Add Store::get_all_versions() for getting all versions of a StoreId entry

libimagstore/src/store.rs

@@ -387,6 +387,45 @@ impl Store {
         }
     }
 
+    /// Same as `Store::get()` but also tries older versions of the entry, returning an iterator
+    /// over all versions of the entry.
+    pub fn get_all_versions<'a, S: IntoStoreId>(&'a self, id: S) -> Result<StoreIdIterator>
+    {
+        // get PathBuf component from storeid, but not version component
+        fn path_component<S: IntoStoreId>(id: S) -> Result<PathBuf> {
+            let p : PathBuf = id.into_storeid().into();
+            match p.to_str() {
+                Some(s) => {
+                    let mut split       = s.split("~");
+                    let path_element    = match split.next() {
+                        Some(s) => s,
+                        None => return Err(SE::new(SEK::StorePathError, None)),
+                    };
+
+                    Ok(PathBuf::from(path_element))
+                },
+
+                None => Err(SE::new(SEK::StorePathError, None)),
+            }
+        }
+
+        fn build_glob_pattern(mut pb: PathBuf) -> Option<String> {
+            pb.push("~*.*.*");
+            pb.to_str().map(String::from)
+        }
+
+        match path_component(id).map(build_glob_pattern) {
+            Err(e) => Err(SE::new(SEK::StorePathError, Some(Box::new(e)))),
+            Ok(None) => Err(SE::new(SEK::StorePathError, None)),
+            Ok(Some(pattern)) => {
+                glob(&pattern[..])
+                    .map(|paths| GlobStoreIdIterator::new(paths).into())
+                    .map_err(|e| SE::new(SEK::GlobError, Some(Box::new(e))))
+            }
+        }
+
+    }
+
     /// Iterate over all StoreIds for one module name
     pub fn retrieve_for_module(&self, mod_name: &str) -> Result<StoreIdIterator> {
         let mut path = self.path().clone();