From: Tom Clegg <tom@curoverse.com>
Date: Mon, 8 Feb 2016 19:18:42 +0000 (-0500)
Subject: 8341: Use a Queue of lines and one thread, instead of a succession of threads and... 
X-Git-Tag: 1.1.0~1126^2
X-Git-Url: https://git.arvados.org/arvados.git/commitdiff_plain/d7e8f7c787b7706937f95c3ed2a5086616d48514?ds=sidebyside

8341: Use a Queue of lines and one thread, instead of a succession of threads and a deque of buffers.
---

diff --git a/tools/crunchstat-summary/crunchstat_summary/reader.py b/tools/crunchstat-summary/crunchstat_summary/reader.py
index 52d7e80f58..049b48f063 100644
--- a/tools/crunchstat-summary/crunchstat_summary/reader.py
+++ b/tools/crunchstat-summary/crunchstat_summary/reader.py
@@ -1,7 +1,7 @@
 from __future__ import print_function
 
 import arvados
-import collections
+import Queue
 import threading
 
 from crunchstat_summary import logger
@@ -23,59 +23,47 @@ class CollectionReader(object):
 
 
 class LiveLogReader(object):
+    EOF = None
+
     def __init__(self, job_uuid):
         logger.debug('load stderr events for job %s', job_uuid)
         self._filters = [
             ['object_uuid', '=', job_uuid],
             ['event_type', '=', 'stderr']]
-        self._buffer = collections.deque()
-        self._got = 0
         self._label = job_uuid
-        self._last_id = 0
-        self._start_getting_next_page()
-
-    def _start_getting_next_page(self):
-        self._thread = threading.Thread(target=self._get_next_page)
-        self._thread.daemon = True
-        self._thread.start()
 
-    def _get_next_page(self):
-        page = arvados.api().logs().index(
-            limit=1000,
-            order=['id asc'],
-            filters=self._filters + [['id','>',str(self._last_id)]],
-        ).execute()
-        self._got += len(page['items'])
-        logger.debug(
-            '%s: received %d of %d log events',
-            self._label, self._got,
-            self._got + page['items_available'] - len(page['items']))
-        self._page = page
-
-    def _buffer_page(self):
-        """Wait for current worker, copy results to _buffer, start next worker.
-
-        Return True if anything was added to the buffer."""
-        if self._thread is None:
-            return False
-        self._thread.join()
-        self._thread = None
-        page = self._page
-        if len(page['items']) == 0:
-            return False
-        if len(page['items']) < page['items_available']:
-            self._start_getting_next_page()
-        for i in page['items']:
-            for line in i['properties']['text'].split('\n'):
-                self._buffer.append(line)
-            self._last_id = i['id']
-        return True
+    def _get_all_pages(self):
+        got = 0
+        last_id = 0
+        while True:
+            page = arvados.api().logs().index(
+                limit=1000,
+                order=['id asc'],
+                filters=self._filters + [['id','>',str(last_id)]],
+            ).execute(num_retries=2)
+            got += len(page['items'])
+            logger.debug(
+                '%s: received %d of %d log events',
+                self._label, got,
+                got + page['items_available'] - len(page['items']))
+            for i in page['items']:
+                for line in i['properties']['text'].split('\n'):
+                    self._queue.put(line+'\n')
+                last_id = i['id']
+            if (len(page['items']) == 0 or
+                len(page['items']) >= page['items_available']):
+                break
+        self._queue.put(self.EOF)
 
     def __iter__(self):
+        self._queue = Queue.Queue()
+        self._thread = threading.Thread(target=self._get_all_pages)
+        self._thread.daemon = True
+        self._thread.start()
         return self
 
     def next(self):
-        if len(self._buffer) == 0:
-            if not self._buffer_page():
-                raise StopIteration
-        return self._buffer.popleft() + '\n'
+        line = self._queue.get()
+        if line is self.EOF:
+            raise StopIteration
+        return line