1 // Copyright (c) 2016 The WebM project authors. All Rights Reserved.
2 //
3 // Use of this source code is governed by a BSD-style license
4 // that can be found in the LICENSE file in the root of the source
5 // tree. An additional intellectual property rights grant can be found
6 // in the file PATENTS.  All contributing project authors may
7 // be found in the AUTHORS file in the root of the source tree.
8 #ifndef SRC_VAR_INT_PARSER_H_
9 #define SRC_VAR_INT_PARSER_H_
10 
11 #include <cassert>
12 #include <cstdint>
13 
14 #include "src/parser.h"
15 #include "webm/callback.h"
16 #include "webm/reader.h"
17 #include "webm/status.h"
18 
19 namespace webm {
20 
21 class VarIntParser : public Parser {
22  public:
23   VarIntParser() = default;
24   VarIntParser(VarIntParser&&) = default;
25   VarIntParser& operator=(VarIntParser&&) = default;
26 
27   VarIntParser(const VarIntParser&) = delete;
28   VarIntParser& operator=(const VarIntParser&) = delete;
29 
30   Status Feed(Callback* callback, Reader* reader,
31               std::uint64_t* num_bytes_read) override;
32 
33   // Gets the parsed value. This must not be called until the parse had been
34   // successfully completed.
value()35   std::uint64_t value() const {
36     assert(num_bytes_remaining_ == 0);
37     return value_;
38   }
39 
40   // Gets the number of bytes which were used to encode the integer value in the
41   // byte stream. This must not be called until the parse had been successfully
42   // completed.
encoded_length()43   int encoded_length() const {
44     assert(num_bytes_remaining_ == 0);
45     return total_data_bytes_ + 1;
46   }
47 
48  private:
49   int num_bytes_remaining_ = -1;
50   int total_data_bytes_;
51   std::uint64_t value_;
52 };
53 
54 }  // namespace webm
55 
56 #endif  // SRC_VAR_INT_PARSER_H_
57