def update_index(self, rebuild=False):
"""Update index.
Arguments:
rebuild -- Rebuild the index from scratch
Otherwise, it only updates count and last_prime
"""
if rebuild:
os.remove(self.index)
self.connect()
files = os.listdir(self.dir_)
for f in files:
if f == "index.db":
continue
print "Adding", f
self.add(polynomial.name_to_polynomial(f))
self.update_index()
else:
for f in self.list():
count = self.count(f, True)
last_prime = self.last_prime(f, True)
if count != self.count(f) or \
last_prime != self.last_prime(f):
print "Updating", f
self.conn.execute("UPDATE polynomials \
SET roots=?, last_prime=? \
WHERE coefficients=?",
(count, last_prime,
polynomial.name_polynomial(f)))
self.conn.commit()
return None
def add(self, f):
"""Add a polynomial to the database."""
coeffs = polynomial.name_polynomial(f)
degree = int(f.degree())
group = int(f.galois_group()._n)
c = self.conn.execute("SELECT count(*) FROM polynomials \
WHERE coefficients=?", (coeffs, ))
if c.fetchone()[0] > 0:
print f, "is already in the database."
return None
fconn = self.connect(f)
fconn.execute("""CREATE TABLE IF NOT EXISTS roots
(root integer,
prime integer,
normalized real,
th integer,
total integer)""")
fconn.commit()
self.conn.execute("INSERT INTO \
polynomials(coefficients, degree, \
galois_group, roots, last_prime) \
VALUES (?,?,?,?,?)",
(coeffs, degree, group, 0, 0))
self.conn.commit()
return None
def save_roots(self, f, p2):
"""Save roots between last prime upto p2."""
p = next_prime(self.last_prime(f))
if p > p2:
print "Already calculated upto", p
return None
roots = polynomial.solve_roots_range(f, p, p2, extra=True)
fconn = self.connect(f)
for r in roots:
fconn.execute("INSERT INTO roots VALUES(?,?,?,?,?)", r)
fconn.commit()
count = len(roots) + self.count(f)
last_prime = r[1]
self.conn.execute("UPDATE polynomials \
SET roots=?, last_prime=? \
WHERE coefficients=?",
(count, last_prime,
polynomial.name_polynomial(f)))
self.conn.commit()
return None
def last_prime(self, f, force=False):
"""Return the last prime in DB."""
if force:
fconn = self.connect(f)
c = fconn.execute("SELECT MAX(PRIME) FROM roots")
else:
c = self.conn.execute("SELECT last_prime FROM polynomials \
WHERE coefficients=?",
(polynomial.name_polynomial(f), ))
return c.fetchone()[0]
def count(self, f, force=False, type_=None):
"""Return count of roots for f."""
if force:
if type_:
where = " WHERE total=" + str(type_)
else:
where = ""
fconn = self.connect(f)
c = fconn.execute("SELECT COUNT(*) FROM roots" + where)
else:
c = self.conn.execute("SELECT roots FROM polynomials \
WHERE coefficients=?",
(polynomial.name_polynomial(f),))
return c.fetchone()[0]
def _filename(self, f):
return polynomial.name_polynomial(f)
