Commit Graph

152 Commits

Author SHA1 Message Date
Brian Warner
ea373de042 move dirnode.CachingDict to dictutil.AuxValueDict, generalize method names,
improve tests. Let dirnode _pack_children accept either dict or AuxValueDict.
2009-10-17 11:00:05 -07:00
Brian Warner
480e1d318d The initial_children= argument to nodemaker.create_new_mutable_directory is
now enabled.
2009-10-12 20:19:22 -07:00
Brian Warner
cf65cc2ae3 replace dirnode.create_empty_directory() with create_subdirectory(), which
takes an initial_children= argument
2009-10-12 19:15:20 -07:00
Brian Warner
d079eb45f6 dirnode.set_children: change return value: fire with self instead of None 2009-10-12 18:50:26 -07:00
Brian Warner
f871c3bb3d dirnode.set_nodes: change return value: fire with self instead of None 2009-10-12 18:45:46 -07:00
Brian Warner
304aadd4f7 dirnode.set_children: take a dict, not a list 2009-10-12 17:24:40 -07:00
Brian Warner
e2ffc3dc03 dirnode.set_uri/set_children: change signature to take writecap+readcap
instead of a single cap. The webapi t=set_children call benefits too.
2009-10-12 16:51:26 -07:00
Brian Warner
0d5dc51617 Overhaul IFilesystemNode handling, to simplify tests and use POLA internally.
* stop using IURI as an adapter
* pass cap strings around instead of URI instances
* move filenode/dirnode creation duties from Client to new NodeMaker class
* move other Client duties to KeyGenerator, SecretHolder, History classes
* stop passing Client reference to dirnode/filenode constructors
  - pass less-powerful references instead, like StorageBroker or Uploader
* always create DirectoryNodes by wrapping a filenode (mutable for now)
* remove some specialized mock classes from unit tests

Detailed list of changes (done one at a time, then merged together)

always pass a string to create_node_from_uri(), not an IURI instance
always pass a string to IFilesystemNode constructors, not an IURI instance
stop using IURI() as an adapter, switch on cap prefix in create_node_from_uri()
client.py: move SecretHolder code out to a separate class
test_web.py: hush pyflakes
client.py: move NodeMaker functionality out into a separate object
LiteralFileNode: stop storing a Client reference
immutable Checker: remove Client reference, it only needs a SecretHolder
immutable Upload: remove Client reference, leave SecretHolder and StorageBroker
immutable Repairer: replace Client reference with StorageBroker and SecretHolder
immutable FileNode: remove Client reference
mutable.Publish: stop passing Client
mutable.ServermapUpdater: get StorageBroker in constructor, not by peeking into Client reference
MutableChecker: reference StorageBroker and History directly, not through Client
mutable.FileNode: removed unused indirection to checker classes
mutable.FileNode: remove Client reference
client.py: move RSA key generation into a separate class, so it can be passed to the nodemaker
move create_mutable_file() into NodeMaker
test_dirnode.py: stop using FakeClient mockups, use NoNetworkGrid instead. This simplifies the code, but takes longer to run (17s instead of 6s). This should come down later when other cleanups make it possible to use simpler (non-RSA) fake mutable files for dirnode tests.
test_mutable.py: clean up basedir names
client.py: move create_empty_dirnode() into NodeMaker
dirnode.py: get rid of DirectoryNode.create
remove DirectoryNode.init_from_uri, refactor NodeMaker for customization, simplify test_web's mock Client to match
stop passing Client to DirectoryNode, make DirectoryNode.create_with_mutablefile the normal DirectoryNode constructor, start removing client from NodeMaker
remove Client from NodeMaker
move helper status into History, pass History to web.Status instead of Client
test_mutable.py: fix minor typo
2009-08-15 04:28:46 -07:00
kevan
18a80d99b1 Alter Adder + Adder tests to look for 'only-files' instead of 'only_files' 2009-07-19 20:43:18 -07:00
kevan
c476c66b0e Add 'only_files' option to the overwrite field in Adder 2009-07-17 20:00:10 -07:00
Brian Warner
531cc7899f rename NewDirectoryNode to DirectoryNode, NewDirectoryURI to DirectoryURI 2009-07-17 17:15:49 -05:00
Zooko O'Whielacronx
2f704ed001 dirnode: finish renaming "iv" to "salt" in the code and the hash tag 2009-07-12 17:13:20 -07:00
Brian Warner
7f1d8b7c46 dirnode.py/_encrypt_rwcap: rename IV to "salt", which is more accurate 2009-07-13 00:50:25 +01:00
Brian Warner
c1d5717cf0 dirnode.py: security bug: also use child writecap to derive child enc key,
not just the dirnode writecap. The previous code (which only hashed the
dirnode writecap) would use the same key for all children, which is very bad.
This is the correct implementation of #750.
2009-07-13 00:47:50 +01:00
kevan
d71adaf1ca Use CachingDict instead of dict in dirnode.py 2009-07-03 20:43:01 -07:00
Zooko O'Whielacronx
34213cd2c7 directories: fix semantic conflict between my "keep track of position" optimization patch and Kevan's "cache serialized entries" optimization patch 2009-07-09 20:20:28 -07:00
Zooko O'Whielacronx
0e2d005146 trivial: removed unused import noticed by pyflakes 2009-07-09 06:05:13 -07:00
Zooko O'Whielacronx
786ed012b3 directories: make the IV for the writecaps in directory entries be computed from the secure hash of the writecap itself
This makes encoding of directory entries deterministic, and it is also a tad faster on Macbook Pro than getting a random IV with os.urandom(16).
2009-07-04 19:48:15 -07:00
kevan
903005a528 Add CachingDict dict subclass to dirnode.py 2009-07-05 14:23:45 -07:00
Zooko O'Whielacronx
efafcfb91a directories: keep track of your position as you decode netstring after netstring from an input buffer instead of copying the trailing part
This makes decoding linear in the number of netstrings instead of O(N^2).
2009-07-04 19:51:09 -07:00
Brian Warner
ef1b6ae8e3 Tolerate unknown URI types in directory structures. Part of #683.
The idea is that future versions of Tahoe will add new URI types that this
version won't recognize, but might store them in directories that we *can*
read. We should handle these "objects from the future" as best we can.
Previous releases of Tahoe would just explode. With this change, we'll
continue to be able to work with everything else in the directory.

