Botan: Botan::DataSource_Stream Class Reference

#include <data_src.h>

Inheritance diagram for Botan::DataSource_Stream:

Public Member Functions
	DataSource_Stream (std::istream &, const std::string &id="<std::istream>")

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

	DataSource_Stream (const DataSource_Stream &)=delete

size_t	discard_next (size_t N)

bool	end_of_data () const

virtual size_t	get_bytes_read () const

std::string	id () const

DataSource_Stream &	operator= (const DataSource_Stream &)=delete

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 141 of file data_src.h.

Constructor & Destructor Documentation

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

Definition at line 174 of file data_src.cpp.

                                                             :
    identifier(name),
    source_p(nullptr),
    source(in),
    total_read(0)
    {

   }

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

Construct a Stream-Based DataSource from file

Parameters

file	the name of the file
use_binary	whether to treat the file as binary or not

Definition at line 155 of file data_src.cpp.

                                                       :
    identifier(path),
    source_p(new std::ifstream(
                path.c_str(),
                use_binary ? std::ios::binary : std::ios::in)),
    source(*source_p),
    total_read(0)
    {
    if(!source.good())
       {
       delete source_p;
       throw Stream_IO_Error("DataSource: Failure opening file " + path);
       }

   }

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

delete

Botan::DataSource_Stream::~DataSource_Stream ( )

Definition at line 186 of file data_src.cpp.

    {
    delete source_p;
    }

Member Function Documentation

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 35 of file data_src.cpp.

References n, and Botan::DataSource::read_byte().

    {
    size_t discarded = 0;
    byte dummy;
    for(size_t j = 0; j != n; ++j)
       discarded += read_byte(dummy);
    return discarded;
    }

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 139 of file data_src.cpp.

Referenced by peek().

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

virtual size_t Botan::DataSource_Stream::get_bytes_read ( ) const

inlinevirtual

Returns: number of bytes read so far.

Implements Botan::DataSource.

Definition at line 165 of file data_src.h.

165 { return total_read; }

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 147 of file data_src.cpp.

    {
    return identifier;
    }

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

delete

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

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 105 of file data_src.cpp.

References end_of_data().

    {
    if(end_of_data())
       throw Invalid_State("DataSource_Stream: Cannot peek when out of data");
 
    size_t got = 0;
 
    if(offset)
       {
       secure_vector<byte> buf(offset);
       source.read(reinterpret_cast<char*>(&buf[0]), buf.size());
       if(source.bad())
          throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
       got = source.gcount();
       }
 
    if(got == offset)
       {
       source.read(reinterpret_cast<char*>(out), length);
       if(source.bad())
          throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
       got = source.gcount();
       }
 
    if(source.eof())
       source.clear();
    source.seekg(total_read, std::ios::beg);
 
    return got;
    }

size_t Botan::DataSource::peek_byte ( byte & 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 27 of file data_src.cpp.

References Botan::DataSource::peek().

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

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

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

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 91 of file data_src.cpp.

    {
    source.read(reinterpret_cast<char*>(out), length);
    if(source.bad())
       throw Stream_IO_Error("DataSource_Stream::read: Source failure");
 
    size_t got = source.gcount();
    total_read += got;
    return got;
    }

size_t Botan::DataSource::read_byte ( byte & 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 19 of file data_src.cpp.

References Botan::DataSource::read().

Referenced by Botan::PEM_Code::decode(), Botan::DataSource::discard_next(), Botan::BER_Decoder::discard_remaining(), Botan::PGP_decode(), and Botan::BER_Decoder::raw_bytes().

    {
    return read(&out, 1);
    }

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation