WIP

py/read_storage.py

@@ -9,24 +9,62 @@ from array import array
 from datetime import datetime as dt
 import os
 
+HEADER = 'SNS-BIET2020'
+HEADER_SZ = 12
+
+ENDRCRD = 254
+ENDFILE = 255
+
+NAME = 1
+UNIXTST = 2
+EPICSTST = 3
+TAG = 4
+DESCR = 5
+
+I32PARM = 6
+I32 = 16
+I32WFPARM = 26
+I32WF = 36
+
+DBLPARM = 7
+DBL = 17
+DBLWFPARM = 27
+DBLWF = 37
+
+U8PARM = 8
+U8 = 18
+U8WFPARM = 28
+U8WF = 38
+
+FLTPARM = 9
+FLT = 19
+FLTWFPARM = 29
+FLT8WF = 39
+
+
+class Writer:
+
+    def __init__(self, path):
+        self.file = open(path, 'wb')
+        self.file.write(HEADER)
+        # print(bytes.decode())
+
+    def close(self):
+        self.file.close()
 
-HEADER_SZ=12
 
 class BinaryStorage:
 
     def __init__(self, path):
-        
         self.file = open(path,'rb')
         bytes = self.file.read(HEADER_SZ)
         # print(bytes.decode())
         self.rec_table = read_epilog(self.file)
         self.file.seek(HEADER_SZ)
-        
-        
+
     def close(self):
         self.file.close()
 
-        
     def read(self):
         return read_record(self.file)
     
@@ -34,20 +72,23 @@ class BinaryStorage:
         offset = self.rec_table[key]
         self.file.seek(offset)
         return read_record(self.file)
-        
-    
+
     def __getitem__(self, key):
         
         if isinstance(key,slice):
             return [self.readAt(i) for i in range(key.start,key.stop,key.step)]
         else:
             return self.readAt(key)
-        
 
     def __len__(self):
         return len(self.rec_table)
 
 
+"""
+    Internal implementation
+"""
+
+
 def read_size(file, long=True):
     if long:
         bytes = array('I',file.read(4))
@@ -56,11 +97,11 @@ def read_size(file, long=True):
     else:
         return read_byte(file)
 
+
 def read_byte(file):
     return int.from_bytes(file.read(1),'big')
 
 
-
 def short_str(file):
     length = read_size(file,False)
     return file.read(length).decode()
@@ -120,10 +161,11 @@ def param_value(param=False,wf=False, vtype='I'):
 
 def description(file, rec):
     length = read_size(file,True)
-    description = file.read(length).decode()
-    rec['description'] = description
+    desc = file.read(length).decode()
+    rec['description'] = desc
     return True
 
+
 def tag(file, rec):
     length = read_size(file,False)
     tag = file.read(length).decode()
@@ -132,49 +174,51 @@ def tag(file, rec):
     rec['tags'] = tags
     return True
 
+
 def end_record(file, rec):
     return False
 
+
 def end_file(file, rec):
     rec['EOF']=True
     return False
 
 
 parser = {
-    5: description,
-    4: tag,
-    1: name,
-    2: tst,
-
-    6: param_value(param=True,wf=False,vtype='I'),
-    16: param_value(param=False,wf=False,vtype='I'),
-    36: param_value(param=False,wf=True,vtype='I'),
-    26: param_value(param=True,wf=True,vtype='I'),
-
-    7: param_value(param=True,wf=False,vtype='d'),
-    17: param_value(param=False,wf=False,vtype='d'),
-    37: param_value(param=False,wf=True,vtype='d'),
-    27: param_value(param=True,wf=True,vtype='d'),
-
-    8: param_value(param=True,wf=False,vtype='B'),
-    18: param_value(param=False,wf=False,vtype='B'),
-    38: param_value(param=False,wf=True,vtype='B'),
-    28: param_value(param=True,wf=True,vtype='B'),
-
-    9: param_value(param=True,wf=False,vtype='f'),
-    19: param_value(param=False,wf=False,vtype='f'),
-    39: param_value(param=False,wf=True,vtype='f'),
-    29: param_value(param=True,wf=True,vtype='f'),
-
-    254: end_record,
-    255: end_file
+    DESCR: description,
+    TAG: tag,
+    NAME: name,
+    UNIXTST: tst,
+
+    I32PARM: param_value(param=True,wf=False,vtype='I'),
+    I32: param_value(param=False,wf=False,vtype='I'),
+    I32WF: param_value(param=False,wf=True,vtype='I'),
+    I32WFPARM: param_value(param=True,wf=True,vtype='I'),
+
+    DBLPARM: param_value(param=True,wf=False,vtype='d'),
+    DBL: param_value(param=False,wf=False,vtype='d'),
+    DBLWF: param_value(param=False,wf=True,vtype='d'),
+    DBLWFPARM: param_value(param=True,wf=True,vtype='d'),
+
+    U8PARM: param_value(param=True,wf=False,vtype='B'),
+    U8: param_value(param=False,wf=False,vtype='B'),
+    U8WF: param_value(param=False,wf=True,vtype='B'),
+    U8WFPARM: param_value(param=True,wf=True,vtype='B'),
+
+    FLTPARM: param_value(param=True,wf=False,vtype='f'),
+    FLT: param_value(param=False,wf=False,vtype='f'),
+    FLT8WF: param_value(param=False,wf=True,vtype='f'),
+    FLTWFPARM: param_value(param=True,wf=True,vtype='f'),
+
+    ENDRCRD: end_record,
+    ENDFILE: end_file
 }
 
 
 def read_record(file):
     rec_size = read_size(file)
-    #print(rec_size)
-    #buffer = file.read(rec_size)
+    # print(rec_size)
+    # buffer = file.read(rec_size)
     record = {}
 
     while True: