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This Technical Note contains a collection of archived Q&As relating to a specific
topic - questions sent the Developer Support Center (DSC) along with
answers from the DSC engineers. Current Q&A's can be found on the Macintosh Technical Q&A's web site.
[Oct 01 1990]
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AFP error codes -5060,-5061, -5062, and -5063
Date Written: 1/18/93
Last reviewed: 6/14/93
What's AppleTalk error -5062? It seems to be an AppleTalk Filing Protocol error
of sorts but I can't find it documented anywhere.
Error -5062 is an afpAlreadyMounted error. You'll get it from the AppleShare
external file system if you try to mount an AppleShare volume that's already
mounted with PBVolumeMount. The three PBVolumeMount-related functions were
added to System 7 very late during development, so afpAlreadyMounted (-5062),
afpBadDirIDType (-5060), afpCantMountMoreSrvrs (-5061), and afpSameNodeEr
(-5063) never made it into the public interface files.
References:
Inside Macintosh Volume VI, pages 25-49 and 25-50
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How an AFP volume's allocation block size is calculated
Date Written: 8/15/91
Last reviewed: 8/16/91
The AppleTalk Filing Protocol (AFP) doesn't appear provide a way to learn about
the allocation block size of a server volume. So, how is the allocation block
size determined on AFP server volumes? I noticed that the Macintosh Finder
seems to calculate "size on disk" erratically for files on some AFP server
volumes. Is that a related problem?
All the workstation can get from an AFP server is the Bytes Total and Bytes
Free (returned by FPGetVolParms and FPOpenVol), so the AFP workstation code
estimates the value it uses in the allocation block size field (vcbAlBlkSiz) of
the volume control block (VCB). The workstation code comes up with a value for
vcbAlBlkSiz from the Bytes Total value returned to FPOpenVol when the volume is
opened. The calculation used is:
This is the same value a local HFS volume would use. If an AFP server is not
running on a Macintosh (and then, probably not using HFS), then this value may
not be what the server platform is actually using. And yes, the Finder uses the
allocation block size in its calculations to decide how much space is used by a
file, so the "size on disk" may not exactly reflect the amount of disk space
actually used.
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Inside Macintosh Volume VI PBGetVolMountInfoSize typo
Date Written: 1/22/92
Last reviewed: 6/14/93
When I call PBGetVolMountInfoSize to get the size of an AppleShare volume's
mounting information record, the function returns with no errors but ioBuffer
points to garbage instead of the size of an AFPVolMountInfo record.
The problem you're having with PBGetVolMountInfoSize is a typo in Inside
Macintosh Volume VI on page 25-48. In that call, the ioBuffer field should
be a pointer to a word (2-byte) size variable, not a long (4-byte) size
variable.
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AFP 2.0 FPRead NewLine Mask change
Date Written: 5/3/89
Last reviewed: 11/21/90
I'm confused about the changes to FPRead in AFP (AppleTalk Filing Protocol)
version 2.0. How do I use the NewLine Mask?
The difference between AFP 1.1 and AFP 2.0 as far as the NewLine Mask is
concerned is that, in AFP 1.1, the only legal values of NewLine Mask are $00
and $FF, whereas in AFP 2.0, all values of NewLine Mask are allowed. The
NewLine Mask is logically ANDed with a copy of each byte read. If the result
matches the NewLine character, the read terminates. The NewLine character is
returned as the last byte of data that was read from the fork.
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