⟦09615f113⟧

TextFile

(**************************************************************************)
--
--   RC3502 Local File System Access Method
--
--   Name:   Local File system on rc3502 ENVironment
--   Author: Bo Bagger /bb
--
(**************************************************************************)

lf3502env;

-- 861125 bb 1.1 First version.
-- 870306 bb 1.2 Lf_init introduced.
-- 870317 bb 1.3 Lf_entry_info_type and lf_file_info_type opened.
-- 870319 bb 1.4 Lf_exceptions extended to 16 exceptions.
-- 870320 bb 1.5 Lf_reset and lf_rewrite changed to set the filepointer
--               to zero.
-- 870327 bb 1.6 Lf_set_mode introduced.
-- 870511 bb 1.7 Lf_test introduced.
-- 871215 bb 1.8 Lf_conname introduced.
--               Position outside file trickers exception now,
--               no rounding takes place.
--               Patname_size extended from 40 to 64 bytes (FTAM).
--               The 'bytes' parameter removed from lf_create.
--               The type of lf_ioresult changed from integer to byte.
--               Besides the sequence in declarations is reorganized .
-- 890512 bb 1.9 The type lf_entry_info_type for user scan of catalogs
--               extended to correct size.
--               User programs using this type and lf_lookup and lf_set_tail
--               must recompile.


(**************************************************************************)
--
--               SHORT DESCRIPTION
--
(**************************************************************************)

-- The LF3502 access method defines a datafile
-- as a sequence of bytes numbered according
-- to the bufferconventions 0 .. length-1.
-- The access method is built on top of the
-- block oriented RC-FS File System Nucleus.
-- Files are controlled via objects of type ZONE,
-- which are defined in IOENVIR. 
-- The environment IOENVIR must occur before LF3502ENV
-- when compiling.
-- An open file is associated a file pointer,
-- which points to the byte position,
-- where the next read- or write operation
-- will be commenced.
-- After the operation, the file pointer will
-- be updated accordingly.
-- The following routines realizes both sequential
-- and random access.
-- It should be noticed, that besides the read- and write routines
-- mentioned below, the existing zone procedures for
-- character reading and writing,
-- defined in IOENVIR, may be used.
-- A pathname is a sequence of entrynames separated by "/".
-- If a pathname begins with a "/", the first entryname
-- is searched for in the rootcatalog, i.e. the pathname is absolute.
-- If a pathname doesn't begin with a "/", the pathname is relativ
-- to the current catalog (curcat).
-- Some entrynames are especial:
--   .     refers to current catalog (lf_ownname).
--   ..    refers to the parent catalog (lf_parentname).
--   'con' refers to the RC3502 console (lf_conname).
-- A file is automatically extended during writing.
-- If extension is impossible by various reasons,
-- you may be hit by an exception. To avoid that,
-- a file may be explicitly extended by a call of
-- the routine LF_EXTEND before writing.
-- I/O control may be defined at run time. The procedures
-- LF_DISABLE and LF_ENABLE switches I/O exceptions off and on
-- during run time.
-- If exceptions are disabled the latest I/O result on a zone
-- may be optained by a call of LF_IORESULT.
--
-- Note however, that LF_DISABLE and LF_ENABLE has no effect in
--      the current version of LF3502.


(**************************************************************************)
--
--               CONSTANTS AND TYPES
--
(**************************************************************************)

const
  lf_identifier_size = 16;
type
  lf_identifier = array(1..lf_identifier_size) of char;
const
  lf_noname     = lf_identifier (lf_identifier_size *** " ");
  lf_ownname    = '. ';
  lf_parentname = '..';
  lf_conname    = 'con';
  lf_delimiter  = "/";

const
  lf_pathname_size = 64;
type
  lf_pathname = array (1..lf_pathname_size) of char;
  
