X-Git-Url: http://gitweb.hachti.de/?a=blobdiff_plain;f=pc-tools%2Fldc2%2Fsrc%2Ftape_block.hh;fp=pc-tools%2Fldc2%2Fsrc%2Ftape_block.hh;h=8c1231f389a3cda158e683b4443577887139564b;hb=97b26985c0190e2fded0f098819a23e892b381f0;hp=0000000000000000000000000000000000000000;hpb=70896a91a15781c49bce37b0101466c83c51dd24;p=h316.git

diff --git a/pc-tools/ldc2/src/tape_block.hh b/pc-tools/ldc2/src/tape_block.hh
new file mode 100644
index 0000000..8c1231f
--- /dev/null
+++ b/pc-tools/ldc2/src/tape_block.hh
@@ -0,0 +1,150 @@
+#ifndef TAPE_BLOCK_H
+#define TAPE_BLOCK_H
+
+
+/*!
+ *\brief Tape data block base class
+ *
+ * This class represents a Honeywell paper tape block.
+ * That may be some kind of data block or a end of tape mark.
+ */
+class tape_block{
+
+public: // types
+
+  /*!
+   * The block's initialisation state
+   */
+  typedef enum {
+    TBS_OK,          //!< Block successfully initialised
+    TBS_EOF_LEGAL,   //!< Legal EOF while initialising
+    TBS_EOF_ILLEGAL, //!< Illegal EOF while initialising
+    TBS_CHECKSUM,    //!< Checksum error 
+    TBS_IOERR,       //!< I/O-Error while reading
+    TBS_DEFAULT      //!< Block not initialised.
+  } tb_state_t;
+
+  /*!
+   * Tape block types
+   */
+  typedef enum {
+    TBT_DATA=0x10,   //!< Data block
+    TBT_EOT,         //!< End of tape block
+    TBT_DISCARD      //!< Invalid block, check block_type
+  } tb_type_t;
+
+protected: // methods
+  /*!
+   *\brief Protected default constructor
+   */
+  tape_block();
+
+public: // methods
+
+  tape_block(tape_block &);
+
+  /*!
+   *\brief Read-in constructor for file descriptor
+   *
+   * This constructor is used to read in the block's data via a file 
+   * descriptor.\\
+   * 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_p A pointer to the device descriptor where 
+   * the data 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 (int  fd_p,
+	      void(*input_start)(void *)=0,
+	      void (*input_stop)(void *)=0,
+	      void * start_stop_arg=0
+	      );
+ 
+  /*!
+   * The virtual destructor
+   */
+  virtual ~tape_block();
+
+  /*!
+   *\brief Query the block's state.
+   *
+   * If the state is not TBS_OK, the block must be discarded.
+   *\return The block's initialisation state
+   */
+  tb_state_t get_state();
+
+  /*!
+   *\brief Get size of the internal raw data buffer
+   *\return The size of the internal raw data buffer
+   */
+  int get_raw_size();
+
+  /*!
+   *\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 * get_raw_data();
+
+  /*
+   *\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.
+   */
+  virtual int get_type();
+  
+  /*!
+   *\brief Determine the block's subtype
+   *
+   * Some data block types have a subtype. This can be determined this way.
+   *\return Block subtype if the block object is of a suitable subclass
+   */
+  virtual int get_subtype();
+
+private:   // methods
+  /*!
+   *\brief Initialize word representation of data
+   *\retval 0 on success
+   *\retval 1 on error
+   */
+  int init_words(void);
+
+  /*!
+   *\brief Calculate and check checksum
+   *\retval 0 on success
+   *\retval 1 on error
+   */
+  int test_checksum(); 
+
+protected: // members
+  int block_type;             //!< type of this block
+  tb_state_t init_state;      //!< Initialisation state
+  int data_read;              //!< Total data consumption during intialisation
+  unsigned char * raw_data;   //!< Raw block data in bytes
+  int raw_size;               //!< Size of the raw data
+  unsigned short * word_data; //!< Data organized in machine words
+  int word_size;              //!< Size of the blocks in machine words
+
+}; // tape_block
+
+
+#endif