def fetch_data(self, mnemonic, starttime, endtime):
"""
Get data for a mnemonic.
Parameters
mnemonic: str
The engineering mnemonic to retrieve
starttime: str or astropy.time.Time
The, inclusive, start time to retireve from.
endttime: str or astropy.time.Time
The, inclusive, end time to retireve from.
Returns
-------
mnemonic_data: dict
The returned structure
"""
with open(os.path.join(self.db_path, mnemonic_data_fname(mnemonic)),
'r') as fp:
db_data = json.load(fp)
# Find the range of data
stime = Time(starttime, format='iso')
etime = Time(endtime, format='iso')
stime_mil = int(stime.unix * 1000)
etime_mil = int(etime.unix * 1000)
data = db_data['Data']
start_idx = 0
try:
while engdb_tools.extract_db_time(
data[start_idx]['ObsTime']) < stime_mil:
start_idx += 1
except IndexError:
pass
end_idx = start_idx
try:
while engdb_tools.extract_db_time(
data[end_idx]['ObsTime']) <= etime_mil:
end_idx += 1
except IndexError:
end_idx -= 1
# Real database always returns a bracketed result.
start_idx = max(0, start_idx - 1)
end_idx = min(len(data), end_idx + 1)
# Construct the resultant data
data_return = [data[idx] for idx in range(start_idx, end_idx)]
# Construct the return structure
db_data['ReqSTime'] = '/Date({:013d}+0000)/'.format(stime_mil)
db_data['ReqETime'] = '/Date({:013d}+0000)/'.format(etime_mil)
db_data['Count'] = len(data_return)
db_data['Data'] = data_return
return db_data
def test_cache_partial_data(db_cache, engdb):
"""
Test read of some data.
"""
data = db_cache.fetch_data(GOOD_MNEMONIC, GOOD_STARTTIME, GOOD_ENDTIME)
assert data['Count'] > 4 # Just to make sure we have some data
endtime = Time(engdb_tools.extract_db_time(data['Data'][1]['ObsTime']) /
1000.,
format='unix')
data_short = db_cache.fetch_data(GOOD_MNEMONIC, GOOD_STARTTIME,
endtime.iso)
live_data_short = engdb.get_records(GOOD_MNEMONIC, GOOD_STARTTIME,
endtime.iso)
assert data_short == live_data_short
def fetch_data(self, mnemonic, starttime, endtime):
"""
Get data for a mnemonic.
Parameters
mnemonic: str
The engineering mnemonic to retrieve
starttime: str or astropy.time.Time
The, inclusive, start time to retireve from.
endttime: str or astropy.time.Time
The, inclusive, end time to retireve from.
Returns
-------
mnemonic_data: dict
The returned structure
"""
with open(
os.path.join(
self.db_path,
mnemonic_data_fname(mnemonic)),
'r') as fp:
db_data = json.load(fp)
# Find the range of data
stime = Time(starttime, format='iso')
etime = Time(endtime, format='iso')
stime_mil = int(stime.unix * 1000)
etime_mil = int(etime.unix * 1000)
data = db_data['Data']
start_idx = 0
try:
while engdb_tools.extract_db_time(data[start_idx]['ObsTime']) < stime_mil:
start_idx += 1
except IndexError:
pass
end_idx = start_idx
try:
while engdb_tools.extract_db_time(data[end_idx]['ObsTime']) <= etime_mil:
end_idx += 1
except IndexError:
end_idx -= 1
# Real database always returns a bracketed result.
start_idx = max(0, start_idx - 1)
end_idx = min(len(data), end_idx + 1)
# Construct the resultant data
data_return = [
data[idx]
for idx in range(start_idx, end_idx)
]
# Construct the return structure
db_data['ReqSTime'] = '/Date({:013d}+0000)/'.format(stime_mil)
db_data['ReqETime'] = '/Date({:013d}+0000)/'.format(etime_mil)
db_data['Count'] = len(data_return)
db_data['Data'] = data_return
return db_data
def test_db_time():
time = 1234567890123
stime = ''.join(['/Date(', str(time), '+1234', ')/'])
result = engdb_tools.extract_db_time(stime)
assert result == time