[bb] Check Free Disk Space by Danny [ 1+ years ago ]

[BlitzBot]

Title : Check Free Disk Space
Author : Danny
Posted : 1+ years ago

Description : The routine below is based on Yasha's example in the forum.
See here: <a href="../Community/postsea57.html?topic=97357" target="_blank">http://www.blitzbasic.com/Community/posts.php?topic=97357[/url]

It may help you when you want to check that there's enough space left on a given device before saving an amount of data to it. Since B3D doesn't support long integers, it can only check up to a specific max of 2.1 Gb being free - or not.
Also note that you should supply the path you intend to write data to, not just the drive, since some windows configurations might use user-based disk quotas. See here for more info on that: <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/aa364937(v=vs.85).aspx" target="_blank">http://msdn.microsoft.com/en-us/library/windows/desktop/aa364937%28v=vs.85%29.aspx[/url]

Enjoy.

Danny

Code :

Code: BlitzBasic

1. ; Add to Kernal32.decls:
2. ;
3. ; .lib "Kernel32.dll"
4. ; API_GetDiskFreeSpaceEx%(lpDirectoryName$, lpFreeBytesAvailable*, lpTotalNumberOfBytes*, lpTotalNumberOfFreeBytes*) : "GetDiskFreeSpaceExA"
5.  
6.  
7. Type LongInt
8.         Field a%, b%
9. End Type
10.  
11. Function HasFreeSpace%(path$, minFreeBytes%)
12.        
13.         ;# Returns TRUE (1), FALSE(0) or -1 when path not found/accessible/mounted
14.         ;
15.         ;# Max bytes that can be tested is 2,147,483,647 bytes (=2.1Gb = 2048 Mb)
16.         ;# Thus always returns TRUE if more than 2.1Gb is free!
17.        
18.         If minFreeBytes < 0 Then minFreeBytes = ((2048 *1024) *1024) -1
19.        
20.         GFS_out_FABytes.LongInt = New LongInt
21.         GFS_out_TotBytes.LongInt = New LongInt
22.         GFS_out_TFBytes.LongInt = New LongInt
23.        
24.         Local ret% = False
25.        
26.         If API_GetDiskFreeSpaceEx(path, GFS_out_FABytes, GFS_out_TotBytes, GFS_out_TFBytes)
27.                
28.                 If GFS_out_FABytes <> 0
29.                         ; when B <> 0 then MORE than 4.2Gb free
30.                         ret = True
31.                 ElseIf (GFS_out_FABytes = 0) And (GFS_out_FABytesa < 0)
32.                         ; when B = 0, A < 0, MORE than 2.1Gb free
33.                         ret = True
34.                 ElseIf GFS_out_FABytesa > minFreeBytes Then
35.                         ; A contains remaining bytes free
36.                         ret = True
37.                 Else
38.                         ; NOT ENOUGH SPACE FREE!
39.                         ret = False
40.                 EndIf
41.                
42.         Else
43.                 ; Path not found, drive doesn't exist or media not mounted
44.                 ret = -1
45.                
46.         EndIf
47.        
48.         ; purge
49.         Delete GFS_out_FABytes
50.         Delete GFS_out_TotBytes
51.         Delete GFS_out_TFBytes
52.         ; return
53.         Return ret
54.        
55. End Function
56.  
57.  
58. ; EXAMPLE USE
59.  
60. Local drive$ = "C:"
61.  
62. Local megabyte% = 100
63. Local bytes% = ((megabyte *1024) *1024)
64.  
65. Select HasFreeSpace(drive, bytes)
66.         Case True
67.                 Print " "+drive+" has more than "+megabyte+" Mb free ("+bytes+" bytes)"
68.         Case False
69.                 Print " "+drive+" DOES NOT have "+megabyte+" Mb free ("+bytes+" bytes) !"
70.         Case -1
71.                 Print " "+drive+" not accessible, found or mounted!"
72. End Select
73.  
74. Print "" : Print " <any key>"
75. WaitKey
76. End

Comments :


Yasha(Posted 1+ years ago)

 This version has a (kinda) memory leak - you're creating the three LongInt objects anew each time but not freeing them afterwards (this is why in the original example I cached them in a global). If you use this function more than once, it will start to waste space.You don't have to store them between calls, if you want to keep the surrounding code tidier, but in that case you do need to have a corresponding Delete section at the bottom.(I say "kinda" because objects in B3D created with New are never truly unreachable - you can quickly kill 'em all with "Delete Each LongInt". However, unless you do something like this somewhere in your program it's effectively the same as a leak.)


Danny(Posted 1+ years ago)

 Ay, yes I thought about then when removing the Globals, but forgot to put the Deletes in. The code above is updated so should be safe now.Thanks for pointing that out