do_api_query: Reduce error handling code duplication.

Also fixes bugs where the retry code wouldn't work correctly if
verbose wasn't set, prints out which API query had the error, and is
more consistent about printing something to end the "..." sequences.

(imported from commit 15c1e0e4a14c5c5559b43bafe4ec268451ee04f5)

common.py

@@ -32,6 +32,7 @@ import os
 # Check that we have a recent enough version
 # Older versions don't provide the 'json' attribute on responses.
 assert(requests.__version__ > '0.12')
+API_VERSTRING = "/api/v1/"
 
 class HumbugAPI(object):
     def __init__(self, email, api_key=None, api_key_file=None,
@@ -54,34 +55,54 @@ class HumbugAPI(object):
         self.client_name = client
 
     def do_api_query(self, request, url, longpolling = False):
-        had_error_retry = False
         request["email"] = self.email
         request["api-key"] = self.api_key
         request["client"] = self.client_name
-        failures = 0
 
         for (key, val) in request.iteritems():
             if not (isinstance(val, str) or isinstance(val, unicode)):
                 request[key] = simplejson.dumps(val)
 
-        while True:
-            try:
-                res = requests.post(urlparse.urljoin(self.base_url, url), data=request,
-                                    verify=True, timeout=55)
+        query_state = {
+            'had_error_retry': False,
+            'request': request,
+            'failures': 0,
+        }
 
-                # On 50x errors, try again after a short sleep
-                if str(res.status_code).startswith('5') and self.retry_on_errors and failures < 10:
+        def error_retry(error_string):
+            if not self.retry_on_errors or query_state["failures"] >= 10:
+                return False
             if self.verbose:
-                        if not had_error_retry:
-                            sys.stdout.write("connection error %s -- retrying." % (res.status_code,))
-                            had_error_retry = True
-                            request["dont_block"] = simplejson.dumps(True)
+                if not query_state["had_error_retry"]:
+                    sys.stdout.write("humbug API(%s): connection error%s -- retrying." % \
+                            (url.split(API_VERSTRING, 2)[1], error_string,))
+                    query_state["had_error_retry"] = True
                 else:
                     sys.stdout.write(".")
                 sys.stdout.flush()
+            query_state["request"]["dont_block"] = simplejson.dumps(True)
             time.sleep(1)
-                    failures += 1
+            query_state["failures"] += 1
+            return True
+
+        def end_error_retry(succeeded):
+            if query_state["had_error_retry"] and self.verbose:
+                if succeeded:
+                    print "Success!"
+                else:
+                    print "Failed!"
+
+        while True:
+            try:
+                res = requests.post(urlparse.urljoin(self.base_url, url),
+                                    data=query_state["request"],
+                                    verify=True, timeout=55)
+
+                # On 50x errors, try again after a short sleep
+                if str(res.status_code).startswith('5'):
+                    if error_retry(" (server %s)" % (res.status_code,)):
                         continue
+                    # Otherwise fall through and process the python-requests error normally
             except (requests.exceptions.Timeout, requests.exceptions.SSLError) as e:
                 # Timeouts are either a Timeout or an SSLError; we
                 # want the later exception handlers to deal with any
@@ -94,21 +115,13 @@ class HumbugAPI(object):
                     # and the correct response is to just retry
                     continue
                 else:
+                    end_error_retry(False)
                     return {'msg': "Connection error:\n%s" % traceback.format_exc(),
                             "result": "connection-error"}
             except requests.exceptions.ConnectionError:
-                if self.retry_on_errors and failures < 10:
-                    if self.verbose:
-                        if not had_error_retry:
-                            sys.stdout.write("connection error -- retrying.")
-                            had_error_retry = True
-                            request["dont_block"] = simplejson.dumps(True)
-                        else:
-                            sys.stdout.write(".")
-                        sys.stdout.flush()
-                    time.sleep(1)
-                    failures += 1
+                if error_retry(""):
                     continue
+                end_error_retry(False)
                 return {'msg': "Connection error:\n%s" % traceback.format_exc(),
                         "result": "connection-error"}
             except Exception:
@@ -116,10 +129,10 @@ class HumbugAPI(object):
                 return {'msg': "Unexpected error:\n%s" % traceback.format_exc(),
                         "result": "unexpected-error"}
 
-            if self.verbose and had_error_retry:
-                print "Success!"
             if res.json is not None:
+                end_error_retry(True)
                 return res.json
+            end_error_retry(False)
             return {'msg': res.text, "result": "http-error",
                     "status_code": res.status_code}
 
@@ -129,7 +142,7 @@ class HumbugAPI(object):
             url = name
         def call(self, *args, **kwargs):
             request = make_request(*args, **kwargs)
-            return self.do_api_query(request, '/api/v1/' + url, **query_kwargs)
+            return self.do_api_query(request, API_VERSTRING + url, **query_kwargs)
         call.func_name = name
         setattr(cls, name, call)