Add a new incremental parsing API

Change-Id: I6b921766836d58df0281fb23b2add3f62a478e14

webm_parser/src/segment_parser.h

@@ -0,0 +1,53 @@
+// 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 SRC_SEGMENT_PARSER_H_
+#define SRC_SEGMENT_PARSER_H_
+
+#include <cstdint>
+
+#include "src/master_parser.h"
+#include "webm/callback.h"
+#include "webm/reader.h"
+#include "webm/status.h"
+
+namespace webm {
+
+// Parses Segment elements from a WebM byte stream. This class adheres to the
+// ElementParser interface; see element_parser.h for further documentation on
+// how it should be used.
+// Spec reference:
+// http://matroska.org/technical/specs/index.html#Segment
+// http://www.webmproject.org/docs/container/#Segment
+class SegmentParser : public MasterParser {
+ public:
+  SegmentParser();
+
+  Status Init(const ElementMetadata& metadata, std::uint64_t max_size) override;
+
+  void InitAfterSeek(const Ancestory& child_ancestory,
+                     const ElementMetadata& child_metadata) override;
+
+  Status Feed(Callback* callback, Reader* reader,
+              std::uint64_t* num_bytes_read) override;
+
+  bool WasSkipped() const override;
+
+ private:
+  // Set to true iff Callback::OnSegmentBegin has completed.
+  bool begin_done_;
+
+  // Set to true iff the base class has completed parsing.
+  bool parse_completed_;
+
+  // The action requested by Callback::OnSegmentBegin.
+  Action action_;
+};
+
+}  // namespace webm
+
+#endif  // SRC_SEGMENT_PARSER_H_