feat(core): add TABBY_MODEL_CACHE_ROOT to allow individually set tabb… (

#1121)

* feat(core): add TABBY_MODEL_CACHE_ROOT to allow individually set tabby model cache dir

* docs: update changelog

* [autofix.ci] apply automated fixes

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -7,6 +7,7 @@
 * Add windows cpu binary distribution.
 * Add linux rocm (AMD GPU) binary distribution.
 * Fix cached permanent redirection on certain browsers(e.g chrome) when `--webserver` is not enabled.
+* Add environment variable `TABBY_MODEL_CACHE_ROOT` to override models cache directory individually.
 
 # v0.7.0 (12/15/2023)
 

crates/tabby-common/src/path.rs

@@ -9,6 +9,8 @@ lazy_static! {
             Err(_) => home::home_dir().unwrap().join(".tabby"),
         }))
     };
+    static ref TABBY_MODEL_CACHE_ROOT: Option<PathBuf> =
+        env::var("TABBY_MODEL_CACHE_ROOT").ok().map(PathBuf::from);
 }
 
 #[cfg(feature = "testutils")]
@@ -48,7 +50,11 @@ pub fn dataset_dir() -> PathBuf {
 }
 
 pub fn models_dir() -> PathBuf {
-    tabby_root().join("models")
+    if let Some(cache_root) = &*TABBY_MODEL_CACHE_ROOT {
+        cache_root.clone()
+    } else {
+        tabby_root().join("models")
+    }
 }
 
 pub fn events_dir() -> PathBuf {