Simon Bazley, Thanks for replying ! I managed to figure out what the problem was- I had mentioned this in my previous email to the list.
I have a question to which maybe you or someone from the list knows the answer - At the moment I'm wondering how to determine the number of index nodes needed for a catalog tree. I have determined the number of catalog nodes needed and my question is : Does every leaf node in the catalog-tree have
to
be referenced in the index-nodes? In a broadly logical sense I would say that it has to ...since a leaf without an index in a 'real' tree would probably be like a leaf falling
off
a branch in autumn :). The HFS reference (Inside Macintosh) has this
figure
of a sample B-Tree where a reference to every leaf-node is maintained in
the
index nodes. But I came across a sample HFS-image (which is readable on my Mac) which shattered all my illusions since the root-node (the only index node in
this
image) doesn't maintain references to all leaf nodes, only to a few of
them.
Does anyone from Apple (or others) maybe know how the index nodes are to built up i.e. to which leaf-nodes (if not to all) a reference has to necessarily be maintained ? I guess a Mac internally should be doing some kind of optimization to reduce the search-time in finding a
leaf-record....
but all I need to know is what I should take into account while
constructing
my index-nodes to make the job easier for the Mac when an external HFS-volume is mounted.
Would be grateful for any tips.
Regards, Nandini Hengen
----- Original Message ----- From: "Simon Bazley sibaz@sibaz.com" simon@sibaz.com To: "Entwicklung" entwicklung@whengenibk.de Cc: hfs-user@lists.mars.org Sent: Monday, February 11, 2002 2:41 AM Subject: Re: [hfs-user] Volume-Names in HFS
Have you checked Inside Macintosh Files to see what it says about the
MDB
record (assuming its an HFS volume) or the equivalent in the HFS+
Technote
(assuming its HFS+). My understanding was that volume name was pretty bullet proof.
Simon
On Thu, 7 Feb 2002, Entwicklung wrote:
Hello, My HFS-Volume seems to be recognized if I give the Volume a
name
with an odd no. of characters say "NEW" but fails to be recognized if the name is say "NAND_HFS". Does anybody know of a possible reason why this is happening ?
I think this had something to do with the key length field. In my
case -
if the volume name is even hence implying that the associated key does not end on an even byte boundary (where applicable), i byte is added for
padding
but the key-length and name length fields are maintained as before. In
those
keys which have to be of size=maximum key length the padding with zeroes
is
done in any case.
Does anybody know if something else needs to be changed ?
TIA, Nandini Hengen
Hi,
Yes, every leaf node should have a record in some index node at the next level. Each one of those, in turn, should have a record pointing to them in the next higher level, etc.
If you have a leaf record that isn't directly pointed to by an index record a search by name for any entries in there will fail, although opening the folder and enumerating the contents of a folder will show all the entries.
Hope that helps, -Pat Dirks.
On Monday, February 11, 2002, at 01:15 AM, Entwicklung wrote:
Simon Bazley, Thanks for replying ! I managed to figure out what the problem was- I had mentioned this in my previous email to the list.
I have a question to which maybe you or someone from the list knows the answer - At the moment I'm wondering how to determine the number of index nodes needed for a catalog tree. I have determined the number of catalog nodes needed and my question is : Does every leaf node in the catalog-tree have
to
be referenced in the index-nodes? In a broadly logical sense I would say that it has to ...since a leaf without an index in a 'real' tree would probably be like a leaf falling
off
a branch in autumn :). The HFS reference (Inside Macintosh) has this
figure
of a sample B-Tree where a reference to every leaf-node is maintained in
the
index nodes. But I came across a sample HFS-image (which is readable on my Mac) which shattered all my illusions since the root-node (the only index node in
this
image) doesn't maintain references to all leaf nodes, only to a few of
them.
Does anyone from Apple (or others) maybe know how the index nodes are to built up i.e. to which leaf-nodes (if not to all) a reference has to necessarily be maintained ? I guess a Mac internally should be doing some kind of optimization to reduce the search-time in finding a
leaf-record....
but all I need to know is what I should take into account while
constructing
my index-nodes to make the job easier for the Mac when an external HFS-volume is mounted.
Would be grateful for any tips.
Regards, Nandini Hengen
----- Original Message ----- From: "Simon Bazley sibaz@sibaz.com" simon@sibaz.com To: "Entwicklung" entwicklung@whengenibk.de Cc: hfs-user@lists.mars.org Sent: Monday, February 11, 2002 2:41 AM Subject: Re: [hfs-user] Volume-Names in HFS
Have you checked Inside Macintosh Files to see what it says about the
MDB
record (assuming its an HFS volume) or the equivalent in the HFS+
Technote
(assuming its HFS+). My understanding was that volume name was pretty bullet proof.
Simon
On Thu, 7 Feb 2002, Entwicklung wrote:
Hello, My HFS-Volume seems to be recognized if I give the Volume a
name
with an odd no. of characters say "NEW" but fails to be recognized if the name is say "NAND_HFS". Does anybody know of a possible reason why this is happening ?
I think this had something to do with the key length field. In my
case -
if the volume name is even hence implying that the associated key does not end on an even byte boundary (where applicable), i byte is added for
padding
but the key-length and name length fields are maintained as before. In
those
keys which have to be of size=maximum key length the padding with zeroes
is
done in any case.
Does anybody know if something else needs to be changed ?
TIA, Nandini Hengen
-
Entwicklung -
Patrick Dirks