type
  lf_authorities = (lf_read_authority,
                  lf_write_authority,
                  lf_adjust_authority,
                  lf_delete_authority,
                  lf_authorize_authority);
  lf_authority_type =
    record
      authorizations,
      inheritable,
      protections: set of lf_authorities;
    end;
const
  lf_maxauthorities= (.lf_read_authority,
                       lf_write_authority,
                       lf_adjust_authority,
                       lf_delete_authority,
                       lf_authorize_authority.);
  lf_maxauthority = 
    lf_authority_type (lf_maxauthorities,
                       lf_maxauthorities,
                       lf_maxauthorities);
type
  lf_accessmode = (lf_read,lf_write,lf_exclusive);

type
  lf_entrytype_type = (lf_datafile, lf_catalog);

type
  lf_exceptions =(lf_exception1 ,lf_exception2 ,lf_exception3 ,lf_exception4,
                  lf_exception5 ,lf_exception6 ,lf_exception7 ,lf_exception8,
                  lf_exception9 ,lf_exception10,lf_exception11,lf_exception12,
                  lf_exception13,lf_exception14,lf_exception15,lf_exception16);

type
  lf_time =
    record
      date: coded_date;
      time: coded_time;
    end;

const
  lf_entry_tail_size = 5; (* bytes *)
type
  lf_entry_tail_type = array(1..lf_entry_tail_size) of byte;
  lf_entry_info_type =
    record
      name      : lf_identifier;
      authority : lf_authority_type;
      ?, ?      : integer;
      entrytype : lf_entrytype_type;
      tail      : lf_entry_tail_type;
    end;
const
-- size of an entry in a catalog file
  lf_entry_info_size = typesize (lf_entry_info_type);

const
  lf_file_tail_size = 8;
type
  lf_file_tail_type = 
    record
      length   : double;
      contents : integer;
      not_used : array ((typesize (double)+typesize (integer)+1)..lf_file_tail_size) of byte;
    end;

  lf_file_info_type =
    record
      written:    double;
      allocated:  double;
      creation:   lf_time;
      last_write: lf_time;
      tail:       lf_file_tail_type;
    end;


(**************************************************************************)
--
--               INITIALIZATION
--
(**************************************************************************)

procedure lf_init
   (max_files : integer);
external;
-- Configurates the access method to the requested 
-- maximum number of simultanously opened files.
-- If zero is specified a default number is taken.
-- If not called before the first file is opened,
-- lf_init is implicitly called.

(**************************************************************************)
--
--               CATALOG HANDLING
--
(**************************************************************************)

procedure lf_select
  (var pathname : ! lf_pathname;
   mode : set of lf_accessmode;
   var result : byte);
external;
-- Places the current catalog pointer (curcat)
-- at a new catalog described by pathname.
-- The already opened files are not disturbed.

procedure lf_deselect;
external;
-- Sets the curcat pointer to nil.

procedure lf_lookup
  (var name : ! lf_identifier;
   var entry: lf_entry_info_type;
   var descriptor: lf_file_info_type;
   var result: byte);
external;
-- The entry identified by 'name' is looked up in curcat.
-- Exception if the curcat pointer is nil.

(**************************************************************************)
--
--               FILE HANDLING
--
(**************************************************************************)

procedure lf_open
  (var file: zone;
   var name : ! lf_identifier;
   mode: set of lf_accessmode);
external;
-- If exception is disabled the result may be obtained
-- by a call of LF_IORESULT.
-- If mode contains lf_write and the file does not
-- exist in curcat, the file is created in curcat.
-- Otherwise exception 'file does not exist' will occur.
-- Exception if already opened.
-- Catalogs may be opened for reading, not for writing.
-- After the call the filepointer equals zero.

procedure lf_reset
  (var file: zone);
external;
-- The zonestate is changed to read_mode.
-- Current filepointer is set to zero.
-- Exception if the file is not opened.

procedure lf_rewrite
  (var file: zone);
external;
-- The zonestate is changed to write_mode.
-- Current filepointer and length are set to zero.
-- Exception if the file is not opened.

