DataChannel.hxx

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//-----------------------------------------------------------------------------
// CVS: $Revision: 2105 $, $Date: 2006-04-17 17:58:30 +0100 (Mon, 17 Apr 2006) $, $Author: rsc $
//-----------------------------------------------------------------------------
#ifndef DATACHANNEL_H
#define DATACHANNEL_H

#include <cmath>
#include <string>

#include "ByteArray.h"
#include "MyException.h"
#include "TableData.hxx"
//-----------------------------------------------------------------------------
template<typename DataType>
class DataChannel
{
public:
  virtual void input(TableData<DataType>& data,
                                      int colNo,
                               ByteArray& bytes) = 0;

  virtual void output(TableData<DataType>& data,
                                       int colNo,
                                ByteArray& bytes) = 0;

  virtual void output(DataType& data, ByteArray& bytes) = 0;

  virtual int getWordSize() = 0;

  virtual ~DataChannel() {}
};
//-----------------------------------------------------------------------------
template<typename DataType>
class DataChannel_SQL_tinyint : public DataChannel<DataType>
{
public:
  void input(TableData<DataType>& data, int colNo, ByteArray& bytes)
  {

    char word;
    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {

      // Get the single byte from the array
      bytes.getNextWord(1, &word);

      // WARNING: I've cast this directly as Numeric (ie double). I'm
      // sure if this this is OK.
      data.assign(colNo, recNo, (Numeric)word);
    }

  }

  void output(TableData<DataType>& data, int colNo, ByteArray& bytes)
  {
    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo)
    {
      Numeric v;
      data.value(colNo, recNo, v);

      // WARNING: I want to cast this double as a single byte. Not
      // sure if this is the correct way to do it,
      char word = static_cast<char>(floor(v));

      bytes.putNextWord(1, &word);
    }
  }

  void output(DataType& data, ByteArray& bytes)
  {
    // WARNING: I want to cast this double as a single byte. Not
    // sure if this is the correct way to do it,
    char word = (char)floor(data);
    //cout << recNo << " " << word << " " << v << endl;
    bytes.putNextWord(1, &word);
  }

  int getWordSize() {
    return 1;
  }

  // Virtual destructor.
  virtual ~DataChannel_SQL_tinyint() {}
};
//-----------------------------------------------------------------------------
template<typename DataType>
class DataChannel_SQL_smallint : public DataChannel<DataType> {

private:

  static const int wordSize = 2;

  union {
    char bytes[wordSize];
    short x;
  } word;

public:

  void input(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      bytes.getNextWord(wordSize, word.bytes);
      data.assign(colNo, recNo, (Numeric)word.x);
    }

  }

  void output(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      Numeric v;
      data.value(colNo, recNo, v);
      word.x = (short)floor(v);
      bytes.putNextWord(wordSize, word.bytes);
    }

  }

  void output(DataType& data, ByteArray& bytes)
  {
    word.x = (short)floor(data);
    bytes.putNextWord(wordSize, word.bytes);
  }

  int getWordSize() {
    return wordSize;
  }

  // Virtual destructor.
  virtual ~DataChannel_SQL_smallint() {}
};
//-----------------------------------------------------------------------------
template<typename DataType>
class DataChannel_SQL_int : public DataChannel<DataType> {

private:

  static const int wordSize = 4;

  union {
    char bytes[wordSize];
    int x;
  } word;

public:

  void input(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      bytes.getNextWord(wordSize, word.bytes);
      data.assign(colNo, recNo, (Numeric)word.x);
    }

  }

  void output(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      Numeric v;
      data.value(colNo, recNo, v);
      word.x = (int)floor(v);
      bytes.putNextWord(wordSize, word.bytes);
    }

  }

  void output(DataType& data, ByteArray& bytes)
  {
    word.x = (int)floor(data);
    bytes.putNextWord(wordSize, word.bytes);
  }

  int getWordSize() {
    return wordSize;
  }

  // Virtual destructor.
  virtual ~DataChannel_SQL_int() {}
};
//-----------------------------------------------------------------------------
template<typename DataType>
class DataChannel_SQL_bigint : public DataChannel<DataType> {

private:

  static const int wordSize = 8;

  union {
    char bytes[wordSize];
    long long x;
  } word;

public:

  void input(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      bytes.getNextWord(wordSize, word.bytes);
      data.assign(colNo, recNo, (Numeric)word.x);
    }

  }

  void output(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      Numeric v;
      data.value(colNo, recNo, v);
      word.x = (long long)floor(v);
      bytes.putNextWord(wordSize, word.bytes);
    }

  }

  void output(DataType& data, ByteArray& bytes)
  {
    word.x = (long long)floor(data);
    bytes.putNextWord(wordSize, word.bytes);
  }

  int getWordSize() {
    return wordSize;
  }

  // Virtual destructor.
  virtual ~DataChannel_SQL_bigint() {}
};
//-----------------------------------------------------------------------------
template<typename DataType>
class DataChannel_SQL_real : public DataChannel<DataType> {

private:

  static const int wordSize = 4;

  union {
    char bytes[wordSize];
    float x;
  } word;

public:

  void input(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      bytes.getNextWord(wordSize, word.bytes);
      data.assign(colNo, recNo, (Numeric)word.x);
    }

  }

  void output(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      Numeric v;
      data.value(colNo, recNo, v);
      word.x = (float)v;
      bytes.putNextWord(wordSize, word.bytes);
    }

  }

  void output(DataType& data, ByteArray& bytes)
  {
    word.x = (float)data;
    bytes.putNextWord(wordSize, word.bytes);
  }

  int getWordSize() {
    return wordSize;
  }

  // Virtual destructor.
  virtual ~DataChannel_SQL_real() {}
};
//-----------------------------------------------------------------------------
template<typename DataType>
class DataChannel_SQL_float : public DataChannel<DataType> {

private:

  static const int wordSize = 8;

  union {
    char bytes[wordSize];
    double x;
  } word;

public:

  void input(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      bytes.getNextWord(wordSize, word.bytes);
      data.assign(colNo, recNo, (Numeric)word.x);
    }

  }

  void output(TableData<DataType>& data, int colNo, ByteArray& bytes) {

    for (int recNo = 0; recNo < bytes.getNumRecords(); ++recNo) {
      Numeric v;
      data.value(colNo, recNo, v);
      word.x = (double)v;
      bytes.putNextWord(wordSize, word.bytes);
    }

  }

  void output(DataType& data, ByteArray& bytes)
  {
    word.x = (double)data;
    bytes.putNextWord(wordSize, word.bytes);
  }

  int getWordSize() {
    return wordSize;
  }

  // Virtual destructor.
  virtual ~DataChannel_SQL_float() {}
};
//-----------------------------------------------------------------------------
extern inline DataChannel<Numeric>* selectChannel(const std::string& type)
{
  if (type == "tinyint") {
    return new DataChannel_SQL_tinyint<Numeric>();
  }
  else if (type == "smallint") {
    return new DataChannel_SQL_smallint<Numeric>();
  }
  else if (type == "int") {
    return new DataChannel_SQL_int<Numeric>();
  }
  else if (type == "bigint") {
    return new DataChannel_SQL_bigint<Numeric>();
  }
  else if (type == "real") {
    return new DataChannel_SQL_real<Numeric>();
  }
  else if (type == "float") {
    return new DataChannel_SQL_float<Numeric>();
  }
  else {
    throw MyException("Cannot open a data channel for type " + type);
  }
}
//-----------------------------------------------------------------------------
#endif
//-----------------------------------------------------------------------------
// Change log:
//
// 15-Jun-2004,  IAB: Original version.
//  3-Sep-2004,  NCH: Fixed bug in data channel class for SQL type "float":
//                    all floats where being truncated to integers.
//  6-Jun-2005,  NCH: Added all virtual destructors to fix memory leaks.
// 27-Sep-2005,  RSC: Removed illegal "delete &word;" statements to prevent
//                    segmentation faults upon deletion of DataChannels.
//  2-Nov-2005,  RSC: Moved selectChannel from mkmerge.cpp to here
// 22-Feb-2006,  RSC: Extended DataChannel output() to support entry by entry
//                    output (previously would output entire column at a time)
//                    for OutputData::DataDumper::dumpAsBinary() for exnumeric
// 16-Apr-2006,  RSC: Moved ByteArray into it's own file

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