+"""An sqlite database for storing persistent files and hashes."""
+
from datetime import datetime, timedelta
from pysqlite2 import dbapi2 as sqlite
from binascii import a2b_base64, b2a_base64
assert sqlite.version_info >= (2, 1)
class DBExcept(Exception):
+ """An error occurred in accessing the database."""
pass
class khash(str):
"""Dummy class to convert all hashes to base64 for storing in the DB."""
-
+
+# Initialize the database to work with 'khash' objects (binary strings)
sqlite.register_adapter(khash, b2a_base64)
sqlite.register_converter("KHASH", a2b_base64)
sqlite.register_converter("khash", a2b_base64)
sqlite.enable_callback_tracebacks(True)
class DB:
- """Database access for storing persistent data."""
+ """An sqlite database for storing persistent files and hashes.
+
+ @type db: L{twisted.python.filepath.FilePath}
+ @ivar db: the database file to use
+ @type conn: L{pysqlite2.dbapi2.Connection}
+ @ivar conn: an open connection to the sqlite database
+ """
def __init__(self, db):
+ """Load or create the database file.
+
+ @type db: L{twisted.python.filepath.FilePath}
+ @param db: the database file to use
+ """
self.db = db
self.db.restat(False)
if self.db.exists():
self.conn.row_factory = sqlite.Row
def _loadDB(self):
+ """Open a new connection to the existing database file"""
try:
self.conn = sqlite.connect(database=self.db.path, detect_types=sqlite.PARSE_DECLTYPES)
except:
raise DBExcept, "Couldn't open DB", traceback.format_exc()
def _createNewDB(self):
+ """Open a connection to a new database and create the necessary tables."""
if not self.db.parent().exists():
self.db.parent().makedirs()
self.conn = sqlite.connect(database=self.db.path, detect_types=sqlite.PARSE_DECLTYPES)
self.conn.commit()
def _removeChanged(self, file, row):
+ """If the file has changed or is missing, remove it from the DB.
+
+ @type file: L{twisted.python.filepath.FilePath}
+ @param file: the file to check
+ @type row: C{dictionary}-like object
+ @param row: contains the expected 'size' and 'mtime' of the file
+ @rtype: C{boolean}
+ @return: True if the file is unchanged, False if it is changed,
+ and None if it is missing
+ """
res = None
if row:
file.restat(False)
if file.exists():
+ # Compare the current with the expected file properties
res = (row['size'] == file.getsize() and row['mtime'] == file.getmtime())
if not res:
+ # Remove the file from the database
c = self.conn.cursor()
c.execute("DELETE FROM files WHERE path = ?", (file.path, ))
self.conn.commit()
def storeFile(self, file, hash, pieces = ''):
"""Store or update a file in the database.
+ @type file: L{twisted.python.filepath.FilePath}
+ @param file: the file to check
+ @type hash: C{string}
+ @param hash: the hash of the file
+ @type pieces: C{string}
+ @param pieces: the concatenated list of the hashes of the pieces of
+ the file (optional, defaults to the empty string)
@return: True if the hash was not in the database before
(so it needs to be added to the DHT)
"""
+ # Hash the pieces to get the piecehash
piecehash = ''
if pieces:
s = sha.new().update(pieces)
piecehash = sha.digest()
+
+ # Check the database for the hash
c = self.conn.cursor()
c.execute("SELECT hashID, piecehash FROM hashes WHERE hash = ?", (khash(hash), ))
row = c.fetchone()
new_hash = False
hashID = row['hashID']
else:
+ # Add the new hash to the database
c = self.conn.cursor()
c.execute("INSERT OR REPLACE INTO hashes (hash, pieces, piecehash, refreshed) VALUES (?, ?, ?)",
(khash(hash), khash(pieces), khash(piecehash), datetime.now()))
self.conn.commit()
new_hash = True
hashID = c.lastrowid
-
+
+ # Add the file to the database
file.restat()
c.execute("INSERT OR REPLACE INTO files (path, hashID, size, mtime) VALUES (?, ?, ?, ?)",
(file.path, hashID, file.getsize(), file.getmtime()))
If it has changed or is missing, it is removed from the database.
