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 show(self, degree=None, group=None):
"""Show database contents."""
data = self.list(degree, group, info=True)
current_degree = str(0)
current_group = str(0)
for row in data:
id = "(" + str(row[0]) + ")"
id = id.ljust(6)
f = polynomial.name_to_polynomial(row[1])
degree = str(row[2])
group = str(row[3])
count = str(row[4]).center(10)
last_prime = str(row[5]).center(10)
if current_degree != degree:
current_degree = degree
print
print "Degree", degree
if current_group != group:
current_group = group
print
print "Galois Group", group
print id, count, last_prime, f
return None
def list(self, degree=None, group=None, info=False):
"""List polynomials in database."""
if degree is not None and group is not None:
degree = int(degree)
group = int(group)
c = self.conn.execute("SELECT * FROM polynomials \
WHERE degree=? AND galois_group=? \
ORDER BY coefficients",
(degree, group))
elif degree is not None and group is None:
degree = int(degree)
c = self.conn.execute("SELECT * FROM polynomials \
WHERE degree=? \
ORDER BY galois_group, coefficients",
(degree, ))
else:
c = self.conn.execute("SELECT * FROM polynomials \
ORDER BY degree, galois_group, \
coefficients")
fs = list()
if info:
for row in c:
fs.append(row)
else:
for row in c:
fs.append(polynomial.name_to_polynomial(row[1]))
return fs
def load(self, id_):
"""Return a Sage polynomial object.
Arguments:
id -- number assigned by the database, shows up when DB.show()
is called
"""
c = self.conn.execute("SELECT coefficients FROM polynomials \
WHERE id=?", (int(id_), ))
return polynomial.name_to_polynomial(c.fetchone()[0])