From f967d3c50fb3207c62f8267e0b19a77331bddd5f Mon Sep 17 00:00:00 2001
From: Marat Safin <jeizsm@gmail.com>
Date: Mon, 28 Aug 2017 12:09:02 +0300
Subject: [PATCH] list column family

---
 src/db.rs                   | 27 +++++++++++++++++++++++++++
 tests/test_column_family.rs | 11 +++++++++++
 2 files changed, 38 insertions(+)

diff --git a/src/db.rs b/src/db.rs
index 3067928..9e53be7 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -659,6 +659,33 @@ impl DB {
         })
     }
 
+    pub fn list_cf<P: AsRef<Path>>(opts: &Options, path: P) -> Result<Vec<String>, Error> {
+        let path = path.as_ref();
+        let cpath = match CString::new(path.to_string_lossy().as_bytes()) {
+            Ok(c) => c,
+            Err(_) => {
+                return Err(Error::new("Failed to convert path to CString \
+                                       when opening DB."
+                                      .to_owned()))
+            }
+        };
+
+        let mut length = 0;
+        let vec;
+
+        unsafe {
+            let ptr = ffi_try!(ffi::rocksdb_list_column_families(opts.inner,
+                                                                 cpath.as_ptr() as *const _,
+                                                                 &mut length));
+
+            vec = Vec::from_raw_parts(ptr, length, length).iter().map(|&ptr| {
+                CString::from_raw(ptr).into_string().unwrap()
+            }).collect();
+        }
+        Ok(vec)
+    }
+
+
     pub fn destroy<P: AsRef<Path>>(opts: &Options, path: P) -> Result<(), Error> {
         let cpath = CString::new(path.as_ref().to_string_lossy().as_bytes()).unwrap();
         unsafe {
diff --git a/tests/test_column_family.rs b/tests/test_column_family.rs
index 8644aaa..02d9220 100644
--- a/tests/test_column_family.rs
+++ b/tests/test_column_family.rs
@@ -62,6 +62,17 @@ pub fn test_column_family() {
             Err(e) => panic!("failed to open db with column family: {}", e),
         }
     }
+
+    // should be able to list a cf
+    {
+        let opts = Options::default();
+        let vec = DB::list_cf(&opts, path);
+        match vec {
+            Ok(vec) => println!("list cf: {:?}", vec),
+            Err(e) => panic!("failed to drop column family: {}", e),
+        }
+    }
+
     // TODO should be able to use writebatch ops with a cf
     {
     }