble_up(entry->index);
+  }
+}
+
+template <typename T, typename Comp>
+void
+PriorityQueue<T, Comp>::_swap(uint32_t i, uint32_t j)
+{
+  PriorityQueueEntry<T> *tmp = _v[i];
+  _v[i] = _v[j];
+  _v[j] = tmp;
+
+  _v[i]->index = i;
+  _v[j]->index = j;
+}
+
+
+template <typename T, typename Comp>
+void
+PriorityQueue<T, Comp>::_bubble_up(uint32_t index)
+{
+  if (empty()) {
+    ink_release_assert(false);
+  }
+
+  Comp comp;
+
+  uint32_t parent;
+  while (index != 0) {
+    parent = (index - 1) / 2;
+    if (comp(_v[index]->node, _v[parent]->node)) {
+      _swap(parent, index);
+      index = parent;
+      continue;
+    }
+
+    break;
+  }
+}
+
+template <typename T, typename Comp>
+void
+PriorityQueue<T, Comp>::_bubble_down(uint32_t index)
+{
+  if (empty()) {
+    // Do nothing
+    return;
+  }
+
+  uint32_t left, right, smaller;
+
+  Comp comp;
+
+  while (true) {
+    if ((left = index * 2 + 1) >= _v.length()) {
+      break;
+    } else if ((right = index * 2 + 2) >= _v.length()) {
+      smaller = left;
+    } else {
+      smaller = comp(_v[left]->node, _v[right]->node) ? left : right;
+    }
+
+    if (comp(_v[smaller]->node, _v[index]->node)) {
+      _swap(smaller, index);
+      index = smaller;
+      continue;
+    }
+
+    break;
+  }
+}
+
+#endif // __PRIORITY_QUEUE_H__

lib/ts/Regression.cc

@@ -86,7 +86,7 @@ start_test(RegressionTest *t)
 }
 
 int
-RegressionTest::run(char *atest)
+RegressionTest::run(const char *atest)
 {
   if (atest)
     dfa.compile(atest);

lib/ts/Regression.h

@@ -79,7 +79,7 @@ struct RegressionTest {
   static int ran_tests;
   static DFA dfa;
   static RegressionTest *current;
-  static int run(char *name = NULL);
+  static int run(const char *name = NULL);
   static int run_some();
   static int check_status();
 };

lib/ts/TestBox.h

@@ -25,6 +25,7 @@
 */
 
 #include <stdarg.h>
+#include "ts/ink_apidefs.h"
 #include "ts/Regression.h"
 
 namespace