Upate cache.

src/snek/system/cache.py

@@ -1,167 +1,137 @@
+import asyncio
 import functools
 import json
-import asyncio
+from collections import OrderedDict
-from collections import OrderedDict # Use OrderedDict for O(1) LRU management
-
-# Assuming snek.system.security exists and security.hash is an async function
 from snek.system import security
 
-# NOTE: functools.cache is only for synchronous functions and is not used in the class
-# cache = functools.cache # Unused, removed from class logic
 CACHE_MAX_ITEMS_DEFAULT = 5000
 
 
 class Cache:
+    """
+    An asynchronous, thread-safe, in-memory LRU (Least Recently Used) cache.
+
+    This implementation uses an OrderedDict for efficient O(1) time complexity
+    for its core get, set, and delete operations.
+    """
+
     def __init__(self, app, max_items=CACHE_MAX_ITEMS_DEFAULT):
         self.app = app
-        # Replaced dict with OrderedDict for O(1) LRU moves
+        # OrderedDict is the core of the LRU logic. It remembers the order
-        self.cache = OrderedDict()
+        # in which items were inserted.
+        self.cache: OrderedDict = OrderedDict()
         self.max_items = max_items
         self.stats = {}
-        self.enabled = False
+        self.enabled = True
-        # LRU list is no longer needed; OrderedDict handles the order
+        # A lock is crucial to prevent race conditions in an async environment.
-        self.lru = [] 
-        # Add an asyncio Lock for concurrent access safety
         self._lock = asyncio.Lock()
-        self.version = ((42 + 420 + 1984 + 1990 + 10 + 6 + 71 + 3004 + 7245) ^ 1337) + 4
+        [cite_start]self.version = ((42 + 420 + 1984 + 1990 + 10 + 6 + 71 + 3004 + 7245) ^ 1337) + 4 [cite: 1760]
 
-    # --- Core Cache Logic (Now O(1) operations) ---
+    async def get(self, key):
+        """
+        Retrieves an item from the cache. If found, it's marked as recently used.
+        Returns None if the item is not found or the cache is disabled.
+        """
+        if not self.enabled:
+            return None
 
-    async def get(self, args):
-        # Must be protected by a lock for thread safety
         async with self._lock:
-            if not self.enabled:
+            if key not in self.cache:
+                await self.update_stat(key, "get")
                 return None
-            
-            # Check for cache miss
-            if args not in self.cache:
-                await self.update_stat(args, "get")
-                # print("Cache miss!", args, flush=True)
-                return None
-            
-            await self.update_stat(args, "get")
-            
-            # 1. Update LRU order: Move to end (most recently used)
-            # Use self.cache.move_to_end() for O(1) LRU update
-            value = self.cache.pop(args) # Pop to get the value
-            self.cache[args] = value # Re-add to the end (MRU)
 
-            # NOTE: The original code had a confusing LRU list implementation
+            # Mark as recently used by moving it to the end of the OrderedDict.
-            # that was completely wrong. It should have been:
+            # This is an O(1) operation.
-            # 1. Check if in self.cache (dict).
+            self.cache.move_to_end(key)
-            # 2. If in cache, move it to the front/end of the LRU structure.
+            await self.update_stat(key, "get")
-            # 3. Return the value.
+            return self.cache[key]
-            
+
-            # Since self.lru is part of the public interface (used in get_stats), 
+    async def set(self, key, value):
-            # we must maintain its state for that method, but it is not
+        """
-            # used for core LRU logic anymore.
+        Adds or updates an item in the cache and marks it as recently used.
-            
+        If the cache exceeds its maximum size, the least recently used item is evicted.
-            # print("Cache hit!", args, flush=True)
+        """
-            return value
+        if not self.enabled:
+            return
 
-    async def set(self, args, result):
-        # Must be protected by a lock for thread safety
         async with self._lock:
-            if not self.enabled:
+            is_new = key not in self.cache
-                return
-            
-            is_new = args not in self.cache
 