procedure lf_set_mode
  (var file : zone;
   mode : lf_accessmode);
external;
-- The zonestate is changed to mode.
-- Current filepointer is not changed.
-- Exception if the file is not opened.

procedure lf_close
  (var file: zone);
external;
-- The file is closed. 
-- The call is dummy if the file is already closed.
-- The routine LF_FLUSH must be called prior to the
-- call of LF_CLOSE, if you want to ensure, that
-- all data is written to disc.

procedure lf_create
  (var name: ! lf_identifier;
       authority: lf_authority_type; 
       entrytype: lf_entrytype_type;
   var result: byte);
external;
-- A file of type 'entrytype' is created in curcat.

procedure lf_delete
  (var name : ! lf_identifier;
   var result: byte);
external;
-- The entry identified by 'name' is deleted from curcat.

procedure lf_link
  (var name : ! lf_identifier;
   var pathname: ! lf_pathname;
   var result: byte);
external;
-- In curcat an entry is inserted, pointing
-- to the same file as 'pathname'.

procedure lf_rename
  (var name: ! lf_identifier;
   var oldname : ! lf_identifier;
   var result: byte);
external;
-- Renaming of a file in curcat.

procedure lf_extend
  (var name : ! lf_identifier;
   bytes: double;
   var result: byte);
external;
-- Extends a file in curcat with 'bytes' bytes.
-- The file must be closed.

procedure lf_truncate
  (var name : ! lf_identifier;
   bytes: double;
   var result: byte);
external;
-- Truncates the file in curcat with 'bytes' bytes.
-- The file must be closed.
   
procedure lf_set_tail
  (var name : ! lf_identifier;
   var entry: ! lf_entry_info_type;
   var descriptor: ! lf_file_info_type;
   var result: byte);
external;

(**************************************************************************)
--
--               FILE POSITIONING
--
(**************************************************************************)

function lf_eof
  (var file: zone): boolean;
external;
-- True if current filepointer is at the end of the file,
-- i.e. points at position 'length',
-- otherwise false.
-- Exception if the file is not opened.

function lf_length
  (var file : zone) : double;
external;
-- Returns the length of the file in bytes.
-- The length may also be obtained by a call
-- of LF_LOOKUP.
-- Exception if the file is not opened.

procedure lf_offset
  (var file : zone;
   offset : double);
external;
-- Relative updating of current filepointer.
-- Exception if 'position' is outside the file.
-- Exception if the file is not opened.

function lf_position
  (var file : zone) : double;
external;
-- Returns the current value of the filepointer.
-- Exception if the file is not opened.

procedure lf_seek
  (var file : zone; 
   position : double); 
external;
-- Sets the current filepointer to the value 'position'.
-- The first byte in the file has position 0.
-- The last byte in the file has position length-1.
-- Exception if 'position' is outside the file.
-- Exception if the file is not opened.

(**************************************************************************)
--
--               FILE READING AND WRITING
--
(**************************************************************************)

function lf_readblock
  (var file : zone;
   var to_ref : reference;
   to_index : integer;
   bytes : integer) : integer;
external;
-- A maximum of 'bytes' bytes is read to the message 'to_ref'
-- starting at position 'to_index'.
-- The resulting number of bytes is returned.
-- Exception if not read_mode.
-- Exception if the file is not opened.

procedure lf_readbyte
  (var file: zone;
   var b: byte);
external;
-- Exception if reading is past 'end_of_file.
-- Exception if not read_mode
-- Exception if the file is not opened.
-- If exception is disabled LF_IORESULT gives the reason.

procedure lf_readinteger
  (var file: zone;
   var j: integer);
external;
-- Exception if reading is past 'end_of_file.
-- Exception if not read_mode
-- Exception if the file is not opened.
-- If exception is disabled LF_IORESULT gives the reason.

