feat: expose read-only local review CLI

src/review.rs

@@ -299,6 +299,50 @@ pub struct Store {
 }
 
 impl Store {
+    /// Open existing storage without creating files, changing permissions, or migrating schemas.
+    pub fn open_read_only(directory: &Path) -> Result<Option<Self>, String> {
+        let path = directory.join("reviews.sqlite3");
+        let metadata = match fs::symlink_metadata(&path) {
+            Ok(metadata) => metadata,
+            Err(error) if error.kind() == std::io::ErrorKind::NotFound => return Ok(None),
+            Err(error) => return Err(error.to_string()),
+        };
+        if !metadata.is_file() || metadata.file_type().is_symlink() {
+            return Err("Review database must be a regular file, not a symbolic link".into());
+        }
+        let path = fs::canonicalize(directory)
+            .map_err(|error| format!("Cannot resolve review directory: {error}"))?
+            .join("reviews.sqlite3");
+        let connection = Connection::open_with_flags(
+            &path,
+            OpenFlags::SQLITE_OPEN_READ_ONLY
+                | OpenFlags::SQLITE_OPEN_NO_MUTEX
+                | OpenFlags::SQLITE_OPEN_NOFOLLOW,
+        )
+        .map_err(database_error)?;
+        Self::check_schema(&connection)?;
+        Ok(Some(Self { connection }))
+    }
+
+    fn check_schema(connection: &Connection) -> Result<(), String> {
+        let version: i64 = connection
+            .pragma_query_value(None, "user_version", |row| row.get(0))
+            .map_err(database_error)?;
+        let schema: Vec<String> = connection
+            .prepare("SELECT sql FROM sqlite_schema WHERE name NOT GLOB 'sqlite_*' ORDER BY name")
+            .map_err(database_error)?
+            .query_map([], |row| row.get(0))
+            .map_err(database_error)?
+            .collect::<Result<_, _>>()
+            .map_err(database_error)?;
+        if version != 1 || schema != [SCHEMA] {
+            return Err(format!(
+                "Unsupported review database schema (version {version}); existing data was not changed"
+            ));
+        }
+        Ok(())
+    }
+
     pub fn open(directory: &Path) -> Result<Self, String> {
         let mut builder = fs::DirBuilder::new();
         builder.recursive(true);
@@ -352,23 +396,7 @@ impl Store {
                 .map_err(database_error)?;
             transaction.commit().map_err(database_error)?;
         } else {
-            let version: i64 = connection
-                .pragma_query_value(None, "user_version", |row| row.get(0))
-                .map_err(database_error)?;
-            let schema: Vec<String> = connection
-                .prepare(
-                    "SELECT sql FROM sqlite_schema WHERE name NOT GLOB 'sqlite_*' ORDER BY name",
-                )
-                .map_err(database_error)?
-                .query_map([], |row| row.get(0))
-                .map_err(database_error)?
-                .collect::<Result<_, _>>()
-                .map_err(database_error)?;
-            if version != 1 || schema != [SCHEMA] {
-                return Err(format!(
-                    "Unsupported review database schema (version {version}); existing data was not changed"
-                ));
-            }
+            Self::check_schema(&connection)?;
         }
         #[cfg(unix)]
         {