Add DSLogic capture, signal conversion and DSView decoders

python/logic_analyzer/files.py

@@ -42,6 +42,7 @@ class DigitalCapture:
     start: float
     end: float
     sample_rate: float = 0
+    trigger_time: float = None
 
 
 def _check(cancel):
@@ -54,12 +55,14 @@ def read_capture(path, progress=lambda value: None, cancel=lambda: False):
     try:
         if path.suffix.lower() == '.csv':
             result = _csv(path, progress, cancel)
+        elif path.suffix.lower() == '.json':
+            result = _json(path, progress, cancel)
         elif path.suffix.lower() in ('.sal', '.dsl'):
             with zipfile.ZipFile(path) as archive:
                 result = (_sal if path.suffix.lower() == '.sal' else _dsl)(
                     path, archive, progress, cancel)
         else:
-            raise ValueError('Выберите цифровую запись CSV, SAL или DSL.')
+            raise ValueError('Выберите цифровую запись CSV, JSON, SAL или DSL.')
     except (KeyError, struct.error, zipfile.BadZipFile, EOFError,
             configparser.Error, UnicodeError) as exc:
         raise ValueError('Повреждённый или неподдерживаемый файл: %s' % exc) from exc
@@ -70,6 +73,58 @@ def read_capture(path, progress=lambda value: None, cancel=lambda: False):
     return result
 
 
+def _json(path, progress, cancel):
+    def unique_object(pairs):
+        result = {}
+        for key, value in pairs:
+            if key in result:
+                raise ValueError('Повторяющееся поле JSON: %s.' % key)
+            result[key] = value
+        return result
+
+    _check(cancel)
+    with path.open(encoding='utf-8-sig') as stream:
+        rows = json.load(stream, object_pairs_hook=unique_object)
+    _check(cancel)
+    if not isinstance(rows, list) or not rows or not isinstance(rows[0], dict):
+        raise ValueError('Ожидается JSON: непустой массив объектов с Time [s] и каналами 0/1.')
+    names = list(rows[0])
+    if ('Time [s]' not in names or not 2 <= len(names) <= 65
+            or any(not name.strip() for name in names)):
+        raise ValueError('JSON должен содержать Time [s] и от 1 до 64 цифровых каналов.')
+    channels = [DigitalChannel(name, 0, array('d')) for name in names if name != 'Time [s]']
+    fields = set(names)
+    start = end = None
+    previous = []
+    for index, row in enumerate(rows):
+        if index % 4096 == 0:
+            _check(cancel)
+            progress(index * 99 // len(rows))
+        try:
+            if not isinstance(row, dict) or set(row) != fields:
+                raise ValueError('набор полей должен быть одинаковым во всех строках')
+            time = row['Time [s]']
+            if (type(time) not in (int, float) or not math.isfinite(time)
+                    or (end is not None and time <= end)):
+                raise ValueError('время должно быть числом, строго возрастать и быть конечным')
+            values = [row[c.name] for c in channels]
+            if any(type(v) not in (int, float, bool) or v not in (0, 1) for v in values):
+                raise ValueError('цифровые уровни должны быть 0 или 1')
+            if start is None:
+                start = time
+                for channel, value in zip(channels, values):
+                    channel.initial = int(value)
+            else:
+                for channel, old, value in zip(channels, previous, values):
+                    if old != value:
+                        channel.edges.append(time)
+            previous = values
+            end = time
+        except (ValueError, OverflowError) as exc:
+            raise ValueError('JSON, строка %d: %s' % (index + 1, exc)) from exc
+    return DigitalCapture(str(path), 'JSON', channels, start, end)
+
+
 def _csv(path, progress, cancel):
     size = max(1, path.stat().st_size)
     consumed = 0