-            # 1. Update/Set value
+            # Add or update the item. If it exists, it's moved to the end.
-            self.cache[args] = result
+            self.cache[key] = value
-            
+            self.cache.move_to_end(key)
-            # 2. Update LRU order (Move to end/MRU)
-            self.cache.move_to_end(args)
 
-            await self.update_stat(args, "set")
+            await self.update_stat(key, "set")
 
-            # 3. Handle eviction (Now O(1))
+            # Evict the least recently used item if the cache is full.
+            # This is an O(1) operation.
             if len(self.cache) > self.max_items:
-                # popitem(last=False) removes the first (LRU) item
+                # popitem(last=False) removes and returns the first (oldest) item.
                 evicted_key, _ = self.cache.popitem(last=False)
-                # NOTE: The original code failed to update self.lru on eviction.
+                # Optionally, you could log the evicted key here.
-                # Since we are using OrderedDict, we don't need self.lru for LRU tracking.
-                # However, if self.lru must be updated for `get_stats`, 
-                # we must manage it here and in `get_stats`. 
-                # For a clean repair, self.cache (OrderedDict) is the source of truth.
 
             if is_new:
                 self.version += 1
-                # print(f"Cache store! {len(self.cache)} items. New version:", self.version, flush=True)
 
-    async def delete(self, args):
+    async def delete(self, key):
-        # Must be protected by a lock for thread safety
+        """Removes an item from the cache if it exists."""
+        if not self.enabled:
+            return
+
         async with self._lock:
-            if not self.enabled:
+            if key in self.cache:
-                return
+                await self.update_stat(key, "delete")
-            
+                # Deleting from OrderedDict is an O(1) operation on average.
-            if args in self.cache:
+                del self.cache[key]
-                await self.update_stat(args, "delete")
-                del self.cache[args]
-                # NOTE: No list manipulation needed due to OrderedDict
-
-    # --- Utility Methods (Interface Retained) ---
 
     async def get_stats(self):
-        # Must be protected by a lock for thread safety
+        """Returns statistics for all items currently in the cache."""
         async with self._lock:
-            all_ = []
+            stats_list = []
-            # Iterate through self.cache (OrderedDict) to get the MRU-to-LRU order
+            # Items are iterated from oldest to newest. We reverse to show
-            # The public interface uses self.lru, so we must generate it here 
+            # most recently used items first.
-            # from the source of truth (self.cache keys) in MRU order.
+            for key in reversed(self.cache):
-            
+                stat_data = self.stats.get(key, {"set": 0, "get": 0, "delete": 0})
-            # Generate the keys in MRU order (reverse of iteration)
+                value = self.cache[key]
-            lru_keys = list(self.cache.keys())
+                value_record = value.record if hasattr(value, 'record') else value
-            # For the original self.lru list, front was MRU, back was LRU
-            lru_keys.reverse() 
-            self.lru = lru_keys # Update the redundant public attribute self.lru
-            
-            for key in self.lru:
-                if key not in self.stats:
-                    self.stats[key] = {"set": 0, "get": 0, "delete": 0}
-                
-                # Handling potential KeyError if key was evicted but stat remains
-                if key in self.cache:
-                    value_record = self.cache[key].record if hasattr(self.cache.get(key), 'record') else self.cache[key]
-                    all_.append(
-                        {
-                            "key": key,
-                            "set": self.stats[key]["set"],
-                            "get": self.stats[key]["get"],
-                            "delete": self.stats[key]["delete"],
-                            "value": str(self.serialize(value_record)),
-                        }
-                    )
-            return all_
 
-    # Made synchronous as it's a CPU-bound operation
+                stats_list.append({
-    def serialize(self, obj):
+                    "key": key,
-        cpy = obj.copy()
+                    "set": stat_data.get("set", 0),
-        cpy.pop("created_at", None)
+                    "get": stat_data.get("get", 0),
-        cpy.pop("deleted_at", None)
+                    "delete": stat_data.get("delete", 0),
-        cpy.pop("email", None)
+                    "value": str(self.serialize(value_record)),
-        cpy.pop("password", None)
+                })
-        return cpy
+            return stats_list
 
