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[h316.git] / pc-tools / ldc2 / src / tape_block.cpp

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>

#include "tape_block.hh"
#include "data_block.hh"
#include "data_block_0.hh"
#include "data_block_0_0.hh"
#include "data_block_0_1.hh"
#include "data_block_0_2.hh"
#include "data_block_0_3.hh"
#include "data_block_0_4.hh"
#include "data_block_0_10.hh"
#include "data_block_0_14.hh"
#include "data_block_0_24.hh"
#include "data_block_0_44.hh"
#include "data_block_0_30.hh"
#include "data_block_0_54.hh"
#include "data_block_0_60.hh"
#include "data_block_0_50.hh"
#include "data_block_0_64.hh"
#include "data_block_1.hh"
#include "data_block_2.hh"
#include "data_block_3.hh"
#include "data_block_4.hh"
#include "data_block_5.hh"
#include "data_block_6.hh"
#include "data_block_7.hh"

#include "eot_block.hh"
#include "discard_block.hh"
#include "silent_code.hh"
#include "hw_constants.hh"

using namespace std;

/***************************************************************/
/*!
 *\brief Destructor.
 */
tape_block::~tape_block(){
  free(raw_data);
  free(word_data);
}

/***************************************************************/
/*!
 *\brief Copy constructor.
 */
tape_block::tape_block(tape_block & org){
  operator=(org);
}

/***************************************************************/
/*!
 *\brief Assignment operator.
 */
void tape_block::operator=(tape_block &org){
  block_type=org.block_type;
  init_state=org.init_state;
  discarded_bytes=org.discarded_bytes;
  raw_data=0;  
  raw_size=org.raw_size;  
  word_data=0;
  word_size=org.word_size;              
   if (raw_size){
     raw_data=(unsigned char *)malloc(raw_size);
     memcpy(raw_data,org.raw_data,raw_size);
   }
   if (word_size){
     word_data=(unsigned short *)malloc(word_size*sizeof(unsigned short));
     memcpy(word_data,org.word_data,word_size*sizeof(unsigned short));
   }
}

/***************************************************************/
/*!
 *\brief Query the block's state.
 *
 * If the state is not TBS_OK, the block must be discarded.
 *\return The block's initialisation state
 */
tape_block::tb_state_t tape_block::get_state(){
  return init_state;
}

/***************************************************************/
/*!
 *\brief Determine the block's type
 *
 * This routine returns the block's type.\\
 *\retval TBT_DATA if it's a data block
 *\retval TBT_EOT if it's an end of tape mark
 *\retval TBR_DISCARD if the block is unusable
 *
 *\note This function is virtual. That means that if the tape block in
 * question is of the subtype data_block which overwrites this method,
 * it will return the block type contained in the upper 4 bits of the
 * first data word! Try to avoid testing for TBT_DATA. \n
 * Blocks generated by gen_from_fd should never have TBT_DATA.
 */
int tape_block::get_type(){
  return block_type;
}

/***************************************************************/
/*!
 *\brief Determine the block's subtype
 *
 * Some data block types have a subtype.
 *\note This is a virtual method and to be used in derived classes.
 *\return Always 0
 */
int tape_block::get_subtype(){
  return 0;
}

/***************************************************************/
/*!
 *\brief Get a cleartext description of the block.
 *\return ldc style descriptive line for the block
 */
vector<string> tape_block:: get_description(){
  vector<string> result;
  result.insert(result.end(),
		"*****      "+get_typestring()+"Untyped tape block");
  return result;
}

/***************************************************************/
/*!
 *\brief Get size of the internal raw data buffer
 *\return The size of the internal raw data buffer
 */
int tape_block::get_raw_size(){
  return raw_size;
}

/***************************************************************/
/*!
 *\brief Get amount of bytes discarded before beginning
 *       of block sensed.
 *\return Length of unusable tape before block start delimiter. 
 */
int tape_block::get_discarded_bytes(){
  return discarded_bytes;
}

/***************************************************************/
/*!
 *\brief Access internal raw data buffer
 *
 * The raw data buffer contains all block data except the \	\
 * block start delimiter and block end delimiter.
 *\return Pointer to internal raw data buffer of the block
 */
unsigned char * tape_block::get_raw_data(){
  return raw_data;
}

/***************************************************************/
/*!
 *\brief Static factory method with file descriptor support.
 *
 * This method creates a tape_block by using the private
 * constructor with file descriptor support.\n
 * It always returns a valid pointer, errors
 * or exceptional conditions during creation are marked in the
 * object's state.\n
 * The factory method tries to determine the block's type and then
 * looks for appropriate subclasses. If there's an appropriate
 * subclass fitting the newly-created object, an
 * object of the subclass will be created and a pointer to this
 * object will be returned to the caller.\n
 * This allows for easy use of the object using it's virtual
 * interface methods or a cast of the pointer to a sub type pointer 
 * according to the type information, and then using the subtype's
 * methods not already present in tape_block.\n
 * Objects of the  following subclasses are automagically generated:\n
 * - eot_block
 * - discard_block
 * - data_block
 *   - data_block_0
 *     - data_block_0_0
 *     - data_block_0_1
 *     - data_block_0_2
 *     - data_block_0_3
 *     - data_block_0_4
 *     - data_block_0_10
 *     - data_block_0_14
 *     - data_block_0_24
 *     - data_block_0_30
 *     - data_block_0_50
 *     - data_block_0_54
 *     - data_block_0_60
 *     - data_block_0_64
 *   - data_block_1
 *   - data_block_2
 *   - data_block_3
 *   - data_block_4
 *   - data_block_5
 *   - data_block_6
 *   - data_block_7
 *
 *\return Pointer to an object of type tape_block or a subclass.
 *\param fd A file descriptor where the read is taken from.
 *\param input_start A pointer to a function 
 *       called before reading data from fd.
 *\param input_stop A pointer to a function
 *       called after reading data from fd.
 * 
 *\param start_stop_arg A pointer passed to input_start 
 *       and input_stop(). Can be anything.
 */
tape_block * tape_block::gen_from_fd(int  fd,
				     void(*input_start)(void *),
				     void (*input_stop)(void *),
				     void * start_stop_arg)
{
  tape_block  * n_tape_block=0;
  data_block  * n_data_block=0;
  data_block  * n_data_block_x=0;
  data_block_0  * n_data_block_0=0;
  data_block_0  * n_data_block_0_x=0;
  eot_block * n_eot_block=0;
  discard_block * n_discard_block=0;
  
  //Use the private constructor which reads in the block from a file descriptor
  n_tape_block=new tape_block(fd,input_start,input_stop,start_stop_arg);
  
  // Retype to data_block, eot_block, discard_block - if possible
  switch(n_tape_block->get_type()){
  case tape_block::TBT_DATA:
    n_data_block = new data_block(*n_tape_block); 
    break;
  case tape_block::TBT_EOT:
    n_eot_block=new eot_block(*n_tape_block); 
    delete n_tape_block;
    return n_eot_block;
  case tape_block::TBT_DISCARD:
    n_discard_block = new discard_block(*n_tape_block); 
    delete n_tape_block;
    return n_discard_block;
  default: // Unknown block, a bad thing!         
    return n_tape_block; 
  }
  delete n_tape_block;

  // Now only data blocks are left

  switch(n_data_block->get_type()){
  case 00: n_data_block_0=new data_block_0(*n_data_block); break;
  case 01: n_data_block_x=new data_block_1(*n_data_block); break;
  case 02: n_data_block_x=new data_block_2(*n_data_block); break;
  case 03: n_data_block_x=new data_block_3(*n_data_block); break;
  case 04: n_data_block_x=new data_block_4(*n_data_block); break;
  case 05: n_data_block_x=new data_block_5(*n_data_block); break;
  case 06: n_data_block_x=new data_block_6(*n_data_block); break;
  case 07: n_data_block_x=new data_block_7(*n_data_block); break;
  default:
    return n_data_block;
  }
  if (n_data_block_0==0){ // So we must have found another one
    delete n_data_block;
    return n_data_block_x;
  }
  
