Send data to detection in chunks #489 (#503)

* Add `get_data_chunks` generator to `utils/dataframe.py`
* Add chunks generator usage to `analytic_worker.py`
* Add tests to `tests/test_detector_chunks.py`
* Minor fixes (constants, etc)

analytics/analytics/analytic_unit_manager.py

@@ -74,7 +74,7 @@ class AnalyticUnitManager:
         data = prepare_data(payload['data'])
         if task['type'] == 'PUSH':
             # TODO: do it a better way
-            res = await worker.recieve_data(data, payload['cache'])
+            res = await worker.consume_data(data, payload['cache'])
             if res:
                 res.update({ 'analyticUnitId': analytic_unit_id })
             return res

analytics/analytics/analytic_unit_worker.py

@@ -2,17 +2,21 @@ import config
 import detectors
 import logging
 import pandas as pd
-from typing import Optional, Union
+from typing import Optional, Union, Generator
 from models import ModelCache
 import concurrent.futures
 import asyncio
 
+from utils import get_data_chunks
+
 
 logger = logging.getLogger('AnalyticUnitWorker')
 
 
 class AnalyticUnitWorker:
 
+    CHUNK_WINDOW_SIZE_FACTOR = 100
+
     def __init__(self, analytic_unit_id: str, detector: detectors.Detector, executor: concurrent.futures.Executor):
         self.analytic_unit_id = analytic_unit_id
         self._detector = detector
@@ -35,12 +39,55 @@ class AnalyticUnitWorker:
             raise Exception('Timeout ({}s) exceeded while learning'.format(config.LEARNING_TIMEOUT))
 
     async def do_detect(self, data: pd.DataFrame, cache: Optional[ModelCache]) -> dict:
-        # TODO: return without await
-        return await self._detector.detect(data, cache)
+        if cache is None:
+            msg = f'{self.analytic_unit_id} detection got invalid cache, skip detection'
+            logger.error(msg)
+            raise ValueError(msg)
+        
+        window_size = self._detector.get_window_size(cache)
+
+        detection_result = {
+          'cache': None,
+          'segments': [],
+          'lastDetectionTime': None
+        }
+
+        for chunk in get_data_chunks(data, window_size, window_size * self.CHUNK_WINDOW_SIZE_FACTOR):
+            await asyncio.sleep(0)
+            detected = self._detector.detect(chunk, cache)
+            self.__append_detection_result(detection_result, detected)
+
+        return detection_result
 
     def cancel(self):
         if self._training_future is not None:
             self._training_future.cancel()
 
-    async def recieve_data(self, data: pd.DataFrame, cache: Optional[ModelCache]):
-        return self._detector.recieve_data(data, cache)
+    async def consume_data(self, data: pd.DataFrame, cache: Optional[ModelCache]):
+        if cache is None:
+            msg = f'{self.analytic_unit_id} consume_data got invalid cache, skip detection'
+            logger.error(msg)
+            raise ValueError(msg)
+
+        window_size = self._detector.get_window_size(cache)
+
+        #TODO: make class DetectionResult
+        detection_result = {
+          'cache': None,
+          'segments': [],
+          'lastDetectionTime': None
+        }
+
+        #TODO: remove code duplication with do_detect
+        for chunk in get_data_chunks(data, window_size, window_size * self.CHUNK_WINDOW_SIZE_FACTOR):
+            await asyncio.sleep(0)
+            detected = self._detector.consume_data(chunk, cache)
+            self.__append_detection_result(detection_result, detected)
+
+        return detection_result
+
+    def __append_detection_result(self, detection_result: dict, new_chunk: dict):
+        if new_chunk is not None:
+            detection_result['cache'] = new_chunk['cache']
+            detection_result['lastDetectionTime'] = new_chunk['lastDetectionTime']
+            detection_result['segments'].extend(new_chunk['segments'])

analytics/analytics/detectors/detector.py

@@ -18,5 +18,9 @@ class Detector(ABC):
         pass
 
     @abstractmethod
-    def recieve_data(self, data: DataFrame, cache: Optional[ModelCache]) -> Optional[dict]:
+    def consume_data(self, data: DataFrame, cache: Optional[ModelCache]) -> Optional[dict]:
+        pass
+
+    @abstractmethod
+    def get_window_size(self, cache: Optional[ModelCache]) -> int:
         pass

analytics/analytics/detectors/pattern_detector.py

@@ -35,6 +35,8 @@ AnalyticUnitId = str
 class PatternDetector(Detector):
 