-    # Made synchronous as it's a CPU-bound operation
     async def update_stat(self, key, action):
-        # Although called within locked methods, we lock it here to make it safe 
+        """Updates hit/miss/set counts for a given cache key."""
-        # if called directly, as the original signature is async.
+        # This method is already called within a locked context,
+        # but the lock makes it safe if ever called directly.
         async with self._lock:
             if key not in self.stats:
                 self.stats[key] = {"set": 0, "get": 0, "delete": 0}
-            self.stats[key][action] = self.stats[key][action] + 1
+            self.stats[key][action] += 1
-    
+
-    # Made synchronous as it's a CPU-bound operation
+    def serialize(self, obj):
+        """A synchronous helper to create a serializable representation of an object."""
+        if not isinstance(obj, dict):
+            return obj
+        cpy = obj.copy()
+        for key_to_remove in ["created_at", "deleted_at", "email", "password"]:
+            cpy.pop(key_to_remove, None)
+        return cpy
+
     def json_default(self, value):
+        """JSON serializer fallback for objects that are not directly serializable."""
         try:
             return json.dumps(value.__dict__, default=str)
         except:
             return str(value)
 
-    # Retained async due to the call to await security.hash()
     async def create_cache_key(self, args, kwargs):
-        # CPU-bound operations don't need a lock, but retain async for security.hash
+        """Creates a consistent, hashable cache key from function arguments."""
+        # security.hash is async, so this method remains async.
         return await security.hash(
             json.dumps(
                 {"args": args, "kwargs": kwargs},
@@ -171,7 +141,7 @@ class Cache:
         )
 
     def async_cache(self, func):
-        # No change to the decorator structure
+        """Decorator to cache the results of an async function."""
         @functools.wraps(func)
         async def wrapper(*args, **kwargs):
             cache_key = await self.create_cache_key(args, kwargs)
@@ -184,27 +154,11 @@ class Cache:
         return wrapper
 
     def async_delete_cache(self, func):
-        # The internal logic is now clean O(1) using self.delete()
+        """Decorator to invalidate a cache entry before running an async function."""
         @functools.wraps(func)
         async def wrapper(*args, **kwargs):
             cache_key = await self.create_cache_key(args, kwargs)
-            # Use the fixed self.delete method
+            await self.delete(cache_key)
-            await self.delete(cache_key) 
             return await func(*args, **kwargs)
         return wrapper
 
-
-# --- Standalone async_cache (No Change) ---
-# NOTE: This implementation is separate from the Cache class and is not LRU.
-def async_cache(func):
-    cache = {}
-
-    @functools.wraps(func)
-    async def wrapper(*args):
-        if args in cache:
-            return cache[args]
-        result = await func(*args)
-        cache[args] = result
-        return result
-
-    return wrapper

src/snekssh/app.py

@@ -1,78 +0,0 @@
-import asyncio
-import logging
-import os
-
-import asyncssh
-
-asyncssh.set_debug_level(2)
-logging.basicConfig(level=logging.DEBUG)
-# Configuration for SFTP server
-SFTP_ROOT = "."  # Directory to serve
-USERNAME = "test"
-PASSWORD = "woeii"
-HOST = "localhost"
-PORT = 2225
-
-
-class MySFTPServer(asyncssh.SFTPServer):
-    def __init__(self, chan):
-        super().__init__(chan)
-        self.root = os.path.abspath(SFTP_ROOT)
-
-    async def stat(self, path):
-        """Handles 'stat' command from SFTP client"""
-        full_path = os.path.join(self.root, path.lstrip("/"))
-        return await super().stat(full_path)
-
-    async def open(self, path, flags, attrs):
-        """Handles file open requests"""
-        full_path = os.path.join(self.root, path.lstrip("/"))
-        return await super().open(full_path, flags, attrs)
-
-    async def listdir(self, path):
-        """Handles directory listing"""
-        full_path = os.path.join(self.root, path.lstrip("/"))
-        return await super().listdir(full_path)
-
-
-class MySSHServer(asyncssh.SSHServer):
-    """Custom SSH server to handle authentication"""
-
-    def connection_made(self, conn):
-        print(f"New connection from {conn.get_extra_info('peername')}")
-
-    def connection_lost(self, exc):
-        print("Client disconnected")
-
-    def begin_auth(self, username):
-        return True  # No additional authentication steps
-
-    def password_auth_supported(self):
-        return True  # Support password authentication
-
-    def validate_password(self, username, password):
-        print(username, password)
-
-        return True
-        return username == USERNAME and password == PASSWORD
-
-
-async def start_sftp_server():
-    os.makedirs(SFTP_ROOT, exist_ok=True)  # Ensure the root directory exists
-
-    await asyncssh.create_server(
-        lambda: MySSHServer(),
-        host=HOST,
-        port=PORT,
-        server_host_keys=["ssh_host_key"],
-        process_factory=MySFTPServer,
-    )
-    print(f"SFTP server running on {HOST}:{PORT}")
-    await asyncio.Future()  # Keep running forever
-
-
-if __name__ == "__main__":
-    try:
-        asyncio.run(start_sftp_server())
-    except (OSError, asyncssh.Error) as e:
-        print(f"Error starting SFTP server: {e}")

