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    Length: 10752 (0x2a00)
    Types: TextFile
    Names: »ACCESS3.BOX«

└─⟦5e4548e7d⟧ Bits:30005778 Turbo Pascal v.3.01A (CP/M-86)
    └─ ⟦this⟧ »ACCESS3.BOX« 

TextFile

(***********************************************************)
(*                                                         *)
(*           TURBO-access version 3.00 (CP/M-86)           *)
(*                                                         *)
(*                       ACCESS module                     *)
(*                                                         *)
(*               TURBO Pascal 3.00 or later                *)
(*                                                         *)
(*                   Copyright (C) 1984,85 by              *)
(*                        BORLAND Int.                     *)
(*                                                         *)
(***********************************************************)
æ
  This module is provided as an update for TURBO TOOLBOX programmers.

    Use  ACCESS.BOX when compiling with TURBO 2.0.
    Use ACCESS3.BOX when compiling with TURBO 3.0.

  For information about TURBO TOOLBOX, please refer to the product
  descriptions in the back of your Version 3.0 Reference Manual.

å

(*$A+,I-,R-*)

type
  TaStr14   =  stringÆ14Å;
  DataFile  =  record
               case Integer of
                 0 : (F          : file of Byte;
                      FirstFree,
                      NumberFree,
                      Int1,
                      Int2       : Integer);
                 1 : (Fil1,
                      NewRec,
                      RecL,
                      Fil2,
                      TaRec,
                      Fil3       : Integer;
                      TaDrive    : Byte;
                      TaName     : arrayÆ1..8Å of Char;
                      TaType     : arrayÆ1..3Å of Char);
               end;
  TaKeyStr  =  stringÆMaxKeyLenÅ;
  TaItem    =  record
                 DataRef,PageRef : Integer;
                 Key : TaKeyStr;
               end;
  TaPage    =  record
                 ItemsOnPage : 0..PageSize;
                 BckwPageRef : Integer;
                 ItemArray   : arrayÆ1..PageSizeÅ of TaItem;
               end;
  TaPagePtr =  ^TaPage;
  TaSearchStep =
               record
                 PageRef,ItemArrIndex : Integer;
               end;
  TaPath    =  arrayÆ1..MaxHeightÅ of TaSearchStep;
  IndexFile =  record
                 DataF         : DataFile;
                 AllowDuplKeys : Boolean;
                 KeyL,RR,PP    : Integer;
                 Path          : TaPath;
               end;
  IndexFilePtr = ^IndexFile;
  TaStackRec =
               record
                 Page      : TaPage;
                 IndexFPtr : IndexFilePtr;
                 PageRef   : Integer;
                 Updated   : Boolean;
               end;
  TaStackRecPtr = ^TaStackRec;
  TaPageStack = arrayÆ1..PageStackSizeÅ of TaStackRec;
  TaPageMap  =  arrayÆ1..PageStackSizeÅ of Integer;
  TaRecordBuffer  =
               record
                 case Integer of
                   0 : (Page : TaStackRec);
                   1 : (R : arrayÆ1..MaxDataRecSizeÅ of Byte);
               end;

var
  IOstatus  : Integer;
  OK        : Boolean;
  TaRecBuf  : TaRecordBuffer;
  TaPageStk : TaPageStack;
  TaPgMap   : TaPageMap;


procedure TaIOcheck(var DatF : DataFile; R : Integer);
begin
  if IOstatus <> 0 then with DatF do
  begin
    Writeln;
    Writeln('TURBO-access I/O error ',IOstatus);
    Writeln('file ',Chr(TaDrive + 64),':',TaName,'.',TaType,' record ',R);
    Writeln('Program terminated');
    Halt;
  end;
end;

procedure GetRec(var DatF   : DataFile;
                     R      : Integer;
                 var Buffer           );
var
  B : Byte absolute Buffer;
begin
  Seek(DatF.F,R);
  Read(DatF.F,B);
  IOstatus := IOresult;
  TaIOcheck(DatF,R);
end;

procedure PutRec(var DatF   : DataFile;
                     R      : Integer;
                 var Buffer           );
var
  B : Byte absolute Buffer;
begin
  Seek(DatF.F,R);
  Write(DatF.F,B);
  IOstatus := IOresult;
  TaIOcheck(DatF,R);
end;

