Make cache dir configurable

(cherry picked from commit a8760bc)

src/pg_access.rs

@@ -63,9 +63,13 @@ impl PgAccess {
     pub async fn new(
         fetch_settings: &PgFetchSettings,
         database_dir: &PathBuf,
+        cache_dir: Option<&PathBuf>,
     ) -> Result<Self, PgEmbedError> {
-        // cache directory
-        let cache_dir = Self::create_cache_dir_structure(&fetch_settings).await?;
+        let cache_dir = match cache_dir {
+            Some(d) => d.clone(),
+            None => Self::create_cache_dir_structure(&fetch_settings).await?,
+        };
+
         Self::create_db_dir_structure(database_dir).await?;
         // pg_ctl executable
         let mut pg_ctl = cache_dir.clone();

src/postgres.rs

@@ -35,6 +35,8 @@ use crate::pg_types::PgResult;
 pub struct PgSettings {
     /// postgresql database directory
     pub database_dir: PathBuf,
+    // cache directory
+    pub cache_dir: Option<PathBuf>,
     /// postgresql port
     pub port: u16,
     /// postgresql user name
@@ -100,7 +102,12 @@ impl PgEmbed {
             &password,
             pg_settings.port.to_string()
         );
-        let pg_access = PgAccess::new(&fetch_settings, &pg_settings.database_dir).await?;
+        let pg_access = PgAccess::new(
+            &fetch_settings,
+            &pg_settings.database_dir,
+            pg_settings.cache_dir.as_ref(),
+        )
+        .await?;
         Ok(PgEmbed {
             pg_settings,
             fetch_settings,