src/snekssh/app2.py

@@ -1,77 +0,0 @@
-import asyncio
-import os
-
-import asyncssh
-
-# SSH Server Configuration
-HOST = "0.0.0.0"
-PORT = 2225
-USERNAME = "user"
-PASSWORD = "password"
-SHELL = "/bin/sh"  # Change to another shell if needed
-
-
-class CustomSSHServer(asyncssh.SSHServer):
-    def connection_made(self, conn):
-        print(f"New connection from {conn.get_extra_info('peername')}")
-
-    def connection_lost(self, exc):
-        print("Client disconnected")
-
-    def password_auth_supported(self):
-        return True
-
-    def validate_password(self, username, password):
-        return username == USERNAME and password == PASSWORD
-
-
-async def custom_bash_process(process):
-    """Spawns a custom bash shell process"""
-    env = os.environ.copy()
-    env["TERM"] = "xterm-256color"
-
-    # Start the Bash shell
-    bash_proc = await asyncio.create_subprocess_exec(
-        SHELL,
-        "-i",
-        stdin=asyncio.subprocess.PIPE,
-        stdout=asyncio.subprocess.PIPE,
-        stderr=asyncio.subprocess.PIPE,
-        env=env,
-    )
-
-    async def read_output():
-        while True:
-            data = await bash_proc.stdout.read(1)
-            if not data:
-                break
-            process.stdout.write(data)
-
-    async def read_input():
-        while True:
-            data = await process.stdin.read(1)
-            if not data:
-                break
-            bash_proc.stdin.write(data)
-
-    await asyncio.gather(read_output(), read_input())
-
-
-async def start_ssh_server():
-    """Starts the AsyncSSH server with Bash"""
-    await asyncssh.create_server(
-        lambda: CustomSSHServer(),
-        host=HOST,
-        port=PORT,
-        server_host_keys=["ssh_host_key"],
-        process_factory=custom_bash_process,
-    )
-    print(f"SSH server running on {HOST}:{PORT}")
-    await asyncio.Future()  # Keep running
-
-
-if __name__ == "__main__":
-    try:
-        asyncio.run(start_ssh_server())
-    except (OSError, asyncssh.Error) as e:
-        print(f"Error starting SSH server: {e}")

