1#ifndef MARISA_READER_H_
2#define MARISA_READER_H_
3
4#include <cstdio>
5#include <iostream>
6
7#include "base.h"
8
9namespace marisa {
10
11class Reader {
12 public:
13  Reader();
14  explicit Reader(std::FILE *file);
15  explicit Reader(int fd);
16  explicit Reader(std::istream *stream);
17  ~Reader();
18
19  void open(const char *filename, long offset = 0, int whence = SEEK_SET);
20
21  template <typename T>
22  void read(T *obj) {
23    MARISA_THROW_IF(obj == NULL, MARISA_PARAM_ERROR);
24    read_data(obj, sizeof(T));
25  }
26
27  template <typename T>
28  void read(T *objs, std::size_t num_objs) {
29    MARISA_THROW_IF((objs == NULL) && (num_objs != 0), MARISA_PARAM_ERROR);
30    MARISA_THROW_IF(num_objs > (MARISA_UINT32_MAX / sizeof(T)),
31        MARISA_SIZE_ERROR);
32    if (num_objs != 0) {
33      read_data(objs, sizeof(T) * num_objs);
34    }
35  }
36
37  bool is_open() const {
38    return (file_ != NULL) || (fd_ != -1) || (stream_ != NULL);
39  }
40
41  void clear();
42  void swap(Reader *rhs);
43
44 private:
45  std::FILE *file_;
46  int fd_;
47  std::istream *stream_;
48  bool needs_fclose_;
49
50  void read_data(void *buf, std::size_t size);
51
52  // Disallows copy and assignment.
53  Reader(const Reader &);
54  Reader &operator=(const Reader &);
55};
56
57}  // namespace marisa
58
59#endif  // MARISA_READER_H_
60