From 51acc885fa5eb8bc42e645371d4e3d5384c59811 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BB=BB=E9=B9=8F?= <renpeng@xiaoice.com>
Date: Wed, 26 Jun 2024 17:01:22 +0800
Subject: [PATCH] Delete specific cache and check if cache exists

---
 src/persist_cache/caching.py       | 17 +++++++++++++++++
 src/persist_cache/persist_cache.py | 26 ++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/src/persist_cache/caching.py b/src/persist_cache/caching.py
index da9fd5d..245cc8b 100644
--- a/src/persist_cache/caching.py
+++ b/src/persist_cache/caching.py
@@ -49,6 +49,23 @@ def get(key: str, dir: str, expiry: Union[int, float, timedelta, None] = None) -
         with open(path, 'rb') as file:
                 return deserialize(file.read())
 
+def remove(key: str, dir: str) -> None:
+    """Remove the given key of the provided cache to the specified value."""
+    
+    path = f'{dir}/{key}.msgpack'
+    
+    # Lock the entry before writing to it.
+    with FileLock(f'{path}.lock'):
+        if os.path.exists(path):
+            os.remove(path)
+
+def exists(key: str, dir: str) -> bool:
+    """Check if the given key exists in the provided cache."""
+    
+    path = f'{dir}/{key}.msgpack'
+    
+    return os.path.exists(path)
+
 def hash(data: Any) -> str:
     """Hash the given data."""
 
diff --git a/src/persist_cache/persist_cache.py b/src/persist_cache/persist_cache.py
index 2a8e0b3..74459b4 100644
--- a/src/persist_cache/persist_cache.py
+++ b/src/persist_cache/persist_cache.py
@@ -185,11 +185,37 @@ def set_expiry(value: Union[int, float, timedelta, None]) -> None:
             
             expiry = value
         
+        def delete_once(*args, **kwargs) -> None:
+            """Remove the cache."""
+            nonlocal dir, expiry, is_method
+            
+            # Map arguments to their keywords or the keyword of the args parameter where necessary, filtering out the first argument if the function is a method, to enable the consistent caching of function calls where positional arguments are used on some occasions and keyword arguments are used on others.
+            arguments = inflate_arguments(signature, args_parameter, args_i, args[is_method:], kwargs)
+            
+            # Hash the arguments to produce the cache key.
+            key = caching.hash(arguments)
+
+            caching.remove(key, dir)
+        
+        def exists(*args, **kwargs) -> None:
+            """Check if cache exists"""
+            nonlocal dir, expiry, is_method
+            
+            # Map arguments to their keywords or the keyword of the args parameter where necessary, filtering out the first argument if the function is a method, to enable the consistent caching of function calls where positional arguments are used on some occasions and keyword arguments are used on others.
+            arguments = inflate_arguments(signature, args_parameter, args_i, args[is_method:], kwargs)
+            
+            # Hash the arguments to produce the cache key.
+            key = caching.hash(arguments)
+
+            return caching.exists(key, dir)            
+        
         wrapper.delete_cache = delete_cache
         wrapper.clear_cache = clear_cache
         wrapper.cache_clear = wrapper.clear_cache # Add an alias for cache_clear which is used by lru_cache.
         wrapper.flush_cache = flush_cache
         wrapper.set_expiry = set_expiry
+        wrapper.delete_once = delete_once
+        wrapper.exists = exists
                 
         # Preserve the original function.
         wrapper.__wrapped__ = func