The code change is to wrap anything we don't recognize as an UnknownNode
instance (as opposed to a FileNode or DirectoryNode). Then webapi knows how
to render these (mostly by leaving fields blank), deep-check knows to skip
over them, deep-stats counts them in "count-unknown". You can rename and
delete these things, but you can't add new ones (because we wouldn't know how
to generate a readcap to put into the dirnode's rocap slot, and because this
lets us catch typos better).
2009-07-02 18:07:49 -07:00
Brian Warner
6237aeabd7 create_node_from_uri: take both writecap+readcap, move logic out of dirnode.py 2009-07-02 15:25:37 -07:00
Brian Warner
656277ac98 dirnode.py: prepare to preserve both rwcap+rocap when copying
This will make it easier to tolerate unknown nodes safely.
2009-07-02 14:12:54 -07:00
Brian Warner
52fa421430 use 522-bit RSA keys in all unit tests (except one)
This reduces the total test time on my laptop from 400s to 283s.
* src/allmydata/test/test_system.py (SystemTest.test_mutable._test_debug):
  Remove assertion about container_size/data_size, this changes with keysize
  and was too variable anyways.
* src/allmydata/mutable/filenode.py (MutableFileNode.create): add keysize=
* src/allmydata/dirnode.py (NewDirectoryNode.create): same
* src/allmydata/client.py (Client.DEFAULT_MUTABLE_KEYSIZE): add default,
  this overrides the one in MutableFileNode
2009-06-29 15:31:24 -07:00
Brian Warner
c9803d5217 switch all foolscap imports to use foolscap.api or foolscap.logging 2009-05-21 17:38:23 -07:00
Zooko O'Whielacronx
9729753692 dirnode: add 'tahoe'/'linkcrtime' and 'tahoe'/'linkmotime' to take the place of what 'mtime'/'ctime' originally did, and make the 'tahoe' subdict be unwritable through the set_children API
Also add extensive documentation in docs/frontends/webapi.txt about the behaviors of these values.  See ticket #628.
2009-04-11 15:52:05 -07:00
Brian Warner
6e57576f2e dirnode deep_traverse: insert a turn break (fireEventually) at least once every 100 files, otherwise a CHK followed by more than 158 LITs can overflow the stack, sort of like #237. 2009-03-13 16:31:35 -07:00
Brian Warner
1a741fdb03 dirnode.py: when doing deep-traverse, walk each directory in alphabetical order, to make things like 'manifest' more predictable 2009-03-12 23:50:46 -07:00
Brian Warner
bce4a5385b add --add-lease to 'tahoe check', 'tahoe deep-check', and webapi. 2009-02-17 19:32:43 -07:00
Brian Warner
72adeccf2d dirnode: add get_repair_cap() 2009-01-22 21:44:49 -07:00
Brian Warner
94ab90273d dirnode.deep_traverse: fix docstring to describe the correct return value 2009-01-22 21:39:50 -07:00
Brian Warner
39a089dc7e dirnode deep-traversal: remove use of Limiter, stick with strict depth-first-traversal, to reduce memory usage during very large (300k+ dirnode) traversals 2009-01-08 19:41:16 -07:00
Zooko O'Whielacronx
5e6f90a015 rename "checker results" to "check results", because it is more parallel to "check-and-repair results" 2009-01-06 13:37:03 -07:00
Zooko O'Whielacronx
f1fbd4feae dirnode: don't check MAC on entries in dirnodes
In an ancient version of directories, we needed a MAC on each entry.  In modern times, the entire dirnode comes with a digital signature, so the MAC on each entry is redundant.
With this patch, we no longer check those MACs when reading directories, but we still produce them so that older readers will accept directories that we write.
2008-12-21 17:35:18 -07:00
Zooko O'Whielacronx
471e1f1b9b try to tidy up uri-as-string vs. uri-as-object
I get confused about whether a given argument or return value is a uri-as-string or uri-as-object.  This patch adds a lot of assertions that it is one or the other, and also changes CheckerResults to take objects not strings.
In the future, I hope that we generally use Python objects except when importing into or exporting from the Python interpreter e.g. over the wire, the UI, or a stored file.
2008-12-19 08:39:24 -07:00
Zooko O'Whielacronx
c456ff8591 rename "get_verifier()" to "get_verify_cap()" 2008-12-08 12:44:11 -07:00
Zooko O'Whielacronx
b58875fe43 mutable: rename mutable/node.py to mutable/filenode.py and mutable/repair.py to mutable/repairer.py
To be more consistent with the immutable layout that I am working on.
2008-12-07 08:20:08 -07:00
Brian Warner
7a0afb59a4 dirnode.py: dirnode.delete which hits UCWE should not fail with NoSuchChildError. Fixes #550. 2008-12-05 22:08:37 -07:00
Brian Warner
fb9af2c7a0 MutableFileNode.modify: pass first_time= and servermap= to the modifier callback 2008-12-05 22:07:10 -07:00
Zooko O'Whielacronx
b315619d6b download: refactor handling of URI Extension Block and crypttext hash tree, simplify things
Refactor into a class the logic of asking each server in turn until one of them gives an answer 
that validates.  It is called ValidatedThingObtainer.

