def retrieve_history_record(model, behaviour, creation_time):
""""
Get model's history record at a specific time.
"""
data_db = db_account.database('model_history_db')
index = {
'owner': model.owner.username,
'model_name': model.model_name,
'creation_time': creation_time,
'behaviour': behaviour
}
query_sort = [{
'owner': 'desc'
}, {
'model_name': 'desc'
}, {
'creation_time': 'desc'
}, {
'behaviour': 'desc'
}]
if behaviour == 'refresh':
#if behaviour is refreshing,
#we might also want the source used to refresh
fields = ['value', 'source']
else:
fields = ['value']
try:
records = query(data_db, index, fields=fields, sort=query_sort)['docs']
return records
except e.UnknownDatabaseError as error:
raise e.UnknownDatabaseError('Retrieving history record at time:'+\
creation_time+' failed: '+error.msg)
def store_history_record(model, behaviour, value, **kwargs):
"""
Store history record to 'model_history_db' database.
Raises:
-------
UnknownDatabaseError
"""
data_db = db_account.database('model_history_db')
data = {}
data['owner'] = model.owner.username
data['type'] = 'history'
data['behaviour'] = behaviour
data['model_name'] = model.model_name
data['value'] = value
data['creation_time'] = strftime("%Y-%m-%d %H:%M:%S", gmtime())
data['bound_service'] = model.bound_service
for arg_name, arg in kwargs.items():
data[arg_name] = arg
res = data_db.post('', params=data)
if res.status_code != 201:
raise e.UnknownDatabaseError('Storing refreshing history failed \
with status code ' +
str(res.status_code))
else:
pass
def del_model_from_database(user, model_name):
"""
Delete model from 'model_info_db' database.
Raises:
------
ModelNotExistsError
UnknownDatabaseError
"""
#firstly find the model in 'model_info_db' database and delete it
info_db = db_account.database('model_info_db')
model = query(info_db, {
'owner': user.username,
'model_name': model_name
})['docs']
if not model:
#if model is not found, raise an exception
raise e.ModelNotExistsError(
model_name, 'Model ' + model_name + ' does not exist in database.')
else:
try_delete = info_db.delete(model[0]['_id'],
params={'rev': model[0]['_rev']})
if try_delete.status_code != 200:
raise e.UnknownDatabaseError("Unable to delete "+model_name+ \
" from database model_info_db.")
#then delete the model's relevant data in 'model_history_db'
history_db = db_account.database('model_history_db')
#get all history records in 'model_history_db'
selector = {
'owner': user.username,
'model_name': model_name,
'type': 'history'
}
sort = [{'owner': 'desc'}, {'model_name': 'desc'}, {'type': 'desc'}]
fields = ['_id', '_rev']
documents = query(history_db, selector=selector, sort=sort)['docs']
for doc in documents:
try_delete_history = history_db.delete(doc['_id'],
params={'rev': doc['_rev']})
#if delete history data is not successful, raise an exception
if try_delete_history.status_code != 200:
raise e.UnknownDatabaseError("Unable to delete "+model_name+ \
"'s history records from database 'model_history_db'."
" Reason: " + try_delete_history.text)
def retrieve_history(model, behaviour, sort):
"""
Get model's history records from Cloudant 'model_info_db' database.
Raises:
-------
UnknowDatabaseError
"""
data_db = db_account.database('model_history_db')
if behaviour == 'all':
query_sort = [{
'owner': sort
}, {
'model_name': sort
}, {
'creation_time': sort
}, {
'type': sort
}]
index = {
'owner': model.owner.username,
'model_name': model.model_name,
'creation_time': {
"$gt": None
},
'type': 'history'
}
else:
query_sort = [{
'owner': sort
}, {
'model_name': sort
}, {
'creation_time': sort
}]
index = {
'owner': model.owner.username,
'model_name': model.model_name,
'behaviour': behaviour,
'creation_time': {
"$gt": None
}
}
fields = ['behaviour', 'value', 'creation_time']
try:
records = query(data_db, index, fields=fields, sort=query_sort)['docs']
return records
except e.UnknownDatabaseError as error:
raise e.UnknownDatabaseError('Retrieving history records failed: ' +
error.msg)
def update_create_user_in_database(document_id, document_content):
"""
Update/create a user document to 'user_db'.
Raises:
------
UnknownDatabaseError
"""
db = db_account.database('user_db')
try_put = db.put(document_id, params=document_content)
if try_put.status_code != 201:
raise e.UnknownDatabaseError("Failed to update/create user "+document_content['username']+ \
" in user_db database. Reason: "+ try_put.text)
return try_put.json()
def create_model_in_database(document_content):
"""
Create a model document to 'model_info_db'.
Raises:
------
UnknownDatabaseError
"""
db = db_account.database('model_info_db')
try_create = db.post('', params=document_content)
if try_create.status_code != 201:
raise e.UnknownDatabaseError("Failed to create model "+document_content['model_name']+ \
" in model_info_db database. Reason: "+ try_create.text)
return try_create.json()
def update_model_in_database(document_id, document_content):
"""
Updata a model document to 'model_info_db'.
Raises:
------
UnknownDatabaseError
"""
db = db_account.database('model_info_db')
try_put = db.put(document_id, params=document_content)
if try_put.status_code != 201:
raise e.UnknownDatabaseError("Failed to update model "+document_content['model_name']+ \
" in model_info_db database. Reason: "+ try_put.text)
return try_put.json()
def query(db, selector, fields=[], sort=[]):
"""
Make a query to given database.
Returns:
-------
dict
A dict with key 'docs'.
"""
query = {"selector": selector, "fields": fields, "sort": sort}
res = db.post(path='_find', params=query)
if res.status_code != 200:
raise e.UnknownDatabaseError('Retrieving documents failed with status code ' \
+ str(res.status_code) + '; details: '+ res.text)
else:
return res.json()