You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
soil/soil/history.py

292 lines
9.4 KiB
Python

import time
import os
import pandas as pd
import sqlite3
import copy
from collections import UserDict, namedtuple
from . import utils
class History:
"""
Store and retrieve values from a sqlite database.
"""
def __init__(self, db_path=None, name=None, dir_path=None, backup=True):
if db_path is None and name:
db_path = os.path.join(dir_path or os.getcwd(),
'{}.db.sqlite'.format(name))
if db_path:
if backup and os.path.exists(db_path):
newname = db_path + '.backup{}.sqlite'.format(time.time())
os.rename(db_path, newname)
else:
db_path = ":memory:"
self.db_path = db_path
self.db = db_path
with self.db:
self.db.execute('''CREATE TABLE IF NOT EXISTS history (agent_id text, t_step int, key text, value text text)''')
self.db.execute('''CREATE TABLE IF NOT EXISTS value_types (key text, value_type text)''')
self.db.execute('''CREATE UNIQUE INDEX IF NOT EXISTS idx_history ON history (agent_id, t_step, key);''')
self._dtypes = {}
self._tups = []
@property
def db(self):
try:
self._db.cursor()
except (sqlite3.ProgrammingError, AttributeError):
self.db = None # Reset the database
return self._db
@db.setter
def db(self, db_path=None):
db_path = db_path or self.db_path
if isinstance(db_path, str):
self._db = sqlite3.connect(db_path)
else:
self._db = db_path
@property
def dtypes(self):
self.read_types()
return {k:v[0] for k, v in self._dtypes.items()}
def save_tuples(self, tuples):
'''
Save a series of tuples, converting them to records if necessary
'''
self.save_records(Record(*tup) for tup in tuples)
def save_records(self, records):
'''
Save a collection of records
'''
for record in records:
if not isinstance(record, Record):
record = Record(*record)
self.save_record(*record)
def save_record(self, agent_id, t_step, key, value):
'''
Save a collection of records to the database.
Database writes are cached.
'''
value = self.convert(key, value)
self._tups.append(Record(agent_id=agent_id,
t_step=t_step,
key=key,
value=value))
if len(self._tups) > 100:
self.flush_cache()
def convert(self, key, value):
"""Get the serialized value for a given key."""
if key not in self._dtypes:
self.read_types()
if key not in self._dtypes:
name = utils.name(value)
serializer = utils.serializer(name)
deserializer = utils.deserializer(name)
self._dtypes[key] = (name, serializer, deserializer)
with self.db:
self.db.execute("replace into value_types (key, value_type) values (?, ?)", (key, name))
return self._dtypes[key][1](value)
def recover(self, key, value):
"""Get the deserialized value for a given key, and the serialized version."""
if key not in self._dtypes:
self.read_types()
if key not in self._dtypes:
raise ValueError("Unknown datatype for {} and {}".format(key, value))
return self._dtypes[key][2](value)
def flush_cache(self):
'''
Use a cache to save state changes to avoid opening a session for every change.
The cache will be flushed at the end of the simulation, and when history is accessed.
