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annotate lib/patchsource.py @ 427:db031d9ec28e
don't use 'connected' for time and for network. add rdf:type.
Ignore-this: 59899796d4785300f40137de2c2c44d5
| author | drewp@bigasterisk.com |
|---|---|
| date | Thu, 04 Apr 2019 02:19:10 -0700 |
| parents | 7716b1810d6c |
| children | fcd2c026f51e |
| rev | line source |
|---|---|
|
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170dc9b1e789
fix input graph web display by dirtying combinedGraph better.
drewp@bigasterisk.com
parents:
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diff
changeset
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1 import sys, logging |
| 302 | 2 import traceback |
| 3 from twisted.internet import reactor, defer | |
| 4 from twisted_sse_demo.eventsource import EventSource | |
| 5 from rdflib import ConjunctiveGraph | |
| 6 from rdflib.parser import StringInputSource | |
| 7 | |
| 8 sys.path.append("../../lib") | |
| 9 from patchablegraph import patchFromJson | |
| 10 | |
|
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reasoning & collector move into docker images
drewp@bigasterisk.com
parents:
312
diff
changeset
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11 sys.path.append("/my/proj/rdfdb") |
|
7716b1810d6c
reasoning & collector move into docker images
drewp@bigasterisk.com
parents:
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changeset
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12 from rdfdb.patch import Patch |
| 302 | 13 |
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312
170dc9b1e789
fix input graph web display by dirtying combinedGraph better.
drewp@bigasterisk.com
parents:
306
diff
changeset
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14 log = logging.getLogger('fetch') |
| 302 | 15 |
| 16 class PatchSource(object): | |
| 17 """wrap EventSource so it emits Patch objects and has an explicit stop method.""" | |
| 18 def __init__(self, url): | |
| 19 self.url = url | |
| 20 | |
| 21 # add callbacks to these to learn if we failed to connect | |
| 22 # (approximately) or if the ccnnection was unexpectedly lost | |
| 23 self.connectionFailed = defer.Deferred() | |
| 24 self.connectionLost = defer.Deferred() | |
| 25 | |
| 26 self._listeners = set() | |
| 27 log.info('start read from %s', url) | |
|
312
170dc9b1e789
fix input graph web display by dirtying combinedGraph better.
drewp@bigasterisk.com
parents:
306
diff
changeset
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28 # note: fullGraphReceived isn't guaranteed- the stream could |
|
170dc9b1e789
fix input graph web display by dirtying combinedGraph better.
drewp@bigasterisk.com
parents:
306
diff
changeset
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29 # start with patches |
| 302 | 30 self._fullGraphReceived = False |
| 31 self._eventSource = EventSource(url.toPython().encode('utf8')) | |
| 32 self._eventSource.protocol.delimiter = '\n' | |
| 33 | |
| 34 self._eventSource.addEventListener('fullGraph', self._onFullGraph) | |
| 35 self._eventSource.addEventListener('patch', self._onPatch) | |
| 36 self._eventSource.onerror(self._onError) | |
| 37 | |
| 38 origSet = self._eventSource.protocol.setFinishedDeferred | |
| 39 def sfd(d): | |
| 40 origSet(d) | |
| 41 d.addCallback(self._onDisconnect) | |
| 42 self._eventSource.protocol.setFinishedDeferred = sfd | |
| 306 | 43 |
| 44 def stats(self): | |
| 45 return { | |
| 46 'url': self.url, | |
| 47 'fullGraphReceived': self._fullGraphReceived, | |
| 48 } | |
| 302 | 49 |
| 50 def addPatchListener(self, func): | |
| 51 """ | |
| 52 func(patch, fullGraph=[true if the patch is the initial fullgraph]) | |
| 53 """ | |
| 54 self._listeners.add(func) | |
| 55 | |
| 56 def stop(self): | |
| 57 log.info('stop read from %s', self.url) | |
| 58 try: | |
| 59 self._eventSource.protocol.stopProducing() # needed? | |
| 60 except AttributeError: | |
| 61 pass | |
| 62 self._eventSource = None | |
| 63 | |
| 64 def _onDisconnect(self, a): | |
| 65 log.debug('PatchSource._onDisconnect from %s', self.url) | |
| 66 # skip this if we're doing a stop? | |
| 67 self.connectionLost.callback(None) | |
| 68 | |
| 69 def _onError(self, msg): | |
| 70 log.debug('PatchSource._onError from %s %r', self.url, msg) | |
| 71 if not self._fullGraphReceived: | |
| 72 self.connectionFailed.callback(msg) | |
| 73 else: | |
| 74 self.connectionLost.callback(msg) | |
| 75 | |
| 76 def _onFullGraph(self, message): | |
| 77 try: | |
| 78 g = ConjunctiveGraph() | |
| 79 g.parse(StringInputSource(message), format='json-ld') | |
| 80 p = Patch(addGraph=g) | |
| 81 self._sendPatch(p, fullGraph=True) | |
| 82 except: | |
| 83 log.error(traceback.format_exc()) | |
| 84 raise | |
| 85 self._fullGraphReceived = True | |
| 86 | |
| 87 def _onPatch(self, message): | |
| 88 try: | |
| 89 p = patchFromJson(message) | |
| 90 self._sendPatch(p, fullGraph=False) | |
| 91 except: | |
| 92 log.error(traceback.format_exc()) | |
| 93 raise | |
| 94 | |
| 95 def _sendPatch(self, p, fullGraph): | |
| 96 log.debug('PatchSource %s received patch %s (fullGraph=%s)', self.url, p.shortSummary(), fullGraph) | |
| 97 for lis in self._listeners: | |
| 98 lis(p, fullGraph=fullGraph) | |
| 99 | |
| 100 def __del__(self): | |
| 101 if self._eventSource: | |
| 102 raise ValueError | |
| 103 | |
| 104 class ReconnectingPatchSource(object): | |
| 105 """ | |
| 106 PatchSource api, but auto-reconnects internally and takes listener | |
| 107 at init time to not miss any patches. You'll get another | |
| 108 fullGraph=True patch if we have to reconnect. | |
| 109 | |
| 110 todo: generate connection stmts in here | |
| 111 """ | |
| 112 def __init__(self, url, listener): | |
| 113 self.url = url | |
| 114 self._stopped = False | |
| 115 self._listener = listener | |
| 116 self._reconnect() | |
| 117 | |
| 118 def _reconnect(self): | |
| 119 if self._stopped: | |
| 120 return | |
| 121 self._ps = PatchSource(self.url) | |
| 122 self._ps.addPatchListener(self._onPatch) | |
| 123 self._ps.connectionFailed.addCallback(self._onConnectionFailed) | |
| 124 self._ps.connectionLost.addCallback(self._onConnectionLost) | |
| 125 | |
| 126 def _onPatch(self, p, fullGraph): | |
| 127 self._listener(p, fullGraph=fullGraph) | |
| 306 | 128 |
| 129 def stats(self): | |
| 130 return { | |
| 131 'reconnectedPatchSource': self._ps.stats(), | |
| 132 } | |
| 302 | 133 |
| 134 def stop(self): | |
| 135 self._stopped = True | |
| 136 self._ps.stop() | |
| 137 | |
| 138 def _onConnectionFailed(self, arg): | |
| 139 reactor.callLater(60, self._reconnect) | |
| 140 | |
| 141 def _onConnectionLost(self, arg): | |
| 142 reactor.callLater(60, self._reconnect) | |
| 143 |