Cleaned up the database driver.

- The SQLDatabase class now uses a context manager for mysql access.
- Most of the error handling is done by the context manager now
- Optimized several methods that returned a list into returning a generator
- Optimized return_matches to use an IN query instead.
- Other small fixes.
This commit is contained in:
Wessie 2013-12-17 01:39:03 +01:00
parent f918b6b7e0
commit 0bd7219b87
2 changed files with 243 additions and 206 deletions

52
dejavu/cursor.py Normal file
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@ -0,0 +1,52 @@
from __future__ import unicode_literals
from __future__ import absolute_import
import Queue
import pymysql
import pymysql.cursors
def cursor_factory(**factory_options):
def cursor(**options):
options.update(factory_options)
return Cursor(**options)
return cursor
class Cursor(object):
"""
Establishes a connection to the database and returns an open cursor.
```python
# Use as context manager
with Cursor() as cur:
cur.execute(query)
```
"""
_cache = Queue.Queue(maxsize=5)
def __init__(self, cursor_type=pymysql.cursors.DictCursor, **options):
super(Cursor, self).__init__()
try:
conn = self._cache.get_nowait()
except Queue.Empty:
conn = pymysql.connect(**options)
self.conn = conn
self.cursor_type = cursor_type
def __enter__(self):
self.cursor = self.conn.cursor(self.cursor_type)
return self.cursor
def __exit__(self, type, value, traceback):
self.cursor.close()
self.conn.commit()
# Put it back on the queue
try:
self._cache.put_nowait(self.conn)
except Queue.Full:
self.conn.close()

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@ -1,40 +1,44 @@
import MySQLdb as mysql
import MySQLdb.cursors as cursors
import os
from __future__ import absolute_import
from binascii import unhexlify
class SQLDatabase():
class Database(object):
def __init__(self):
super(Database, self).__init__()
class SQLDatabase(Database):
"""
Queries:
1) Find duplicates (shouldn't be any, though):
select `hash`, `song_id`, `offset`, count(*) cnt
from fingerprints
group by `hash`, `song_id`, `offset`
select `hash`, `song_id`, `offset`, count(*) cnt
from fingerprints
group by `hash`, `song_id`, `offset`
having cnt > 1
order by cnt asc;
2) Get number of hashes by song:
select song_id, song_name, count(song_id) as num
from fingerprints
select song_id, song_name, count(song_id) as num
from fingerprints
natural join songs
group by song_id
group by song_id
order by count(song_id) desc;
3) get hashes with highest number of collisions
select
hash,
count(distinct song_id) as n
from fingerprints
group by `hash`
select
hash,
count(distinct song_id) as n
from fingerprints
group by `hash`
order by n DESC;
=> 26 different songs with same fingerprint (392 times):
select songs.song_name, fingerprints.offset
from fingerprints natural join songs
select songs.song_name, fingerprints.offset
from fingerprints natural join songs
where fingerprints.hash = "08d3c833b71c60a7b620322ac0c0aba7bf5a3e73";
