1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
import sys
import time
import sickle
from confluent_kafka import Producer, KafkaException
from .harvest_common import HarvestState
class HarvestOaiPmhWorker:
"""
Base class for OAI-PMH harvesters. Uses the 'sickle' protocol library.
Typically run as a single process; harvests records and publishes in raw
(XML) format to a Kafka topic, one-message-per-document.
Based on Crossref importer, with the HarvestState internal class managing
progress with day-level granularity. Note that this depends on the OAI-PMH
endpoint being correct! In that it must be possible to poll for only
records updated on a particular date (typically "yesterday").
Was very tempted to re-use <https://github.com/miku/metha> for this OAI-PMH
stuff to save on dev time, but i'd already built the Crossref harvester and
would want something similar operationally. Oh well!
"""
def __init__(self, kafka_hosts, produce_topic, state_topic,
start_date=None, end_date=None):
self.produce_topic = produce_topic
self.state_topic = state_topic
self.kafka_config = {
'bootstrap.servers': kafka_hosts,
'message.max.bytes': 20000000, # ~20 MBytes; broker is ~50 MBytes
}
self.loop_sleep = 60*60 # how long to wait, in seconds, between date checks
self.endpoint_url = None # needs override
self.metadata_prefix = None # needs override
self.name = "unnamed"
self.state = HarvestState(start_date, end_date)
self.state.initialize_from_kafka(self.state_topic, self.kafka_config)
print(self.state, file=sys.stderr)
def fetch_date(self, date):
def fail_fast(err, msg):
if err is not None:
print("Kafka producer delivery error: {}".format(err), file=sys.stderr)
print("Bailing out...", file=sys.stderr)
# TODO: should it be sys.exit(-1)?
raise KafkaException(err)
producer_conf = self.kafka_config.copy()
producer_conf.update({
'delivery.report.only.error': True,
'default.topic.config': {
'request.required.acks': -1, # all brokers must confirm
},
})
producer = Producer(producer_conf)
api = sickle.Sickle(self.endpoint_url)
date_str = date.isoformat()
# this dict kwargs hack is to work around 'from' as a reserved python keyword
# recommended by sickle docs
try:
records = api.ListRecords(**{
'metadataPrefix': self.metadata_prefix,
'from': date_str,
'until': date_str,
})
except sickle.oaiexceptions.NoRecordsMatch:
print("WARN: no OAI-PMH records for this date: {} (UTC)".format(date_str), file=sys.stderr)
return
count = 0
for item in records:
count += 1
if count % 50 == 0:
print("... up to {}".format(count), file=sys.stderr)
producer.produce(
self.produce_topic,
item.raw.encode('utf-8'),
key=item.header.identifier.encode('utf-8'),
on_delivery=fail_fast)
producer.flush()
def run(self, continuous=False):
while True:
current = self.state.next_span(continuous)
if current:
print("Fetching DOIs updated on {} (UTC)".format(current), file=sys.stderr)
self.fetch_date(current)
self.state.complete(current,
kafka_topic=self.state_topic,
kafka_config=self.kafka_config)
continue
if continuous:
print("Sleeping {} seconds...".format(self.loop_sleep), file=sys.stderr)
time.sleep(self.loop_sleep)
else:
break
print("{} OAI-PMH ingest caught up".format(self.name), file=sys.stderr)
class HarvestArxivWorker(HarvestOaiPmhWorker):
"""
Arxiv refs:
- http://export.arxiv.org/oai2?verb=GetRecord&identifier=oai:arXiv.org:0804.2273&metadataPrefix=arXiv
- http://export.arxiv.org/oai2?verb=GetRecord&identifier=oai:arXiv.org:0804.2273&metadataPrefix=arXivRaw
All records are work-level. Some metadata formats have internal info about
specific versions. The 'arXivRaw' format does, so i'm using that.
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.endpoint_url = "https://export.arxiv.org/oai2"
self.metadata_prefix = "arXivRaw"
self.name = "arxiv"
class HarvestDoajJournalWorker(HarvestOaiPmhWorker):
"""
WARNING: DOAJ OAI-PMH doesn't seem to respect 'from' and 'until' params
As an alternative, could use:
- https://github.com/miku/doajfetch
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.endpoint_url = "https://www.doaj.org/oai"
self.metadata_prefix = "oai_dc"
self.name = "doaj-journal"
class HarvestDoajArticleWorker(HarvestOaiPmhWorker):
"""
WARNING: DOAJ OAI-PMH doesn't seem to respect 'from' and 'until' params
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.endpoint_url = "https://www.doaj.org/oai.article"
self.metadata_prefix = "oai_doaj"
self.name = "doaj-article"
|