+ @type file: L{twisted.python.filepath.FilePath}
+ @param file: the file to check
@return: dictionary of info for the file, False if changed, or
None if not in database or missing
"""
@return: list of dictionaries of info for the found files
"""
+ # Try to find the hash in the files table
c = self.conn.cursor()
c.execute("SELECT path, size, mtime, refreshed, pieces FROM files JOIN hashes USING (hashID) WHERE hash = ?", (khash(hash), ))
row = c.fetchone()
files = []
while row:
+ # Save the file to the list of found files
file = FilePath(row['path'])
res = self._removeChanged(file, row)
if res:
row = c.fetchone()
if not filesOnly and not files:
+ # No files were found, so check the piecehashes as well
c.execute("SELECT refreshed, pieces, piecehash FROM hashes WHERE piecehash = ?", (khash(hash), ))
row = c.fetchone()
if row:
def isUnchanged(self, file):
"""Check if a file in the file system has changed.
- If it has changed, it is removed from the table.
+ If it has changed, it is removed from the database.
@return: True if unchanged, False if changed, None if not in database
"""
return self._removeChanged(file, row)
def refreshHash(self, hash):
- """Refresh the publishing time all files with a hash."""
+ """Refresh the publishing time of a hash."""
c = self.conn.cursor()
c.execute("UPDATE hashes SET refreshed = ? WHERE hash = ?", (datetime.now(), khash(hash)))
c.close()
"""
t = datetime.now() - timedelta(seconds=expireAfter)
- # First find the hashes that need refreshing
+ # Find all the hashes that need refreshing
c = self.conn.cursor()
c.execute("SELECT hashID, hash, pieces FROM hashes WHERE refreshed < ?", (t, ))
row = c.fetchone()
valid = True
row = c.fetchone()
if not valid:
+ # Remove hashes for which no files are still available
del expired[hash['hash']]
c.execute("DELETE FROM hashes WHERE hashID = ?", (hash['hashID'], ))
return expired
def removeUntrackedFiles(self, dirs):
- """Find files that are no longer tracked and so should be removed.
-
- Also removes the entries from the table.
+ """Remove files that are no longer tracked by the program.
+ @type dirs: C{list} of L{twisted.python.filepath.FilePath}
+ @param dirs: a list of the directories that we are tracking
@return: list of files that were removed
"""
assert len(dirs) >= 1
+
+ # Create a list of globs and an SQL statement for the directories
newdirs = []
sql = "WHERE"
for dir in dirs:
sql += " path NOT GLOB ? AND"
sql = sql[:-4]
+ # Get a listing of all the files that will be removed
c = self.conn.cursor()
c.execute("SELECT path FROM files " + sql, newdirs)
row = c.fetchone()
removed.append(FilePath(row['path']))
row = c.fetchone()
+ # Delete all the removed files from the database
if removed:
c.execute("DELETE FROM files " + sql, newdirs)
self.conn.commit()
+
return removed
def close(self):
+ """Close the database connection."""
self.conn.close()
class TestDB(unittest.TestCase):
self.store.storeFile(self.file, self.hash)
def test_openExistingDB(self):
+ """Tests opening an existing database."""
self.store.close()
self.store = None
sleep(1)
self.failUnless(res)
def test_getFile(self):
+ """Tests retrieving a file from the database."""
res = self.store.getFile(self.file)
self.failUnless(res)
self.failUnlessEqual(res['hash'], self.hash)
def test_lookupHash(self):
+ """Tests looking up a hash in the database."""
res = self.store.lookupHash(self.hash)
self.failUnless(res)
self.failUnlessEqual(len(res), 1)
self.failUnlessEqual(res[0]['path'].path, self.file.path)
def test_isUnchanged(self):
+ """Tests checking if a file in the database is unchanged."""
res = self.store.isUnchanged(self.file)
self.failUnless(res)
sleep(2)
self.failUnless(res is None)
def test_expiry(self):
+ """Tests retrieving the files from the database that have expired."""
res = self.store.expiredHashes(1)
self.failUnlessEqual(len(res.keys()), 0)
sleep(2)
self.store.storeFile(file, self.hash)
def test_multipleHashes(self):
+ """Tests looking up a hash with multiple files in the database."""
self.build_dirs()
res = self.store.expiredHashes(1)
self.failUnlessEqual(len(res.keys()), 0)
self.failUnlessEqual(len(res.keys()), 0)
def test_removeUntracked(self):
+ """Tests removing untracked files from the database."""
self.build_dirs()
res = self.store.removeUntrackedFiles(self.dirs)
self.failUnlessEqual(len(res), 1, 'Got removed paths: %r' % res)
projects / quix0rs-apt-p2p.git / commitdiff