comp_filter.cpp

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/*
* Filter interface for compression
* (C) 2014,2015,2016 Jack Lloyd
* (C) 2015 Matej Kenda
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
 
#include <botan/filters.h>
 
#include <botan/exceptn.h>
#include <botan/internal/fmt.h>
 
#if defined(BOTAN_HAS_COMPRESSION)
   #include <botan/compression.h>
#endif
 
namespace Botan {
 
#if defined(BOTAN_HAS_COMPRESSION)
 
Compression_Filter::Compression_Filter(std::string_view type, size_t level, size_t bs) :
      m_comp(Compression_Algorithm::create(type)), m_buffersize(std::max<size_t>(bs, 256)), m_level(level) {
   if(!m_comp) {
      throw Invalid_Argument(fmt("Compression type '{}' not found", type));
   }
}
 
Compression_Filter::~Compression_Filter() = default;
 
std::string Compression_Filter::name() const {
   return m_comp->name();
}
 
void Compression_Filter::start_msg() {
   m_comp->start(m_level);
}
 
void Compression_Filter::write(const uint8_t input[], size_t input_length) {
   while(input_length) {
      const size_t take = std::min(m_buffersize, input_length);
      BOTAN_ASSERT(take > 0, "Consumed something");
 
      m_buffer.assign(input, input + take);
      m_comp->update(m_buffer);
 
      send(m_buffer);
 
      input += take;
      input_length -= take;
   }
}
 
void Compression_Filter::flush() {
   m_buffer.clear();
   m_comp->update(m_buffer, 0, true);
   send(m_buffer);
}
 
void Compression_Filter::end_msg() {
   m_buffer.clear();
   m_comp->finish(m_buffer);
   send(m_buffer);
}
 
Decompression_Filter::Decompression_Filter(std::string_view type, size_t bs) :
      m_comp(Decompression_Algorithm::create(type)), m_buffersize(std::max<size_t>(bs, 256)) {
   if(!m_comp) {
      throw Invalid_Argument(fmt("Compression type '{}' not found", type));
   }
}
 
Decompression_Filter::~Decompression_Filter() = default;
 
std::string Decompression_Filter::name() const {
   return m_comp->name();
}
 
void Decompression_Filter::start_msg() {
   m_comp->start();
}
 
void Decompression_Filter::write(const uint8_t input[], size_t input_length) {
   while(input_length) {
      const size_t take = std::min(m_buffersize, input_length);
      BOTAN_ASSERT(take > 0, "Consumed something");
 
      m_buffer.assign(input, input + take);
      m_comp->update(m_buffer);
 
      send(m_buffer);
 
      input += take;
      input_length -= take;
   }
}
 
void Decompression_Filter::end_msg() {
   m_buffer.clear();
   m_comp->finish(m_buffer);
   send(m_buffer);
}
 
#endif
 
}  // namespace Botan