Botan  2.8.0
Crypto and TLS for C++11
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Botan::DataSource_Stream Class Referencefinal

#include <data_src.h>

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

Public Member Functions

bool check_available (size_t n) override
 
 DataSource_Stream (std::istream &, const std::string &id="<std::istream>")
 
 DataSource_Stream (const DataSource_Stream &)=delete
 
size_t discard_next (size_t N)
 
bool end_of_data () const override
 
size_t get_bytes_read () const override
 
std::string id () const override
 
DataSource_Streamoperator= (const DataSource_Stream &)=delete
 
size_t peek (uint8_t[], size_t, size_t) const override
 
size_t peek_byte (uint8_t &out) const
 
size_t read (uint8_t[], size_t) override
 
size_t read_byte (uint8_t &out)
 
 ~DataSource_Stream ()
 

Detailed Description

This class represents a Stream-Based DataSource.

Definition at line 143 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 201 of file data_src.cpp.

202  :
203  m_identifier(name),
204  m_source(in),
205  m_total_read(0)
206  {
207  }
std::string name

◆ DataSource_Stream() [2/2]

Botan::DataSource_Stream::DataSource_Stream ( const DataSource_Stream )
delete

◆ ~DataSource_Stream()

Botan::DataSource_Stream::~DataSource_Stream ( )

Definition at line 209 of file data_src.cpp.

210  {
211  // for ~unique_ptr
212  }

Member Function Documentation

◆ check_available()

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

Implements Botan::DataSource.

Definition at line 119 of file data_src.cpp.

120  {
121  const std::streampos orig_pos = m_source.tellg();
122  m_source.seekg(0, std::ios::end);
123  const size_t avail = static_cast<size_t>(m_source.tellg() - orig_pos);
124  m_source.seekg(orig_pos);
125  return (avail >= n);
126  }

◆ 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 39 of file data_src.cpp.

References Botan::DataSource::read().

40  {
41  uint8_t buf[64] = { 0 };
42  size_t discarded = 0;
43 
44  while(n)
45  {
46  const size_t got = this->read(buf, std::min(n, sizeof(buf)));
47  discarded += got;
48  n -= got;
49 
50  if(got == 0)
51  break;
52  }
53 
54  return discarded;
55  }
virtual size_t read(uint8_t out[], size_t length) BOTAN_WARN_UNUSED_RESULT=0

◆ end_of_data()

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

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

Returns
true if there is no more data to read, false otherwise

Implements Botan::DataSource.

Definition at line 165 of file data_src.cpp.

Referenced by peek().

166  {
167  return (!m_source.good());
168  }

◆ get_bytes_read()

size_t Botan::DataSource_Stream::get_bytes_read ( ) const
inlineoverridevirtual
Returns
number of bytes read so far.

Implements Botan::DataSource.

Definition at line 170 of file data_src.h.

170 { return m_total_read; }

◆ id()

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

return the id of this data source

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

Reimplemented from Botan::DataSource.

Definition at line 173 of file data_src.cpp.

174  {
175  return m_identifier;
176  }

◆ operator=()

DataSource_Stream& Botan::DataSource_Stream::operator= ( const DataSource_Stream )
delete

◆ peek()

size_t Botan::DataSource_Stream::peek ( uint8_t  out[],
size_t  length,
size_t  peek_offset 
) const
overridevirtual

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 131 of file data_src.cpp.

References Botan::cast_uint8_ptr_to_char(), and end_of_data().

132  {
133  if(end_of_data())
134  throw Invalid_State("DataSource_Stream: Cannot peek when out of data");
135 
136  size_t got = 0;
137 
138  if(offset)
139  {
140  secure_vector<uint8_t> buf(offset);
141  m_source.read(cast_uint8_ptr_to_char(buf.data()), buf.size());
142  if(m_source.bad())
143  throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
144  got = static_cast<size_t>(m_source.gcount());
145  }
146 
147  if(got == offset)
148  {
149  m_source.read(cast_uint8_ptr_to_char(out), length);
150  if(m_source.bad())
151  throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
152  got = static_cast<size_t>(m_source.gcount());
153  }
154 
155  if(m_source.eof())
156  m_source.clear();
157  m_source.seekg(m_total_read, std::ios::beg);
158 
159  return got;
160  }
const char * cast_uint8_ptr_to_char(const uint8_t *b)
Definition: mem_ops.h:136
bool end_of_data() const override
Definition: data_src.cpp:165

◆ peek_byte()

size_t Botan::DataSource::peek_byte ( uint8_t &  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 31 of file data_src.cpp.

References Botan::DataSource::peek().

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

32  {
33  return peek(&out, 1, 0);
34  }
virtual size_t peek(uint8_t out[], size_t length, size_t peek_offset) const BOTAN_WARN_UNUSED_RESULT=0

◆ read()

size_t Botan::DataSource_Stream::read ( uint8_t  out[],
size_t  length 
)
overridevirtual

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 108 of file data_src.cpp.

References Botan::cast_uint8_ptr_to_char().

109  {
110  m_source.read(cast_uint8_ptr_to_char(out), length);
111  if(m_source.bad())
112  throw Stream_IO_Error("DataSource_Stream::read: Source failure");
113 
114  const size_t got = static_cast<size_t>(m_source.gcount());
115  m_total_read += got;
116  return got;
117  }
const char * cast_uint8_ptr_to_char(const uint8_t *b)
Definition: mem_ops.h:136

◆ read_byte()

size_t Botan::DataSource::read_byte ( uint8_t &  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 23 of file data_src.cpp.

References Botan::DataSource::read().

Referenced by Botan::PEM_Code::decode(), Botan::BER_Decoder::discard_remaining(), and Botan::ASN1::maybe_BER().

24  {
25  return read(&out, 1);
26  }
virtual size_t read(uint8_t out[], size_t length) BOTAN_WARN_UNUSED_RESULT=0

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