intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 109 insertions, 0 deletions

diff --git a/library/cpp/containers/bitseq/bititerator_ut.cpp b/library/cpp/containers/bitseq/bititerator_ut.cpp
new file mode 100644
index 0000000000..ed0925866f
--- /dev/null
+++ b/library/cpp/containers/bitseq/bititerator_ut.cpp
@@ -0,0 +1,109 @@
+#include "bititerator.h"
+
+#include <library/cpp/testing/unittest/registar.h>
+#include <util/generic/vector.h>
+
+Y_UNIT_TEST_SUITE(TBitIteratorTest) {
+    TVector<ui16> GenWords() {
+        TVector<ui16> words(1, 0);
+        for (ui16 word = 1; word; ++word)
+            words.push_back(word);
+        return words;
+    }
+
+    template <typename TWord>
+    void AssertPeekRead(TBitIterator<TWord> & iter, ui8 count, TWord expected) {
+        auto peek = iter.Peek(count);
+        auto read = iter.Read(count);
+        UNIT_ASSERT_EQUAL(peek, read);
+        UNIT_ASSERT_EQUAL(peek, expected);
+    }
+
+    Y_UNIT_TEST(TestNextAndPeek) {
+        const auto& words = GenWords();
+
+        TBitIterator<ui16> iter(words.data());
+        ui16 word = 0;
+        for (int i = 0; i != (1 << 16); ++i, ++word) {
+            for (int bit = 0; bit != 16; ++bit) {
+                auto peek = iter.Peek();
+                auto next = iter.Next();
+                UNIT_ASSERT_EQUAL(peek, next);
+                UNIT_ASSERT_EQUAL(peek, (word >> bit) & 1);
+            }
+            UNIT_ASSERT_EQUAL(iter.NextWord(), words.data() + i + 1);
+        }
+
+        UNIT_ASSERT_EQUAL(iter.NextWord(), words.data() + words.size());
+    }
+
+    Y_UNIT_TEST(TestAlignedReadAndPeek) {
+        const auto& words = GenWords();
+
+        TBitIterator<ui16> iter(words.data());
+        ui16 word = 0;
+        for (int i = 0; i != (1 << 16); ++i, ++word) {
+            AssertPeekRead(iter, 16, word);
+            UNIT_ASSERT_EQUAL(iter.NextWord(), words.data() + i + 1);
+        }
+
+        UNIT_ASSERT_EQUAL(iter.NextWord(), words.data() + words.size());
+    }
+
+    Y_UNIT_TEST(TestForward) {
+        TVector<ui32> words;
+        words.push_back((1 << 10) | (1 << 20) | (1 << 25));
+        words.push_back(1 | (1 << 5) | (1 << 6) | (1 << 30));
+        for (int i = 0; i < 3; ++i)
+            words.push_back(0);
+        words.push_back(1 << 10);
+
+        TBitIterator<ui32> iter(words.data());
+        UNIT_ASSERT(!iter.Next());
+        UNIT_ASSERT(!iter.Next());
+        UNIT_ASSERT(!iter.Next());
+        iter.Forward(6);
+        UNIT_ASSERT(!iter.Next());
+        UNIT_ASSERT(iter.Next());
+        UNIT_ASSERT(!iter.Next());
+        iter.Forward(8);
+        UNIT_ASSERT(iter.Next());
+        iter.Forward(4);
+        UNIT_ASSERT(iter.Next());
+        iter.Forward(5);
+        UNIT_ASSERT(!iter.Next());
+        UNIT_ASSERT(iter.Next());
+        iter.Forward(4);
+        UNIT_ASSERT(iter.Next());
+
+        iter.Reset(words.data());
+        iter.Forward(38);
+        UNIT_ASSERT(iter.Next());
+        UNIT_ASSERT(!iter.Next());
+        UNIT_ASSERT_EQUAL(iter.NextWord(), words.data() + 2);
+
+        iter.Forward(24 + 32 * 3 + 9);
+        UNIT_ASSERT(!iter.Next());
+        UNIT_ASSERT(iter.Next());
+        UNIT_ASSERT(!iter.Next());
+        UNIT_ASSERT_EQUAL(iter.NextWord(), words.data() + 6);
+    }
+
+    Y_UNIT_TEST(TestUnalignedReadAndPeek) {
+        TVector<ui32> words;
+        words.push_back((1 << 10) | (1 << 20) | (1 << 25));
+        words.push_back(1 | (1 << 5) | (1 << 6) | (1 << 30));
+        for (int i = 0; i < 5; ++i)
+            words.push_back(1 | (1 << 10));
+
+        TBitIterator<ui32> iter(words.data());
+        AssertPeekRead(iter, 5, ui32(0));
+        AssertPeekRead(iter, 7, ui32(1 << 5));
+        AssertPeekRead(iter, 21, ui32((1 << 8) | (1 << 13) | (1 << 20)));
+        AssertPeekRead(iter, 32, (words[1] >> 1) | (1 << 31));
+        iter.Forward(8);
+        UNIT_ASSERT(!iter.Next());
+        UNIT_ASSERT(iter.Next());
+        UNIT_ASSERT(!iter.Next());
+    }
+}