Add a new incremental parsing API

Change-Id: I6b921766836d58df0281fb23b2add3f62a478e14

webm_parser/test_utils/parser_test.h

@@ -0,0 +1,104 @@
+// Copyright (c) 2016 The WebM project authors. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS.  All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+#ifndef TEST_UTILS_PARSER_TEST_H_
+#define TEST_UTILS_PARSER_TEST_H_
+
+#include <cstdint>
+#include <new>
+#include <vector>
+
+#include "gtest/gtest.h"
+
+#include "test_utils/limited_reader.h"
+#include "test_utils/mock_callback.h"
+#include "webm/buffer_reader.h"
+#include "webm/reader.h"
+#include "webm/status.h"
+
+namespace webm {
+
+// Base class for unit tests that test an instance of the Parser inteface. The
+// template parameter T is the parser class being tested.
+template <typename T> class ParserTest : public testing::Test {
+ public:
+  // Sets the reader's internal buffer to the given buffer.
+  virtual void SetReaderData(std::vector<std::uint8_t> data) {
+    reader_ = BufferReader(std::move(data));
+  }
+
+  // Destroys and recreates the parser, forwarding the arguments to the
+  // constructor. This is primarily useful for tests that require the parser to
+  // have different constructor parameters.
+  template <typename... Args> void ResetParser(Args&&... args) {
+    parser_.~T();
+    new (&parser_) T(std::forward<Args>(args)...);
+  }
+
+  // Calls Feed() on the parser, making sure it completes successfully and reads
+  // size number of bytes.
+  virtual void ParseAndVerify(std::uint64_t size) {
+    std::uint64_t num_bytes_read = 0;
+    const Status status = parser_.Feed(&callback_, &reader_, &num_bytes_read);
+    ASSERT_EQ(Status::kOkCompleted, status.code);
+    ASSERT_EQ(size, num_bytes_read);
+  }
+
+  // Calls Feed() on the parser, making sure it completes successfully and reads
+  // all the data available in the reader.
+  virtual void ParseAndVerify() { ParseAndVerify(reader_.size()); }
+
+  // Similar to ParseAndVerify(), but instead artificially limits the reader to
+  // providing one byte per call to Feed(). If Feed() returns
+  // Status::kWouldBlock or Status::kOkPartial, Feed() will be called again
+  // (feeding it another byte).
+  virtual void IncrementalParseAndVerify() {
+    const std::uint64_t expected_num_bytes_read = reader_.size();
+
+    webm::LimitedReader limited_reader(
+        std::unique_ptr<webm::Reader>(new BufferReader(std::move(reader_))));
+
+    Status status;
+    std::uint64_t num_bytes_read = 0;
+    do {
+      limited_reader.set_total_read_skip_limit(1);
+      std::uint64_t local_num_bytes_read = 0;
+      status = parser_.Feed(&callback_, &limited_reader, &local_num_bytes_read);
+      num_bytes_read += local_num_bytes_read;
+      ASSERT_GE(1, local_num_bytes_read);
+    } while (status.code == Status::kWouldBlock ||
+             status.code == Status::kOkPartial);
+
+    ASSERT_EQ(Status::kOkCompleted, status.code);
+    ASSERT_EQ(expected_num_bytes_read, num_bytes_read);
+  }
+
+  // Calls Feed() on the parser, making sure it returns the expected status
+  // code.
+  virtual void ParseAndExpectResult(Status::Code expected) {
+    std::uint64_t num_bytes_read = 0;
+    const Status status = parser_.Feed(&callback_, &reader_, &num_bytes_read);
+    ASSERT_EQ(expected, status.code);
+  }
+
+ protected:
+  // These members are protected (not private) so unit tests have access to
+  // them. This is intentional.
+
+  // The parser that the unit tests will be testing.
+  T parser_;
+
+  // The callback that is used during parsing.
+  MockCallback callback_;
+
+  // The reader used for feeding data into the parser.
+  BufferReader reader_;
+};
+
+}  // namespace webm
+
+#endif  // TEST_UTILS_PARSER_TEST_H_