diff --git a/AK/Bitmap.h b/AK/Bitmap.h
index dd76c1666bf..8a7349100b0 100644
--- a/AK/Bitmap.h
+++ b/AK/Bitmap.h
@@ -243,6 +243,18 @@ public:
}
if (free_chunks < min_length) {
+ size_t first_trailing_bit = (m_size / 32) * 32;
+ size_t trailing_bits = size() % 32;
+ for (size_t i = 0; i < trailing_bits; ++i) {
+ if (!get(first_trailing_bit + i)) {
+ if (!free_chunks)
+ *start_of_free_chunks = first_trailing_bit + i;
+ if (++free_chunks >= min_length)
+ return min(free_chunks, max_length);
+ } else {
+ free_chunks = 0;
+ }
+ }
return {};
}
@@ -340,7 +352,7 @@ public:
static constexpr u32 max_size = 0xffffffff;
private:
- size_t size_in_bytes() const { return ceil_div(m_size, 8); }
+ size_t size_in_bytes() const { return ceil_div(m_size, static_cast<size_t>(8)); }
u8* m_data { nullptr };
size_t m_size { 0 };
diff --git a/AK/Tests/TestBitmap.cpp b/AK/Tests/TestBitmap.cpp
new file mode 100644
index 00000000000..4a722597693
--- /dev/null
+++ b/AK/Tests/TestBitmap.cpp
@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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.
+ */
+
+#include <AK/TestSuite.h>
+
+#include <AK/Bitmap.h>
+
+TEST_CASE(construct_empty)
+{
+ Bitmap bitmap;
+ EXPECT_EQ(bitmap.size(), 0u);
+}
+
+TEST_CASE(find_first_set)
+{
+ Bitmap bitmap(128, false);
+ bitmap.set(69, true);
+ EXPECT_EQ(bitmap.find_first_set().value(), 69u);
+}
+
+TEST_CASE(find_first_unset)
+{
+ Bitmap bitmap(128, true);
+ bitmap.set(51, false);
+ EXPECT_EQ(bitmap.find_first_unset().value(), 51u);
+}
+
+TEST_CASE(find_first_range)
+{
+ Bitmap bitmap(128, true);
+ bitmap.set(47, false);
+ bitmap.set(48, false);
+ bitmap.set(49, false);
+ bitmap.set(50, false);
+ bitmap.set(51, false);
+ size_t found_range_size = 0;
+ auto result = bitmap.find_longest_range_of_unset_bits(5, found_range_size);
+ EXPECT_EQ(result.has_value(), true);
+ EXPECT_EQ(found_range_size, 5u);
+ EXPECT_EQ(result.value(), 47u);
+}
+
+TEST_CASE(set_range)
+{
+ Bitmap bitmap(128, false);
+ bitmap.set_range(41, 10, true);
+ EXPECT_EQ(bitmap.get(40), false);
+ EXPECT_EQ(bitmap.get(41), true);
+ EXPECT_EQ(bitmap.get(42), true);
+ EXPECT_EQ(bitmap.get(43), true);
+ EXPECT_EQ(bitmap.get(44), true);
+ EXPECT_EQ(bitmap.get(45), true);
+ EXPECT_EQ(bitmap.get(46), true);
+ EXPECT_EQ(bitmap.get(47), true);
+ EXPECT_EQ(bitmap.get(48), true);
+ EXPECT_EQ(bitmap.get(49), true);
+ EXPECT_EQ(bitmap.get(50), true);
+ EXPECT_EQ(bitmap.get(51), false);
+}
+
+TEST_CASE(find_first_fit)
+{
+ {
+ Bitmap bitmap(32, true);
+ auto fit = bitmap.find_first_fit(1);
+ EXPECT_EQ(fit.has_value(), false);
+ }
+ {
+ Bitmap bitmap(32, true);
+ bitmap.set(31, false);
+ auto fit = bitmap.find_first_fit(1);
+ EXPECT_EQ(fit.has_value(), true);
+ EXPECT_EQ(fit.value(), 31u);
+ }
+
+ for (size_t i = 0; i < 128; ++i) {
+ Bitmap bitmap(128, true);
+ bitmap.set(i, false);
+ auto fit = bitmap.find_first_fit(1);
+ EXPECT_EQ(fit.has_value(), true);
+ EXPECT_EQ(fit.value(), i);
+ }
+
+ for (size_t i = 0; i < 127; ++i) {
+ Bitmap bitmap(128, true);
+ bitmap.set(i, false);
+ bitmap.set(i + 1, false);
+ auto fit = bitmap.find_first_fit(2);
+ EXPECT_EQ(fit.has_value(), true);
+ EXPECT_EQ(fit.value(), i);
+ }
+
+ size_t bitmap_size = 1024;
+ for (size_t chunk_size = 1; chunk_size < 64; ++chunk_size) {
+ for (size_t i = 0; i < bitmap_size - chunk_size; ++i) {
+ Bitmap bitmap(bitmap_size, true);
+ for (size_t c = 0; c < chunk_size; ++c)
+ bitmap.set(i + c, false);
+ auto fit = bitmap.find_first_fit(chunk_size);
+ EXPECT_EQ(fit.has_value(), true);
+ EXPECT_EQ(fit.value(), i);
+ }
+ }
+}
+
+TEST_CASE(find_longest_range_of_unset_bits_edge)
+{
+ Bitmap bitmap(36, true);
+ bitmap.set_range(32, 4, false);
+ size_t found_range_size = 0;
+ auto result = bitmap.find_longest_range_of_unset_bits(1, found_range_size);
+ EXPECT_EQ(result.has_value(), true);
+ EXPECT_EQ(result.value(), 32u);
+}
+
+TEST_MAIN(Bitmap)