README
1the catalog database keeps track of three mappings:
2 CNID -> dev/ino and did/name
3 dev/ino -> CNID
4 did/name -> CNID
5
6dev/ino is used to keep track of magically moved files. did/name is
7for quick lookups of CNIDs.
8
9NOTE: the database will append a nul byte to the end of name. in
10addition, name should be given as it appears on disk. this allows the
11creation of cnid updating/cleaning programs that don't have to deal
12with knowing what the particular codepage is.
13
14here's the ritual:
15 1) open a volume. call cnid_open.
16 2) every time you need a CNID, call cnid_add(). it will
17 automatically look for an existing cnid and add a new one
18 if one isn't already there. you can pass a hint if you
19 want. the only use this has right now is to enable
20 consistency between AFP and HFS. in the future, it would
21 allow people to write conversion utilities that
22 pre-instantiate a database without needing to re-assign
23 CNIDs.
24 3) if you want to just look for a CNID without automatically
25 adding one in, you have two choices:
26 a) cnid_resolve takes a CNID, returns name, and
27 over-writes the CNID given with the parent DID. this
28 is good for FPResolveID.
29 b) cnid_lookup returns a CNID corresponding to the
30 dev/ino,did/name keys. it will auto-update the catalog
31 database if there's a discrepancy.
32 NOTE: cnid_add calls this before adding a new CNID.
33 4) when you delete a file or directory, you need to call
34 cnid_delete with the CNID for that file/directory.
35 5) call cnid_close when closing the volume.
36