mORMot Open Source

Thank you very much,
I did not know how to change the page count of a newly created :Memory: db.
I found a different solution, similar to your decryption:
(overwriting WINRead) in SynSQLite3

Copying everything to a MemoryStream, and WinRead gets the data from this stream:
(it works read only and only for one db, filename in SpeiFnam)

********************************************
var SpeiHandle:THandle;
    SpeiStream:TMemoryStream;
    SpeiFnam:String;

function GetFileSize(hFile: THandle; lpFileSizeHigh: Pointer): DWORD; stdcall;
var siz:Int64;
begin
  siz:=SpeiStream.Size;
  Result:= Int64Rec(siz).Lo;
  PCardinal(lpFileSizeHigh)^:= Int64Rec(siz).Hi;
end;

function LockFile(hFile: THandle; dwFileOffsetLow, dwFileOffsetHigh: DWORD;
  nNumberOfBytesToLockLow, nNumberOfBytesToLockHigh: DWORD): BOOL;  stdcall;
begin
  Result:=True;
end;
function LockFileEx(hFile: THandle; dwFlags, dwReserved: DWORD;
  nNumberOfBytesToLockLow, nNumberOfBytesToLockHigh: DWORD;
  const lpOverlapped: TOverlapped): BOOL; stdcall;
begin
  Result:=True;
end;
function UnlockFile(hFile: THandle; dwFileOffsetLow, dwFileOffsetHigh: DWORD;
  nNumberOfBytesToUnlockLow, nNumberOfBytesToUnlockHigh: DWORD): BOOL;stdcall;
begin
  Result:=True;
end;

function CloseHandle(hObject: THandle): BOOL; stdcall;
begin
  Result:=True;
end;

function WinRead(var F: TSQLFile; buf: PByte; buflen: integer; off: Int64): integer; {$ifndef USEFASTCALL}cdecl;{$endif}
// Read data from a file into a buffer.  Return SQLITE_OK on success
// or some other error code on failure
var offset: Int64Rec;
    aSQLEncryptTable: PByteArray;
    i: integer;
begin
  //SynSQLite3Log.Add.Log(sllCustom2,'WinRead % off=% len=%',[F.h,off,buflen]);

  if SpeiHandle<>F.h then
  begin
    SpeiStream:=TMemoryStream.Create;
    SpeiStream.LoadFromFile( SpeiFnam);
    SpeiHandle:=F.h;
    Windows.CloseHandle(F.h);
  end;

  offset.Lo := Int64Rec(off).Lo;
  offset.Hi := Int64Rec(off).Hi and $7fffffff; // offset must be positive (u64)

  SpeiStream.Position:=off;
  cardinal(Result):= SpeiStream.Read(buf^,buflen);
  if Result=0 then
  if buflen>0 then
  begin
      result := SQLITE_FULL;
      exit;
  end;
...