Coverage for mddb_workflow / utils / cache.py: 73%

1from mddb_workflow.utils.auxiliar import load_json, save_json 

2from mddb_workflow.utils.type_hints import * 

3from mddb_workflow.tools.get_inchi_keys import InChIKeyData 

4 

5class Cache: 

6 """The cache is used to store data to be reused between different runs.""" 

7 

8 def __init__ (self, cache_file : 'File'): 

9 # Save the previous cache file 

10 self.file = cache_file 

11 # Set an auxiliar file which is used to not overwrite directly the previous cache 

12 self._aux_file = cache_file.get_prefixed_file('.aux') 

13 # Set a dict to store the actual cached data 

14 self.data = {} 

15 # Load data from the cache file, if it already exists 

16 self.load() 

17 # Save the entry for the first time 

18 self.save() 

19 

20 def retrieve (self, key : str, fallback = None): 

21 """Read a value from the cache.""" 

22 return self.data.get(key, fallback) 

23 

24 def update (self, key : str, value): 

25 """Update the cache and save it to disk.""" 

26 self.data[key] = value 

27 self.save() 

28 

29 def delete (self, key : str): 

30 """Delete a value in the cache.""" 

31 if key not in self.data: return 

32 del self.data[key] 

33 self.save() 

34 

35 def reset (self): 

36 """Reset the cache. This is called when some input files are modified.""" 

37 self.data = {} 

38 self.save() 

39 

40 def load (self): 

41 """Load the cache to memory, as a dict.""" 

42 # Load data from the cache file, if it already exists 

43 if not self.file.exists: return 

44 # Read the cache in disk 

45 self.data = load_json(self.file.path) 

46 if 'inchikeys_task_output' in self.data: 

47 self.data['inchikeys_task_output'] = InChIKeyData.load_cache(self.data['inchikeys_task_output']) 

48 

49 

50 def save (self): 

51 """Save the cache to disk, as a json file.""" 

52 # Write entries to disk 

53 # Write to the auxiliar file, thus not overwritting the original cache yet 

54 save_json(self.data, self._aux_file.path, indent = 4) 

55 # If the new cache is successfully written then replace the old one 

56 self._aux_file.rename_to(self.file)