     MIN_BUCKET_SIZE = 150
+    BUCKET_WINDOW_SIZE_FACTOR = 5
+    DEFAULT_WINDOW_SIZE = 1
 
     def __init__(self, pattern_type: str, analytic_unit_id: AnalyticUnitId):
         self.analytic_unit_id = analytic_unit_id
@@ -51,34 +53,14 @@ class PatternDetector(Detector):
             'cache': new_cache
         }
 
-    async def detect(self, dataframe: pd.DataFrame, cache: Optional[models.ModelCache]) -> dict:
+    def detect(self, dataframe: pd.DataFrame, cache: Optional[models.ModelCache]) -> dict:
         logger.debug('Unit {} got {} data points for detection'.format(self.analytic_unit_id, len(dataframe)))
         # TODO: split and sleep (https://github.com/hastic/hastic-server/pull/124#discussion_r214085643)
 
-        if not cache:
-            msg = f'{self.analytic_unit_id} detection got invalid cache {cache}, skip detection'
-            logger.error(msg)
-            raise ValueError(msg)
-
-        window_size = cache.get('WINDOW_SIZE')
-
-        if not window_size:
-            msg = f'{self.analytic_unit_id} detection got invalid window size {window_size}'
-
-        chunks = self.__get_data_chunks(dataframe, window_size)
-
-        segments = []
-        segment_parser = lambda segment: { 'from': segment[0], 'to': segment[1] }
-        for chunk in chunks:
-            await asyncio.sleep(0)
         detected = self.model.detect(dataframe, self.analytic_unit_id, cache)
-            for detected_segment in detected['segments']:
-                detected_segment = segment_parser(detected_segment)
-                if detected_segment not in segments:
-                    segments.append(detected_segment)
 
+        segments = [{ 'from': segment[0], 'to': segment[1] } for segment in detected['segments']]
         newCache = detected['cache']
-
         last_dataframe_time = dataframe.iloc[-1]['timestamp']
         last_detection_time = convert_pd_timestamp_to_ms(last_dataframe_time)
         return {
@@ -87,8 +69,8 @@ class PatternDetector(Detector):
             'lastDetectionTime': last_detection_time
         }
 
-    def recieve_data(self, data: pd.DataFrame, cache: Optional[ModelCache]) -> Optional[dict]:
-        logging.debug('Start recieve_data for analytic unit {}'.format(self.analytic_unit_id))
+    def consume_data(self, data: pd.DataFrame, cache: Optional[ModelCache]) -> Optional[dict]:
+        logging.debug('Start consume_data for analytic unit {}'.format(self.analytic_unit_id))
         data_without_nan = data.dropna()
 
         if len(data_without_nan) == 0:
@@ -96,45 +78,21 @@ class PatternDetector(Detector):
 
         self.bucket.receive_data(data_without_nan)
         if cache == None:
-            logging.debug('Recieve_data cache is None for task {}'.format(self.analytic_unit_id))
+            logging.debug('consume_data cache is None for task {}'.format(self.analytic_unit_id))
             cache = {}
-        bucket_size = max(cache.get('WINDOW_SIZE', 0) * 3, self.MIN_BUCKET_SIZE)
+        bucket_size = max(cache.get('WINDOW_SIZE', 0) * self.BUCKET_WINDOW_SIZE_FACTOR, self.MIN_BUCKET_SIZE)
 
         res = self.detect(self.bucket.data, cache)
 
         if len(self.bucket.data) > bucket_size:
             excess_data = len(self.bucket.data) - bucket_size
             self.bucket.drop_data(excess_data)
-        logging.debug('End recieve_data for analytic unit: {} with res: {}'.format(self.analytic_unit_id, res))
+        logging.debug('End consume_data for analytic unit: {} with res: {}'.format(self.analytic_unit_id, res))
         if res:
             return res
         else:
             return None
 
-    def __get_data_chunks(self, dataframe: pd.DataFrame, window_size: int) -> Generator[pd.DataFrame, None, None]:
-        """
-        TODO: fix description
-        Return generator, that yields dataframe's chunks. Chunks have 3 WINDOW_SIZE length and 2 WINDOW_SIZE step.
-        Example: recieved dataframe: [0, 1, 2, 3, 4, 5], returned chunks [0, 1, 2], [2, 3, 4], [4, 5].
-        """
-        chunk_size = window_size * 100
-        intersection = window_size
-
-        data_len = len(dataframe)
-
-        if data_len < chunk_size:
-            return (chunk for chunk in (dataframe,))
-
-        def slices():
-            nonintersected = chunk_size - intersection
-            mod = data_len % nonintersected
-            chunks_number = data_len // nonintersected
-
-            offset = 0
-            for i in range(chunks_number):
-                yield slice(offset, offset + nonintersected + 1)
-                offset += nonintersected
-
-            yield slice(offset, offset + mod)
-
-        return (dataframe[chunk_slice] for chunk_slice in slices())
+    def get_window_size(self, cache: Optional[ModelCache]) -> int:
+        if cache is None: return self.DEFAULT_WINDOW_SIZE
+        return cache.get('WINDOW_SIZE', self.DEFAULT_WINDOW_SIZE)

analytics/analytics/detectors/threshold_detector.py

@@ -14,6 +14,8 @@ logger = log.getLogger('THRESHOLD_DETECTOR')
 
 class ThresholdDetector(Detector):
 
