Botan::DataSource_Stream Class Reference

#include <data_src.h>

Inheritance diagram for Botan::DataSource_Stream:

Public Member Functions
bool	check_available (size_t n)
	DataSource_Stream (const std::string &file, bool use_binary=false)
	DataSource_Stream (std::istream &, const std::string &id="<std::istream>")
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.

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

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

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

Definition at line 185 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);
      }
   }

~DataSource_Stream()

Botan::DataSource_Stream::~DataSource_Stream

(

)

Definition at line 216 of file data_src.cpp.

   {
   delete source_p;
   }

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.

   {
   const std::streampos orig_pos = source.tellg();
   source.seekg(0, std::ios::end);
   const size_t avail = source.tellg() - orig_pos;
   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 35 of file data_src.cpp.

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

References read_byte().

Referenced by check_available().

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.

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

Referenced by peek().

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.

   {
   return identifier;
   }

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

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 135 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)
      {
      SecureVector<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;
   }

References end_of_data(), Botan::Invalid_State::Invalid_State(), Botan::MemoryRegion< T >::size(), and Botan::Stream_IO_Error::Stream_IO_Error().

peek_byte()

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.

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

References peek().

Referenced by check_available(), and Botan::ASN1::maybe_BER().

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

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 112 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;
   }

References Botan::Stream_IO_Error::Stream_IO_Error().

read_byte()

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.

   {
   return read(&out, 1);
   }

References read().

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

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

• src/filters/data_src.h
• src/filters/data_src.cpp