Adding support for overlapping ranges to RangeMap.

src/processor/range_map_shrink_down_unittest.cc

Index: src/processor/range_map_shrink_down_unittest.cc
diff --git a/src/processor/range_map_shrink_down_unittest.cc b/src/processor/range_map_shrink_down_unittest.cc
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index 0000000000000000000000000000000000000000..8dd0e709b119b376469dd1120c17efc5a74acf22
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+++ b/src/processor/range_map_shrink_down_unittest.cc
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+// Copyright (c) 2016, Google Inc.
+// All rights reserved.
+//
+// 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 Google Inc. 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
+
+// range_map_shrink_down_unittest.cc: Unit tests for RangeMap that specifically
+// test shrink down when ranges overlap.
+//
+// Author: Ivan Penkov
+
+#include <limits.h>
+#include <stdio.h>
+
+#include "processor/range_map-inl.h"
+
+#include "breakpad_googletest_includes.h"
+#include "common/scoped_ptr.h"
+#include "processor/linked_ptr.h"
+#include "processor/logging.h"
+
+namespace {
+
+using google_breakpad::linked_ptr;
+using google_breakpad::scoped_ptr;
+using google_breakpad::RangeMap;
+
+// A CountedObject holds an int.  A global (not thread safe!) count of
+// allocated CountedObjects is maintained to help test memory management.
+class CountedObject {
+ public:
+  explicit CountedObject(int id) : id_(id) { ++count_; }
+  ~CountedObject() { --count_; }
+
+  static int count() { return count_; }
+  int id() const { return id_; }
+
+ private:
+  static int count_;
+  int id_;
+};
+
+int CountedObject::count_;
+
+typedef int AddressType;
+typedef RangeMap<AddressType, linked_ptr<CountedObject>> TestMap;
+
+// Same range cannot be stored wice.
+TEST(RangeMap, TestShinkDown_SameRange) {
+  TestMap range_map;
+  range_map.SetEnableShrinkDown(true);
+  linked_ptr<CountedObject> object_1(new CountedObject(1));
+  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
+                                   object_1));
+
+  // Same range cannot be stored wice.
+  linked_ptr<CountedObject> object_2(new CountedObject(2));
+  EXPECT_FALSE(range_map.StoreRange(0 /* base address */, 100 /* size */,
+                                    object_2));
+}
+
+// If a range is completely contained by another range, then the larger range
+// should be shrinked down.
+TEST(RangeMap, TestShinkDown_CompletelyContained) {
+  TestMap range_map;
+  range_map.SetEnableShrinkDown(true);
+  // Larger range is added first.
+  linked_ptr<CountedObject> object_1(new CountedObject(1));
+  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
+                                   object_1));
+  // Smaller (contained) range is added second.
+  linked_ptr<CountedObject> object_2(new CountedObject(2));
+  EXPECT_TRUE(range_map.StoreRange(10 /* base address */, 80 /* size */,
+                                   object_2));
+  linked_ptr<CountedObject> object;
+  AddressType retrieved_base = AddressType();
+  AddressType retrieved_delta = AddressType();
+  AddressType retrieved_size = AddressType();
+  // The first range contains the second, so the first range should have been
+  // shrunk to [90, 99].  Range [0, 9] should be free.
+  EXPECT_FALSE(range_map.RetrieveRange(0, &object, &retrieved_base,
+                                       &retrieved_delta, &retrieved_size));
+  EXPECT_FALSE(range_map.RetrieveRange(9, &object, &retrieved_base,
+                                       &retrieved_delta, &retrieved_size));
+  EXPECT_TRUE(range_map.RetrieveRange(90, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(1, object->id());
+  EXPECT_EQ(90, retrieved_base);
+  EXPECT_EQ(90, retrieved_delta);
+  EXPECT_EQ(10, retrieved_size);
+  // Validate the properties of the smaller range (should be untouched).
+  EXPECT_TRUE(range_map.RetrieveRange(10, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(2, object->id());
+  EXPECT_EQ(10, retrieved_base);
+  EXPECT_EQ(0, retrieved_delta);
+  EXPECT_EQ(80, retrieved_size);
+}
+
+// Same as the previous test, however the larger range is added second.
+TEST(RangeMap, TestShinkDown_CompletelyContained_LargerAddedSecond) {
+  TestMap range_map;
+  range_map.SetEnableShrinkDown(true);
+  // Smaller (contained) range is added first.
+  linked_ptr<CountedObject> object_1(new CountedObject(1));
+  EXPECT_TRUE(range_map.StoreRange(10 /* base address */, 80 /* size */,
+                                   object_1));
+  // Larger range is added second.