procedure MakeFile(var DatF   : DataFile;
                       FName  : TaStr14;
                       RecLen : Integer);
begin
  Assign(DatF.F,FName);
  IOstatus:=IOresult;
  TaIOcheck(DatF, 0);
  Rewrite(DatF.F);
  IOstatus := IOresult;
  if IOstatus = $F1 then
    OK := false
  else
  begin
    TaIOcheck(DatF,0);
    DatF.RecL := RecLen;
    DatF.FirstFree := -1;
    DatF.NumberFree := 0;
    DatF.Int1 := 0;
    DatF.Int2 := 0;
    Move(DatF.FirstFree,TaRecBuf,8);
    PutRec(DatF,0,TaRecBuf);
    OK := true;
  end;
end;

procedure OpenFile(var DatF   : DataFile;
                       FName  : TaStr14;
                       RecLen : Integer);
begin
  Assign(DatF.F,FName);
  IOstatus:=IOresult;
  TaIOcheck(DatF, 0);
  Reset(DatF.F);
  IOstatus := IOresult;
  OK:=(IOstatus = 0) or (IOstatus = $90);
  if OK then
  begin
    DatF.RecL := RecLen;
    GetRec(DatF,0,TaRecBuf);
    Move(TaRecBuf,DatF.FirstFree,8);
  end;
end;

procedure CloseFile(var DatF : DataFile);
begin
  Move(DatF.FirstFree,TaRecBuf,8);
  PutRec(DatF,0,TaRecBuf);
  Close(DatF.F);
  IOstatus := IOresult;
  TaIOcheck(DatF,0);
end;

procedure AddRec(var DatF  : DataFile;
                 var R     : Integer;
                 var Buffer           );
begin
  if DatF.FirstFree =  - 1 then
    R := DatF.NewRec
  else
  begin
    R := DatF.FirstFree;
    GetRec(DatF,R,TaRecBuf);
    Move(TaRecBuf,DatF.FirstFree,2);
    DatF.NumberFree := DatF.NumberFree - 1;
  end;
  PutRec(DatF,R,Buffer);
end;

procedure DeleteRec(var DatF : DataFile;
                        R    : Integer);
begin
  Move(DatF.FirstFree,TaRecBuf,2);
  PutRec(DatF,R,TaRecBuf);
  DatF.FirstFree := R;
  DatF.NumberFree := DatF.NumberFree + 1;
end;

function FileLen(var DatF : DataFile) : Integer;
begin
  FileLen := DatF.NewRec;
end;

function UsedRecs(var DatF : DataFile) : Integer;
begin
  UsedRecs := DatF.NewRec - DatF.NumberFree - 1;
end;

procedure InitIndex;
var
  I : Integer;
begin
  for I := 1 to PageStackSize do
  begin
    TaPageStkÆIÅ.IndexFPtr := nil;
    TaPageStkÆIÅ.Updated := false;
    TaPgMapÆIÅ := I;
  end;
end;

procedure TaPack(var Page : TaPage;
                     KeyL : Integer);
var
  I : Integer;
  P : arrayÆ0..MaxIntÅ of Byte absolute Page;
begin
  if KeyL <> MaxKeyLen then
    for I := 1 to PageSize do
      Move(Page.ItemArrayÆIÅ,PÆ(I - 1) * (KeyL + 5) + 3Å,KeyL + 5);
end;

procedure TaUnpack(var Page : TaPage;
                       KeyL : Integer);
var
  I : Integer;
  P : arrayÆ0..MaxIntÅ of Byte absolute Page;
begin
  if KeyL <> MaxKeyLen then
    for I := PageSize downto 1 do
      Move(PÆ(I - 1) * (KeyL + 5) + 3Å,Page.ItemArrayÆIÅ,KeyL + 5);
end;

procedure MakeIndex(var IdxF   : IndexFile;
                        FName  : TaStr14;
                        KeyLen,
                        S      : Integer);
var
  K : Integer;
begin
  K := (KeyLen + 5)*PageSize + 3;
  MakeFile(IdxF.DataF,FName,K);
  IdxF.AllowDuplKeys := S <> 0;
  IdxF.KeyL := KeyLen;
  IdxF.RR := 0;
  IdxF.PP := 0;
end;

