SystemCallWriteFile.cpp

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#ifndef _MADARA_NO_KARL_
 
#include "madara/expression/LeafNode.h"
#include "madara/expression/SystemCallWriteFile.h"
#include "madara/expression/Visitor.h"
 
madara::expression::SystemCallWriteFile::SystemCallWriteFile(
    madara::knowledge::ThreadSafeContext& context, const ComponentNodes& nodes)
  : SystemCallNode(context, nodes)
{
}
 
// Dtor
madara::expression::SystemCallWriteFile::~SystemCallWriteFile(void) {}
 
madara::knowledge::KnowledgeRecord
madara::expression::SystemCallWriteFile::item(void) const
{
  return madara::knowledge::KnowledgeRecord(nodes_.size());
}
 
madara::knowledge::KnowledgeRecord
madara::expression::SystemCallWriteFile::prune(bool& can_change)
{
  // user can always change a function, and we have no control over
  // what it does. Consequently, a function node cannot be pruned out
  // under any situation
  can_change = true;
 
  madara::knowledge::KnowledgeRecord result;
 
  for (ComponentNodes::iterator i = nodes_.begin(); i != nodes_.end(); ++i)
  {
    bool arg_can_change = false;
    result = (*i)->prune(arg_can_change);
 
    if (!arg_can_change && dynamic_cast<LeafNode*>(*i) == 0)
    {
      delete *i;
      *i = new LeafNode(*(this->logger_), result);
    }
  }
 
  if (nodes_.size() != 2)
  {
    madara_logger_ptr_log(logger_, logger::LOG_ERROR,
        "madara::expression::SystemCallWriteFile: "
        "KARL COMPILE ERROR:"
        "System call write_file requires 2 arguments: "
        "a knowledge record and a file name\n");
 
    throw exceptions::KarlException(
        "madara::expression::SystemCallWriteFile: "
        "KARL COMPILE ERROR: "
        "System call write_file requires 2 arguments: "
        "a knowledge record and a file name\n");
  }
 
  return result;
}
 
madara::knowledge::KnowledgeRecord
madara::expression::SystemCallWriteFile::evaluate(
    const madara::knowledge::KnowledgeUpdateSettings& settings)
{
  knowledge::KnowledgeRecord return_value;
 
  if (nodes_.size() == 2)
  {
    // copying strings wastes execution time, so we hold the
    // knowledge::KnowledgeRecord instead of the resulting string filename.
    knowledge::KnowledgeRecord arg1 = nodes_[0]->evaluate(settings);
    knowledge::KnowledgeRecord arg2 = nodes_[1]->evaluate(settings);
 
    knowledge::KnowledgeRecord* filename = &arg1;
    knowledge::KnowledgeRecord* contents = &arg2;
 
    madara_logger_ptr_log(logger_, logger::LOG_MINOR,
        "madara::expression::SystemCallWriteFile: "
        "System call write_file is attempting to open %s.\n",
        filename->to_string().c_str());
 
    ssize_t bytes_written = contents->to_file(filename->to_string());
 
    if (bytes_written <= 0)
    {
      madara_logger_ptr_log(logger_, logger::LOG_MINOR,
          "madara::expression::SystemCallWriteFile: "
          "KARL ERROR: System call write_file could not write to %s\n",
          filename->to_string().c_str());
 
      return madara::knowledge::KnowledgeRecord(bytes_written);
    }
    else
    {
      madara_logger_ptr_log(logger_, logger::LOG_MINOR,
          "madara::expression::SystemCallWriteFile: "
          "System call write_file wrote %zd bytes to %s\n",
          bytes_written, filename->to_string().c_str());
    }
  }
  else
  {
    madara_logger_ptr_log(logger_, logger::LOG_ERROR,
        "madara::expression::SystemCallWriteFile: "
        "KARL RUNTIME ERROR:"
        "System call write_file requires 2 arguments: "
        "a knowledge record and a file name\n");
 
    throw exceptions::KarlException(
        "madara::expression::SystemCallWriteFile: "
        "KARL RUNTIME ERROR: "
        "System call write_file requires 2 arguments: "
        "a knowledge record and a file name\n");
  }
 
  return return_value;
}
 
// accept a visitor
void madara::expression::SystemCallWriteFile::accept(
    madara::expression::Visitor& visitor) const
{
  visitor.visit(*this);
}
 
#endif  // _MADARA_NO_KARL_