+  linked_ptr<CountedObject> object_2(new CountedObject(2));
+  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
+                                   object_2));
+  linked_ptr<CountedObject> object;
+  AddressType retrieved_base = AddressType();
+  AddressType retrieved_delta = AddressType();
+  AddressType retrieved_size = AddressType();
+  // The second range contains the first, so the second range should have been
+  // shrunk to [90, 99].  Range [0, 9] should be free.
+  EXPECT_FALSE(range_map.RetrieveRange(0, &object, &retrieved_base,
+                                       &retrieved_delta, &retrieved_size));
+  EXPECT_FALSE(range_map.RetrieveRange(9, &object, &retrieved_base,
+                                       &retrieved_delta, &retrieved_size));
+  EXPECT_TRUE(range_map.RetrieveRange(90, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(2, object->id());
+  EXPECT_EQ(90, retrieved_base);
+  EXPECT_EQ(90, retrieved_delta);
+  EXPECT_EQ(10, retrieved_size);
+  // Validate the properties of the smaller range (should be untouched).
+  EXPECT_TRUE(range_map.RetrieveRange(10, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(1, object->id());
+  EXPECT_EQ(10, retrieved_base);
+  EXPECT_EQ(0, retrieved_delta);
+  EXPECT_EQ(80, retrieved_size);
+}
+
+TEST(RangeMap, TestShinkDown_PartialOverlap_AtBeginning) {
+  TestMap range_map;
+  range_map.SetEnableShrinkDown(true);
+  linked_ptr<CountedObject> object_1(new CountedObject(1));
+  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
+                                   object_1));
+
+  // Partial overlap at the beginning of the new range.
+  linked_ptr<CountedObject> object_2(new CountedObject(2));
+  EXPECT_TRUE(range_map.StoreRange(90 /* base address */, 110 /* size */,
+                                   object_2));
+
+  linked_ptr<CountedObject> object;
+  AddressType retrieved_base = AddressType();
+  AddressType retrieved_delta = AddressType();
+  AddressType retrieved_size = AddressType();
+  // The second range is supposed to be shrunk down so the following address
+  // should resize in the first range.
+  EXPECT_TRUE(range_map.RetrieveRange(99, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(1, object->id());
+  EXPECT_EQ(0, retrieved_base);
+  EXPECT_EQ(0, retrieved_delta);
+  EXPECT_EQ(100, retrieved_size);
+  // Validate the properties of the shrunk down range.
+  EXPECT_TRUE(range_map.RetrieveRange(100, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(2, object->id());
+  EXPECT_EQ(100, retrieved_base);
+  EXPECT_EQ(10, retrieved_delta);
+  EXPECT_EQ(100, retrieved_size);
+}
+
+TEST(RangeMap, TestShinkDown_PartialOverlap_AtEnd) {
+  TestMap range_map;
+  range_map.SetEnableShrinkDown(true);
+  linked_ptr<CountedObject> object_1(new CountedObject(1));
+  EXPECT_TRUE(range_map.StoreRange(50 /* base address */, 50 /* size */,
+                                   object_1));
+
+  // Partial overlap at the end of the new range.
+  linked_ptr<CountedObject> object_2(new CountedObject(2));
+  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 70 /* size */,
+                                   object_2));
+
+  linked_ptr<CountedObject> object;
+  AddressType retrieved_base = AddressType();
+  AddressType retrieved_delta = AddressType();
+  AddressType retrieved_size = AddressType();
+  // The first range is supposed to be shrunk down so the following address
+  // should resize in the first range.
+  EXPECT_TRUE(range_map.RetrieveRange(69, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(2, object->id());
+  EXPECT_EQ(0, retrieved_base);
+  EXPECT_EQ(0, retrieved_delta);
+  EXPECT_EQ(70, retrieved_size);
+  // Validate the properties of the shrunk down range.
+  EXPECT_TRUE(range_map.RetrieveRange(70, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(1, object->id());
+  EXPECT_EQ(70, retrieved_base);
+  EXPECT_EQ(20, retrieved_delta);
+  EXPECT_EQ(30, retrieved_size);
+}
+
+// A new range is overlapped at both ends.  The new range and the range
+// that overlaps at the end should be shrink.  The range that overlaps at the
+// beginning should be left untouched.
+TEST(RangeMap, TestShinkDown_OverlapAtBothEnds) {
+  TestMap range_map;
+  range_map.SetEnableShrinkDown(true);
+  // This should overlap object_3 at the beginning.
+  linked_ptr<CountedObject> object_1(new CountedObject(1));
+  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
+                                   object_1));
+
+  // This should overlap object_3 at the end.
+  linked_ptr<CountedObject> object_2(new CountedObject(2));
+  EXPECT_TRUE(range_map.StoreRange(100 /* base address */, 100 /* size */,
+                                   object_2));
+
+  // This should be overlapped on both ends by object_1 and object_2.
