Database name mapping (#81)

mvfs/src/vfs.rs

@@ -29,10 +29,17 @@ pub struct MultiVersionVfs {
     pub data_plane: String,
     pub sector_size: usize,
     pub http_client: reqwest::Client,
+    pub db_name_map: Arc<HashMap<String, String>>,
 }
 
 impl MultiVersionVfs {
-    pub fn open(&self, db: &str) -> Result<Connection> {
+    pub fn open(&self, db: &str, map_name: bool) -> Result<Connection> {
+        if map_name {
+            if let Some(mapped) = self.db_name_map.get(db) {
+                return self.open(mapped, false);
+            }
+        }
+
         let (dp, db) = if db.starts_with("http://") || db.starts_with("https://") {
             let url = Url::parse(db)?;
             let dp = Url::parse(&url.origin().ascii_serialization())?;

mvsqlite-fuse/src/main.rs

@@ -95,6 +95,7 @@ async fn main() -> Result<()> {
         data_plane: opt.data_plane.clone(),
         sector_size: opt.sector_size,
         http_client: reqwest::Client::new(),
+        db_name_map: Arc::new(Default::default()),
     };
     let fuse_fs = FuseFs {
         namespaces,
@@ -372,7 +373,7 @@ impl fuser::Filesystem for FuseFs {
                 .unwrap()
                 .remove(&ino);
             let (ns_name, namespace) = self.namespaces.get_index(inode.ns).unwrap();
-            let conn = match self.vfs.open(namespace) {
+            let conn = match self.vfs.open(namespace, false) {
                 Ok(conn) => conn,
                 Err(e) => {
                     tracing::error!(ns = ns_name, error = %e, "failed to open namespace");

mvsqlite/src/lib.rs

@@ -9,6 +9,7 @@ mod util;
 pub mod vfs;
 
 use std::{
+    collections::HashMap,
     ffi::CString,
     sync::{atomic::Ordering, Arc},
     time::Duration,
@@ -88,6 +89,18 @@ fn init_with_options_impl(opts: InitOptions) {
         10
     };
 
+    let mut db_name_map: HashMap<String, String> = HashMap::new();
+    if let Ok(s) = std::env::var("MVSQLITE_DB_NAME_MAP") {
+        for mapping in s.split(',').map(|x| x.trim()).filter(|x| !x.is_empty()) {
+            let mut parts = mapping.splitn(2, '=');
+            let from = parts.next().unwrap();
+            let to = parts.next().unwrap();
+            db_name_map.insert(from.to_string(), to.to_string());
+        }
+        tracing::debug!(num_entries = db_name_map.len(), "configuring db name map");
+    }
+    let db_name_map = Arc::new(db_name_map);
+
     let mut builder = reqwest::ClientBuilder::new();
     builder = builder.timeout(Duration::from_secs(timeout_secs));
     if force_http2 {
@@ -104,6 +117,7 @@ fn init_with_options_impl(opts: InitOptions) {
             data_plane: data_plane.clone(),
             sector_size,
             http_client: http_client.clone(),
+            db_name_map: db_name_map.clone(),
         },
     };
 
@@ -116,6 +130,7 @@ fn init_with_options_impl(opts: InitOptions) {
                 data_plane: data_plane.clone(),
                 sector_size,
                 http_client: http_client.clone(),
+                db_name_map: db_name_map.clone(),
             },
         };
         sqlite_vfs::register(&format!("{}-{}", VFS_NAME, sector_size), vfs, false)

mvsqlite/src/vfs.rs

@@ -27,7 +27,7 @@ impl Vfs for MultiVersionVfs {
 
         let conn = self
             .inner
-            .open(db)
+            .open(db, true)
             .map_err(|e| std::io::Error::new(ErrorKind::Other, e))?;
         Ok(Box::new(Connection {
             io: self.io.clone(),