Add SkTLList, linked list class implemented on top of the internal llist class.

R=robertphillips@google.com
Review URL: https://codereview.appspot.com/6869049

git-svn-id: http://skia.googlecode.com/svn/trunk@6644 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 231 insertions, 0 deletions

diff --git a/tests/LListTest.cpp b/tests/LListTest.cpp
new file mode 100644
index 0000000000..9d48e28135
--- /dev/null
+++ b/tests/LListTest.cpp
@@ -0,0 +1,231 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Test.h"
+#include "SkRandom.h"
+#include "SkTInternalLList.h"
+#include "SkTLList.h"
+
+class ListElement {
+public:
+    ListElement(int id) : fID(id) {
+    }
+    bool operator== (const ListElement& other) { return fID == other.fID; }
+
+#ifdef SK_ENABLE_INST_COUNT
+    // Make the instance count available publicly.
+    static int InstanceCount() { return GetInstanceCount(); }
+#endif
+
+    int fID;
+
+private:
+    SK_DECLARE_INST_COUNT_ROOT(ListElement);
+    SK_DECLARE_INTERNAL_LLIST_INTERFACE(ListElement);
+};
+
+SK_DEFINE_INST_COUNT(ListElement);
+
+static void check_list(const SkTInternalLList<ListElement>& list,
+                       skiatest::Reporter* reporter,
+                       bool empty,
+                       int numElements,
+                       bool in0, bool in1, bool in2, bool in3,
+                       ListElement elements[4]) {
+
+    REPORTER_ASSERT(reporter, empty == list.isEmpty());
+#if SK_DEBUG
+    REPORTER_ASSERT(reporter, numElements == list.countEntries());
+    REPORTER_ASSERT(reporter, in0 == list.isInList(&elements[0]));
+    REPORTER_ASSERT(reporter, in1 == list.isInList(&elements[1]));
+    REPORTER_ASSERT(reporter, in2 == list.isInList(&elements[2]));
+    REPORTER_ASSERT(reporter, in3 == list.isInList(&elements[3]));
+#endif
+}
+
+static void TestTInternalLList(skiatest::Reporter* reporter) {
+    SkTInternalLList<ListElement> list;
+    ListElement elements[4] = {
+        ListElement(0),
+        ListElement(1),
+        ListElement(2),
+        ListElement(3),
+    };
+
+    // list should be empty to start with
+    check_list(list, reporter, true, 0, false, false, false, false, elements);
+
+    list.addToHead(&elements[0]);
+
+    check_list(list, reporter, false, 1, true, false, false, false, elements);
+
+    list.addToHead(&elements[1]);
+    list.addToHead(&elements[2]);
+    list.addToHead(&elements[3]);
+
+    check_list(list, reporter, false, 4, true, true, true, true, elements);
+
+    // test out iterators
+    typedef SkTInternalLList<ListElement>::Iter Iter;
+    Iter iter;
+
+    ListElement* cur = iter.init(list, Iter::kHead_IterStart);
+    for (int i = 0; NULL != cur; ++i, cur = iter.next()) {
+        REPORTER_ASSERT(reporter, cur->fID == 3-i);
+    }
+
+    cur = iter.init(list, Iter::kTail_IterStart);
+    for (int i = 0; NULL != cur; ++i, cur = iter.prev()) {
+        REPORTER_ASSERT(reporter, cur->fID == i);
+    }
+
+    // remove middle, frontmost then backmost
+    list.remove(&elements[1]);
+    list.remove(&elements[3]);
+    list.remove(&elements[0]);
+
+    check_list(list, reporter, false, 1, false, false, true, false, elements);
+
+    // remove last element
+    list.remove(&elements[2]);
+
+    // list should be empty again
+    check_list(list, reporter, true, 0, false, false, false, false, elements);
+}
+
+static void TestTLList(skiatest::Reporter* reporter) {
+    typedef SkTLList<ListElement> ElList;
+    typedef ElList::Iter Iter;
+    SkRandom random;
+
+    for (int i = 1; i <= 16; i *= 2) {
+
+        ElList list1(i);
+        ElList list2(i);
+        Iter iter1;
+        Iter iter2;
+        Iter iter3;
+        Iter iter4;
+
+#ifdef SK_ENABLE_INST_COUNT
+        SkASSERT(0 == ListElement::InstanceCount());
+#endif
+
+        REPORTER_ASSERT(reporter, list1.isEmpty());
+        REPORTER_ASSERT(reporter, NULL == iter1.init(list1, Iter::kHead_IterStart));
+        REPORTER_ASSERT(reporter, NULL == iter1.init(list1, Iter::kTail_IterStart));
+        // Try popping an empty list
+        list1.popHead();
+        list1.popTail();
+        REPORTER_ASSERT(reporter, list1.isEmpty());
+        REPORTER_ASSERT(reporter, list1 == list2);
+
+        // Create two identical lists, one by appending to head and the other to the head.
