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/*************************************************
* DataSource Source File *
* (C) 1999-2008 The Botan Project *
*************************************************/
#include <botan/data_src.h>
#include <fstream>
#include <algorithm>
namespace Botan {
/*************************************************
* Read a single byte from the DataSource *
*************************************************/
u32bit DataSource::read_byte(byte& out)
{
return read(&out, 1);
}
/*************************************************
* Peek a single byte from the DataSource *
*************************************************/
u32bit DataSource::peek_byte(byte& out) const
{
return peek(&out, 1, 0);
}
/*************************************************
* Discard the next N bytes of the data *
*************************************************/
u32bit DataSource::discard_next(u32bit n)
{
u32bit discarded = 0;
byte dummy;
for(u32bit j = 0; j != n; ++j)
discarded = read_byte(dummy);
return discarded;
}
/*************************************************
* Read from a memory buffer *
*************************************************/
u32bit DataSource_Memory::read(byte out[], u32bit length)
{
u32bit got = std::min(source.size() - offset, length);
copy_mem(out, source + offset, got);
offset += got;
return got;
}
/*************************************************
* Peek into a memory buffer *
*************************************************/
u32bit DataSource_Memory::peek(byte out[], u32bit length,
u32bit peek_offset) const
{
const u32bit bytes_left = source.size() - offset;
if(peek_offset >= bytes_left) return 0;
u32bit got = std::min(bytes_left - peek_offset, length);
copy_mem(out, source + offset + peek_offset, got);
return got;
}
/*************************************************
* Check if the memory buffer is empty *
*************************************************/
bool DataSource_Memory::end_of_data() const
{
return (offset == source.size());
}
/*************************************************
* DataSource_Memory Constructor *
*************************************************/
DataSource_Memory::DataSource_Memory(const byte in[], u32bit length)
{
source.set(in, length);
offset = 0;
}
/*************************************************
* DataSource_Memory Constructor *
*************************************************/
DataSource_Memory::DataSource_Memory(const MemoryRegion<byte>& in)
{
source = in;
offset = 0;
}
/*************************************************
* DataSource_Memory Constructor *
*************************************************/
DataSource_Memory::DataSource_Memory(const std::string& in)
{
source.set(reinterpret_cast<const byte*>(in.data()), in.length());
offset = 0;
}
/*************************************************
* Read from a stream *
*************************************************/
u32bit DataSource_Stream::read(byte out[], u32bit length)
{
source->read(reinterpret_cast<char*>(out), length);
if(source->bad())
throw Stream_IO_Error("DataSource_Stream::read: Source failure");
u32bit got = source->gcount();
total_read += got;
return got;
}
/*************************************************
* Peek into a stream *
*************************************************/
u32bit DataSource_Stream::peek(byte out[], u32bit length, u32bit offset) const
{
if(end_of_data())
throw Invalid_State("DataSource_Stream: Cannot peek when out of data");
u32bit got = 0;
if(offset)
{
SecureVector<byte> buf(offset);
source->read(reinterpret_cast<char*>(buf.begin()), 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;
}
/*************************************************
* Check if the stream is empty or in error *
*************************************************/
bool DataSource_Stream::end_of_data() const
{
return (!source->good());
}
/*************************************************
* Return a human-readable ID for this stream *
*************************************************/
std::string DataSource_Stream::id() const
{
return fsname;
}
/*************************************************
* DataSource_Stream Constructor *
*************************************************/
DataSource_Stream::DataSource_Stream(const std::string& file,
bool use_binary) : fsname(file)
{
if(use_binary)
source = new std::ifstream(fsname.c_str(), std::ios::binary);
else
source = new std::ifstream(fsname.c_str());
if(!source->good())
throw Stream_IO_Error("DataSource_Stream: Failure opening " + fsname);
total_read = 0;
}
/*************************************************
* DataSource_Stream Destructor *
*************************************************/
DataSource_Stream::~DataSource_Stream()
{
delete source;
}
}
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