nlib
InputStream.h
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1 
2 /*--------------------------------------------------------------------------------*
3  Project: CrossRoad
4  Copyright (C)Nintendo All rights reserved.
5 
6  These coded instructions, statements, and computer programs contain proprietary
7  information of Nintendo and/or its licensed developers and are protected by
8  national and international copyright laws. They may not be disclosed to third
9  parties or copied or duplicated in any form, in whole or in part, without the
10  prior written consent of Nintendo.
11 
12  The content herein is highly confidential and should be handled accordingly.
13  *--------------------------------------------------------------------------------*/
14 
15 #pragma once
16 #ifndef INCLUDE_NN_NLIB_INPUTSTREAM_H_
17 #define INCLUDE_NN_NLIB_INPUTSTREAM_H_
18 
19 #include "nn/nlib/Config.h"
20 #include "nn/nlib/TypeTraits.h"
21 
22 NLIB_NAMESPACE_BEGIN
23 
24 // code snippets:
25 // InputStream& stream = 'stream that inherits InputStream';
26 // if (!stream.Read(dataptr, nbyte)) { error = stream.GetErrorValue(); ..... }
27 // while ((c = stream.Read()) >= 0) { c is [0x00 - 0xFF] }
28 // if (!stream) { error = stream.GetErrorValue(); ..... }
30  public:
32  is_buf_curidx_(0),
33  is_buf_endidx_(0),
34  is_buf_markidx_(static_cast<size_t>(-1)),
35  is_buf_(NULL),
36  is_bufsize_(0),
37  is_buf_readonly_(false),
38  is_mark_supported_(false),
39  errno_(0) {}
40  NLIB_CEXPR InputStream(bool is_mark_supported, bool is_buf_readonly) :
41  pos_(0),
42  is_buf_curidx_(0),
43  is_buf_endidx_(0),
44  is_buf_markidx_(static_cast<size_t>(-1)),
45  is_buf_(NULL),
46  is_bufsize_(0),
47  is_buf_readonly_(is_buf_readonly),
48  is_mark_supported_(is_mark_supported),
49  errno_(0) {}
51  // NOTE:
52  // cannot call Close_() from this destructor.
53  // the destructor of the derived class has to call Close_() if needed.
54  }
55  // returns true if there has been no errors
56  // you can also write the codes such that 'if (!!stream) { ... }'
57  errno_t GetErrorValue() const NLIB_NOEXCEPT { return errno_; }
58  // use Pos64() if you need a 64bit value on 32bit arch
59  size_t Pos() const NLIB_NOEXCEPT { return static_cast<size_t>(Pos64()); }
60  uint64_t Pos64() const NLIB_NOEXCEPT { return pos_ + is_buf_curidx_; }
62  if (*this && is_buf_curidx_ == is_buf_endidx_) {
63  CheckBuffer_();
64  return *this && is_buf_curidx_ == is_buf_endidx_;
65  }
66  return false;
67  }
68  // < 0 if EOS or error, otherwise returns a byte and ++pos
70  if (NLIB_UNLIKELY(is_buf_curidx_ == is_buf_endidx_)) {
71  CheckBuffer_();
72  if (NLIB_UNLIKELY(is_buf_curidx_ == is_buf_endidx_)) return -1;
73  }
74  return is_buf_[is_buf_curidx_++];
75  }
76  // < 0 if EOS or error, otherwise returns a byte and pos is unchanged
78  if (NLIB_UNLIKELY(is_buf_curidx_ == is_buf_endidx_)) {
79  CheckBuffer_();
80  if (NLIB_UNLIKELY(is_buf_curidx_ == is_buf_endidx_)) return -1;
81  }
82  return is_buf_[is_buf_curidx_];
83  }
84  // returns skipped number of bytes
85  size_t Skip(size_t nbytes) NLIB_NOEXCEPT;
86  size_t Read(void* ptr, size_t nbytes) NLIB_NOEXCEPT {
87 #ifndef NLIB_NONNULL_ENABLED
88  if (!ptr) {
89  this->SetError(EINVAL);
90  return 0;
91  }
92 #endif
93  if (nbytes > RSIZE_MAX) { // INT01-C
94  this->SetError(EINVAL);
95  return 0;
96  }
97  if (is_buf_curidx_ + nbytes <= is_buf_endidx_) {
98  nlib_memcpy(ptr, nbytes, &is_buf_[is_buf_curidx_], nbytes);
99  is_buf_curidx_ += nbytes;
100  return nbytes;
101  }
102  return this->Read_(ptr, nbytes);
103  }
104  template<size_t N>
105  size_t Read(nlib_byte_t (&buf)[N]) NLIB_NOEXCEPT {
106  return Read(&buf[0], N);
107  }
108  bool Close() NLIB_NOEXCEPT;
109  bool Mark(size_t readlimit) NLIB_NOEXCEPT;
110  bool GoBackToMark() NLIB_NOEXCEPT;
111  bool IsMarkSupported() const NLIB_NOEXCEPT { return is_mark_supported_; }
112  NLIB_SAFE_BOOL(InputStream, errno_ == 0)
113 
114  protected:
115  void
116  SetBuffer(void* p, size_t nbytes, bool is_mark_supported, bool is_buf_readonly) NLIB_NOEXCEPT {
117  NLIB_ASSERT(is_buf_readonly || !is_mark_supported);
118  NLIB_ASSERT(p);
119  NLIB_ASSERT(!is_mark_supported_ || is_buf_readonly_ || nbytes >= 1024);
120  is_buf_ = static_cast<unsigned char*>(p);
121  is_bufsize_ = static_cast<int>(nbytes);
122  is_mark_supported_ = is_mark_supported;
123  is_buf_readonly_ = is_buf_readonly;
124  }
125  void SetBuffer(void* p, size_t nbytes) NLIB_NOEXCEPT {
126  NLIB_ASSERT(p);
127  NLIB_ASSERT(!is_mark_supported_ || is_buf_readonly_ || nbytes >= 1024);
128  is_buf_ = static_cast<unsigned char*>(p);
129  is_bufsize_ = static_cast<int>(nbytes);
130  }
132  if (errno_ == 0) errno_ = e;
133  }
134 
135  private:
136  virtual size_t FillBuffer_(void* p, size_t nbytes) NLIB_NOEXCEPT = 0;
137  virtual bool Close_() NLIB_NOEXCEPT = 0;
138  // By default, Skip_() reads data on is_buf_.
139  // you can override it if you can implement more efficient code.
140  virtual size_t Skip_(size_t nbytes) NLIB_NOEXCEPT;
141 
142  private:
143  size_t Read_(void* ptr, size_t nbytes) NLIB_NOEXCEPT;
144  void CheckBuffer_() NLIB_NOEXCEPT;
145 
146  private:
147  uint64_t pos_;
148  size_t is_buf_curidx_;
149  size_t is_buf_endidx_;
150  size_t is_buf_markidx_;
151  unsigned char* is_buf_;
152  size_t is_bufsize_;
153  bool is_buf_readonly_;
154  bool is_mark_supported_;
155  mutable ErrnoT errno_;
156  // errno_ is changed only from derived classes.
157  // FillBuffer_() or Close_() changes errno_ in other words.
158 
160 };
161 
163  public:
165  virtual ~NullInputStream() NLIB_NOEXCEPT {}
166 
167  private:
168  char dummy_buf_[256];
169  virtual size_t FillBuffer_(void* p, size_t nbytes) NLIB_NOEXCEPT NLIB_OVERRIDE;
170  virtual bool Close_() NLIB_NOEXCEPT NLIB_OVERRIDE { return true; }
171  virtual size_t Skip_(size_t nbytes) NLIB_NOEXCEPT NLIB_OVERRIDE;
172 };
173 
174 namespace detail {
175 
176 template<size_t N>
177 class MiniBufIn {
178  public:
179  NLIB_STATIC_ASSERT(N >= 16);
180  static NLIB_CEXPR const size_t buf_size = N;
181  NLIB_ALWAYS_INLINE MiniBufIn() NLIB_NOEXCEPT { cur_ = end_ = &buf_[0]; }
182  template<class IS>
183  NLIB_ALWAYS_INLINE bool Prefetch(IS* stream, size_t n) NLIB_NOEXCEPT {
184  if (cur_ + n > end_) {
185  NLIB_ASSERT(n <= N);
186  size_t rem = end_ - cur_;
187  nlib_memmove(static_cast<void*>(&buf_[0]), N, cur_, rem);
188  size_t nread = stream->Read(&buf_[rem], N - rem);
189  cur_ = &buf_[0];
190  end_ = &buf_[0] + rem + nread;
191  return (nread + rem >= n);
192  }
193  return true;
194  }
195  template<class IS>
196  NLIB_ALWAYS_INLINE int Peek(IS* stream) NLIB_NOEXCEPT {
197  if (NLIB_UNLIKELY(cur_ == end_)) {
198  size_t nread = stream->Read(&buf_[0], N);
199  if (NLIB_UNLIKELY(nread == 0)) return -1;
200  cur_ = &buf_[0];
201  end_ = &buf_[0] + nread;
202  }
203  return *cur_;
204  }
205  template<class IS>
206  NLIB_ALWAYS_INLINE int Read(IS* stream) NLIB_NOEXCEPT {
207  if (NLIB_UNLIKELY(cur_ == end_)) {
208  size_t nread = stream->Read(&buf_[0], N);
209  if (NLIB_UNLIKELY(nread == 0)) return -1;
210  cur_ = &buf_[0] + 1;
211  end_ = &buf_[0] + nread;
212  return buf_[0];
213  } else {
214  int c = *cur_;
215  ++cur_;
216  return c;
217  }
218  }
219 
220  NLIB_ALWAYS_INLINE void Advance(size_t n) NLIB_NOEXCEPT {
221  // Prefetch(stream, n) must be successful beforehand
222  cur_ += n;
223  }
224  NLIB_ALWAYS_INLINE const uint8_t& operator[](size_t n) NLIB_NOEXCEPT {
225  // Prefetch(stream, n + 1) must be successful beforehand
226  return cur_[n];
227  }
228  template<class IS>
229  NLIB_ALWAYS_INLINE size_t ReadBytes(IS* stream, void* data, size_t nbytes) NLIB_NOEXCEPT {
230  if (cur_ + nbytes <= end_) {
231  nlib_memcpy(data, nbytes, cur_, nbytes);
232  cur_ += nbytes;
233  return nbytes;
234  }
235  uint8_t* p = static_cast<uint8_t*>(data);
236  size_t rem = end_ - cur_;
237  nlib_memcpy(static_cast<void*>(p), nbytes, cur_, rem);
238  cur_ = end_ = &buf_[0];
239  size_t nread = stream->Read(p + rem, nbytes - rem);
240  return nread + rem;
241  }
242  template<class IS, class T>
243  size_t Read(IS* stream, T* data, size_t count) NLIB_NOEXCEPT {
244  NLIB_STATIC_ASSERT(sizeof(*data) <= N);
245  NLIB_STATIC_ASSERT(IsPod<T>::value);
246  size_t nbytes = sizeof(*data) * count;
247  size_t nread = ReadBytes(stream, data, nbytes);
248  if (NLIB_LIKELY(nread == nbytes)) return count;
249  size_t mod = nread % sizeof(*data);
250  uint8_t* p = static_cast<uint8_t*>(static_cast<void*>(data));
251  nlib_memcpy(static_cast<void*>(&buf_[0]), N, p + nread - mod, mod);
252  end_ = &buf_[mod];
253  return nread / sizeof(*data);
254  }
255  NLIB_ALWAYS_INLINE size_t size() const NLIB_NOEXCEPT { return end_ - cur_; }
256 
257  private:
258  uint8_t* cur_;
259  uint8_t* end_;
260  uint8_t buf_[N];
261 };
262 
263 } // namespace detail
264 NLIB_NAMESPACE_END
265 
266 #endif // INCLUDE_NN_NLIB_INPUTSTREAM_H_
#define NLIB_OVERRIDE
Defines override if it is available for use. If not, holds an empty string.
