AK: Add InputStream abstraction and InputMemoryStream implementation.

1 files changed, 111 insertions, 0 deletions

diff --git a/AK/Tests/TestMemoryStream.cpp b/AK/Tests/TestMemoryStream.cpp
new file mode 100644
index 0000000000..2234ae5078
--- /dev/null
+++ b/AK/Tests/TestMemoryStream.cpp
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * 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/Stream.h>
+
+bool compare(ReadonlyBytes lhs, ReadonlyBytes rhs)
+{
+    if (lhs.size() != rhs.size())
+        return false;
+
+    for (size_t idx = 0; idx < lhs.size(); ++idx) {
+        if (lhs[idx] != rhs[idx])
+            return false;
+    }
+
+    return true;
+}
+
+TEST_CASE(read_an_integer)
+{
+    u32 expected = 0x01020304, actual;
+
+    InputMemoryStream stream { { &expected, sizeof(expected) } };
+    stream >> actual;
+
+    EXPECT(!stream.error() && !stream.fatal() && stream.eof());
+    EXPECT_EQ(expected, actual);
+}
+
+TEST_CASE(recoverable_error)
+{
+    u32 expected = 0x01020304, actual = 0;
+    u64 to_large_value = 0;
+
+    InputMemoryStream stream { { &expected, sizeof(expected) } };
+
+    EXPECT(!stream.error() && !stream.fatal() && !stream.eof());
+    stream >> to_large_value;
+    EXPECT(stream.error() && !stream.fatal() && !stream.eof());
+
+    EXPECT(stream.handle_error());
+    EXPECT(!stream.error() && !stream.fatal() && !stream.eof());
+
+    stream >> actual;
+    EXPECT(!stream.error() && !stream.fatal() && stream.eof());
+    EXPECT_EQ(expected, actual);
+}
+
+TEST_CASE(chain_stream_operator)
+{
+    u8 expected[] { 0, 1, 2, 3 }, actual[4];
+
+    InputMemoryStream stream { { expected, sizeof(expected) } };
+
+    stream >> actual[0] >> actual[1] >> actual[2] >> actual[3];
+    EXPECT(!stream.error() && !stream.fatal() && stream.eof());
+
+    EXPECT(compare({ expected, sizeof(expected) }, { actual, sizeof(actual) }));
+}
+
+TEST_CASE(seeking_slicing_offset)
+{
+    u8 input[] { 0, 1, 2, 3, 4, 5, 6, 7 },
+        expected0[] { 0, 1, 2, 3 },
+        expected1[] { 4, 5, 6, 7 },
+        expected2[] { 1, 2, 3, 4 },
+        actual0[4], actual1[4], actual2[4];
+
+    InputMemoryStream stream { { input, sizeof(input) } };
+
+    stream >> Bytes { actual0, sizeof(actual0) };
+    EXPECT(!stream.error() && !stream.fatal() && !stream.eof());
+    EXPECT(compare({ expected0, sizeof(expected0) }, { actual0, sizeof(actual0) }));
+
+    stream.seek(4);
+    stream >> Bytes { actual1, sizeof(actual1) };
+    EXPECT(!stream.error() && !stream.fatal() && stream.eof());
+    EXPECT(compare({ expected1, sizeof(expected1) }, { actual1, sizeof(actual1) }));
+
+    stream.seek(1);
+    stream >> Bytes { actual2, sizeof(actual2) };
+    EXPECT(!stream.error() && !stream.fatal() && !stream.eof());
+    EXPECT(compare({ expected2, sizeof(expected2) }, { actual2, sizeof(actual2) }));
+}
+
+TEST_MAIN(MemoryStream)