Refactor the downloading and verification of the URI Extension Block into a class named 
ValidatedExtendedURIProxy.

The new logic of validating UEBs is minimalist: it doesn't require the UEB to contain any 
unncessary information, but of course it still accepts such information for backwards 
compatibility (so that this new download code is able to download files uploaded with old, and 
for that matter with current, upload code).

The new logic of validating UEBs follows the practice of doing all validation up front.  This 
practice advises one to isolate the validation of incoming data into one place, so that all of 
the rest of the code can assume only valid data.

If any redundant information is present in the UEB+URI, the new code cross-checks and asserts 
that it is all fully consistent.  This closes some issues where the uploader could have 
uploaded inconsistent redundant data, which would probably have caused the old downloader to 
simply reject that download after getting a Python exception, but perhaps could have caused 
greater harm to the old downloader.

I removed the notion of selecting an erasure codec from codec.py based on the string that was 
passed in the UEB.  Currently "crs" is the only such string that works, so 
"_assert(codec_name == 'crs')" is simpler and more explicit.  This is also in keeping with the 
"validate up front" strategy -- now if someone sets a different string than "crs" in their UEB, 
the downloader will reject the download in the "validate this UEB" function instead of in a 
separate "select the codec instance" function.

I removed the code to check plaintext hashes and plaintext Merkle Trees.  Uploaders do not 
produce this information any more (since it potentially exposes confidential information about 
the file), and the unit tests for it were disabled.  The downloader before this patch would 
check that plaintext hash or plaintext merkle tree if they were present, but not complain if 
they were absent.  The new downloader in this patch complains if they are present and doesn't 
check them.  (We might in the future re-introduce such hashes over the plaintext, but encrypt 
the hashes which are stored in the UEB to preserve confidentiality.  This would be a double-
check on the correctness of our own source code -- the current Merkle Tree over the ciphertext 
is already sufficient to guarantee the integrity of the download unless there is a bug in our 
Merkle Tree or AES implementation.) 

This patch increases the lines-of-code count by 8 (from 17,770 to 17,778), and reduces the 
uncovered-by-tests lines-of-code count by 24 (from 1408 to 1384).  Those numbers would be more 
meaningful if we omitted src/allmydata/util/ from the test-coverage statistics.
2008-12-05 08:17:54 -07:00
Brian Warner
bc53c24003 dirnode manifest: add verifycaps, both to internal API and to webapi. This will give the manual-GC tools more to work with, so they can estimate how much space will be freed. 2008-11-24 14:40:46 -07:00
Brian Warner
b84c2c6541 manifest: add storage-index strings to the json results 2008-11-19 16:00:27 -07:00
Brian Warner
815e0673e6 manifest: include stats in results. webapi is unchanged. 2008-11-19 15:03:47 -07:00
Brian Warner
d6a67cd566 dirnode manifest/stats: process more than one LIT file per tree; we were accidentally ignoring all but the first 2008-11-14 22:50:49 -07:00
Brian Warner
fca158e83a dirnode lookup: use distinct NoSuchChildError instead of the generic KeyError when a child can't be found 2008-10-27 13:15:25 -07:00
Brian Warner
977c6ac510 more #514: pass a Monitor to all checker operations, make mutable-checker honor the cancel flag 2008-10-22 01:38:18 -07:00
Brian Warner
8178b10ef1 dirnode.py: check for cancel during deep-traverse operations, and don't initiate any new ones if we've been cancelled. Gets us closer to #514. 2008-10-22 00:55:52 -07:00
Brian Warner
ad3d9207a9 Change deep-size/stats/check/manifest to a start+poll model instead of a single long-running synchronous operation. No cancel or handle-expiration yet. #514. 2008-10-21 17:03:07 -07:00
Brian Warner
9d4749d546 dirnode.build_manifest: include node.list in the limiter, that's the most important thing to slow down 2008-10-07 13:19:29 -07:00
Brian Warner
3ffaded809 web: change t=manifest to return a list of (path,read/writecap) tuples, instead of a list of verifycaps. Add output=html,text,json. 2008-10-06 21:36:18 -07:00
Brian Warner
09341a969a dirnode: fix my remarkably-consistent 'metdadata' typo 2008-10-02 18:08:45 -07:00
Brian Warner
d0bdf9a611 dirnode: add get_child_and_metadata_at_path 2008-10-02 17:52:03 -07:00
Brian Warner
e8cf581e3f move netstring() and split_netstring() into a separate util.netstring module 2008-09-25 21:38:24 -07:00
Brian Warner
f570ad7ba5 disallow deep-check on non-directories, simplifies the code a bit 2008-09-10 13:44:58 -07:00
Brian Warner
4bb88fd2ee dirnode: refactor recursive-traversal methods, add stats to deep_check() method results and t=deep-check webapi 2008-09-10 01:45:04 -07:00
Brian Warner
f6eeb3161f dirnode: cleanup, make get_verifier() always return a URI instance, not a string 2008-09-10 01:37:55 -07:00
Brian Warner
3408d552cd checker: overhaul checker results, split check/check_and_repair into separate methods, improve web displays 2008-09-07 12:44:56 -07:00
Brian Warner
c80e352951 IFilesystemNode: add get_storage_index(), it makes tests easier 2008-08-12 16:14:07 -07:00
Brian Warner
1306b11a76 dirnode: add some deep-check logging 2008-08-11 21:23:38 -07:00
Brian Warner
67db0a4967 deep-check: add webapi, add 'DEEP-CHECK' button to wui, add tests, rearrange checker API a bit 2008-07-17 16:47:09 -07:00
Brian Warner
69156aeb28 dirnode deep-check: add tests of cycles, fix failures 2008-07-17 14:37:04 -07:00
Brian Warner
acf3180fac dirnode deep-check: rearrange traversal approach, simplify code a bit 2008-07-17 14:25:04 -07:00
Brian Warner
9289433ba3 first pass at deep-checker, no webapi yet, probably big problems with it, only minimal tests 2008-07-16 18:20:57 -07:00
Brian Warner
94e619c1f6 overhaul checker invocation
Removed the Checker service, removed checker results storage (both in-memory
and the tiny stub of sqlite-based storage). Added ICheckable, all
check/verify is now done by calling the check() method on filenodes and
dirnodes (immutable files, literal files, mutable files, and directory
instances).