Definition: Config.h:249
size_t Read(nlib_byte_t(&buf)[N]) noexcept
A template overload of the above function.
Definition: InputStream.h:105
size_t Read(void *ptr, size_t nbytes) noexcept
Reads the number of bytes of data specified by nbytes into the memory region specified by ptr...
Definition: InputStream.h:86
#define NLIB_ALWAYS_INLINE
Indicates that the compiler is forced to perform inline expansion of functions.
Definition: Platform_unix.h:95
Substitute definitions for the C++11 standard header type_traits. These substitute definitions are us...
uint64_t Pos64() const noexcept
Returns the current position in the stream as a 64-bit value.
Definition: InputStream.h:60
#define NLIB_DISALLOW_COPY_AND_ASSIGN(TypeName)
Prohibits use of the copy constructor and assignment operator for the class specified by TypeName...
Definition: Config.h:183
#define NLIB_SAFE_BOOL(class_name, exp)
Defines a safe operator bool function in the class. Uses the C++11 explicit bool if it is available f...
Definition: Config.h:199
errno_t GetErrorValue() const noexcept
Gets the error value.
Definition: InputStream.h:57
bool IsEos() noexcept
Returns true if the stream is finished being read through to the end. If the stream has not been read...
Definition: InputStream.h:61
#define NLIB_CHECK_RESULT
Indicates that the caller of the function must check the returned value.
int Read() noexcept
Reads one byte of data from the stream.
Definition: InputStream.h:69
#define NLIB_UNLIKELY(x)
Indicates to the compiler that condition x is likely to be false.
Definition: Platform_unix.h:98
#define RSIZE_MAX
Defines a value somewhat smaller than the maximum value of size_t.
Definition: Platform.h:219
#define NLIB_VIS_PUBLIC
Symbols for functions and classes are made available outside of the library.
Definition: Platform_unix.h:87
size_t Pos() const noexcept
Returns the current position in the stream.
Definition: InputStream.h:59
virtual ~InputStream() noexcept
Destructor. This function is called from the derived class.
Definition: InputStream.h:50
#define NLIB_LIKELY(x)
Indicates to the compiler that condition x is likely to be true.
Definition: Platform_unix.h:97
constexpr InputStream() noexcept
Instantiates the object with default parameters (default constructor). This function is called from t...
Definition: InputStream.h:31
The base class for input streams. This class cannot be instantiated.
Definition: InputStream.h:29
Class that wraps errno_t. This class improves visual representations in the Visual Studio debugger...
Definition: Config.h:404
int Peek() noexcept
Reads the next byte without consuming the stream.
Definition: InputStream.h:77
#define NLIB_NOEXCEPT
Defines noexcept geared to the environment, or the equivalent.
Definition: Config.h:109
#define NLIB_CEXPR
Defines constexpr if it is available for use. If not, holds an empty string.
Definition: Config.h:111
A file that contains the configuration information for each development environment.
void SetError(errno_t e) const noexcept
Sets an error to InputStream.
Definition: InputStream.h:131
#define NLIB_FINAL
Defines final if it is available for use. If not, holds an empty string.
Definition: Config.h:250
#define NLIB_STATIC_ASSERT(exp)
Defines a static assertion. Uses static_assert if it is available for use.
Definition: Config.h:174
bool Read(BinaryReader *r, T *x)
You can read to user-defined class objects by specializing this function template.
Definition: BinaryReader.h:161
The class for streams that always load 0.
Definition: InputStream.h:162
unsigned char nlib_byte_t
This type will be defined as std::byte in a typedef of C++17 or later.
Definition: Platform.h:314
static errno_t nlib_memmove(void *s1, size_t s1max, const void *s2, size_t n)
An implementation corresponding to N1078 memmove_s.
Definition: Platform.h:2530
int errno_t
Indicates with an int-type typedef that a POSIX error value is returned as the return value...
Definition: NMalloc.h:37