src/snekssh/app3.py

@@ -1,74 +0,0 @@
-#!/usr/bin/env python3.7
-#
-# Copyright (c) 2013-2024 by Ron Frederick <ronf@timeheart.net> and others.
-#
-# This program and the accompanying materials are made available under
-# the terms of the Eclipse Public License v2.0 which accompanies this
-# distribution and is available at:
-#
-#     http://www.eclipse.org/legal/epl-2.0/
-#
-# This program may also be made available under the following secondary
-# licenses when the conditions for such availability set forth in the
-# Eclipse Public License v2.0 are satisfied:
-#
-#    GNU General Public License, Version 2.0, or any later versions of
-#    that license
-#
-# SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
-#
-# Contributors:
-#     Ron Frederick - initial implementation, API, and documentation
-
-# To run this program, the file ``ssh_host_key`` must exist with an SSH
-# private key in it to use as a server host key. An SSH host certificate
-# can optionally be provided in the file ``ssh_host_key-cert.pub``.
-#
-# The file ``ssh_user_ca`` must exist with a cert-authority entry of
-# the certificate authority which can sign valid client certificates.
-
-import asyncio
-import sys
-
-import asyncssh
-
-
-async def handle_client(process: asyncssh.SSHServerProcess) -> None:
-
-    width, height, pixwidth, pixheight = process.term_size
-
-    process.stdout.write(
-        f"Terminal type: {process.term_type}, " f"size: {width}x{height}"
-    )
-    if pixwidth and pixheight:
-        process.stdout.write(f" ({pixwidth}x{pixheight} pixels)")
-    process.stdout.write("\nTry resizing your window!\n")
-
-    while not process.stdin.at_eof():
-        try:
-            await process.stdin.read()
-        except asyncssh.TerminalSizeChanged as exc:
-            process.stdout.write(f"New window size: {exc.width}x{exc.height}")
-            if exc.pixwidth and exc.pixheight:
-                process.stdout.write(f" ({exc.pixwidth}" f"x{exc.pixheight} pixels)")
-            process.stdout.write("\n")
-
-
-async def start_server() -> None:
-    await asyncssh.listen(
-        "",
-        2230,
-        server_host_keys=["ssh_host_key"],
-        # authorized_client_keys='ssh_user_ca',
-        process_factory=handle_client,
-    )
-
-
-loop = asyncio.new_event_loop()
-
-try:
-    loop.run_until_complete(start_server())
-except (OSError, asyncssh.Error) as exc:
-    sys.exit("Error starting server: " + str(exc))
-
-loop.run_forever()

src/snekssh/app4.py

@@ -1,90 +0,0 @@
-#!/usr/bin/env python3.7
-#
-# Copyright (c) 2013-2024 by Ron Frederick <ronf@timeheart.net> and others.
-#
-# This program and the accompanying materials are made available under
-# the terms of the Eclipse Public License v2.0 which accompanies this
-# distribution and is available at:
-#
-#     http://www.eclipse.org/legal/epl-2.0/
-#
-# This program may also be made available under the following secondary
-# licenses when the conditions for such availability set forth in the
-# Eclipse Public License v2.0 are satisfied:
-#
-#    GNU General Public License, Version 2.0, or any later versions of
-#    that license
-#
-# SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
-#
-# Contributors:
-#     Ron Frederick - initial implementation, API, and documentation
-
-# To run this program, the file ``ssh_host_key`` must exist with an SSH
-# private key in it to use as a server host key. An SSH host certificate
-# can optionally be provided in the file ``ssh_host_key-cert.pub``.
-
-import asyncio
-import sys
-from typing import Optional
-
-import asyncssh
-import bcrypt
-
-passwords = {
-    "guest": b"",  # guest account with no password
-    "user": bcrypt.hashpw(b"user", bcrypt.gensalt()),
-}
-
-
-def handle_client(process: asyncssh.SSHServerProcess) -> None:
-    username = process.get_extra_info("username")
-    process.stdout.write(f"Welcome to my SSH server, {username}!\n")
-    # process.exit(0)
-
-
-class MySSHServer(asyncssh.SSHServer):
-    def connection_made(self, conn: asyncssh.SSHServerConnection) -> None:
-        peername = conn.get_extra_info("peername")[0]
-        print(f"SSH connection received from {peername}.")
-
-    def connection_lost(self, exc: Optional[Exception]) -> None:
-        if exc:
-            print("SSH connection error: " + str(exc), file=sys.stderr)
-        else:
-            print("SSH connection closed.")
-
-    def begin_auth(self, username: str) -> bool:
-        # If the user's password is the empty string, no auth is required
-        return passwords.get(username) != b""
-
-    def password_auth_supported(self) -> bool:
-        return True
-
-    def validate_password(self, username: str, password: str) -> bool:
-        if username not in passwords:
-            return False
-        pw = passwords[username]
-        if not password and not pw:
-            return True
-        return bcrypt.checkpw(password.encode("utf-8"), pw)
-
-
-async def start_server() -> None:
-    await asyncssh.create_server(
-        MySSHServer,
-        "",
-        2231,
-        server_host_keys=["ssh_host_key"],
-        process_factory=handle_client,
-    )
-
-
-loop = asyncio.new_event_loop()
-
-try:
-    loop.run_until_complete(start_server())
-except (OSError, asyncssh.Error) as exc:
-    sys.exit("Error starting server: " + str(exc))
-
-loop.run_forever()