"""
@ -57,269 +61,250 @@ class SQLDatabase():
FIELD_FINGERPRINTED = "fingerprinted"
# creates
CREATE_FINGERPRINTS_TABLE = """
CREATE TABLE IF NOT EXISTS `%s` (
`%s` binary(10) not null,
`%s` mediumint unsigned not null,
`%s` int unsigned not null,
CREATE_FINGERPRINTS_TABLE = """
CREATE TABLE IF NOT EXISTS `%s` (
`%s` binary(10) not null,
`%s` mediumint unsigned not null,
`%s` int unsigned not null,
INDEX(%s),
UNIQUE(%s, %s, %s)
);""" % (FINGERPRINTS_TABLENAME, FIELD_HASH,
FIELD_SONG_ID, FIELD_OFFSET, FIELD_HASH,
FIELD_SONG_ID, FIELD_OFFSET, FIELD_HASH)
);""" % (
FINGERPRINTS_TABLENAME, FIELD_HASH,
FIELD_SONG_ID, FIELD_OFFSET, FIELD_HASH,
FIELD_SONG_ID, FIELD_OFFSET, FIELD_HASH,
)
CREATE_SONGS_TABLE = """
CREATE TABLE IF NOT EXISTS `%s` (
`%s` mediumint unsigned not null auto_increment,
`%s` varchar(250) not null,
`%s` tinyint default 0,
CREATE TABLE IF NOT EXISTS `%s` (
`%s` mediumint unsigned not null auto_increment,
`%s` varchar(250) not null,
`%s` tinyint default 0,
PRIMARY KEY (`%s`),
UNIQUE KEY `%s` (`%s`)
);""" % (SONGS_TABLENAME, FIELD_SONG_ID, FIELD_SONGNAME, FIELD_FINGERPRINTED,
FIELD_SONG_ID, FIELD_SONG_ID, FIELD_SONG_ID)
);""" % (
SONGS_TABLENAME, FIELD_SONG_ID, FIELD_SONGNAME, FIELD_FINGERPRINTED,
FIELD_SONG_ID, FIELD_SONG_ID, FIELD_SONG_ID,
)
# inserts (ignores duplicates)
INSERT_FINGERPRINT = """
INSERT IGNORE INTO %s (%s, %s, %s) VALUES
(UNHEX(%%s), %%s, %%s);
""" % (FINGERPRINTS_TABLENAME, FIELD_HASH, FIELD_SONG_ID, FIELD_OFFSET)
# inserts
INSERT_FINGERPRINT = "INSERT IGNORE INTO %s (%s, %s, %s) VALUES (UNHEX(%%s), %%s, %%s)" % (
FINGERPRINTS_TABLENAME, FIELD_HASH, FIELD_SONG_ID, FIELD_OFFSET) # ignore duplicates and don't insert them
INSERT_SONG = "INSERT INTO %s (%s) VALUES (%%s);" % (
SONGS_TABLENAME, FIELD_SONGNAME)
# selects
SELECT = "SELECT %s, %s FROM %s WHERE %s = UNHEX(%%s);" % (FIELD_SONG_ID, FIELD_OFFSET, FINGERPRINTS_TABLENAME, FIELD_HASH)
SELECT_ALL = "SELECT %s, %s FROM %s;" % (FIELD_SONG_ID, FIELD_OFFSET, FINGERPRINTS_TABLENAME)
SELECT_SONG = "SELECT %s FROM %s WHERE %s = %%s" % (FIELD_SONGNAME, SONGS_TABLENAME, FIELD_SONG_ID)
SELECT_NUM_FINGERPRINTS = "SELECT COUNT(*) as n FROM %s" % (FINGERPRINTS_TABLENAME)
SELECT_UNIQUE_SONG_IDS = "SELECT COUNT(DISTINCT %s) as n FROM %s WHERE %s = 1;" % (FIELD_SONG_ID, SONGS_TABLENAME, FIELD_FINGERPRINTED)
SELECT_SONGS = "SELECT %s, %s FROM %s WHERE %s = 1;" % (FIELD_SONG_ID, FIELD_SONGNAME, SONGS_TABLENAME, FIELD_FINGERPRINTED)
SELECT = """
SELECT %s, %s FROM %s WHERE %s = UNHEX(%%s);
""" % (FIELD_SONG_ID, FIELD_OFFSET, FINGERPRINTS_TABLENAME, FIELD_HASH)
SELECT_MULTIPLE = """
SELECT HEX(%s), %s, %s FROM %s WHERE %s IN (%%s);
""" % (FIELD_HASH, FIELD_SONG_ID, FIELD_OFFSET,
FINGERPRINTS_TABLENAME, FIELD_HASH)
SELECT_ALL = """
SELECT %s, %s FROM %s;
""" % (FIELD_SONG_ID, FIELD_OFFSET, FINGERPRINTS_TABLENAME)
SELECT_SONG = """
SELECT %s FROM %s WHERE %s = %%s
""" % (FIELD_SONGNAME, SONGS_TABLENAME, FIELD_SONG_ID)