Checker results are returned in a Results instance, with an html() method for
display. Checker results have been temporarily removed from the wui directory
listing until we make some other fixes.

Also fixed client.create_node_from_uri() to create LiteralFileNodes properly,
since they have different checking behavior. Previously we were creating full
FileNodes with LIT uris inside, which were downloadable but not checkable.
2008-07-15 17:23:25 -07:00
Brian Warner
87c1e8e066 dirnode: add overwrite= to most API calls, defaulting to True. When False, this raises ExistingChildError rather than overwriting an existing child 2008-05-16 16:09:47 -07:00
Brian Warner
fabdc28c06 deep-stats: add file-size histogram 2008-05-08 16:19:42 -07:00
Brian Warner
e6ae7a2c60 dirnode: refactor deep-stats a bit 2008-05-08 13:33:07 -07:00
Brian Warner
6c00a70dbc dirnode: add a deep_stats(), like deep-size but with more information. webish adds t=deeps-size too. 2008-05-08 13:21:14 -07:00
Brian Warner
3cb361e233 dirnode: use the concurrency limiter in t=manifest and t=deep-size, allow 10 retrievals in parallel 2008-05-07 18:36:37 -07:00
Brian Warner
d7b82f73c5 dirnode: return to 'delete fails if the child wasn't actually there' semantics, to make tests pass. There's a switch to enable/disable this 2008-04-17 20:06:06 -07:00
Brian Warner
1bff08a7df dirnode: update to use MutableFileNode.modify 2008-04-17 19:57:04 -07:00
Brian Warner
a379690b04 mutable: replace MutableFileNode API, update tests. Changed all callers to use overwrite(), but that will change soon 2008-04-17 17:51:38 -07:00
Brian Warner
d4230d1781 mutable WIP: split mutable.py into separate files. All tests pass. 2008-04-11 14:31:16 -07:00
robk-tahoe
5578559b85 added offloaded key generation
this adds a new service to pre-generate RSA key pairs.  This allows
the expensive (i.e. slow) key generation to be placed into a process
outside the node, so that the node's reactor will not block when it
needs a key pair, but instead can retrieve them from a pool of already
generated key pairs in the key-generator service.

it adds a tahoe create-key-generator command which initialises an 
empty dir with a tahoe-key-generator.tac file which can then be run
via twistd.  it stashes its .pem and portnum for furl stability and
writes the furl of the key gen service to key_generator.furl, also
printing it to stdout.