procedure OpenIndex(var IdxF   : IndexFile;
                        FName  : TaStr14;
                        KeyLen,
                        S      : Integer);
var
  K : Integer;
begin
  K := (KeyLen + 5) * PageSize + 3;
  OpenFile(IdxF.DataF,FName,K);
  IdxF.AllowDuplKeys := S <> 0;
  IdxF.KeyL := KeyLen;
  IdxF.RR := IdxF.DataF.Int1;
  IdxF.PP := 0;
end;

procedure CloseIndex(var IdxF : IndexFile);
var
  I : Integer;
begin
  for I := 1 to PageStackSize do
    with TaPageStkÆIÅ do
      if IndexFPtr = Addr(IdxF) then
      begin
        IndexFPtr := nil;
        if Updated then
        begin
          TaPack(Page,IdxF.KeyL);
          PutRec(IdxF.DataF,PageRef,Page);
          Updated := false;
        end;
      end;
  IdxF.DataF.Int1 := IdxF.RR;
  CloseFile(IdxF.DataF);
end;

procedure TaLast(I : Integer);
var
  J,K : Integer;
begin
  J := 1;
  while (TaPgMapÆJÅ <> I) and (J < PageStackSize) do
    J := J + 1;
  for K := J to PageStackSize - 1 do
    TaPgMapÆKÅ := TaPgMapÆK + 1Å;
  TaPgMapÆPageStackSizeÅ := I;
end;

procedure TaGetPage(var IdxF  : IndexFile;
                        R     : Integer;
                    var PgPtr : TaPagePtr);
var
  I,J,K : Integer;
  Found : Boolean;
begin
  Found := false;
  for J := 1 to PageStackSize do
    if not Found then
      with TaPageStkÆJÅ do
        if (IndexFPtr = Addr(IdxF)) and
           (PageRef = R)                 then
  begin
    I := J;
    Found := true;
  end;
  if not Found then
  begin
    I := TaPgMapÆ1Å;
    with TaPageStkÆIÅ do
    begin
      if Updated then
      begin
        TaPack(Page,IndexFPtr^.KeyL);
        PutRec(IndexFPtr^.DataF,PageRef,Page);
      end;
      GetRec(IdxF.DataF,R,Page);
      TaUnpack(Page,IdxF.KeyL);
      IndexFPtr := Addr(IdxF);
      PageRef := R;
      Updated := false;
    end;
  end;
  TaLast(I);
  PgPtr := Addr(TaPageStkÆIÅ);
end;

procedure TaNewPage(var IdxF  : IndexFile;
                    var R     : Integer;
                    var PgPtr : TaPagePtr);
var
  I : Integer;
begin
  I := TaPgMapÆ1Å;
  with TaPageStkÆIÅ do
  begin
    if Updated then
    begin
      TaPack(Page,IndexFPtr^.KeyL);
      PutRec(IndexFPtr^.DataF,PageRef,Page);
    end;
    AddRec(IdxF.DataF,R,Page);
    IndexFPtr := Addr(IdxF);
    PageRef := R;
    Updated := false;
  end;
  TaLast(I);
  PgPtr := Addr(TaPageStkÆIÅ);
end;

procedure TaUpdatePage(PgPtr : TaPagePtr);
var
  P : TaStackRecPtr absolute PgPtr;
begin
  P^.Updated := true;
end;

procedure TaReturnPage(var PgPtr : TaPagePtr);
var
  P : TaStackRecPtr absolute PgPtr;
begin
  with P^ do
  begin
    DeleteRec(IndexFPtr^.DataF,PageRef);
    IndexFPtr := nil;
    Updated := false;
  end;
end;

procedure TaXKey(var K;
                     KeyL : Integer);
var
  Key : TaKeyStr absolute K;
begin
  if Ord(KeyÆ0Å) > KeyL then KeyÆ0Å := Chr(KeyL);
end;

function TaCompKeys(var K1,
                        K2;
                        DR1,
                        DR2 : Integer;
                        Dup : Boolean ) : Integer;
var
  Key1 : TaKeyStr absolute K1;
  Key2 : TaKeyStr absolute K2;
begin
  if Key1 = Key2 then
    if Dup then
      TaCompKeys := DR1 - DR2
    else TaCompKeys := 0
  else
    if Key1 > Key2 then
      TaCompKeys := 1
    else TaCompKeys :=  - 1;
end;

procedure ClearKey(var IdxF : IndexFile);
begin
  IdxF.PP := 0;
end;

«eof»