SELECT_NUM_FINGERPRINTS = """
SELECT COUNT(*) as n FROM %s
""" % (FINGERPRINTS_TABLENAME)
SELECT_UNIQUE_SONG_IDS = """
SELECT COUNT(DISTINCT %s) as n FROM %s WHERE %s = 1;
""" % (FIELD_SONG_ID, SONGS_TABLENAME, FIELD_FINGERPRINTED)
SELECT_SONGS = """
SELECT %s, %s FROM %s WHERE %s = 1;
""" % (FIELD_SONG_ID, FIELD_SONGNAME, SONGS_TABLENAME, FIELD_FINGERPRINTED)
# drops
DROP_FINGERPRINTS = "DROP TABLE IF EXISTS %s;" % FINGERPRINTS_TABLENAME
DROP_SONGS = "DROP TABLE IF EXISTS %s;" % SONGS_TABLENAME
# update
UPDATE_SONG_FINGERPRINTED = "UPDATE %s SET %s = 1 WHERE %s = %%s" % (SONGS_TABLENAME, FIELD_FINGERPRINTED, FIELD_SONG_ID)
UPDATE_SONG_FINGERPRINTED = """
UPDATE %s SET %s = 1 WHERE %s = %%s
""" % (SONGS_TABLENAME, FIELD_FINGERPRINTED, FIELD_SONG_ID)
# delete
DELETE_UNFINGERPRINTED = "DELETE FROM %s WHERE %s = 0;" % (SONGS_TABLENAME, FIELD_FINGERPRINTED)
DELETE_UNFINGERPRINTED = """
DELETE FROM %s WHERE %s = 0;
""" % (SONGS_TABLENAME, FIELD_FINGERPRINTED)
DELETE_ORPHANS = """
delete from fingerprints
where not exists (
select * from songs where fingerprints.song_id = songs.song_id
)"""
def __init__(self, hostname, username, password, database):
# connect
self.database = database
try:
# http://www.halfcooked.com/mt/archives/000969.html
self.connection = mysql.connect(
hostname, username, password,
database, cursorclass=cursors.DictCursor)
delete from fingerprints
where not exists (
select * from songs where fingerprints.song_id = songs.song_id
);
"""
self.connection.autocommit(False) # for fast bulk inserts
self.cursor = self.connection.cursor()
except mysql.Error, e:
print "Connection error %d: %s" % (e.args[0], e.args[1])
def __init__(self, cursor):
super(SQLDatabase, self).__init__()
self.cursor = cursor
def setup(self):
try:
# create fingerprints table
self.cursor.execute("USE %s;" % self.database)
self.cursor.execute(SQLDatabase.CREATE_FINGERPRINTS_TABLE)
self.cursor.execute(SQLDatabase.CREATE_SONGS_TABLE)
self.delete_unfingerprinted_songs()
self.connection.commit()
except mysql.Error, e:
print "Connection error %d: %s" % (e.args[0], e.args[1])
self.connection.rollback()
with self.cursor() as cur:
cur.execute(self.CREATE_FINGERPRINTS_TABLE)
cur.execute(self.CREATE_SONGS_TABLE)
cur.execute(self.DELETE_UNFINGERPRINTED)
def empty(self):
"""
Drops all tables and re-adds them. Be carfeul with this!
"""
try:
self.cursor.execute("USE %s;" % self.database)
with self.cursor() as cur:
cur.execute(self.DROP_FINGERPRINTS)
cur.execute(self.DROP_SONGS)
# drop tables
self.cursor.execute(SQLDatabase.DROP_FINGERPRINTS)
self.cursor.execute(SQLDatabase.DROP_SONGS)
self.setup()
# recreate
self.cursor.execute(SQLDatabase.CREATE_FINGERPRINTS_TABLE)
self.cursor.execute(SQLDatabase.CREATE_SONGS_TABLE)
self.connection.commit()
except mysql.Error, e:
print "Error in empty(), %d: %s" % (e.args[0], e.args[1])
self.connection.rollback()
def delete_orphans(self):
try:
self.cursor = self.connection.cursor()