'''
with self.db:
for rec in self._tups:
self.db.execute("replace into history(agent_id, t_step, key, value) values (?, ?, ?, ?)", (rec.agent_id, rec.t_step, rec.key, rec.value))
self._tups = list()
def to_tuples(self):
self.flush_cache()
with self.db:
res = self.db.execute("select agent_id, t_step, key, value from history ").fetchall()
for r in res:
agent_id, t_step, key, value = r
value = self.recover(key, value)
yield agent_id, t_step, key, value
def read_types(self):
with self.db:
res = self.db.execute("select key, value_type from value_types ").fetchall()
for k, v in res:
serializer = utils.serializer(v)
deserializer = utils.deserializer(v)
self._dtypes[k] = (v, serializer, deserializer)
def __getitem__(self, key):
self.flush_cache()
key = Key(*key)
agent_ids = [key.agent_id] if key.agent_id is not None else []
t_steps = [key.t_step] if key.t_step is not None else []
keys = [key.key] if key.key is not None else []
df = self.read_sql(agent_ids=agent_ids,
t_steps=t_steps,
keys=keys)
r = Records(df, filter=key, dtypes=self._dtypes)
if r.resolved:
return r.value()
return r
def read_sql(self, keys=None, agent_ids=None, t_steps=None, convert_types=False, limit=-1):
self.read_types()
def escape_and_join(v):
if v is None:
return
return ",".join(map(lambda x: "\'{}\'".format(x), v))
filters = [("key in ({})".format(escape_and_join(keys)), keys),
("agent_id in ({})".format(escape_and_join(agent_ids)), agent_ids)
]
filters = list(k[0] for k in filters if k[1])
last_df = None
if t_steps:
# Look for the last value before the minimum step in the query
min_step = min(t_steps)
last_filters = ['t_step < {}'.format(min_step),]
last_filters = last_filters + filters
condition = ' and '.join(last_filters)
last_query = '''
select h1.*
from history h1
inner join (
select agent_id, key, max(t_step) as t_step
from history
where {condition}
group by agent_id, key
) h2
on h1.agent_id = h2.agent_id and
h1.key = h2.key and
h1.t_step = h2.t_step
'''.format(condition=condition)
last_df = pd.read_sql_query(last_query, self.db)
filters.append("t_step >= '{}' and t_step <= '{}'".format(min_step, max(t_steps)))
condition = ''
if filters:
condition = 'where {} '.format(' and '.join(filters))
query = 'select * from history {} limit {}'.format(condition, limit)
df = pd.read_sql_query(query, self.db)
if last_df is not None:
df = pd.concat([df, last_df])
df_p = df.pivot_table(values='value', index=['t_step'],
columns=['key', 'agent_id'],
aggfunc='first')
for k, v in self._dtypes.items():
if k in df_p:
dtype, _, deserial = v
df_p[k] = df_p[k].fillna(method='ffill').astype(dtype)
if t_steps:
df_p = df_p.reindex(t_steps, method='ffill')
return df_p.ffill()
def __getstate__(self):
state = dict(**self.__dict__)
del state['_db']
del state['_dtypes']
return state
def __setstate__(self, state):
self.__dict__ = state
self._dtypes = {}
class Records():
def __init__(self, df, filter=None, dtypes=None):
if not filter:
filter = Key(agent_id=None,
t_step=None,
key=None)
self._df = df
self._filter = filter
self.dtypes = dtypes or {}
super().__init__()
def mask(self, tup):
res = ()
for i, k in zip(tup[:-1], self._filter):
if k is None:
res = res + (i,)
res = res + (tup[-1],)
return res
def filter(self, newKey):
f = list(self._filter)
for ix, i in enumerate(f):
if i is None:
f[ix] = newKey
self._filter = Key(*f)
@property
def resolved(self):
return sum(1 for i in self._filter if i is not None) == 3
def __iter__(self):
for column, series in self._df.iteritems():
key, agent_id = column
for t_step, value in series.iteritems():
r = Record(t_step=t_step,
agent_id=agent_id,
key=key,
value=value)
yield self.mask(r)
def value(self):
if self.resolved:
f = self._filter
try:
i = self._df[f.key][str(f.agent_id)]
ix = i.index.get_loc(f.t_step, method='ffill')
return i.iloc[ix]
except KeyError:
return self.dtypes[f.key][2]()
return list(self)
def __getitem__(self, k):
n = copy.copy(self)
n.filter(k)
if n.resolved:
return n.value()
return n
def __len__(self):
return len(self._df)
def __str__(self):
if self.resolved:
return str(self.value())
return '<Records for [{}]>'.format(self._filter)
Key = namedtuple('Key', ['agent_id', 't_step', 'key'])
Record = namedtuple('Record', 'agent_id t_step key value')