Major Subsystem Rewrite (Reconciler Mk5) (#217)

server/src/snapshot_middleware/mod.rs

@@ -0,0 +1,76 @@
+//! Defines the semantics that Rojo uses to turn entries on the filesystem into
+//! Roblox instances using the instance snapshot subsystem.
+
+#![allow(dead_code)]
+
+mod context;
+mod csv;
+mod dir;
+mod error;
+mod json_model;
+mod lua;
+mod middleware;
+mod project;
+mod rbxm;
+mod rbxmx;
+mod txt;
+
+use rbx_dom_weak::{RbxTree, RbxId};
+
+use crate::imfs::new::{Imfs, ImfsEntry, ImfsFetcher};
+use self::{
+    middleware::{SnapshotInstanceResult, SnapshotFileResult, SnapshotMiddleware},
+    csv::SnapshotCsv,
+    dir::SnapshotDir,
+    json_model::SnapshotJsonModel,
+    lua::SnapshotLua,
+    project::SnapshotProject,
+    rbxm::SnapshotRbxm,
+    rbxmx::SnapshotRbxmx,
+    txt::SnapshotTxt,
+};
+
+macro_rules! middlewares {
+    ( $($middleware: ident,)* ) => {
+        /// Generates a snapshot of instances from the given ImfsEntry.
+        pub fn snapshot_from_imfs<F: ImfsFetcher>(
+            imfs: &mut Imfs<F>,
+            entry: &ImfsEntry,
+        ) -> SnapshotInstanceResult<'static> {
+            $(
+                log::trace!("trying middleware {} on {}", stringify!($middleware), entry.path().display());
+
+                if let Some(snapshot) = $middleware::from_imfs(imfs, entry)? {
+                    log::trace!("middleware {} success on {}", stringify!($middleware), entry.path().display());
+                    return Ok(Some(snapshot));
+                }
+            )*
+
+            log::trace!("no middleware returned Ok(Some)");
+            Ok(None)
+        }
+
+        /// Generates an in-memory filesystem snapshot of the given Roblox
+        /// instance.
+        pub fn snapshot_from_instance(tree: &RbxTree, id: RbxId) -> SnapshotFileResult {
+            $(
+                if let Some(result) = $middleware::from_instance(tree, id) {
+                    return Some(result);
+                }
+            )*
+
+            None
+        }
+    };
+}
+
+middlewares! {
+    SnapshotProject,
+    SnapshotJsonModel,
+    SnapshotRbxmx,
+    SnapshotRbxm,
+    SnapshotLua,
+    SnapshotCsv,
+    SnapshotTxt,
+    SnapshotDir,
+}