  // Here only type 0 left
  switch(n_data_block_0->get_subtype()){
  case 000: n_data_block_0_x=new data_block_0_0(*n_data_block_0); break;
  case 001: n_data_block_0_x=new data_block_0_1(*n_data_block_0); break;
  case 002: n_data_block_0_x=new data_block_0_2(*n_data_block_0); break;
  case 003: n_data_block_0_x=new data_block_0_3(*n_data_block_0); break;
  case 004: n_data_block_0_x=new data_block_0_4(*n_data_block_0); break;
  case 010: n_data_block_0_x=new data_block_0_10(*n_data_block_0); break;
  case 014: n_data_block_0_x=new data_block_0_14(*n_data_block_0); break;
  case 024: n_data_block_0_x=new data_block_0_24(*n_data_block_0); break;
  case 044: n_data_block_0_x=new data_block_0_44(*n_data_block_0); break;
  case 030: n_data_block_0_x=new data_block_0_30(*n_data_block_0); break;
  case 054: n_data_block_0_x=new data_block_0_54(*n_data_block_0); break;
  case 060: n_data_block_0_x=new data_block_0_60(*n_data_block_0); break;
  case 064: n_data_block_0_x=new data_block_0_64(*n_data_block_0); break;
  case 050: n_data_block_0_x=new data_block_0_50(*n_data_block_0); break;
  default:
    return n_data_block_0;
  }
  delete n_data_block_0;
  return n_data_block_0_x;
}

/***************************************************************/
/*!
 *\brief Default constructor.
 */
tape_block::tape_block(){}

/***************************************************************/
/*!
 *\brief get a short type description string.
 *\return A small string to be used in description methods.
 *
 * The string is always 19 characters long.\n
 * An example is "(99-99)   ".
 */
string tape_block::get_typestring(){
  char buffer[13];
  sprintf(buffer,"(%o-%o)      ",get_type(),get_subtype());
  buffer[10]=0;
  return string(buffer);
}

/***************************************************************/
/*!
 *\brief Automatic constructor with file descriptor support
 *
 * This constructor is used to initialise the block read in the block's 
 * data via a file descriptor.\n
 * This is done in the following way:
 * - input_start() is called.
 * - Data is read from fd. Stops on end of file or end of block
 * or IO error. On EOF or IO error input_stop() is NOT called.
 * - If there was no IO error the block's checksum is calculated 
 * and checked.
 * - The block's type field is initialised.
 * - input_stop() is called.
 *
 *\param fd A file descriptor where the read is taken from 
 *\param input_stop A pointer to a function called at the end of input
 *\param input_start A pointer to a function called at the beginning 
 * of input
 *\param start_stop_arg A pointer passed to input_start and input_stop(). 
 */
tape_block::tape_block (int  fd,
			void(*input_start)(void *),
			void (*input_stop)(void *),
			void * start_stop_arg
			)
{
  unsigned char buffer;
  int retval;
  int eot_needed=EOT_LENGTH;
  int eob_needed=EOB_LENGTH;
  int block_complete=0;

  block_type= TBT_DISCARD;
  init_state= TBS_DEFAULT;
  discarded_bytes=0;
  raw_data  = 0;
  raw_size  = 0;
  word_data = 0;
  word_size = 0;
  poolsize  = 1024;

  // Get initial portion of memory
  raw_data=(unsigned char*)malloc(poolsize);

  if (input_start) input_start (start_stop_arg);

