first version of loading data

nixview/file_handler.py

@@ -1,8 +1,12 @@
 import os
 import nixio as nix
+import numpy as np
 from enum import Enum
 import datetime as dt
 
+from numpy.core.defchararray import not_equal
+from nixview.constants import io_chunksize as chunksize
+
 
 class ItemDescriptor():
     def __init__(self, name=None, id=None, type=None, value=None, definition=None, block_id=None, entity_type=None, shape=None, metadata=None, data_type=None, source_id=None, created_at=None, updated_at=None) -> None:
@@ -104,6 +108,54 @@ class NodeType(Enum):
      Feature="Feature"
 
 
+class DataView():
+
+    def __init__(self, item_descriptor, file_handler) -> None:
+        super().__init__()
+        self._item_descriptor = item_descriptor
+        self._file_handler = file_handler
+        self._buffer = None
+        self._full_shape = item_descriptor.shape
+        self._offset = np.zeros(len(self._full_shape), dtype=int)
+        self._count = None
+        self._max_dim = None
+        self.init_buffer()
+        self.request_more()
+
+    def request_more(self):
+        if self.fully_loaded:
+            return
+        data = self._file_handler.request_data(self._item_descriptor, self._offset, self._count)
+        if data is not None and self._buffer is None:
+            self._buffer = data
+            self._offset = data.shape
+        else:
+            print("need to fetch more!")
+        
+    def init_buffer(self):
+        buffer_shape = np.zeros(len(self._full_shape), dtype=int)
+        max_dim_count = chunksize
+        max_dim = np.argmax(self._full_shape)
+        for i, d in enumerate(self._full_shape):
+            if i != max_dim:
+                buffer_shape[i] = self._full_shape[i]
+                max_dim_count /= self._full_shape[i]
+        buffer_shape[max_dim] = max_dim_count
+        self._count = buffer_shape
+        self._max_dim = max_dim
+    
+    
+    @property
+    def fully_loaded(self):
+        return self._buffer is not None and self._full_shape == self._buffer.shape
+    
+    def __str__(self) -> str:
+        r = self._item_descriptor.name + " " + str(self._item_descriptor.entity_type)
+        r += "buffer size: "  + str(self._buffer.shape) if self._buffer is not None else "" + "\n"
+        r += "chunk size:" + str(self._count)
+        r += "is fully loaded: " + str(self.fully_loaded)
+        return r
+    
 class Singleton(type):
     _instances = {}
     def __call__(cls, *args, **kwargs):
@@ -195,6 +247,17 @@ class FileHandler(metaclass=Singleton):
     def filename(self):
         return self._filename
 
+    def request_data(self, entity_descriptor, offset=None, count=None):
+        entity = self._entity_buffer.get(entity_descriptor.id)
+        if entity is None:
+            print("need to do something else")
+        for i, (o, c) in enumerate(zip(offset, count)):
+            if o + c > entity.shape[i]:
+                count[i] = entity.shape[i] - o
+        seg = tuple([slice(o, o + c) for o, c in zip(offset, count)])
+        print(seg)
+        return entity[seg]
+
     def request_section_descriptor(self, id):
         fs = self._entity_buffer.get(id)
         if fs is None:
@@ -271,6 +334,13 @@ class FileHandler(metaclass=Singleton):
             src = e.source if hasattr(e, "source") else None
             itd.source_id = src.id if src is not None else None
             infos.append(itd)
+            if entity_type == NodeType.DataArray:
+                itd.value = "%s %s entries" % (str(e.shape), e.dtype)
+            elif entity_type == NodeType.Tag:
+                point_or_segment = "segment" if e.extent else "point"
+                start = str(e.position)
+                end = ("to " + str(tuple(np.array(e.position) + np.array(e.extent)))) if e.extent else ""
+                itd.value = "tags %s %s %s" %(point_or_segment, start, end) 
             # TODO set the value to something meaningful for the various entity types
         return infos
 

nixview/ui/plotscreen.py

@@ -4,11 +4,12 @@ import matplotlib
 matplotlib.use('Qt5Agg')
 from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg
 from matplotlib.figure import Figure
-
+import nixio as nix
 import numpy as np
 import matplotlib.pyplot as plt
 from matplotlib.widgets import Slider
-import nixio as nix
+
+from nixview.file_handler import FileHandler, DataView
 
 
 
@@ -323,8 +324,9 @@ class MplCanvas(FigureCanvasQTAgg):
 class PlotScreen(QWidget):
     close_signal = pyqtSignal()
     
-    def __init__(self, parent) -> None:
+    def __init__(self, parent=None) -> None:
         super().__init__(parent=parent)
+        self._file_handler = FileHandler()
         sc = MplCanvas(self, width=5, height=4, dpi=100)
         sc.axes.plot([0,1,2,3,4], [10,1,20,3,40])
         
@@ -335,9 +337,16 @@ class PlotScreen(QWidget):
         close_btn.clicked.connect(self.on_close)
         
         self.layout().addWidget(close_btn)
+        self._data_view = None
     
     def on_close(self):
         self.close_signal.emit()
         
     def plot(self, item):
         print("plot!", item)
+        print(item.entity_type, item.shape)
+        self._data_view = DataView(item, self._file_handler)
+        self._data_view.request_more()
+        print(self._data_view)
+        
+