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/*
* DataSource
* (C) 1999-2007 Jack Lloyd
* 2005 Matthew Gregan
*
* Distributed under the terms of the Botan license
*/
#include <botan/data_src.h>
#include <botan/exceptn.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 identifier;
}
/*
* DataSource_Stream Constructor
*/
DataSource_Stream::DataSource_Stream(const std::string& path,
bool use_binary) :
identifier(path), owner(true)
{
if(use_binary)
source = new std::ifstream(path.c_str(), std::ios::binary);
else
source = new std::ifstream(path.c_str());
if(!source->good())
throw Stream_IO_Error("DataSource: Failure opening file " + path);
total_read = 0;
}
/*
* DataSource_Stream Constructor
*/
DataSource_Stream::DataSource_Stream(std::istream& in,
const std::string& name) :
identifier(name), owner(false)
{
source = ∈
total_read = 0;
}
/*
* DataSource_Stream Destructor
*/
DataSource_Stream::~DataSource_Stream()
{
if(owner)
delete source;
}
}
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