from __future__ import absolute_import import contextlib import errno import hashlib import logging import os from pip._internal.utils.temp_dir import TempDirectory logger = logging.getLogger(__name__) class RequirementTracker(object): def __init__(self): self._root = os.environ.get('PIP_REQ_TRACKER') if self._root is None: self._temp_dir = TempDirectory(delete=False, kind='req-tracker') self._temp_dir.create() self._root = os.environ['PIP_REQ_TRACKER'] = self._temp_dir.path logger.debug('Created requirements tracker %r', self._root) else: self._temp_dir = None logger.debug('Re-using requirements tracker %r', self._root) self._entries = set() def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.cleanup() def _entry_path(self, link): hashed = hashlib.sha224(link.url_without_fragment.encode()).hexdigest() return os.path.join(self._root, hashed) def add(self, req): link = req.link info = str(req) entry_path = self._entry_path(link) try: with open(entry_path) as fp: # Error, these's already a build in progress. raise LookupError('%s is already being built: %s' % (link, fp.read())) except IOError as e: if e.errno != errno.ENOENT: raise assert req not in self._entries with open(entry_path, 'w') as fp: fp.write(info) self._entries.add(req) logger.debug('Added %s to build tracker %r', req, self._root) def remove(self, req): link = req.link self._entries.remove(req) os.unlink(self._entry_path(link)) logger.debug('Removed %s from build tracker %r', req, self._root) def cleanup(self): for req in set(self._entries): self.remove(req) remove = self._temp_dir is not None if remove: self._temp_dir.cleanup() logger.debug('%s build tracker %r', 'Removed' if remove else 'Cleaned', self._root) @contextlib.contextmanager def track(self, req): self.add(req) yield self.remove(req)