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- import fcntl
- import io
- import logging
- import time
- import warcio
-
-
- class WARC:
- def __init__(self, prefix, maxFileSize, dedupe):
- '''
- Initialise the WARC writer
-
- prefix: str, path prefix for WARCs; a dash, a five-digit number, and ".warc.gz" will be appended.
- maxFileSize: int, maximum size of an individual WARC. Use 0 to disable splitting.
- dedupe: bool, whether to enable record deduplication
- '''
-
- self._prefix = prefix
- self._counter = 0
- self._maxFileSize = maxFileSize
-
- self._closed = True
- self._file = None
- self._warcWriter = None
-
- self._dedupe = dedupe
- self._dedupeMap = {}
-
- def _ensure_opened(self):
- '''Open the next file that doesn't exist yet if there is currently no file opened'''
-
- if not self._closed:
- return
- while True:
- filename = f'{self._prefix}-{self._counter:05d}.warc.gz'
- try:
- # Try to open the file for writing, requiring that it does not exist yet, and attempt to get an exclusive, non-blocking lock on it
- self._file = open(filename, 'xb')
- fcntl.flock(self._file.fileno(), fcntl.LOCK_EX | fcntl.LOCK_NB)
- except FileExistsError:
- logging.info(f'{filename} already exists, skipping')
- self._counter += 1
- else:
- break
- logging.info(f'Opened {filename}')
- self._warcWriter = warcio.warcwriter.WARCWriter(self._file, gzip = True)
- self._closed = False
- self._counter += 1
-
- def write_client_response(self, response):
- '''
- Write the requests and responses stored in a ClientResponse instance to the currently opened WARC.
- A new WARC will be started automatically if the size of the current file exceeds the limit after writing all requests and responses from this `response` to the current WARC.
- '''
-
- self._ensure_opened()
- for r in response.iter_all():
- requestDate = time.strftime('%Y-%m-%dT%H:%M:%SZ', time.gmtime(r.rawRequestTimestamp))
- requestRecord = self._warcWriter.create_warc_record(
- str(r.url),
- 'request',
- payload = io.BytesIO(r.rawRequestData),
- warc_headers_dict = {
- 'WARC-Date': requestDate,
- 'WARC-IP-Address': r.remoteAddress[0],
- }
- )
- requestRecordID = requestRecord.rec_headers.get_header('WARC-Record-ID')
- responseRecord = self._warcWriter.create_warc_record(
- str(r.url),
- 'response',
- payload = io.BytesIO(r.rawResponseData),
- warc_headers_dict = {
- 'WARC-Date': requestDate,
- 'WARC-IP-Address': r.remoteAddress[0],
- 'WARC-Concurrent-To': requestRecordID,
- }
- )
- payloadDigest = responseRecord.rec_headers.get_header('WARC-Payload-Digest')
- assert payloadDigest is not None
- if self._dedupe and responseRecord.payload_length > 0: # Don't "deduplicate" empty responses
- if payloadDigest in self._dedupeMap:
- refersToRecordId, refersToUri, refersToDate = self._dedupeMap[payloadDigest]
- responseHttpHeaders = responseRecord.http_headers
- responseRecord = self._warcWriter.create_revisit_record(
- str(r.url),
- digest = payloadDigest,
- refers_to_uri = refersToUri,
- refers_to_date = refersToDate,
- http_headers = responseHttpHeaders,
- warc_headers_dict = {
- 'WARC-Date': requestDate,
- 'WARC-IP-Address': r.remoteAddress[0],
- 'WARC-Concurrent-To': requestRecordID,
- 'WARC-Refers-To': refersToRecordId,
- 'WARC-Truncated': 'length',
- }
- )
- else:
- self._dedupeMap[payloadDigest] = (responseRecord.rec_headers.get_header('WARC-Record-ID'), str(r.url), requestDate)
- self._warcWriter.write_record(requestRecord)
- self._warcWriter.write_record(responseRecord)
-
- if self._maxFileSize and self._file.tell() > self._maxFileSize:
- self.close()
-
- def close(self):
- '''Close the currently opened WARC'''
-
- if not self._closed:
- self._file.close()
- self._warcWriter = None
- self._file = None
- self._closed = True
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