Botan::DataSource_Stream Class Reference

#include <data_src.h>

Inheritance diagram for Botan::DataSource_Stream:

Public Member Functions
bool	check_available (size_t n) override
	DataSource_Stream (const DataSource_Stream &)=delete
	DataSource_Stream (std::istream &, std::string_view id="<std::istream>")
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_Stream &	operator= (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 152 of file data_src.h.

Constructor & Destructor Documentation

DataSource_Stream() [1/2]

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

Definition at line 202 of file data_src.cpp.

                                                          :
   m_identifier(name),
   m_source(in),
   m_total_read(0)
   {
   }

DataSource_Stream() [2/2]

Botan::DataSource_Stream::DataSource_Stream ( const DataSource_Stream &  )

delete

~DataSource_Stream()

Botan::DataSource_Stream::~DataSource_Stream ( )

default

Member Function Documentation

check_available()

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

overridevirtual

Implements Botan::DataSource.

Definition at line 120 of file data_src.cpp.

   {
   const std::streampos orig_pos = m_source.tellg();
   m_source.seekg(0, std::ios::end);
   const size_t avail = static_cast<size_t>(m_source.tellg() - orig_pos);
   m_source.seekg(orig_pos);
   return (avail >= n);
   }

discard_next()

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

inherited

Discard the next N bytes of the data

Parameters

N	the number of bytes to discard

Returns

number of bytes actually discarded

Definition at line 40 of file data_src.cpp.

   {
   uint8_t buf[64] = { 0 };
   size_t discarded = 0;
 
   while(n)
      {
      const size_t got = this->read(buf, std::min(n, sizeof(buf)));
      discarded += got;
      n -= got;
 
      if(got == 0)
         break;
      }
 
   return discarded;
   }

References Botan::DataSource::read().

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 166 of file data_src.cpp.

   {
   return (!m_source.good());
   }

Referenced by peek().

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 179 of file data_src.h.

{ 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 174 of file data_src.cpp.

   {
   return m_identifier;
   }

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

out	the byte array to write the output to
length	the length of the byte array out
peek_offset	the 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 132 of file data_src.cpp.

   {
   if(end_of_data())
      throw Invalid_State("DataSource_Stream: Cannot peek when out of data");
 
   size_t got = 0;
 
   if(offset)
      {
      secure_vector<uint8_t> buf(offset);
      m_source.read(cast_uint8_ptr_to_char(buf.data()), buf.size());
      if(m_source.bad())
         throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
      got = static_cast<size_t>(m_source.gcount());
      }
 
   if(got == offset)
      {
      m_source.read(cast_uint8_ptr_to_char(out), length);
      if(m_source.bad())
         throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
      got = static_cast<size_t>(m_source.gcount());
      }
 
   if(m_source.eof())
      m_source.clear();
   m_source.seekg(m_total_read, std::ios::beg);
 
   return got;
   }

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

peek_byte()

size_t Botan::DataSource::peek_byte ( uint8_t &  out ) const

inherited

Peek at one byte.

Parameters

out	an output byte

Returns

length in bytes that was actually read and put into out

Definition at line 32 of file data_src.cpp.

   {
   return peek(&out, 1, 0);
   }

References Botan::DataSource::peek().

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

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

out	the byte array to write the result to
length	the length of the byte array out

Returns

length in bytes that was actually read and put into out

Implements Botan::DataSource.

Definition at line 109 of file data_src.cpp.

   {
   m_source.read(cast_uint8_ptr_to_char(out), length);
   if(m_source.bad())
      throw Stream_IO_Error("DataSource_Stream::read: Source failure");
 
   const size_t got = static_cast<size_t>(m_source.gcount());
   m_total_read += got;
   return got;
   }

References Botan::cast_uint8_ptr_to_char().

read_byte()

size_t Botan::DataSource::read_byte ( uint8_t &  out )

inherited

Read one byte.

Parameters

out	the byte to read to

Returns

length in bytes that was actually read and put into out

Definition at line 24 of file data_src.cpp.

   {
   return read(&out, 1);
   }

References Botan::DataSource::read().

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

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

• src/lib/utils/data_src.h
• src/lib/utils/data_src.cpp