  /* Look for block start in input stream */
  do { 
    retval=read(fd, &buffer, 1);
    if (retval == 0){             // End of file
      block_type=TBT_DISCARD;
      init_state=TBS_EOF_LEGAL;
      return;
    }
    if (retval == -1){            // Error reading from fd
      block_type=TBT_DISCARD;
      init_state=TBS_IOERR;
      return;
    }
    discarded_bytes++;
    
    /* Look for end ot tape sequence */
    switch(eot_needed){
    case 3:
      if (buffer==EOT_SEQ_1) eot_needed--;
      else eot_needed=EOT_LENGTH;
      break;
    case 2:
      if (buffer==EOT_SEQ_2) eot_needed--;
      else eot_needed=EOT_LENGTH;
      break;
    case 1:
      if (buffer==EOT_SEQ_3){
	raw_data=(unsigned char*)malloc(3);
	raw_size=3;
	discarded_bytes-=3;
	raw_data[0]=EOT_SEQ_1;
	raw_data[1]=EOT_SEQ_2;
	raw_data[2]=EOT_SEQ_3;
	block_type =TBT_EOT;
 	init_state =TBS_OK;
	return;
      }
      else eot_needed=EOT_LENGTH;
      break;
    }
  } while (buffer != (unsigned char) BLOCK_START_DELIMITER);
  discarded_bytes--; // Dont want to declare the start delimiter discarded!
  raw_size=1;        // But we want to account it here!

  /* Now input the block data */
  block_complete = 0;
  do {
    retval = read (fd, &buffer, 1);

    if (retval == 0){             // End of file
      block_type=TBT_DISCARD;
      init_state=TBS_EOF_ILLEGAL;
      return;
    }
    if (retval == -1){            // Error reading from fd
      block_type=TBT_DISCARD;
      init_state=TBS_IOERR;
      return;
    }
    
    /* sort in the new byte */
    raw_size++;
    // Need more memory??
    if (raw_size==poolsize){
      poolsize+=1024;
      raw_data=(unsigned char*)realloc(raw_data,poolsize);
    }

    raw_data[raw_size-2]=buffer;

    /* Look for end ot block sequence */
    switch(eob_needed){
    case 2:
      if (buffer==BLOCK_END_DELIMITER_1) eob_needed--;
      else eob_needed=EOB_LENGTH;
      break;
    case 1:
      if (buffer==BLOCK_END_DELIMITER_2){
	raw_size-=EOB_LENGTH; // Don't want the delimiter(s) in the data!
	block_complete=1;
      }
      else eob_needed=EOB_LENGTH;
      break;
    }
  }while (!block_complete);
  if (input_stop) input_stop (start_stop_arg);
  
  /* Now we have the data in. */
  
  if (init_words()!=0){
    init_state=TBS_CHECKSUM;
    return;
  }
  
  if (test_checksum()!=0){
    init_state=TBS_CHECKSUM;
    return;
  }
  raw_size+=EOB_LENGTH; // Now we want it...

  block_type=TBT_DATA;    
  init_state=TBS_OK;
}


/***************************************************************/
/*!
 *\brief Initialize word representation of data.
 *\retval 0 on success.
 *\retval 1 on error.
 */
int tape_block::init_words(){
  word_size=raw_size/3;
  if (word_size<MINIMUM_DATA_BLOCK_WORDSIZE) return 1; // Block too short!
  word_data=(unsigned short *)malloc(raw_size*sizeof(unsigned short));
  for (int pos=0; pos<word_size; pos++)
    word_data[pos]=combine466(raw_data+3*pos);
  return 0;
}

/***************************************************************/
/*!
 *\brief Calculate and check checksum.
 *\retval 0 on success.
 *\retval 1 on error.
 */
int tape_block::test_checksum(){
  unsigned short sum=0;
  for (int pos=0; pos<word_size-1;pos++)
    sum^=word_data[pos];
  if (sum==word_data[word_size-1]) return 0;
  else return 1;
}