Add cache functionality to Proofreader class

demo.py

@@ -27,7 +27,7 @@ def demo():
             print("Correct!")
         else:
             print("Incorrect!")
-            similar = proofreader.get_similar(word, 0.5, chunks=20, upto=5)
+            similar = proofreader.get_similar(word, 0.5, chunks=20, upto=5, set_cache=True, use_cache=True)
             if similar is None:
                 print("No similar words found.")
             elif showallsimilarities == "True":

lesp/autocorrect.py

@@ -1,12 +1,16 @@
 from typing import List, Optional, Union
-
 import concurrent.futures
 import os
+import json
 
 class Proofreader:
-    def __init__(self, wordlist_path: str = "lesp-wordlist.txt") -> None:
+    def __init__(self, wordlist_path: str = "lesp-wordlist.txt", cache_file: str = "lesp_cache/lesp.cache") -> None:
         self.wordlist_path: str = wordlist_path
         self.load_wordlist()
+        self.cache_file: str = cache_file
+        self.cache: dict = {}
+        if cache_file:
+            self.load_cache(cache_file)
 
     def load_wordlist(self) -> None:
         try:
@@ -20,6 +24,34 @@ def load_wordlist(self) -> None:
                 raise ValueError("Invalid wordlist format. Words must contain only alphabetic characters.")
         except FileNotFoundError:
             raise FileNotFoundError(f"{self.wordlist_path} not found!")
+
+    def load_cache(self, cache_file: str = "lesp.cache") -> None:
+        try:
+            with open(cache_file, "r") as f:
+                # Validate cache file format and how words are stored
+                temp_cache: dict = json.load(f)
+                # Must follow the format {"word": ["similar", "words"]}
+                if not all(isinstance(word, str) for word in temp_cache.keys() and not all(word.islower() and word.isalpha() for word in temp_cache.keys())):
+                    raise ValueError("Invalid cache file format. Keys must be strings. Also the strings must be all-lowercase and contain only alphabetic characters.")
+                self.cache: dict = json.load(f)
+        except FileNotFoundError:
+            # Create the cache file (and directory. also possible if multiple directories are missing)
+            try:
+                os.makedirs(os.path.dirname(cache_file), exist_ok=True)
+                with open(cache_file, "w") as f:
+                    json.dump({}, f)
+            except:
+                with open(cache_file, "w") as f:
+                    json.dump({}, f)
+        except json.JSONDecodeError:
+            raise ValueError("Invalid cache file format. Must be a valid JSON file.")
+
+    def save_cache(self) -> None:
+        try:
+            with open(self.cache_file, "w") as f:
+                json.dump(self.cache, f)
+        except FileNotFoundError:
+            raise FileNotFoundError(f"{self.cache_file} not found!")
 
     @staticmethod
     def get_similarity_score(word1: str, word2: str) -> float:
@@ -56,7 +88,7 @@ def get_similar_worker(args: tuple) -> List[str]:
     def is_correct(self, word: str) -> bool:
         return word.lower() in self.wordlist
 
-    def get_similar(self, word: str, similarity_rate: float, chunks: int = 4, upto: int = 3) -> Optional[List[str]]:
+    def get_similar(self, word: str, similarity_rate: float, chunks: int = 4, upto: int = 3, use_cache: bool = False, set_cache: bool = False) -> Optional[List[str]]:
         if upto < 1:
             raise ValueError("Can only return 1 or more similar words.")
         if chunks < 1:
@@ -68,6 +100,12 @@ def get_similar(self, word: str, similarity_rate: float, chunks: int = 4, upto:
         similar_words: List[str] = []
         chunk_size: int = len(self.wordlist) // chunks
 
+        if use_cache and self.cache and self.cache_file and word in self.cache:
+            if self.cache[word] != []:
+                return self.cache[word][:upto]
+            else:
+                return None
+
         chunks: List[tuple] = [(word, similarity_rate, self.wordlist[i:i + chunk_size]) for i in range(0, len(self.wordlist), chunk_size)]
 
         with concurrent.futures.ThreadPoolExecutor() as executor:
@@ -78,6 +116,12 @@ def get_similar(self, word: str, similarity_rate: float, chunks: int = 4, upto:
 
         similar_words = list(set(similar_words))
 
+        if set_cache and self.cache_file and word not in self.cache:
+            print("Setting cache for \"" + word + "\"")
+            self.cache[word] = similar_words
+            self.save_cache()
+
+
         if len(similar_words) == 0:
             return None
         else:
@@ -202,3 +246,18 @@ def merge_delete(source: str, destination: str) -> None:
             raise FileNotFoundError(f"File not found: {str(e)}")
         except Exception as e:
             raise ValueError(f"Error during merge delete: {str(e)}")
+
+    def clear_cache(self, cache_file: str = "lesp_cache/lesp.cache") -> None:
+        if cache_file:
+            try:
+                os.remove(cache_file)
+                self.cache = {}
+                # If there also was a directory, remove it
+                if os.path.isdir(os.path.dirname(cache_file)):
+                    os.rmdir(os.path.dirname(cache_file))
+            except FileNotFoundError:
+                raise FileNotFoundError(f"{cache_file} not found!")
+        else:
+            raise ValueError("Cache file not specified!")
+
+