Handle buffer boundaries in the WebVTT parser

Source/core/html/track/BufferedLineReaderTest.cpp

Index: Source/core/html/track/BufferedLineReaderTest.cpp
diff --git a/Source/core/html/track/BufferedLineReaderTest.cpp b/Source/core/html/track/BufferedLineReaderTest.cpp
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+/*
+ * Copyright (C) 2013, Opera Software ASA. 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.
+ */
+
+#include "config.h"
+#include "core/html/track/BufferedLineReader.h"
+
+#include "wtf/text/CString.h"
+#include "wtf/text/WTFString.h"
+#include "wtf/unicode/CharacterNames.h"
+
+#include <gtest/gtest.h>
+
+using WebCore::BufferedLineReader;
+
+namespace {
+
+TEST(BufferedLineReader, Constructor)
+{
+    BufferedLineReader reader;
+    ASSERT_FALSE(reader.isAtEOS());
+    String line;
+    ASSERT_FALSE(reader.getLine(line));
+}
+
+TEST(BufferedLineReader, EOSNoInput)
+{
+    BufferedLineReader reader;
+    String line;
+    ASSERT_FALSE(reader.getLine(line));
+    reader.setEndOfStream(true);
+    // No input observed, so still no line.
+    ASSERT_FALSE(reader.getLine(line));
+}
+
+TEST(BufferedLineReader, EOSInput)
+{
+    BufferedLineReader reader;
+    reader.append("A");
+    reader.setEndOfStream(true);
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "A");
+}
+
+TEST(BufferedLineReader, EOSMultipleReads_1)
+{
+    BufferedLineReader reader;
+    reader.append("A");
+    reader.setEndOfStream(true);
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "A");
+    // No more lines returned.
+    ASSERT_FALSE(reader.getLine(line));
+    ASSERT_FALSE(reader.getLine(line));
+}
+
+TEST(BufferedLineReader, EOSMultipleReads_2)
+{
+    BufferedLineReader reader;
+    reader.append("A\x0a");
+    reader.setEndOfStream(true);
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "A");
+    // No more lines returned.
+    ASSERT_FALSE(reader.getLine(line));
+    ASSERT_FALSE(reader.getLine(line));
+}
+
+TEST(BufferedLineReader, LineEndingCR)
+{
+    BufferedLineReader reader;
+    reader.append("X\x0dY");
+    reader.setEndOfStream(true);
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "X");
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "Y");
+}
+
+TEST(BufferedLineReader, LineEndingCR_EOS)
+{
+    BufferedLineReader reader;
+    reader.append("X\x0d");
+    reader.setEndOfStream(true);
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "X");
+    ASSERT_FALSE(reader.getLine(line));
+}
+
+TEST(BufferedLineReader, LineEndingLF)
+{
+    BufferedLineReader reader;
+    reader.append("X\x0aY");
+    reader.setEndOfStream(true);
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "X");
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "Y");
+}
+
+TEST(BufferedLineReader, LineEndingLF_EOS)
+{
+    BufferedLineReader reader;
+    reader.append("X\x0a");
+    reader.setEndOfStream(true);
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "X");
+    ASSERT_FALSE(reader.getLine(line));
+}
+
+TEST(BufferedLineReader, LineEndingCRLF)
+{
+    BufferedLineReader reader;
+    reader.append("X\x0d\x0aY");
+    reader.setEndOfStream(true);
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "X");
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "Y");
+}
+
+TEST(BufferedLineReader, LineEndingCRLF_EOS)
+{
+    BufferedLineReader reader;
+    reader.append("X\x0d\x0a");
+    reader.setEndOfStream(true);
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "X");
+    ASSERT_FALSE(reader.getLine(line));
+}
+
+enum LineBreakType {
+    Cr,
+    Lf,
+    CrLf
+};
+
+static String LineBreakString(LineBreakType type)

[jochen (gone - plz use gerrit), 2013/11/08 11:59:44]

nit. you don't need static inside an anonymous namespace

+{
+    static const char breakStrings[] = "\x0d\x0a";

[jochen (gone - plz use gerrit), 2013/11/08 11:59:44]

\r\n?

+    return String(type == Lf ? breakStrings + 1 : breakStrings, type == CrLf ? 2 : 1);
+}
+
+static String MakeTestData(const char** lines, const LineBreakType* breaks, int count)
+{
+    StringBuilder builder;
+    for (int i = 0; i < count; ++i) {
+        builder.append(lines[i]);
+        builder.append(LineBreakString(breaks[i]));
+    }
+    return builder.toString();
+}
+
+static const size_t blockSizes[] = { 64, 32, 16, 8, 4, 2, 1, 3, 5, 7, 9, 11, 13, 17, 19, 23 };
+
+TEST(BufferedLineReader, BufferSizes)
+{
+    const char* lines[] = {
+        "aaaaaaaaaaaaaaaa",
+        "bbbbbbbbbb",
+        "ccccccccccccc",
+        "",
+        "dddddd",
+        "",
+        "eeeeeeeeee"
+    };
+    const LineBreakType breaks[] = { Lf, Lf, Lf, Lf, Lf, Lf, Lf };
+    const size_t numTestLines = WTF_ARRAY_LENGTH(lines);
+    COMPILE_ASSERT(numTestLines == WTF_ARRAY_LENGTH(breaks), DifferentLengths_lines_and_breaks);
+    String data = MakeTestData(lines, breaks, numTestLines);
+
+    for (size_t k = 0; k < WTF_ARRAY_LENGTH(blockSizes); ++k) {
+        int lineCount = 0;
+        BufferedLineReader reader;
+        size_t blockSize = blockSizes[k];
+        for (size_t i = 0; i < data.length(); i += blockSize) {
+            reader.append(data.substring(i, blockSize));
+
+            String line;
+            while (reader.getLine(line)) {
+                ASSERT_LT(lineCount, numTestLines);
+                ASSERT_EQ(line, lines[lineCount++]);
+            }
+        }
+        ASSERT_EQ(lineCount, numTestLines);
+    }
+}
+
+TEST(BufferedLineReader, BufferSizesMixedEndings)
+{
+    const char* lines[] = {
+        "aaaaaaaaaaaaaaaa",
+        "bbbbbbbbbb",
+        "ccccccccccccc",
+        "",
+        "dddddd",
+        "eeeeeeeeee",
+        "fffffffffffffffffff"
+    };
+    const LineBreakType breaks[] = { Cr, Lf, CrLf, Cr, Lf, CrLf, Lf };
+    const size_t numTestLines = WTF_ARRAY_LENGTH(lines);
+    COMPILE_ASSERT(numTestLines == WTF_ARRAY_LENGTH(breaks), DifferentLengths_lines_and_breaks);
+    String data = MakeTestData(lines, breaks, numTestLines);
+
+    for (size_t k = 0; k < WTF_ARRAY_LENGTH(blockSizes); ++k) {
+        int lineCount = 0;
+        BufferedLineReader reader;
+        size_t blockSize = blockSizes[k];
+        for (size_t i = 0; i < data.length(); i += blockSize) {
+            reader.append(data.substring(i, blockSize));
+
+            String line;
+            while (reader.getLine(line)) {
+                ASSERT_LT(lineCount, numTestLines);
+                ASSERT_EQ(line, lines[lineCount++]);
+            }
+        }
+        ASSERT_EQ(lineCount, numTestLines);
+    }
+}
+
+TEST(BufferedLineReader, BufferBoundaryInCRLF_1)
+{
+    BufferedLineReader reader;
+    reader.append("X\x0d");
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "X");
+    reader.append("\x0a");
+    ASSERT_FALSE(reader.getLine(line));
+}
+
+TEST(BufferedLineReader, BufferBoundaryInCRLF_2)
+{
+    BufferedLineReader reader;
+    reader.append("X\x0d");
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "X");
+    ASSERT_FALSE(reader.getLine(line));
+    reader.append("\x0a");
+    ASSERT_FALSE(reader.getLine(line));
+    reader.append("Y\x0a");
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line, "Y");
+}
+
+TEST(BufferedLineReader, NormalizedNUL)
+{
+    BufferedLineReader reader;
+    reader.append(String("X\0Y\x0a", 4));
+    String line;
+    ASSERT_TRUE(reader.getLine(line));
+    ASSERT_EQ(line[1], WTF::Unicode::replacementCharacter);
+}
+
+} // namespace