File Search speed


I have to search thru 2000 file names looking for a specific one and its really slow. I started with this code:

If f <> Nil then u = f.Count for i = 1 to u if not f.item(i).Directory Then TheFileName = f.Item(i).DisplayName if Instr(TheFileName,BoardCards) > 0 Then FoundIt = 1 end if if FoundIt = 1 then exit Next end

but it took 32 seconds to complete the search.

I then tried putting the filenames into an array first then searching but it still took 10 seconds:

[code]If f <> Nil then
u = f.Count
for i = 1 to u
if not f.item(i).Directory Then
TheFiles(i) = f.Item(i).DisplayName
end if

for i = 1 to u
TheFileName = TheFiles(i)
if Instr(TheFileName,BoardCards) > 0 Then FoundIt = 1
if FoundIt = 1 then exit

Any ideas on how to make this faster? This is really bogging my program down. Any help would be appreciated.


Using the collection of files in Xojo’s folderitem is slow.

If you are on Windows, one technique I have seen used is to shell out to a command, and do a

Then open LISTOFFILES.TXT as a textinput stream, reading the lot into a string.
And use INSTR() on the string.

or perhaps

DIR searchstring.* > LISTOFFILES.TXT to get DOS to do the wildcard search for you!

I imagine a similar technique is possible in OSX using a command such as ls

Hi Jeff. I will try the shell wildcard search and report back. thanks for the info!

from somewhere-I-dont-remember of this forum…


Function ItemNames(extends f as folderItem, ReturnFileNames as boolean = true, ReturnFolderNames as boolean = true) As String()
// Returns an array containing the names of child items
// within the given folder item. Returns files and/or
// folders, as directed by the input booleans.
// Returns an empty array if f doesn’t exist, or if f
// isn’t a directory, or if both input booleans are false.
// The iteration is not recursive. On Windows, the special
// directories “.” and “…” are ignored.

dim result() as string

if f.Directory then

#if TargetWin32
  // On Windows, RB's f.Item(i) is slow for folders with large
  // child item counts, so we use Declares on Windows instead.
  // Adapted from Aaron Ballman - see
  Soft Declare Function FindFirstFileA Lib "Kernel32" (path as CString, data as Ptr) as Integer
  Soft Declare Function FindFirstFileW Lib "Kernel32" (path as WString, data as Ptr) as Integer
  Soft Declare Function FindNextFileA Lib "Kernel32" (handle as Integer, data as Ptr) as Boolean
  Soft Declare Function FindNextFileW Lib "Kernel32" (handle as Integer, data as Ptr) as Boolean
  Declare Sub FindClose Lib "Kernel32" (handle as Integer)
  dim UnicodeIsAvailable as boolean = System.IsFunctionAvailable("FindFirstFileW", "Kernel32")
  dim ChildData as MemoryBlock // WIN32_FIND_DATA struct
  dim ChildHandle as integer
  if UnicodeIsAvailable then
    ChildData = new MemoryBlock(592)
    ChildHandle = FindFirstFileW(f.AbsolutePath + "*.*", ChildData)
    ChildData = new MemoryBlock(318)
    ChildHandle = FindFirstFileA(f.AbsolutePath + "*.*", ChildData)
  end if
  if ChildHandle <> -1 then
    dim ChildAttrs as UInt32 // first 4 bytes of WIN32_FIND_DATA
    dim ChildName as string
    // Loop through remaining items in the folder.
    dim FoundNextChild as Boolean
    do // loop through remaining children
      ChildAttrs = ChildData.UInt32Value(0)
      const NameOffset = 44
      if UnicodeIsAvailable then
        ChildName = ChildData.WString(NameOffset)
        FoundNextChild = FindNextFileW(ChildHandle, ChildData)
        ChildName = ChildData.CString(NameOffset)
        FoundNextChild = FindNextFileA(ChildHandle, ChildData)
      end if
      // Now that we have its name and attributes, we can decide
      // whether this child should be added to our return array.
      dim ChildIsFolder as boolean = (ChildAttrs and UInt32(16)) <> 0
      if (ReturnFileNames and not ChildIsFolder) or _
        (ReturnFolderNames and ChildIsFolder) then
        if childName <> "." and childName <> ".." then
        end if
      end if
    loop until not FoundNextChild // should really test GetLastError for ERROR_NO_MORE_FILES
    FindClose ChildHandle
  end if
  // On non-Windows systems, pure RB code seems pretty fast.
  dim child as FolderItem, ub as Integer = F.Count
  for i as integer = 1 to ub
    child = f.TrueItem(i)
    if (ReturnFileNames and not Child.Directory) or _
      (ReturnFolderNames and Child.Directory) then
      result.Append child.Name
    end if
  next i

end if

return result

End Function[/code]

Hey! That method above was nearly instant! thanks for the code :slight_smile:

just seeing the code again, may be it will not work for 64 bits (windows) …

Works just fine on 64 bits Windows 10, no problem at all.

the code came from here :