+    WINDOW_SIZE = 3
+
     def __init__(self):
         pass
 
@@ -25,7 +27,7 @@ class ThresholdDetector(Detector):
             }
         }
 
-    async def detect(self, dataframe: pd.DataFrame, cache: ModelCache) -> dict:
+    def detect(self, dataframe: pd.DataFrame, cache: ModelCache) -> dict:
         if cache == None:
             raise 'Threshold detector error: cannot detect before learning'
         value = cache['value']
@@ -68,6 +70,9 @@ class ThresholdDetector(Detector):
             'lastDetectionTime': now
         }
 
-    def recieve_data(self, data: pd.DataFrame, cache: Optional[ModelCache]) -> Optional[dict]:
+    def consume_data(self, data: pd.DataFrame, cache: Optional[ModelCache]) -> Optional[dict]:
         result = self.detect(data, cache)
         return result if result else None
+
+    def get_window_size(self, cache: Optional[ModelCache]) -> int:
+        return self.WINDOW_SIZE

analytics/analytics/utils/__init__.py

@@ -1,3 +1,4 @@
 from utils.common import *
 from utils.segments import *
 from utils.time import *
+from utils.dataframe import *

analytics/analytics/utils/dataframe.py

@@ -0,0 +1,30 @@
+from typing import Generator
+import pandas as pd
+
+def get_data_chunks(dataframe: pd.DataFrame, window_size: int, chunk_size: int) -> Generator[pd.DataFrame, None, None]:
+        """
+        Returns generator that splits dataframe on intersected segments.
+        Intersection makes it able to detect pattern that present in dataframe on the border between chunks.
+        window_size - length of intersection. 
+        chunk_size - length of chunk
+        """
+
+        data_len = len(dataframe)
+
+        if data_len <= chunk_size:
+            yield dataframe
+            return
+
+        nonintersected = chunk_size - window_size
+
+        offset = 0
+        while True:
+            left_values = data_len - offset
+            if left_values == 0:
+                break
+            if left_values <= chunk_size:
+                yield dataframe[offset : data_len].reset_index()
+                break
+            else:
+                yield dataframe[offset: offset + chunk_size].reset_index()
+                offset += min(nonintersected, left_values)

analytics/tests/test_detector_chunks.py

@@ -1,21 +1,38 @@
 import unittest
-from detectors.pattern_detector import PatternDetector
+from utils import get_data_chunks
+import pandas as pd
+
 
-def rlist(start, stop):
-        return [x for x in range(start, stop + 1)]
 class TestUtils(unittest.TestCase):
 
     def test_chunks_generator(self):
         window_size = 1
+        chunk_window_size_factor = 3
 
         cases = [
+            (list(range(7)), [[0,1,2], [2,3,4], [4,5,6]]),
             ([], [[]]),
-            (rlist(0, 300), [rlist(0,99),rlist(99,198),rlist(198,297),rlist(297,300)])
+            (list(range(1)), [[0]]),
+            (list(range(3)), [[0,1,2]]),
+            (list(range(8)), [[0,1,2], [2,3,4], [4,5,6], [6,7]]),
+            (list(range(6)), [[0,1,2], [2,3,4], [4,5]])
         ]
 
         for data, expected_chunks in cases:
-            chunks = tuple(PatternDetector._PatternDetector__get_data_chunks(None, data, window_size))
-            self.assertSequenceEqual(chunks, expected_chunks)
+            data = [(x,x) for x in data]
+            data = pd.DataFrame(data, columns=['timestamp', 'value'])
+
+            df_expected_chunks = []
+            for chunk in expected_chunks:
+                chunk = [(x,x) for x in chunk]
+                df_expected_chunks.append(chunk)
+            df_expected_chunks = [pd.DataFrame(chunk, columns=['timestamp', 'value']) for chunk in df_expected_chunks]
+            chunks = tuple(get_data_chunks(data, window_size, window_size * chunk_window_size_factor))
+            df_expected_chunks = [df.reset_index() for df in df_expected_chunks]
+
+            zipped = zip(chunks, df_expected_chunks)
+            map(lambda a,b: self.assertTrue(a.equals(b)), zipped)
+
 
 
 if __name__ == '__main__':