Feature: New TDI python function that query Influxdb data from an MDSplus node

deploy/packaging/debian/kernel.noarch

@@ -156,6 +156,7 @@
 ./usr/local/mdsplus/tdi/python/intersect1d.py
 ./usr/local/mdsplus/tdi/python/pyfun.py
 ./usr/local/mdsplus/tdi/python/setdiff1d.py
+./usr/local/mdsplus/tdi/python/influxSignal.py
 ./usr/local/mdsplus/tdi/remote/GetManyExecute.fun
 ./usr/local/mdsplus/tdi/remote/ListConnections.fun
 ./usr/local/mdsplus/tdi/remote/MdsConnect.fun

deploy/packaging/redhat/kernel.noarch

@@ -182,6 +182,7 @@
 ./usr/local/mdsplus/tdi/python/intersect1d.py
 ./usr/local/mdsplus/tdi/python/pyfun.py
 ./usr/local/mdsplus/tdi/python/setdiff1d.py
+./usr/local/mdsplus/tdi/python/influxSignal.py
 ./usr/local/mdsplus/tdi/remote
 ./usr/local/mdsplus/tdi/remote/GetManyExecute.fun
 ./usr/local/mdsplus/tdi/remote/ListConnections.fun

pydevices/HtsDevices/acq2106_435st.py

@@ -273,6 +273,10 @@ def lcma(arr):
                 except Empty:
                     continue
 
+                if self.dev.trig_time.getDataNoRaise() is None:
+                    self.dev.trig_time.record = self.device_thread.trig_time - \
+                        ((self.device_thread.io_buffer_size / np.int32(0).nbytes) * dt)
+
                 buffer = np.right_shift(np.frombuffer(buf, dtype='int32'), 8)
                 i = 0
                 for c in self.chans:

tdi/python/influxSignal.py

@@ -0,0 +1,150 @@
+#
+# Copyright (c) 2021, Massachusetts Institute of Technology All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# Redistributions of source code must retain the above copyright notice, this
+# list of conditions and the following disclaimer.
+#
+# Redistributions in binary form must reproduce the above copyright notice, this
+# list of conditions and the following disclaimer in the documentation and/or
+# other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+import MDSplus
+
+try:
+    from influxdb import InfluxDBClient
+except:
+    print(
+        "You must install the `influxdb` python package.")
+    exit(1)
+
+def influxSignal(fieldKey, where, series=None, database=None, config=None, shotStartTime=None, shotEndTime=None): 
+    tree = MDSplus.Tree()
+
+    if series is None:
+        series = tree.getNode('\INFLUX_SERIES')
+
+    if database is None:
+        database = tree.getNode('\INFLUX_DATABASE')
+
+    if config is None:
+        config = tree.getNode('\INFLUX_CONFIG')
+
+    if shotStartTime is None:
+        shotStartTime = tree.getNode('\INFLUX_START_TIME')
+
+    if shotEndTime is None:
+        shotEndTime = tree.getNode('\INFLUX_END_TIME')
+
+    """Instantiate a connection to the InfluxDB."""
+    username = ''
+    password = ''
+    try:
+        with open(config.data()) as file:
+            lines = file.readlines()
+
+            if len(lines) < 2:
+                print("Failed to read influx config from file %s" %(config.data(),))
+
+            host = lines[0].strip('\n')
+            username = lines[1].strip('\n')
+            password = lines[2].strip('\n')
+
+    except IOError as e:
+        print("Failed to open credentials file %s" %(config.data(),))
+
+    port = 8086
+    if ':' in host:
+        parts = host.split(':')
+        host = parts[0]
+        port = int(parts[1])
+
+    database = database.data()
+    series = series.data()
+    fieldKey = fieldKey.data()
+    shotStartTime = shotStartTime.data()
+    shotEndTime = shotEndTime.getDataNoRaise()
+
+    if where == '':
+        return
+
+    whereList = [where.data()]
+
+    timeContext = MDSplus.Tree.getTimeContext()
+
+    startTime = shotStartTime
+    endTime = shotEndTime
+
+    #print('Getting time context from the tree: %s '%(timeContext,))
+
+    # The time context is in seconds relative to the start of the shot.
+    if timeContext[0] is not None:
+        startTime = shotStartTime + (int(timeContext[0]) * 1000)
+    if timeContext[1] is not None:
+        endTime   = shotStartTime + (int(timeContext[1]) * 1000)
+
+    # TODO: timeContext[2] is the interval which influx supports, therefore we should support it too.
+
+    # Clamp the computed start/end time within the time bounds of the shot
+    if startTime < shotStartTime:
+        startTime = shotStartTime
+    if endTime is not None and endTime > shotEndTime:
+        endTime = shotEndTime
+
+    startTimeQuery = ''
+    endTimeQuery = ''
+
+    # Convert to nanosecond UNIX timestamp
+    startTimeQuery = 'time > %d' % (startTime * 1000000,)
+
+    # Convert to nanosecond UNIX timestamp
+    if endTime is not None:
+        endTimeQuery = 'time < %d' % (endTime * 1000000,)
+
+    if startTimeQuery != '':
+        whereList.append(startTimeQuery)
+
+    if endTimeQuery != '':
+        whereList.append(endTimeQuery)
+
+    where = ''
+    if len(whereList) > 0:
+        where = 'WHERE %s' % (' AND '.join(whereList),)
+
+    client = InfluxDBClient(host, port, username, password, database)
+
+    query = 'SELECT "%s" AS value FROM "%s" %s;' % (fieldKey, series, where)
+    #print('Query: %s' % query)
+
+    result = client.query(query, params={'epoch': 'ms'})
+
+    data = list(result.get_points())
+
+    valueData = [None] * len(data)
+    timeData  = [None] * len(data)
+
+    i = 0
+    for row in data:
+        valueData[i] = float(row['value'])
+        timeData[i] = (row['time'] - shotStartTime) / 1000
+        i += 1
+
+    values = MDSplus.Float32Array(valueData)
+    times  = MDSplus.Float32Array(timeData)
+
+    return MDSplus.Signal(values, None, times)
+