+  linked_ptr<CountedObject> object_3(new CountedObject(3));
+  EXPECT_TRUE(range_map.StoreRange(50 /* base address */, 100 /* size */,
+                                   object_3));
+
+  linked_ptr<CountedObject> object;
+  AddressType retrieved_base = AddressType();
+  AddressType retrieved_delta = AddressType();
+  AddressType retrieved_size = AddressType();
+  // The first range should be intact.
+  EXPECT_TRUE(range_map.RetrieveRange(0, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(1, object->id());
+  EXPECT_EQ(0, retrieved_base);
+  EXPECT_EQ(0, retrieved_delta);
+  EXPECT_EQ(100, retrieved_size);
+  // The second range should be shrunk down by 50.
+  EXPECT_TRUE(range_map.RetrieveRange(150, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(2, object->id());
+  EXPECT_EQ(150, retrieved_base);
+  EXPECT_EQ(50, retrieved_delta);
+  EXPECT_EQ(50, retrieved_size);
+  // The third range (in the middle) should be shrunk down by 50.
+  EXPECT_TRUE(range_map.RetrieveRange(100, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(3, object->id());
+  EXPECT_EQ(100, retrieved_base);
+  EXPECT_EQ(50, retrieved_delta);
+  EXPECT_EQ(50, retrieved_size);
+}
+
+TEST(RangeMap, TestShinkDown_MultipleConflicts) {
+  TestMap range_map;
+  range_map.SetEnableShrinkDown(true);
+  // This should overlap with object_3.
+  linked_ptr<CountedObject> object_1(new CountedObject(1));
+  EXPECT_TRUE(range_map.StoreRange(10 /* base address */, 90 /* size */,
+                                   object_1));
+
+  // This should also overlap with object_3 but after object_1.
+  linked_ptr<CountedObject> object_2(new CountedObject(2));
+  EXPECT_TRUE(range_map.StoreRange(100 /* base address */, 100 /* size */,
+                                   object_2));
+
+  // This should be overlapped on both object_1 and object_2.  Since
+  // object_3 ends with the higher address it must be shrunk.
+  linked_ptr<CountedObject> object_3(new CountedObject(3));
+  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 300 /* size */,
+                                   object_3));
+
+  linked_ptr<CountedObject> object;
+  AddressType retrieved_base = AddressType();
+  AddressType retrieved_delta = AddressType();
+  AddressType retrieved_size = AddressType();
+  // The first range should be intact.
+  EXPECT_TRUE(range_map.RetrieveRange(99, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(1, object->id());
+  EXPECT_EQ(10, retrieved_base);
+  EXPECT_EQ(0, retrieved_delta);
+  EXPECT_EQ(90, retrieved_size);
+  // The second range should be intact.
+  EXPECT_TRUE(range_map.RetrieveRange(199, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(2, object->id());
+  EXPECT_EQ(100, retrieved_base);
+  EXPECT_EQ(0, retrieved_delta);
+  EXPECT_EQ(100, retrieved_size);
+  // The third range should be shrunk down by 200.
+  EXPECT_TRUE(range_map.RetrieveRange(299, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(3, object->id());
+  EXPECT_EQ(200, retrieved_base);
+  EXPECT_EQ(200, retrieved_delta);
+  EXPECT_EQ(100, retrieved_size);
+}
+
+// Adding two ranges without overlap should succeed and the ranges should
+// be left intact.
+TEST(RangeMap, TestShinkDown_NoConflicts) {
+  TestMap range_map;
+  range_map.SetEnableShrinkDown(true);
+  // Adding range 1.
+  linked_ptr<CountedObject> object_1(new CountedObject(1));
+  EXPECT_TRUE(range_map.StoreRange(10 /* base address */, 90 /* size */,
+                                   object_1));
+
+  // Adding range 2 - no overlap with range 1.
+  linked_ptr<CountedObject> object_2(new CountedObject(2));
+  EXPECT_TRUE(range_map.StoreRange(110 /* base address */, 90 /* size */,
+                                   object_2));
+
+  linked_ptr<CountedObject> object;
+  AddressType retrieved_base = AddressType();
+  AddressType retrieved_delta = AddressType();
+  AddressType retrieved_size = AddressType();
+  // The first range should be intact.
+  EXPECT_TRUE(range_map.RetrieveRange(99, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(1, object->id());
+  EXPECT_EQ(10, retrieved_base);
+  EXPECT_EQ(0, retrieved_delta);
+  EXPECT_EQ(90, retrieved_size);
+  // The second range should be intact.
+  EXPECT_TRUE(range_map.RetrieveRange(199, &object, &retrieved_base,
+                                      &retrieved_delta, &retrieved_size));
+  EXPECT_EQ(2, object->id());
+  EXPECT_EQ(110, retrieved_base);
+  EXPECT_EQ(0, retrieved_delta);
+  EXPECT_EQ(90, retrieved_size);
+}
+
+}  // namespace