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/*
* DataSource
* (C) 1999-2007 Jack Lloyd
* 2005 Matthew Gregan
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/data_src.h>
#include <botan/exceptn.h>
#include <algorithm>
#if defined(BOTAN_TARGET_OS_HAS_FILESYSTEM)
#include <fstream>
#endif
namespace Botan {
/*
* Read a single byte from the DataSource
*/
size_t DataSource::read_byte(uint8_t& out)
{
return read(&out, 1);
}
/*
* Peek a single byte from the DataSource
*/
size_t DataSource::peek_byte(uint8_t& out) const
{
return peek(&out, 1, 0);
}
/*
* Discard the next N bytes of the data
*/
size_t DataSource::discard_next(size_t n)
{
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;
}
/*
* Read from a memory buffer
*/
size_t DataSource_Memory::read(uint8_t out[], size_t length)
{
size_t got = std::min<size_t>(m_source.size() - m_offset, length);
copy_mem(out, m_source.data() + m_offset, got);
m_offset += got;
return got;
}
bool DataSource_Memory::check_available(size_t n)
{
return (n <= (m_source.size() - m_offset));
}
/*
* Peek into a memory buffer
*/
size_t DataSource_Memory::peek(uint8_t out[], size_t length,
size_t peek_offset) const
{
const size_t bytes_left = m_source.size() - m_offset;
if(peek_offset >= bytes_left) return 0;
size_t got = std::min(bytes_left - peek_offset, length);
copy_mem(out, &m_source[m_offset + peek_offset], got);
return got;
}
/*
* Check if the memory buffer is empty
*/
bool DataSource_Memory::end_of_data() const
{
return (m_offset == m_source.size());
}
/*
* DataSource_Memory Constructor
*/
DataSource_Memory::DataSource_Memory(const std::string& in) :
m_source(reinterpret_cast<const uint8_t*>(in.data()),
reinterpret_cast<const uint8_t*>(in.data()) + in.length()),
m_offset(0)
{
}
/*
* Read from a stream
*/
size_t DataSource_Stream::read(uint8_t out[], size_t length)
{
m_source.read(reinterpret_cast<char*>(out), length);
if(m_source.bad())
throw Stream_IO_Error("DataSource_Stream::read: Source failure");
size_t got = m_source.gcount();
m_total_read += got;
return got;
}
bool DataSource_Stream::check_available(size_t n)
{
const std::streampos orig_pos = m_source.tellg();
m_source.seekg(0, std::ios::end);
const size_t avail = m_source.tellg() - orig_pos;
m_source.seekg(orig_pos);
return (avail >= n);
}
/*
* Peek into a stream
*/
size_t DataSource_Stream::peek(uint8_t out[], size_t length, size_t offset) const
{
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(reinterpret_cast<char*>(buf.data()), buf.size());
if(m_source.bad())
throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
got = m_source.gcount();
}
if(got == offset)
{
m_source.read(reinterpret_cast<char*>(out), length);
if(m_source.bad())
throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
got = m_source.gcount();
}
if(m_source.eof())
m_source.clear();
m_source.seekg(m_total_read, std::ios::beg);
return got;
}
/*
* Check if the stream is empty or in error
*/
bool DataSource_Stream::end_of_data() const
{
return (!m_source.good());
}
/*
* Return a human-readable ID for this stream
*/
std::string DataSource_Stream::id() const
{
return m_identifier;
}
#if defined(BOTAN_TARGET_OS_HAS_FILESYSTEM)
/*
* DataSource_Stream Constructor
*/
DataSource_Stream::DataSource_Stream(const std::string& path,
bool use_binary) :
m_identifier(path),
m_source_memory(new std::ifstream(path, use_binary ? std::ios::binary : std::ios::in)),
m_source(*m_source_memory),
m_total_read(0)
{
if(!m_source.good())
{
throw Stream_IO_Error("DataSource: Failure opening file " + path);
}
}
#endif
/*
* DataSource_Stream Constructor
*/
DataSource_Stream::DataSource_Stream(std::istream& in,
const std::string& name) :
m_identifier(name),
m_source(in),
m_total_read(0)
{
}
DataSource_Stream::~DataSource_Stream()
{
// for ~unique_ptr
}
}
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