+        list1.addToHead(ListElement(1));
+        list2.addToTail(ListElement(1));
+#ifdef SK_ENABLE_INST_COUNT
+        SkASSERT(2 == ListElement::InstanceCount());
+#endif
+        iter1.init(list1, Iter::kHead_IterStart);
+        iter2.init(list1, Iter::kTail_IterStart);
+        REPORTER_ASSERT(reporter, iter1.get()->fID == iter2.get()->fID);
+        iter3.init(list2, Iter::kHead_IterStart);
+        iter4.init(list2, Iter::kTail_IterStart);
+        REPORTER_ASSERT(reporter, iter3.get()->fID == iter1.get()->fID);
+        REPORTER_ASSERT(reporter, iter4.get()->fID == iter1.get()->fID);
+        REPORTER_ASSERT(reporter, list1 == list2);
+    
+        // add an element to the second list, check that iters are still valid
+        list2.addToHead(ListElement(2));
+#ifdef SK_ENABLE_INST_COUNT
+        SkASSERT(3 == ListElement::InstanceCount());
+#endif
+        REPORTER_ASSERT(reporter, iter3.get()->fID == iter1.get()->fID);
+        REPORTER_ASSERT(reporter, iter4.get()->fID == iter1.get()->fID);
+        REPORTER_ASSERT(reporter, 1 == Iter(list2, Iter::kTail_IterStart).get()->fID);
+        REPORTER_ASSERT(reporter, 2 == Iter(list2, Iter::kHead_IterStart).get()->fID);
+        REPORTER_ASSERT(reporter, list1 != list2);
+        list1.addToHead(ListElement(2));
+        REPORTER_ASSERT(reporter, list1 == list2);
+#ifdef SK_ENABLE_INST_COUNT
+        SkASSERT(4 == ListElement::InstanceCount());
+#endif
+        list1.reset();
+        list2.reset();
+#ifdef SK_ENABLE_INST_COUNT
+        SkASSERT(0 == ListElement::InstanceCount());
+#endif
+        REPORTER_ASSERT(reporter, list1.isEmpty() && list2.isEmpty());
+
+        int count = 0;
+        for (int j = 0; j < 100; ++j) {
+            if (list1.isEmpty() || random.nextBiasedBool(3  * SK_Scalar1 / 4)) {
+                int id = static_cast<int>(random.nextU());
+                if (random.nextBool()) {
+                    list1.addToHead(ListElement(id));
+                } else {
+                    list1.addToTail(ListElement(id));
+                }
+                ++count;
+            } else {
+                // walk to a random place either forward or backwards and remove.
+                int n = random.nextULessThan(list1.count());
+                Iter::IterStart start;
+                ListElement* (Iter::*incrFunc)();
+                
+                if (random.nextBool()) {
+                    start = Iter::kHead_IterStart;
+                    incrFunc = &Iter::next;
+                } else {
+                    start = Iter::kTail_IterStart;
+                    incrFunc = &Iter::prev;
+                }
+
+                // find the element
+                Iter iter(list1, start);
+                while (n--) {
+                    REPORTER_ASSERT(reporter, NULL != iter.get());
+                    (iter.*incrFunc)();
+                }
+                REPORTER_ASSERT(reporter, NULL != iter.get());
+
+                // remember the prev and next elements from the element to be removed
+                Iter prev = iter;
+                Iter next = iter;
+                prev.prev();
+                next.next();
+                list1.remove(iter.get());
+
+                // make sure the remembered next/prev iters still work
+                Iter pn = prev; pn.next();
+                Iter np = next; np.prev();
+                // pn should match next unless the target node was the head, in which case prev
+                // walked off the list.
+                REPORTER_ASSERT(reporter, pn.get() == next.get() || NULL == prev.get());
+                // Similarly, np should match prev unless next originally walked off the tail.
+                REPORTER_ASSERT(reporter, np.get() == prev.get() || NULL == next.get());
+                --count;
+            }
+            REPORTER_ASSERT(reporter, count == list1.count());
+#ifdef SK_ENABLE_INST_COUNT
+            SkASSERT(count == ListElement::InstanceCount());
+#endif
+        }
+        list1.reset();
+#ifdef SK_ENABLE_INST_COUNT
+        SkASSERT(0 == ListElement::InstanceCount());
+#endif
+    }
+}
+
+static void test_llists(skiatest::Reporter* reporter) {
+    TestTInternalLList(reporter);
+    TestTLList(reporter);
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("LList", TestLListClass, test_llists)