### TODO: SQLDatabase.DELETE_ORPHANS is not performant enough, need better query
### to delete fingerprints for which no song is tied to.
#self.cursor.execute(SQLDatabase.DELETE_ORPHANS)
#self.connection.commit()
except mysql.Error, e:
print "Error in delete_orphans(), %d: %s" % (e.args[0], e.args[1])
self.connection.rollback()
# TODO: SQLDatabase.DELETE_ORPHANS is not
# performant enough, need better query to
# delete fingerprints for which no song is tied to.
# with self.cursor() as cur:
# cur.execute(self.DELETE_ORPHANS)
pass
def delete_unfingerprinted_songs(self):
try:
self.cursor = self.connection.cursor()
self.cursor.execute(SQLDatabase.DELETE_UNFINGERPRINTED)
self.connection.commit()
except mysql.Error, e:
print "Error in delete_unfingerprinted_songs(), %d: %s" % (e.args[0], e.args[1])
self.connection.rollback()
with self.cursor() as cur:
cur.execute(self.DELETE_UNFINGERPRINTED)
def get_num_songs(self):
"""
Returns number of songs the database has fingerprinted.
Returns number of songs the database has fingerprinted.
"""
try:
self.cursor = self.connection.cursor()
self.cursor.execute(SQLDatabase.SELECT_UNIQUE_SONG_IDS)
record = self.cursor.fetchone()
return int(record['n'])
except mysql.Error, e:
print "Error in get_num_songs(), %d: %s" % (e.args[0], e.args[1])
with self.cursor() as cur:
cur.execute(self.SELECT_UNIQUE_SONG_IDS)
for row in cur:
return row['n']
def get_num_fingerprints(self):
"""
Returns number of fingerprints the database has fingerprinted.
Returns number of fingerprints the database has fingerprinted.
"""
try:
self.cursor = self.connection.cursor()
self.cursor.execute(SQLDatabase.SELECT_NUM_FINGERPRINTS)
record = self.cursor.fetchone()
return int(record['n'])
except mysql.Error, e:
print "Error in get_num_songs(), %d: %s" % (e.args[0], e.args[1])
with self.cursor() as cur:
cur.execute(self.SELECT_NUM_FINGERPRINTS)
def set_song_fingerprinted(self, song_id):
for row in cur:
return row['n']
def set_song_fingerprinted(self, sid):
"""
Set the fingerprinted flag to TRUE (1) once a song has been completely
fingerprinted in the database.
Set the fingerprinted flag to TRUE (1) once a song has been completely
fingerprinted in the database.
"""
try:
self.cursor = self.connection.cursor()
self.cursor.execute(SQLDatabase.UPDATE_SONG_FINGERPRINTED, song_id)
self.connection.commit()
except mysql.Error, e:
print "Error in set_song_fingerprinted(), %d: %s" % (e.args[0], e.args[1])
self.connection.rollback()
with self.cursor() as cur:
cur.execute(self.UPDATE_SONG_FINGERPRINTED, (sid,))
def get_songs(self):
"""
Return songs that have the fingerprinted flag set TRUE (1).
Return songs that have the fingerprinted flag set TRUE (1).
"""
try:
self.cursor.execute(SQLDatabase.SELECT_SONGS)
return self.cursor.fetchall()
except mysql.Error, e:
print "Error in get_songs(), %d: %s" % (e.args[0], e.args[1])
return None
with self.cursor() as cur:
cur.execute(self.SELECT_SONGS)
for row in cur:
yield row
def get_song_by_id(self, sid):
"""
Returns song by its ID.
Returns song by its ID.
"""
try:
self.cursor.execute(SQLDatabase.SELECT_SONG, (sid,))
return self.cursor.fetchone()
except mysql.Error, e:
print "Error in get_songs(), %d: %s" % (e.args[0], e.args[1])
return None
with self.cursor() as cur:
cur.execute(self.SELECT_SONG, (sid,))
return cur.fetchone()
def insert(self, key, value):
def insert(self, hash, sid, offset):
"""
Insert a (sha1, song_id, offset) row into database.
key is a sha1 hash, value = (song_id, offset)
Insert a (sha1, song_id, offset) row into database.
