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mimetype.py
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# Copyright (C) 2016-2017 The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information
import click
from subprocess import Popen, PIPE
from swh.scheduler import utils
from .indexer import ContentIndexer
def compute_mimetype_encoding(raw_content):
"""Determine mimetype and encoding from the raw content.
Args:
raw_content (bytes): content's raw data
Returns:
A dict with mimetype and encoding key and corresponding values.
"""
with Popen(['file', '--mime', '-'], stdin=PIPE,
stdout=PIPE, stderr=PIPE) as p:
properties, _ = p.communicate(raw_content)
if properties:
res = properties.split(b': ')[1].strip().split(b'; ')
mimetype = res[0]
encoding = res[1].split(b'=')[1]
return {
'mimetype': mimetype,
'encoding': encoding
}
class ContentMimetypeIndexer(ContentIndexer):
"""Indexer in charge of:
- filtering out content already indexed
- reading content from objstorage per the content's id (sha1)
- computing {mimetype, encoding} from that content
- store result in storage
"""
ADDITIONAL_CONFIG = {
# chained queue message, e.g:
# swh.indexer.tasks.SWHOrchestratorTextContentsTask
'destination_queue': ('str', None),
'tools': ('dict', {
'name': 'file',
'version': '5.22',
'configuration': {
'command_line': 'file --mime <filename>',
},
}),
}
CONFIG_BASE_FILENAME = 'indexer/mimetype'
def prepare(self):
super().prepare()
destination_queue = self.config.get('destination_queue')
if destination_queue:
self.task_destination = utils.get_task(destination_queue)
else:
self.task_destination = None
self.tools = self.retrieve_tools_information()
def filter(self, sha1s):
"""Filter out known sha1s and return only missing ones.
"""
yield from self.storage.content_mimetype_missing((
{
'id': sha1,
'indexer_configuration_id': self.tools['id'],
} for sha1 in sha1s
))
def index(self, sha1, raw_content):
"""Index sha1s' content and store result.
Args:
sha1 (bytes): content's identifier
raw_content (bytes): raw content in bytes
Returns:
A dict, representing a content_mimetype, with keys:
- id (bytes): content's identifier (sha1)
- mimetype (bytes): mimetype in bytes
- encoding (bytes): encoding in bytes
"""
properties = compute_mimetype_encoding(raw_content)
properties.update({
'id': sha1,
'indexer_configuration_id': self.tools['id'],
})
return properties
def persist_index_computations(self, results, policy_update):
"""Persist the results in storage.
Args:
results ([dict]): list of content_mimetype, dict with the
following keys:
- id (bytes): content's identifier (sha1)
- mimetype (bytes): mimetype in bytes
- encoding (bytes): encoding in bytes
policy_update ([str]): either 'update-dups' or 'ignore-dups' to
respectively update duplicates or ignore them
"""
self.storage.content_mimetype_add(
results, conflict_update=(policy_update == 'update-dups'))
def _filter_text(self, results):
"""Filter sha1 whose raw content is text.
"""
for result in results:
if b'binary' in result['encoding']:
continue
yield result['id']
def next_step(self, results):
"""When the computations is done, we'd like to send over only text
contents to the text content orchestrator.
Args:
results ([dict]): List of content_mimetype results, dict
with the following keys:
- id (bytes): content's identifier (sha1)
- mimetype (bytes): mimetype in bytes
- encoding (bytes): encoding in bytes
"""
if self.task_destination:
self.task_destination.delay(list(self._filter_text(results)))
@click.command()
@click.option('--path', help="Path to execute index on")
def main(path):
with open(path, 'rb') as f:
raw_content = f.read()
print(compute_mimetype_encoding(raw_content))
if __name__ == '__main__':
main()

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text/x-python
Expires
Jul 4 2025, 7:02 PM (6 w, 18 h ago)
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blob
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Raw Data
Storage Handle
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