function lf_writeblock
  (var file : zone;
   var from_ref : reference;
   from_index,
   bytes : integer) : integer;
external;
-- The resulting number of bytes is returned.
-- Exception if the file cannot be extended.
-- If exception is disabled, the result
-- may be obtained by a call of LF_IORESULT.
-- Exception if not write_mode.
-- Exception if file is not opened.

procedure lf_writebyte
  (var file: zone;
   b: byte);
external;
-- Exception if the file cannot be extended.
-- If exception is disabled, the result
-- may be obtained by a call of LF_IORESULT.
-- Exception if not write_mode.
-- Exception if file is not opened.

procedure lf_writeinteger
  (var file: zone;
   j: integer);
external;
-- Exception if the file cannot be extended.
-- If exception is disabled, the result
-- may be obtained by a call of LF_IORESULT.
-- Exception if not write_mode.
-- Exception if file is not opened.

(**************************************************************************)
--
--               AUTHORIZATION ENFORCEMENT
--
(**************************************************************************)

procedure lf_set_authority
  (var name : ! lf_identifier;
   authorization: set of lf_authorities;
   var result: byte);
external;
-- If LF_AUTHORIZE_AUTHORITY is contained in the set
-- of authorizations for the entry named 'name',
-- the authorizations are redefined to 'authorization'.

procedure lf_set_inheritance
  (var name : ! lf_identifier;
   inheritable: set of lf_authorities;
   var result: byte);
external;
-- The subset of 'inheritable' authorizations
-- for the entry named 'name' are set to 'inheritable'.

procedure lf_set_protection
  (var name : ! lf_identifier;
   protections: set of lf_authorities;
   var result: byte);
external;
-- The temporary set of protections for the
-- entry named 'name' are redefined to 'protections'.

(**************************************************************************)
--
--               FILE INPUT/OUTPUT CONTROL
--
(**************************************************************************)

procedure lf_flush 
  (var file : zone);
external;
-- After return all the buffers of the file are written to disc.
-- If exception is disabled, the result may be obtained
-- by a call of LF_IORESULT.
-- Dummy if not write_mode.
-- Dummy if not opened.

function lf_ioresult
  (var file : zone) : byte;
external;
-- Returns the result af the last I/O operation
-- performed on the file.
-- If not 'end_of_file', the current result is set to OK,
-- after the call, 

procedure lf_disable
  (mask : set of lf_exceptions);
external;
-- Suppresses lf_exceptions by NOTOK results
-- after I/O operations.
-- The result may be obtained by a call of LF_IORESULT.

procedure lf_enable
  (mask : set of lf_exceptions);
external;
-- Enables exceptions by NOTOK results
-- after I/O operations.
-- All lf_exceptions are enabled as a default.

(**************************************************************************)
--
--               MISCELLANEOUS ROUTINES
--
(**************************************************************************)

procedure lf_test
  (onoff : boolean);
external;
-- Controls generation of testoutput
-- from the lf3502 access methode
-- Default is no testoutput (onoff = false).

(**************************************************************************)
--
--               RESULTS
--
(**************************************************************************)

(* error codes *)
const
  ok=0;
  lf_catconnection      =   35;     lf_fileconnection   =   36;
  lf_name_inexisting    =    6;     lf_name_exists      =    5;
  lf_name_error         =   12;     lf_unauthorized     =   30;
  lf_deleted            =    7;     lf_filelimit        =   29;
  lf_buffersize         =   21;     lf_catalog_full     =   13;
  lf_rejected           =   28;     lf_mount_error      =    9;

  lf_openlimit          =   17;     lf_includelimit     =   18;
  lf_indexlimit         =   15;     lf_flt_overflow     =    8;
  lf_volumelimit        =   16;

  lf_parity             =    2;     lf_harderror        =    3;
  lf_disconnected       =   25;

  lf_version            =   22;     lf_not_implemented  =   23;
  lf_software           =   14;

(***** end lf3502env *****)
.
▶EOF◀
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⟦09615f113⟧ TextFile

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