From: david-sarah Date: Mon, 12 Jul 2010 02:55:37 +0000 (-0700) Subject: SFTP: address some of the comments in zooko's review (#1106). X-Git-Url: https://git.rkrishnan.org/vdrive/%22news.html/frontends/reliability?a=commitdiff_plain;h=15ddab08edebd7fe493ae2488713b9e7063f7fed;p=tahoe-lafs%2Ftahoe-lafs.git SFTP: address some of the comments in zooko's review (#1106). --- diff --git a/src/allmydata/frontends/sftpd.py b/src/allmydata/frontends/sftpd.py index 72a21238..5980effb 100644 --- a/src/allmydata/frontends/sftpd.py +++ b/src/allmydata/frontends/sftpd.py @@ -78,6 +78,9 @@ def _to_sftp_time(t): def _convert_error(res, request): + """If res is not a Failure, return it, otherwise reraise the appropriate + SFTPError.""" + if not isinstance(res, Failure): logged_res = res if isinstance(res, str): logged_res = "" % (len(res),) @@ -88,11 +91,11 @@ def _convert_error(res, request): logmsg("RAISE %r %r" % (request, err.value), level=OPERATIONAL) try: if noisy: logmsg(traceback.format_exc(err.value), level=NOISY) - except: # pragma: no cover + except Exception: # pragma: no cover pass # The message argument to SFTPError must not reveal information that - # might compromise anonymity. + # might compromise anonymity, if we are running over an anonymous network. if err.check(SFTPError): # original raiser of SFTPError has responsibility to ensure anonymity @@ -140,9 +143,6 @@ def _lsLine(name, attrs): st_gid = "tahoe" st_mtime = attrs.get("mtime", 0) st_mode = attrs["permissions"] - # TODO: check that clients are okay with this being a "?". - # (They should be because the longname is intended for human - # consumption.) st_size = attrs.get("size", "?") # We don't know how many links there really are to this object. st_nlink = 1 @@ -389,14 +389,18 @@ class OverwriteableFileConsumer(PrefixingLogMixin): self.overwrite(self.current_size, "\x00" * (size - self.current_size)) self.current_size = size - # invariant: self.download_size <= self.current_size + # make the invariant self.download_size <= self.current_size be true again if size < self.download_size: self.download_size = size + if self.downloaded >= self.download_size: self.finish() def registerProducer(self, p, streaming): if noisy: self.log(".registerProducer(%r, streaming=%r)" % (p, streaming), level=NOISY) + if self.producer is not None: + raise RuntimeError("producer is already registered") + self.producer = p if streaming: # call resumeProducing once to start things off @@ -470,7 +474,7 @@ class OverwriteableFileConsumer(PrefixingLogMixin): return if noisy: self.log("MILESTONE %r %r" % (next, d), level=NOISY) heapq.heappop(self.milestones) - eventually_callback(d)(None) + eventually(d.callback, None) if milestone >= self.download_size: self.finish() @@ -543,6 +547,9 @@ class OverwriteableFileConsumer(PrefixingLogMixin): return self.done def finish(self): + """Called by the producer when it has finished producing, or when we have + received enough bytes, or as a result of a close. Defined by IFinishableConsumer.""" + while len(self.milestones) > 0: (next, d) = self.milestones[0] if noisy: self.log("MILESTONE FINISH %r %r" % (next, d), level=NOISY) @@ -550,14 +557,14 @@ class OverwriteableFileConsumer(PrefixingLogMixin): # The callback means that the milestone has been reached if # it is ever going to be. Note that the file may have been # truncated to before the milestone. - eventually_callback(d)(None) + eventually(d.callback, None) def close(self): if not self.is_closed: self.is_closed = True try: self.f.close() - except BaseException, e: + except Exception, e: self.log("suppressed %r from close of temporary file %r" % (e, self.f), level=WEIRD) self.finish() @@ -572,7 +579,8 @@ class ShortReadOnlySFTPFile(PrefixingLogMixin): implements(ISFTPFile) """I represent a file handle to a particular file on an SFTP connection. I am used only for short immutable files opened in read-only mode. - The file contents are downloaded to memory when I am created.""" + When I am created, the file contents start to be downloaded to memory. + self.async is used to delay read requests until the download has finished.""" def __init__(self, userpath, filenode, metadata): PrefixingLogMixin.__init__(self, facility="tahoe.sftp", prefix=userpath) @@ -606,9 +614,9 @@ class ShortReadOnlySFTPFile(PrefixingLogMixin): # i.e. we respond with an EOF error iff offset is already at EOF. if offset >= len(data): - eventually_errback(d)(SFTPError(FX_EOF, "read at or past end of file")) + eventually(d.errback, SFTPError(FX_EOF, "read at or past end of file")) else: - eventually_callback(d)(data[offset:min(offset+length, len(data))]) + eventually(d.callback, data[offset:offset+length]) # truncated if offset+length > len(data) return data self.async.addCallbacks(_read, eventually_errback(d)) d.addBoth(_convert_error, request) @@ -703,7 +711,6 @@ class GeneralSFTPFile(PrefixingLogMixin): else: assert IFileNode.providedBy(filenode), filenode - # TODO: use download interface described in #993 when implemented. if filenode.is_mutable(): self.async.addCallback(lambda ign: filenode.download_best_version()) def _downloaded(data): @@ -721,7 +728,7 @@ class GeneralSFTPFile(PrefixingLogMixin): filenode.read(self.consumer, 0, None) self.async.addCallback(_read) - eventually_callback(self.async)(None) + eventually(self.async.callback, None) if noisy: self.log("open done", level=NOISY) return self @@ -909,7 +916,7 @@ class GeneralSFTPFile(PrefixingLogMixin): # self.filenode might be None, but that's ok. attrs = _populate_attrs(self.filenode, self.metadata, size=self.consumer.get_current_size()) - eventually_callback(d)(attrs) + eventually(d.callback, attrs) return None self.async.addCallbacks(_get, eventually_errback(d)) d.addBoth(_convert_error, request) @@ -947,7 +954,7 @@ class GeneralSFTPFile(PrefixingLogMixin): # TODO: should we refuse to truncate a file opened with FXF_APPEND? # self.consumer.set_current_size(size) - eventually_callback(d)(None) + eventually(d.callback, None) return None self.async.addCallbacks(_set, eventually_errback(d)) d.addBoth(_convert_error, request)