moved try catch into read_value

Author: A-Baji

datajoint/blob.py

@@ -68,6 +68,7 @@ def __init__(self, squeeze=False, is_32_bit = False):
         self._squeeze = squeeze
         self._blob = None
         self._pos = 0
+        self._pos_prev = 0
         self.protocol = None
         self.is_32_bit = is_32_bit
 
@@ -435,7 +436,13 @@ def read_zero_terminated_string(self):
     def read_value(self, dtype=None, count=1):
         if dtype is None:
             dtype = 'uint32' if self.is_32_bit else 'uint64'
-        data = np.frombuffer(self._blob, dtype=dtype, count=count, offset=self._pos)
+        try:
+            data = np.frombuffer(self._blob, dtype=dtype, count=count, offset=self._pos)
+        except ValueError:
+            self.is_32_bit = True
+            self._pos = self._pos_prev
+            data = np.frombuffer(self._blob, dtype='uint32', count=self.read_value(), offset=self._pos)
+        self._pos_prev = self._pos
         self._pos += data.dtype.itemsize * data.size
         return data[0] if count == 1 else data
 
@@ -468,7 +475,4 @@ def unpack(blob, squeeze=False):
         assert isinstance(blob, bytes) and blob.startswith((b'ZL123\0', b'mYm\0', b'dj0\0'))
         return blob
     if blob is not None:
-        try:
-            return Blob(squeeze=squeeze).unpack(blob)
-        except:
-            return Blob(squeeze=squeeze, is_32_bit=True).unpack(blob)
+        return Blob(squeeze=squeeze).unpack(blob)

tests/test_blob.py

@@ -134,11 +134,19 @@ def test_complex():
 
 
 def test_insert_longblob():
-    import numpy as np
-    # schema.Testmym.insert1({'id': 1, 'data': np.recarray(np.array([[(np.array([[np.nan,  1.,  1.,  0.,  1.,  0., np.nan]]), np.array(['llllrrl'], dtype='<U7'), np.array(['ddddddd'], dtype='<U7'), np.array(['Stage 10'], dtype='<U8'))]]), dtype=[('hits', 'O'), ('sides', 'O'), ('tasks', 'O'), ('stage', 'O')])})
-    dj.conn().query("INSERT INTO djtest_test1.testmym (id, data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fetchall()
-    # dj.conn().query("INSERT INTO djtest_test1.testmym (id, data) VALUES (1, X'646A300002060000000000000004000000000000000A01000104000000000000000A01000204000000000000000A01000304000000000000000A01000404000000000000000A01000504000000000000000A010006')").fetchall()
-    print('\n',dj.conn().query("SELECT hex(data) FROM djtest_test1.testmym").fetchall())
-    print((schema.Testmym & 'id=1').fetch1())
-    schema.Testmym.drop()
-    assert True
+    query = ("INSERT INTO djtest_test1.testmym (id, data) VALUES (1, "
+            "X'6D596D00530200000001000000010000000400000068697473007369646573007461736B73007374"
+            "616765004D000000410200000001000000070000000600000000000000000000000000F8FF00000000"
+            "0000F03F000000000000F03F0000000000000000000000000000F03F00000000000000000000000000"
+            "00F8FF230000004102000000010000000700000004000000000000006C006C006C006C00720072006C"
+            "0023000000410200000001000000070000000400000000000000640064006400640064006400640025"
+            "00000041020000000100000008000000040000000000000053007400610067006500200031003000')")
+    dj.conn().query(query).fetchall()
+    data_32 = {'id': 1, 'data':np.rec.array([[(
+        np.array([[
+            np.nan,  1.,  1.,  0.,  1.,  0., np.nan]]),
+            np.array(['llllrrl'], dtype='<U7'),
+            np.array(['ddddddd'], dtype='<U7'),
+            np.array(['Stage 10'], dtype='<U8'))]],
+        dtype=[('hits', 'O'), ('sides', 'O'), ('tasks', 'O'), ('stage', 'O')])}
+    assert (schema.Testmym & 'id=1').fetch1() == data_32