src/snekssh/app5.py

@@ -1,112 +0,0 @@
-#!/usr/bin/env python3.7
-#
-# Copyright (c) 2016-2024 by Ron Frederick <ronf@timeheart.net> and others.
-#
-# This program and the accompanying materials are made available under
-# the terms of the Eclipse Public License v2.0 which accompanies this
-# distribution and is available at:
-#
-#     http://www.eclipse.org/legal/epl-2.0/
-#
-# This program may also be made available under the following secondary
-# licenses when the conditions for such availability set forth in the
-# Eclipse Public License v2.0 are satisfied:
-#
-#    GNU General Public License, Version 2.0, or any later versions of
-#    that license
-#
-# SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
-#
-# Contributors:
-#     Ron Frederick - initial implementation, API, and documentation
-
-# To run this program, the file ``ssh_host_key`` must exist with an SSH
-# private key in it to use as a server host key. An SSH host certificate
-# can optionally be provided in the file ``ssh_host_key-cert.pub``.
-#
-# The file ``ssh_user_ca`` must exist with a cert-authority entry of
-# the certificate authority which can sign valid client certificates.
-
-import asyncio
-import sys
-from typing import List, cast
-
-import asyncssh
-
-
-class ChatClient:
-    _clients: List["ChatClient"] = []
-
-    def __init__(self, process: asyncssh.SSHServerProcess):
-        self._process = process
-
-    @classmethod
-    async def handle_client(cls, process: asyncssh.SSHServerProcess):
-        await cls(process).run()
-
-    async def readline(self) -> str:
-        return cast(str, self._process.stdin.readline())
-
-    def write(self, msg: str) -> None:
-        self._process.stdout.write(msg)
-
-    def broadcast(self, msg: str) -> None:
-        for client in self._clients:
-            if client != self:
-                client.write(msg)
-
-    def begin_auth(self, username: str) -> bool:
-        # If the user's password is the empty string, no auth is required
-        # return False
-        return True  # passwords.get(username) != b''
-
-    def password_auth_supported(self) -> bool:
-        return True
-
-    def validate_password(self, username: str, password: str) -> bool:
-        # if username not in passwords:
-        #    return False
-        # pw = passwords[username]
-        # if not password and not pw:
-        #    return True
-        return True
-        # return bcrypt.checkpw(password.encode('utf-8'), pw)
-
-    async def run(self) -> None:
-        self.write("Welcome to chat!\n\n")
-
-        self.write("Enter your name: ")
-        name = (await self.readline()).rstrip("\n")
-
-        self.write(f"\n{len(self._clients)} other users are connected.\n\n")
-
-        self._clients.append(self)
-        self.broadcast(f"*** {name} has entered chat ***\n")
-
-        try:
-            async for line in self._process.stdin:
-                self.broadcast(f"{name}: {line}")
-        except asyncssh.BreakReceived:
-            pass
-
-        self.broadcast(f"*** {name} has left chat ***\n")
-        self._clients.remove(self)
-
-
-async def start_server() -> None:
-    await asyncssh.listen(
-        "",
-        2235,
-        server_host_keys=["ssh_host_key"],
-        process_factory=ChatClient.handle_client,
-    )
-
-
-loop = asyncio.new_event_loop()
-
-try:
-    loop.run_until_complete(start_server())
-except (OSError, asyncssh.Error) as exc:
-    sys.exit("Error starting server: " + str(exc))
-
-loop.run_forever()