"""
try:
args = (key, value[0], value[1])
self.cursor.execute(SQLDatabase.INSERT_FINGERPRINT, args)
except mysql.Error, e:
print "Error in insert(), %d: %s" % (e.args[0], e.args[1])
self.connection.rollback()
with self.cursor() as cur:
cur.execute(self.INSERT_FINGERPRINT, (hash, sid, offset))
def insert_song(self, songname):
"""
Inserts song in the database and returns the ID of the inserted record.
Inserts song in the database and returns the ID of the inserted record.
"""
try:
self.cursor.execute(SQLDatabase.INSERT_SONG, (songname,))
self.connection.commit()
return int(self.cursor.lastrowid)
except mysql.Error, e:
print "Error in insert_song(), %d: %s" % (e.args[0], e.args[1])
self.connection.rollback()
return None
with self.cursor() as cur:
cur.execute(self.INSERT_SONG, (songname,))
return cur.lastrowid
def query(self, key):
def query(self, hash):
"""
Return all tuples associated with hash.
Return all tuples associated with hash.
If hash is None, returns all entries in the
database (be careful with that one!).
If hash is None, returns all entries in the
database (be careful with that one!).
"""
# select all if no key
if key is not None:
sql = SQLDatabase.SELECT
else:
sql = SQLDatabase.SELECT_ALL
query = self.SELECT_ALL if hash is None else self.SELECT
matches = []
try:
self.cursor.execute(sql, (key,))
# collect all matches
records = self.cursor.fetchall()
for record in records:
matches.append((record[SQLDatabase.FIELD_SONG_ID], record[SQLDatabase.FIELD_OFFSET]))
except mysql.Error, e:
print "Error in query(), %d: %s" % (e.args[0], e.args[1])
return matches
with self.cursor() as cur:
cur.execute(query)
for row in cur:
yield (row[self.FIELD_SONG_ID], row[self.FIELD_OFFSET])
def get_iterable_kv_pairs(self):
"""
Returns all tuples in database.
Returns all tuples in database.
"""
return self.query(None)
def insert_hashes(self, hashes):
"""
Insert series of hash => song_id, offset
values into the database.
Insert series of hash => song_id, offset
values into the database.
"""
for h in hashes:
sha1, val = h
self.insert(sha1, val)
self.connection.commit()
# TODO: Fix this when hashes will be a new format.
values = []
for hash, (sid, offset) in hashes:
values.append((hash, sid, offset))
with self.cursor() as cur:
cur.executemany(self.INSERT_FINGERPRINT, values)
def return_matches(self, hashes):
"""
Return the (song_id, offset_diff) tuples associated with
a list of
Return the (song_id, offset_diff) tuples associated with
a list of
sha1 => (None, sample_offset)
values.
"""
matches = []
for h in hashes:
sha1, val = h
list_of_tups = self.query(sha1)
if list_of_tups:
for t in list_of_tups:
# (song_id, db_offset, song_sampled_offset)
matches.append((t[0], t[1] - val[1]))
return matches
from pymysql.cursors import Cursor
# Create a dictionary of hash => offset pairs for later lookups
mapper = {}
for hash, (_, offset) in hashes:
mapper[hash.upper()] = offset
# Get an iteratable of all the hashes we need
values = mapper.keys()
with self.cursor(cursor_type=Cursor) as cur:
for split_values in grouper(values, 1000):
# Create our IN part of the query
query = self.SELECT_MULTIPLE
query = query % ', '.join(['UNHEX(%s)'] * len(split_values))
cur.execute(query, split_values)
for hash, sid, offset in cur:
# (sid, db_offset - song_sampled_offset)
yield (sid, offset - mapper[hash])
from itertools import izip_longest
def grouper(iterable, n, fillvalue=None):
args = [iter(iterable)] * n
return izip_longest(fillvalue=fillvalue, *args)