20260605 ROA增量验证和rsync host失败短路

src/fetch/rsync.rs

@@ -50,6 +50,16 @@ pub trait RsyncFetcher: Send + Sync {
     fn dedup_key(&self, rsync_base_uri: &str) -> String {
         normalize_rsync_base_uri(rsync_base_uri)
     }
+
+    /// Return an optional failure-only deduplication key.
+    ///
+    /// This key is only used to short-circuit repeated failed rsync fallbacks. It must
+    /// not be used to reuse successful fetch results unless it is identical to
+    /// `dedup_key`, because a successful fetch for one publication point does not imply
+    /// that another publication point under the same host has been fetched.
+    fn failure_dedup_key(&self, _rsync_base_uri: &str) -> Option<String> {
+        None
+    }
 }
 
 /// A simple "rsync" implementation backed by a local directory.

src/fetch/rsync_system.rs

@@ -15,23 +15,25 @@ use crate::fetch::rsync::{
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum RsyncScopePolicy {
+    Host,
     PublicationPoint,
     ModuleRoot,
 }
 
 impl Default for RsyncScopePolicy {
     fn default() -> Self {
-        Self::PublicationPoint
+        Self::Host
     }
 }
 
 impl RsyncScopePolicy {
     pub fn parse_cli_value(value: &str) -> Result<Self, String> {
         match value {
+            "host" => Ok(Self::Host),
             "publication-point" => Ok(Self::PublicationPoint),
             "module-root" => Ok(Self::ModuleRoot),
             _ => Err(format!(
-                "invalid --rsync-scope: {value}; expected publication-point or module-root"
+                "invalid --rsync-scope: {value}; expected host, publication-point, or module-root"
             )),
         }
     }
@@ -296,7 +298,9 @@ impl SystemRsyncFetcher {
 
     fn scope_fetch_uri(&self, rsync_base_uri: &str) -> String {
         match self.config.scope_policy {
-            RsyncScopePolicy::PublicationPoint => normalize_rsync_base_uri(rsync_base_uri),
+            RsyncScopePolicy::Host | RsyncScopePolicy::PublicationPoint => {
+                normalize_rsync_base_uri(rsync_base_uri)
+            }
             RsyncScopePolicy::ModuleRoot => rsync_module_root_uri(rsync_base_uri)
                 .unwrap_or_else(|| normalize_rsync_base_uri(rsync_base_uri)),
         }
@@ -348,6 +352,21 @@ impl RsyncFetcher for SystemRsyncFetcher {
     fn dedup_key(&self, rsync_base_uri: &str) -> String {
         self.scope_fetch_uri(rsync_base_uri)
     }
+
+    fn failure_dedup_key(&self, rsync_base_uri: &str) -> Option<String> {
+        match self.config.scope_policy {
+            RsyncScopePolicy::Host => rsync_host_scope_uri(rsync_base_uri),
+            RsyncScopePolicy::PublicationPoint | RsyncScopePolicy::ModuleRoot => None,
+        }
+    }
+}
+
+fn rsync_host_scope_uri(rsync_base_uri: &str) -> Option<String> {
+    let parsed = url::Url::parse(rsync_base_uri).ok()?;
+    if parsed.scheme() != "rsync" {
+        return None;
+    }
+    Some(format!("rsync://{}/", parsed.host_str()?))
 }
 
 struct TempDir {
@@ -535,12 +554,57 @@ mod tests {
     }
 
     #[test]
-    fn system_rsync_dedup_key_uses_publication_point_scope_by_default() {
+    fn rsync_host_scope_uri_returns_host_only() {
+        assert_eq!(
+            rsync_host_scope_uri("rsync://example.net/repo/ta/ca/publication-point/"),
+            Some("rsync://example.net/".to_string())
+        );
+        assert_eq!(rsync_host_scope_uri("https://example.net/repo"), None);
+    }
+
+    #[test]
+    fn system_rsync_dedup_key_uses_host_scope_by_default() {
         let fetcher = SystemRsyncFetcher::new(SystemRsyncConfig::default());
         assert_eq!(
             fetcher.dedup_key("rsync://example.net/repo/ta/ca/publication-point/"),
             "rsync://example.net/repo/ta/ca/publication-point/"
         );
+        assert_eq!(
+            fetcher.failure_dedup_key("rsync://example.net/repo/ta/ca/publication-point/"),
+            Some("rsync://example.net/".to_string())
+        );
+    }
+
+    #[test]
+    fn system_rsync_host_scope_does_not_widen_success_fetch_scope() {
+        let fetcher = SystemRsyncFetcher::new(SystemRsyncConfig {
+            scope_policy: RsyncScopePolicy::Host,
+            ..SystemRsyncConfig::default()
+        });
+        assert_eq!(
+            fetcher.dedup_key("rsync://example.net/repo/ta/ca/publication-point/"),
+            "rsync://example.net/repo/ta/ca/publication-point/"
+        );
+        assert_eq!(
+            fetcher.scope_fetch_uri("rsync://example.net/repo/ta/ca/publication-point/"),
+            "rsync://example.net/repo/ta/ca/publication-point/"
+        );
+        assert_eq!(
+            fetcher.failure_dedup_key("rsync://example.net/repo/ta/ca/publication-point/"),
+            Some("rsync://example.net/".to_string())
+        );
+    }
+
+    #[test]
+    fn system_rsync_dedup_key_uses_publication_point_scope_when_configured() {
+        let fetcher = SystemRsyncFetcher::new(SystemRsyncConfig {
+            scope_policy: RsyncScopePolicy::PublicationPoint,
+            ..SystemRsyncConfig::default()
+        });
+        assert_eq!(
+            fetcher.dedup_key("rsync://example.net/repo/ta/ca/publication-point/"),
+            "rsync://example.net/repo/ta/ca/publication-point/"
+        );
     }
 
     #[test]