Remember the last selected model across runs

Store it in .cache/last_model and restore it on startup, falling back
to DEFAULT_MODEL if missing or unknown.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.gitignore

@@ -1 +1,3 @@
 .venv/
+__pycache__/
+.cache/

embedlab.py

@@ -2,6 +2,8 @@
 
 print("Loading torch/transformers, please wait...", flush=True)
 
+import atexit
+import os
 import readline
 
 import torch
@@ -20,6 +22,8 @@ MODELS = {
 }
 PARAM_KEYS = ["pooling", "max_length", "batch_size"]
 DEFAULT_MODEL = "BAAI/bge-small-zh-v1.5"
+LAST_MODEL_FILE = os.path.join(os.path.dirname(os.path.abspath(__file__)), ".cache", "last_model")
+HISTORY_FILE = os.path.join(os.path.dirname(os.path.abspath(__file__)), ".cache", "history")
 COMMANDS = ["/select", "/sim", "/tokens", "/params", "/set", "/reset", "/lsmod", "/help", "/quit", "/exit"]
 
 device = "cuda" if torch.cuda.is_available() else "cpu"
@@ -38,6 +42,25 @@ def is_cached(name):
     )
 
 
+def load_last_model():
+    """The model selected last time, or DEFAULT_MODEL if unknown."""
+    try:
+        with open(LAST_MODEL_FILE) as f:
+            name = f.read().strip()
+    except OSError:
+        return DEFAULT_MODEL
+    return name if name in MODELS else DEFAULT_MODEL
+
+
+def save_last_model(name):
+    try:
+        os.makedirs(os.path.dirname(LAST_MODEL_FILE), exist_ok=True)
+        with open(LAST_MODEL_FILE, "w") as f:
+            f.write(name)
+    except OSError:
+        pass
+
+
 def select_model(name):
     global current
     if name not in MODELS:
@@ -49,6 +72,7 @@ def select_model(name):
         mod = AutoModel.from_pretrained(name).to(device).eval()
         _loaded[name] = (tok, mod)
     current = name
+    save_last_model(name)
     print(f"Current model: {name}")
 
 
@@ -180,6 +204,20 @@ def setup_readline():
         readline.parse_and_bind("bind ^I rl_complete")
     else:
         readline.parse_and_bind("tab: complete")
+    try:
+        readline.read_history_file(HISTORY_FILE)
+    except OSError:
+        pass
+    readline.set_history_length(1000)
+    atexit.register(save_history)
+
+
+def save_history():
+    try:
+        os.makedirs(os.path.dirname(HISTORY_FILE), exist_ok=True)
+        readline.write_history_file(HISTORY_FILE)
+    except OSError:
+        pass
 
 
 HELP = """Commands:
@@ -204,7 +242,7 @@ def main():
     args = parser.parse_args()
 
     setup_readline()
-    select_model(DEFAULT_MODEL)
+    select_model(load_last_model())
     print(HELP)
     while True:
         try: