1 files changed, 127 insertions, 0 deletions
diff --git a/python/fatcat_tools/harvest/ingest_common.py b/python/fatcat_tools/harvest/ingest_common.py
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+++ b/python/fatcat_tools/harvest/ingest_common.py
@@ -0,0 +1,127 @@
+
+"""
+logic:
+- on start, fetch latest date from state feed
+- in a function (unit-testable), decide which dates to ingest
+- for each date needing update:
+    - start a loop for just that date, using resumption token for this query
+    - when done, publish to state feed, with immediate sync
+"""
+
+import re
+import sys
+import csv
+import json
+import requests
+import itertools
+import datetime
+from pykafka import KafkaClient
+
+from fatcat_tools.workers.worker_common import most_recent_message
+
+DATE_FMT = "%Y-%m-%d"
+
+class DoiApiHarvest:
+    """
+    This class supports core features for both the Crossref and Datacite REST
+    APIs for fetching updated metadata (the Datacite API seems to be moduled on
+    the Crossref API).
+
+    Implementations must provide the push results function.
+    """
+
+    def __init__(self, kafka_hosts, produce_topic, state_topic, api_host_url,
+            contact_email, start_date=None, end_date=None):
+        self.loop_sleep = 60*60 # how long to wait, in seconds, between date checks
+        self.api_batch_size = 50
+        self.api_host_url = api_host_url
+        self.produce_topic = produce_topic
+        self.state_topic = state_topic
+        self.contact_email = contact_email
+        self.kafka = KafkaClient(hosts=kafka_hosts, broker_version="1.0.0")
+        self.is_update_filter = None
+        self.update_filter_name = "index"
+
+        # these are both optional, and should be datetime.date
+        self.start_date = start_date
+        self.end_date = end_date
+
+    def get_latest_date(self):
+
+        state_topic = self.kafka.topics[self.state_topic]
+        latest = most_recent_message(state_topic)
+        if latest:
+            latest = datetime.datetime.strptime(latest.decode('utf-8'), DATE_FMT).date()
+        print("Latest date found: {}".format(latest))
+        return latest
+
+    def fetch_date(self, date):
+
+        state_topic = self.kafka.topics[self.state_topic]
+        produce_topic = self.kafka.topics[self.produce_topic]
+ 
+        date_str = date.strftime(DATE_FMT)
+        filter_param = 'from-{index}-date:{},until-{index}-date:{}'.format(
+            date_str, date_str, index=self.update_filter_name)
+        if self.is_update_filter is not None:
+            filter_param += ',is_update:{}'.format(bool(is_update))
+        params = {
+            'filter': filter_param,
+            'rows': self.api_batch_size,
+            'cursor': '*',
+        }
+        headers = {
+            'User-Agent': 'fatcat_tools/0.1.0 (https://fatcat.wiki; mailto:{}) python-requests'.format(self.contact_email),
+        }
+        count = 0
+        with produce_topic.get_producer() as producer:
+            while True:
+                http_resp = requests.get(self.api_host_url, params, headers=headers)
+                assert http_resp.status_code is 200
+                resp = http_resp.json()
+                items = resp['message']['items']
+                count += len(items)
+                print("... got {} ({} of {}) in {}".format(len(items), count,
+                    resp['message']['total-results']), http_resp.elapsed)
+                #print(json.dumps(resp))
+                for work in items:
+                    producer.produce(json.dumps(work).encode('utf-8'))
+                if len(items) < params['rows']:
+                    break
+                params['cursor'] = resp['message']['next-cursor']
+
+        # record our completion state
+        with state_topic.get_sync_producer() as producer:
+            producer.produce(date.strftime(DATE_FMT).encode('utf-8'))
+        
+
+    def run_once(self):
+        today_utc = datetime.datetime.utcnow().date()
+        if self.start_date is None:
+            self.start_date = self.get_latest_date()
+            if self.start_date: 
+                # if we are continuing, start day after last success
+                self.start_date = self.start_date + datetime.timedelta(days=1)
+        if self.start_date is None:
+            # bootstrap to yesterday (don't want to start on today until it's over)
+            self.start_date = datetime.datetime.utcnow().date()
+        if self.end_date is None:
+            # bootstrap to yesterday (don't want to start on today until it's over)
+            self.end_date = today_utc - datetime.timedelta(days=1)
+        print("Harvesting from {} through {}".format(self.start_date, self.end_date))
+        current = self.start_date
+        while current <= self.end_date:
+            print("Fetching DOIs updated on {} (UTC)".format(current))
+            self.fetch_date(current)
+            current += datetime.timedelta(days=1)
+        print("Crossref DOI ingest caught up through {}".format(self.end_date))
+        return self.end_date
+
+    def run_loop(self):
+        while True:
+            last = self.run_once()
+            self.start_date = last
+            self.end_date = None
+            print("Sleeping {} seconds...".format(self.loop_sleep))
+            time.sleep(self.loop_sleep())
+