by placing a key_generator.furl file into the nodes config directory
(e.g. ~/.tahoe) a node will attempt to connect to such a service, and
will use that when creating mutable files (i.e. directories) whenever
possible.  if the keygen service is unavailable, it will perform the
key generation locally instead, as before.
2008-04-01 18:45:13 -07:00
Brian Warner
2ef70ab814 mutable.py: split replace() into update() and overwrite(). Addresses #328. 2008-03-12 18:00:43 -07:00
Zooko O'Whielacronx
99f006c584 wapi: add POST /uri/$DIRECTORY?t=set_children
Unfinished bits: doc in webapi.txt, test handling of badly formed JSON, return reasonable HTTP response, examination of the effect of this patch on code coverage -- but I'm committing it anyway because MikeB can use it and I'm being called to dinner...
2008-02-29 18:40:27 -07:00
Brian Warner
7927495cbe unicode handling: declare dirnodes to contain unicode child names, update webish to match 2008-02-14 15:45:56 -07:00
Brian Warner
e6ddd9f3da dirnode.py: add metadata= to add_file(), add tests 2008-02-11 14:53:28 -07:00
Brian Warner
622c477e31 dirnode: add ctime/mtime to metadata, update metadata-modifying APIs. Needs more testing and sanity checking. 2008-02-08 18:43:47 -07:00
Brian Warner
66f33ee504 upload: return an UploadResults instance (with .uri) instead of just a URI 2008-02-05 21:01:38 -07:00
Brian Warner
7ac2b94aba remove wait_for_numpeers and the when_enough_peers call in mutable.Publish 2008-01-14 14:55:59 -07:00
Brian Warner
9a8f68c41f dirnode: add set_uris() and set_nodes() (plural), to set multiple children at once. Use it to set up a new webapi test for issue #237. 2007-12-18 23:30:02 -07:00
Brian Warner
0f5ef5184d test_dirnode.py: obtain full coverage of dirnode.py 2007-12-04 14:32:04 -07:00
Brian Warner
cca166a4f5 rename dirnode2.py to dirnode.py 2007-12-04 11:45:20 -07:00
Zooko O'Whielacronx
59d6c3c822 decentralized directories: integration and testing
* use new decentralized directories everywhere instead of old centralized directories
 * provide UI to them through the web server
 * provide UI to them through the CLI
 * update unit tests to simulate decentralized mutable directories in order to test other components that rely on them
 * remove the notion of a "vdrive server" and a client thereof
 * remove the notion of a "public vdrive", which was a directory that was centrally published/subscribed automatically by the tahoe node (you can accomplish this manually by making a directory and posting the URL to it on your web site, for example)
 * add a notion of "wait_for_numpeers" when you need to publish data to peers, which is how many peers should be attached before you start.  The default is 1.
 * add __repr__ for filesystem nodes (note: these reprs contain a few bits of the secret key!)
 * fix a few bugs where we used to equate "mutable" with "not read-only".  Nowadays all directories are mutable, but some might be read-only (to you).
 * fix a few bugs where code wasn't aware of the new general-purpose metadata dict the comes with each filesystem edge
 * sundry fixes to unit tests to adjust to the new directories, e.g. don't assume that every share on disk belongs to a chk file.
2007-12-03 14:52:42 -07:00
Brian Warner
1f22768dc7 webish: add preliminary mutable file support: upload, download, listings, JSON, URI, RO-URI. No replace yet. 2007-11-09 03:54:27 -07:00
Brian Warner
63233ecf37 consolidate dirnode/filenode-creation code into Client 2007-11-09 02:54:51 -07:00
Brian Warner
fb3eddafdb move NotMutableError from dirnode.py into interfaces.py 2007-11-01 15:03:07 -07:00
Brian Warner
b24c2925e8 checkpointing mutable-file work. Storage layer is 80% in place. 2007-10-30 19:47:36 -07:00
Brian Warner
046bda2b47 webish: add checker results and a 'Check' button to the web interface 2007-10-23 17:23:57 -07:00
Brian Warner
9da1d70676 add a simple checker, for both files and directories 2007-10-15 16:16:39 -07:00
Brian Warner
fe06b3be8b dirnode: change the defined behavior of RIVirtualDriveServer.set to allow replace-in-place without raising an exception 2007-08-16 17:03:19 -07:00
Brian Warner
42dcc3088e IDirectoryNode: add has_child() method 2007-08-15 13:22:01 -07:00
Brian Warner
2bc3c163b6 uri.py: get keys and index from the URI instance 2007-07-21 17:45:00 -07:00
Brian Warner
1d9a58977f uri: implement URI-processing classes, IFileURI/IDirnodeURI, use internally 2007-07-21 15:40:36 -07:00
Brian Warner
32fcf0b405 dirnode.build_manifest(): tolerate cycles in the directory graph 2007-07-21 15:40:13 -07:00
Brian Warner
ba7e14a870 fix several methods to handle LIT URIs correctly, rather than assuming that all filenodes are CHK URIs 2007-07-12 16:17:49 -07:00
Brian Warner
0cd730a7b3 web: more test work, now all tests either pass or are skipped (POST, XMLRPC, and URI/) 2007-07-07 10:34:05 -07:00
Brian Warner
71c04fc2e7 web: use KeyError (rather than IndexError) to signal a missing child 2007-07-06 19:40:08 -07:00
Brian Warner
9e42dda6a4 add IDirectoryNode.get_child_at_path 2007-07-06 19:38:37 -07:00