My tools of the trade for python programming.
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# $Id: file_db.py,v 1.4 2010-05-28 18:46:16 wirawan Exp $
#
# wpylib.db.file_db module
# Created: 20100205
# Wirawan Purwanto
#
"""File fingerprint database."""
import md5
import numpy
import os.path
import time
try:
import sqlite3
except:
import pysqlite2.dbapi2 as sqlite3
default_debug_level = 0
class file_rec(tuple):
pass
class file_table(object):
# dtype for numpy (if wanted)
dtype = numpy.dtype([
('filename', 'S256'),
('md5', 'S32'),
('date', 'i4'),
('time', 'i4'),
('size', 'i8'),
])
# dtype map from python types to sqlite3 types:
sqlite_dtype_map = {
str: 'TEXT',
int: 'INTEGER',
float: 'REAL',
}
indexable_row_type = sqlite3.Row
def __init__(self, src_name, table_name='filedb', extra_fields=[]):
self.src_name = src_name
self.table_name = table_name
if isinstance(src_name, str): # os.path.isfile(src_name):
self.db = sqlite3.connect(src_name)
self.dbc = self.db.cursor()
elif isinstance(src_name, sqlite3.Connection):
self.db = src_name
self.dbc = self.db.cursor()
else:
raise ValueError, "Invalid src_name data type"
self.db.text_factory = str
self.sql_params = {
'table_name': table_name,
}
self.debug = default_debug_level
create_sql = """\
CREATE TABLE IF NOT EXISTS '%(table_name)s' (
filename TEXT,
md5sum TEXT,
date INTEGER,
time INTEGER,
size INTEGER""" \
+ "".join([", '%s' %s" % (dname, self.sqlite_dtype_map[dtyp])
for (dname,dtyp) in extra_fields
]) \
+ """
);
"""
self.exec_sql(create_sql)
self.db.commit()
def exec_sql(self, stmt, params=None):
sql_stmt = stmt % self.sql_params
if params:
if self.debug:
print "--SQL::", sql_stmt.rstrip()
print "--val::", params
return self.dbc.execute(sql_stmt, params)
else:
if self.debug:
print "--SQL::", sql_stmt.rstrip()
return self.dbc.execute(sql_stmt)
def add_fields(self, dtypes):
"""Adds columns to the table."""
for (dname, dtyp) in dtypes:
self.exec_sql("ALTER TABLE '%(table_name)s' ADD COLUMN" \
+ " '%s' %s;" % (dname, self.sqlite_dtype_map[dtyp])
)
self.db.commit()
def register_file(self, filename, replace=False, extra_values=None):
"""Register a file, note its mtime, and size, and digests its content."""
filestats = get_file_stats(filename)
fields = [
('md5sum', filestats['md5sum']),
('date', filestats['mdate']),
('time', filestats['mtime']),
('size', filestats['size']),
] + [
kwpair for kwpair in extra_values
]
dnames = [ dname for (dname,dval) in fields ]
dvals = [ dval for (dname,dval) in fields ]
if replace:
# Test if we want to replace or to add.
count = [
x for x in self.exec_sql(
"SELECT count(*) from '%(table_name)s' where filename = ?;",
(filename,)
)
][0][0]
if count == 0: replace = False
if replace:
# WARNING: This will replace all the occurences of the entry with
# the same filename.
# Replaceable insert is not intended for tables with duplicate entries
# of the same filename.
insert_sql = "UPDATE '%(table_name)s' SET " \
+ ', '.join(["'%s' = ?" % d for d in dnames]) \
+ " WHERE filename = ?;"
vals = tuple(dvals + [filename])
else:
insert_sql = "INSERT INTO '%(table_name)s' (filename, " \
+ ", ".join(["'%s'" % d for d in dnames]) \
+ ") VALUES (?" + ',?'*(len(fields)) + ");"
vals = tuple([filename] + dvals)
self.exec_sql(insert_sql, vals)
def flush(self):
self.db.commit()
def get_filenames(self):
"""Reads all the file names in the table to memory."""
return [
rslt[0] for rslt in
self.exec_sql("SELECT filename FROM '%(table_name)s' ORDER BY filename;")
]
def __getitem__(self, filename):
"""Reads all the entries matching in the `filename' field."""
if filename.find("%") >= 0:
sql_stmt = "SELECT * FROM '%(table_name)s' WHERE filename LIKE ?;"
else:
sql_stmt = "SELECT * FROM '%(table_name)s' WHERE filename = ?;"
return [ rslt for rslt in self.exec_sql(sql_stmt, (filename,)) ]
def __setitem__(self, filename, newdata):
"""Updates the metadata on the filename. Any other field than the filename
can be updated. The filename serves as a unique key here.
The newdata can be a hash, like this:
A_file_table[filename] = {'date': 20041201, 'time': 122144}
or a list of tuples:
A_file_table[filename] = [('date': 20041201), ('time': 122144)]
"""
if isinstance(newdata, dict) or "keys" in dir(newdata):
dnames = newdata.keys()
dvals = [ newdata[k] for k in dnames ]
else:
# Assuming an iterable with ('field', 'value') tuples.
dnames = [ dname for (dname,dval) in newdata ]
dvals = [ dval for (dname,dval) in newdata ]
update_sql = "UPDATE '%(table_name)s' SET " \
+ ', '.join(["'%s' = ?" % d for d in dnames]) \
+ " WHERE filename = ?;"
vals = tuple(dvals + [filename])
self.exec_sql(update_sql, vals)
def __contains__(self, filename):
"""Counts the number of record entries matching in the `filename' field."""
if filename.find("%") >= 0:
sql_stmt = "SELECT count(*) FROM '%(table_name)s' WHERE filename LIKE ?;"
else:
sql_stmt = "SELECT count(*) FROM '%(table_name)s' WHERE filename = ?;"
return [ rslt for rslt in self.exec_sql(sql_stmt, (filename,)) ][0][0]
count = __contains__
def fields(self):
"""Returns the field names of the table of the latest query."""
return [ z[0] for z in self.dbc.description ]
def row_kind(self, kind=None):
if kind:
self.db.row_factory = kind
# We will reload the cursor to account for the new factory
self.dbc = self.db.cursor()
return self.db.row_factory
def md5_digest_file(filename):
"""Digests the content of a file."""
ff = open(filename, "rb")
bufsize = 32768
stuff = ff.read(bufsize)
digest = md5.new()
while len(stuff) > 0:
digest.update(stuff)
stuff = ff.read(bufsize)
ff.close()
return digest.digest()
def str2hexstr(md5sum):
"""Return the hex representation of a string."""
return "".join([ "%02x" % ord(c) for c in md5sum ])
def get_file_stats(filename, get_md5sum=True):
stats = os.stat(filename)
mtime = time.localtime(stats.st_mtime)
Mdate = mtime.tm_year * 10000 + mtime.tm_mon * 100 + mtime.tm_mday
Mtime = mtime.tm_hour * 10000 + mtime.tm_min * 100 + mtime.tm_sec
size = stats.st_size
if get_md5sum:
md5sum = str2hexstr(md5_digest_file(filename)) # this step is EXPEN$IVE
else:
md5sum = None
return {
'filename': filename,
'mdate': Mdate,
'mtime': Mtime,
'size': size,
'md5sum': md5sum,
}