Botan  1.10.16
Public Member Functions | List of all members
Botan::DataSource_Stream Class Reference

#include <data_src.h>

Inheritance diagram for Botan::DataSource_Stream:
Botan::DataSource

Public Member Functions

bool check_available (size_t n)
 
 DataSource_Stream (std::istream &, const std::string &id="<std::istream>")
 
 DataSource_Stream (const std::string &file, bool use_binary=false)
 
size_t discard_next (size_t N)
 
bool end_of_data () const
 
std::string id () const
 
size_t peek (byte[], size_t, size_t) const
 
size_t peek_byte (byte &out) const
 
size_t read (byte[], size_t)
 
size_t read_byte (byte &out)
 
 ~DataSource_Stream ()
 

Detailed Description

This class represents a Stream-Based DataSource.

Definition at line 128 of file data_src.h.

Constructor & Destructor Documentation

◆ DataSource_Stream() [1/2]

Botan::DataSource_Stream::DataSource_Stream ( std::istream &  in,
const std::string &  id = "<std::istream>" 
)

Definition at line 204 of file data_src.cpp.

205  :
206  identifier(name),
207  source_p(0),
208  source(in),
209  total_read(0)
210  {
211  }

◆ DataSource_Stream() [2/2]

Botan::DataSource_Stream::DataSource_Stream ( const std::string &  file,
bool  use_binary = false 
)

Construct a Stream-Based DataSource from file

Parameters
filethe name of the file
use_binarywhether to treat the file as binary or not

Definition at line 185 of file data_src.cpp.

186  :
187  identifier(path),
188  source_p(new std::ifstream(
189  path.c_str(),
190  use_binary ? std::ios::binary : std::ios::in)),
191  source(*source_p),
192  total_read(0)
193  {
194  if(!source.good())
195  {
196  delete source_p;
197  throw Stream_IO_Error("DataSource: Failure opening file " + path);
198  }
199  }

◆ ~DataSource_Stream()

Botan::DataSource_Stream::~DataSource_Stream ( )

Definition at line 216 of file data_src.cpp.

217  {
218  delete source_p;
219  }

Member Function Documentation

◆ check_available()

bool Botan::DataSource_Stream::check_available ( size_t  n)
virtual

Implements Botan::DataSource.

Definition at line 123 of file data_src.cpp.

124  {
125  const std::streampos orig_pos = source.tellg();
126  source.seekg(0, std::ios::end);
127  const size_t avail = source.tellg() - orig_pos;
128  source.seekg(orig_pos);
129  return (avail >= n);
130  }

◆ discard_next()

size_t Botan::DataSource::discard_next ( size_t  N)
inherited

Discard the next N bytes of the data

Parameters
Nthe number of bytes to discard
Returns
number of bytes actually discarded

Definition at line 35 of file data_src.cpp.

36  {
37  size_t discarded = 0;
38  byte dummy;
39  for(size_t j = 0; j != n; ++j)
40  discarded += read_byte(dummy);
41  return discarded;
42  }
unsigned char byte
Definition: types.h:22
size_t read_byte(byte &out)
Definition: data_src.cpp:19

◆ end_of_data()

bool Botan::DataSource_Stream::end_of_data ( ) const
virtual

Test whether the source still has data that can be read.

Returns
true if there is still data to read, false otherwise

Implements Botan::DataSource.

Definition at line 169 of file data_src.cpp.

170  {
171  return (!source.good());
172  }

◆ id()

std::string Botan::DataSource_Stream::id ( ) const
virtual

return the id of this data source

Returns
std::string representing the id of this data source

Reimplemented from Botan::DataSource.

Definition at line 177 of file data_src.cpp.

178  {
179  return identifier;
180  }

◆ peek()

size_t Botan::DataSource_Stream::peek ( byte  out[],
size_t  length,
size_t  peek_offset 
) const
virtual

Read from the source but do not modify the internal offset. Consecutive calls to peek() will return portions of the source starting at the same position.

Parameters
outthe byte array to write the output to
lengththe length of the byte array out
peek_offsetthe offset into the stream to read at
Returns
length in bytes that was actually read and put into out

Implements Botan::DataSource.

Definition at line 135 of file data_src.cpp.

References Botan::MemoryRegion< T >::clear(), Botan::DataSource_Memory::end_of_data(), and Botan::MemoryRegion< T >::size().

136  {
137  if(end_of_data())
138  throw Invalid_State("DataSource_Stream: Cannot peek when out of data");
139 
140  size_t got = 0;
141 
142  if(offset)
143  {
144  SecureVector<byte> buf(offset);
145  source.read(reinterpret_cast<char*>(&buf[0]), buf.size());
146  if(source.bad())
147  throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
148  got = source.gcount();
149  }
150 
151  if(got == offset)
152  {
153  source.read(reinterpret_cast<char*>(out), length);
154  if(source.bad())
155  throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
156  got = source.gcount();
157  }
158 
159  if(source.eof())
160  source.clear();
161  source.seekg(total_read, std::ios::beg);
162 
163  return got;
164  }
bool end_of_data() const
Definition: data_src.cpp:169

◆ peek_byte()

size_t Botan::DataSource::peek_byte ( byte out) const
inherited

Peek at one byte.

Parameters
outan output byte
Returns
length in bytes that was actually read and put into out

Definition at line 27 of file data_src.cpp.

References Botan::DataSource::peek().

Referenced by Botan::ASN1::maybe_BER().

28  {
29  return peek(&out, 1, 0);
30  }
virtual size_t peek(byte out[], size_t length, size_t peek_offset) const =0

◆ read()

size_t Botan::DataSource_Stream::read ( byte  out[],
size_t  length 
)
virtual

Read from the source. Moves the internal offset so that every call to read will return a new portion of the source.

Parameters
outthe byte array to write the result to
lengththe length of the byte array out
Returns
length in bytes that was actually read and put into out

Implements Botan::DataSource.

Definition at line 112 of file data_src.cpp.

113  {
114  source.read(reinterpret_cast<char*>(out), length);
115  if(source.bad())
116  throw Stream_IO_Error("DataSource_Stream::read: Source failure");
117 
118  size_t got = source.gcount();
119  total_read += got;
120  return got;
121  }

◆ read_byte()

size_t Botan::DataSource::read_byte ( byte out)
inherited

Read one byte.

Parameters
outthe byte to read to
Returns
length in bytes that was actually read and put into out

Definition at line 19 of file data_src.cpp.

References Botan::DataSource::read().

Referenced by Botan::PEM_Code::decode(), and Botan::PGP_decode().

20  {
21  return read(&out, 1);
22  }
virtual size_t read(byte out[], size_t length)=0

The documentation for this class was generated from the following files: