+import logging
+import os
+import sqlite3
+import time
+
+import misc
+
+class Locator:
+ def __init__(self, base_dir, exclude_dir, db_file):
+ self._base_dir = base_dir
+ self._exclude_dir = exclude_dir
+ if not os.path.isfile(db_file):
+ self._conn = sqlite3.connect(db_file)
+ self._create_db()
+ else:
+ self._conn = sqlite3.connect(db_file)
+ logging.info("Opened locator for %s.", self._base_dir)
+
+ def locate_file(self, name, size, meta_time):
+ c = self._conn.cursor()
+ c.execute("SELECT file_dir FROM cache WHERE name=? AND size=? AND meta_time=?",
+ (name, size, meta_time))
+ cached = c.fetchone()
+ if cached:
+ if os.path.isfile(cached[0]) and \
+ os.path.getsize(cached[0]) == size and \
+ misc.extract_meta_time(cached[0]) == meta_time:
+ self._update_cache_access_time(name, size, meta_time)
+ return cached[0]
+ else:
+ self._remove_from_cache(name, size, meta_time)
+ else:
+ file_dir = misc.find_file(name, size, meta_time)
+ if file_dir:
+ self._clean_cache()
+ self._add_to_cache(name, size, meta_time, file_dir)
+ return file_dir
+
+ def close(self):
+ logging.info("Closing locator for %s...", self._base_dir)
+ self._conn.close()
+
+ def _update_cache_access_time(self, name, size, meta_time):
+ c = self._conn.cursor()
+ c.execute("UPDATE cache SET access_time=? WHERE name=? AND size=? AND meta_time=?",
+ (int(time.time()), name, size, meta_time))
+ self._conn.commit()
+
+ def _remove_from_cache(self, name, size, meta_time):
+ c = self._conn.cursor()
+ c.execute("DELETE FROM cache WHERE name=? AND size=? AND meta_time=?",
+ (name, size, meta_time))
+ self._conn.commit()
+
+ def _add_to_cache(self, name, size, meta_time, file_dir):
+ c = self._conn.cursor()
+ c.execute('''INSERT INTO cache (name, size, meta_time, file_dir, access_time)
+ VALUES (?, ?, ?, ?, ?)''',
+ (name, size, meta_time, file_dir, int(time.time())))
+ self._conn.commit()
+
+ def _clean_cache(self):
+ c = self._conn.cursor()
+ c.execute("DELETE FROM cache WHERE access_time<?", (int(time.time()) - 604800))
+ self._conn.commit()
+
+ def _create_db(self):
+ logging.info("Creating locator database for %s...", self._base_dir)
+ c = self._conn.cursor()
+ c.execute('''CREATE TABLE cache
+ (name TEXT, size INTEGER, meta_time INTEGER, file_dir TEXT,
+ access_time INTEGER)
+ PRIMARY KEY (name, size, meta_time)''')
+ self._conn.commit()