OpenEuphoria

Re: Changing data types, Continued

• Posted by "H.W Overman" <euman at bellsouth.net> Mar 22, 2004
• 407 views

Kat,

This was a preliminary version I wrote for Allen back at the beginning
of his project, I have several versions I sent him but this one is what
you would probably be interested in...

Two parts (.exw programs) are here, one to create and write the file, the
other to read the file...

I hope I hadnt changed anything to screw this up over time, Im in Linux right
now so I cant test it but it should still be ok... 
Note: possible to tweak further!

-- Code part 1

-- PART 1 speedread_write.exw creates the 8mg file

-- SpeedRead_write Binary file in Windows
-- Euman 2004
-- Based on Allen V. Robnett's idea for nodes rambase

without type_check
without trace
without warning

include get.e

integer fn, fp, x

constant max_node_level = 20

fn = -1
while fn=-1 do
  fn = open("nodes.dat", "rb")
  if fn=-1 then
     puts(1,"No Nodes file. Create it (Y/N)? \n")    
     x = wait_key()
     if x='y' or x='Y' then
        fn = open("nodes.dat", "wb")
        puts(1,"Creating node table...Please wait\n")
        for i=1 to power(2, max_node_level) do
            for j = 1 to 8 do
                puts(fn, '_')
            end for  
        end for
        puts(1,"Done...\n")
        close(fn)
     end if
  else
  close(fn)
  end if
  exit  
end while

-- PART 2 speedread.exw reads written file from output of above code

-- SpeedRead Binary file in Windows
-- LOOK FOR: pass name of file (below) and .dat file containing 8mg
-- Euman 2004
-- W/ minor tweak by Tommy Carlier noted below

without type_check
with trace

include machine.e
include file.e
include dll.e

atom t1, t2, fn, lFileLen, result
sequence lFile, line
integer char

atom kernel32
kernel32 = open_dll("kernel32.dll")

constant
xCreateFile = define_c_func(kernel32,"CreateFileA",
{C_POINTER,C_LONG,C_LONG,C_POINTER
,C_LONG,C_LONG,C_INT},C_LONG),
xReadFile = define_c_func(kernel32,"ReadFile",
{C_INT,C_POINTER,C_UINT,C_POINTER,
C_POINTER},C_LONG)

global constant 
  GENERIC_READ             = #80000000,
  FILE_ATTRIBUTE_NORMAL    = #80,
  FILE_FLAG_SEQUENTIAL_SCAN= #8000000,
  OPEN_EXISTING            = 3

atom hFile
  
global function CreateFile(sequence fname)
atom FileName 
     FileName = allocate_string(fname)
     hFile = c_func(xCreateFile,{FileName,
                                GENERIC_READ,
                                0,
                                NULL,
                                OPEN_EXISTING,
                                FILE_ATTRIBUTE_NORMAL+FILE_FLAG_SEQUENTIAL_SCAN,
                                NULL})
    return hFile
end function

atom lpNumberOfBytesRead
lpNumberOfBytesRead = allocate(4) --lpNumberOfBytesRead

function ReadFile(atom hFile, atom lpBuffer, atom nNumberOfBytesToRead)
  return c_func(xReadFile,
{hFile,lpBuffer,nNumberOfBytesToRead,lpNumberOfBytesRead,
0})
end function

sequence yourfile
yourfile = "nodes.dat" -- pass name of file

fn = open(yourfile, "r") 
lFileLen = seek(fn, -1)                                 
lFileLen = where(fn)
close(fn)

atom lpFileBuff, cIN, cIndex, cMaxIndex
lpFileBuff = allocate(lFileLen)
cIN = 0

t1 = time()
hFile = CreateFile(yourfile) 
result = ReadFile(hFile, lpFileBuff, lFileLen) 

-- we havent checked lpNumberOfBytesRead perhaps you may want to
-- compare this to lFileLen before you start the loop, in this case
-- the file is pretty small. '8,000,000 chars'

-- Plus, this assumes binary read and no crlf chars exist
trace(1)
line = repeat(0, lFileLen / 8)
atom lIndex

if result then
      
   cMaxIndex = lpFileBuff + lFileLen
   cIndex = lpFileBuff
   lIndex = 1
   
  -- tweak by Tommy Carlier
   while cIndex < cMaxIndex do
      line[lIndex] = peek({cIndex, 8})
      cIndex += 8
      lIndex += 1
   end while
     
end if
free(lpFileBuff)

-- take trace out to get correct speed!
t2 = time()- t1                                 
printf(1,"Average Time : %1.4f sec\n", t2 )

if getc(0) then end if

-- END CODES

Euman

On Monday 22 March 2004 11:17 am, Kat wrote:
> On 22 Mar 2004, at 10:35, H.W Overman wrote:
> >
> > > I am very interested in seeing code for how you are loading and
> > > accessing 200meg file in ram now.
> > >
> > > Kat,
> >
> > Sure Kat, I wrote it! Allen shouldve mentioned that...
>
> I did a search in the RDS archives for Euman and Overman, and nothing
> showed on the memory stash code. I remember you were doing something
> about this, or someone was, last year, i think.
>
> Kat,
> looking interested,
> powered by caffine and cheetoes.

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