feat(dump): Provide the same cli options as the snapshots

Add two cli options for the dump:
- `--ignore-missing-dump`
- `--ignore-dump-if-db-exists`

Fix #2087

meilisearch-lib/src/lib.rs

@@ -10,6 +10,8 @@ mod snapshot;
 pub mod tasks;
 mod update_file_store;
 
+use std::path::Path;
+
 pub use index_controller::MeiliSearch;
 
 pub use milli;
@@ -33,3 +35,19 @@ impl EnvSizer for heed::Env {
             .fold(0, |acc, m| acc + m.len())
     }
 }
+
+/// Check if a db is empty. It does not provide any information on the
+/// validity of the data in it.
+/// We consider a database as non empty when it's a non empty directory.
+pub fn is_empty_db(db_path: impl AsRef<Path>) -> bool {
+    let db_path = db_path.as_ref();
+
+    if !db_path.exists() {
+        true
+    // if we encounter an error or if the db is a file we consider the db non empty
+    } else if let Ok(dir) = db_path.read_dir() {
+        dir.count() == 0
+    } else {
+        true
+    }
+}