Added a helper function `get_cf_names` and doc-tests refactoring

src/compaction_filter.rs

@@ -131,4 +131,6 @@ fn compaction_filter_test() {
         assert!(db.get(b"_k").unwrap().is_none());
         assert_eq!(&*db.get(b"%k").unwrap().unwrap(), b"secret");
     }
+    let result = DB::destroy(&opts, path);
+    assert!(result.is_ok());
 }

src/db.rs

@@ -67,16 +67,18 @@ pub enum DBRecoveryMode {
 /// Making an atomic commit of several writes:
 ///
 /// ```
-/// use rocksdb::{DB, WriteBatch};
+/// use rocksdb::{DB, Options, WriteBatch};
 ///
-/// let db = DB::open_default("path/for/rocksdb/storage1").unwrap();
+/// let path = "_path_for_rocksdb_storage1";
 /// {
+///     let db = DB::open_default(path).unwrap();
 ///     let mut batch = WriteBatch::default();
 ///     batch.put(b"my key", b"my value");
 ///     batch.put(b"key2", b"value2");
 ///     batch.put(b"key3", b"value3");
 ///     db.write(batch); // Atomically commits the batch
 /// }
+/// let _ = DB::destroy(&Options::default(), path);
 /// ```
 pub struct WriteBatch {
     inner: *mut ffi::rocksdb_writebatch_t,
@@ -89,11 +91,15 @@ pub struct ReadOptions {
 /// A consistent view of the database at the point of creation.
 ///
 /// ```
-/// use rocksdb::{DB, IteratorMode};
+/// use rocksdb::{DB, IteratorMode, Options};
 ///
-/// let db = DB::open_default("path/for/rocksdb/storage3").unwrap();
+/// let path = "_path_for_rocksdb_storage3";
+/// {
+///     let db = DB::open_default(path).unwrap();
 ///     let snapshot = db.snapshot(); // Creates a longer-term snapshot of the DB, but closed when goes out of scope
 ///     let mut iter = snapshot.iterator(IteratorMode::Start); // Make as many iterators as you'd like from one snapshot
+/// }
+/// let _ = DB::destroy(&Options::default(), path);
 /// ```
 ///
 pub struct Snapshot<'a> {
@@ -110,9 +116,11 @@ pub struct Snapshot<'a> {
 /// widely recognised Rust idioms.
 ///
 /// ```
-/// use rocksdb::DB;
+/// use rocksdb::{DB, Options};
 ///
-/// let mut db = DB::open_default("path/for/rocksdb/storage4").unwrap();
+/// let path = "_path_for_rocksdb_storage4";
+/// {
+///     let db = DB::open_default(path).unwrap();
 ///     let mut iter = db.raw_iterator();
 ///
 ///     // Forwards iteration
@@ -144,6 +152,8 @@ pub struct Snapshot<'a> {
 ///         println!("Saw {:?} {:?}", iter.key(), iter.value());
 ///         iter.prev();
 ///     }
+/// }
+/// let _ = DB::destroy(&Options::default(), path);
 /// ```
 pub struct DBRawIterator {
     inner: *mut ffi::rocksdb_iterator_t,
@@ -153,9 +163,11 @@ pub struct DBRawIterator {
 /// ranges and direction.
 ///
 /// ```
-/// use rocksdb::{DB, Direction, IteratorMode};
+/// use rocksdb::{DB, Direction, IteratorMode, Options};
 ///
-/// let mut db = DB::open_default("path/for/rocksdb/storage2").unwrap();
+/// let path = "_path_for_rocksdb_storage2";
+/// {
+///     let db = DB::open_default(path).unwrap();
 ///     let mut iter = db.iterator(IteratorMode::Start); // Always iterates forward
 ///     for (key, value) in iter {
 ///         println!("Saw {:?} {:?}", key, value);
@@ -175,6 +187,8 @@ pub struct DBRawIterator {
 ///     for (key, value) in iter {
 ///         println!("Saw {:?} {:?}", key, value);
 ///     }
+/// }
+/// let _ = DB::destroy(&Options::default(), path);
 /// ```
 pub struct DBIterator {
     raw: DBRawIterator,
@@ -228,23 +242,22 @@ impl DBRawIterator {
     /// # Examples
     ///
     /// ```rust
-    /// use rocksdb::DB;
+    /// use rocksdb::{DB, Options};
     ///
-    /// let mut db = DB::open_default("path/for/rocksdb/storage5").unwrap();
+    /// let path = "_path_for_rocksdb_storage5";
+    /// {
+    ///     let db = DB::open_default(path).unwrap();
     ///     let mut iter = db.raw_iterator();
     ///
     ///     // Iterate all keys from the start in lexicographic order
-    ///
     ///     iter.seek_to_first();
     ///
     ///     while iter.valid() {
     ///         println!("{:?} {:?}", iter.key(), iter.value());
-    ///
     ///         iter.next();
     ///     }
     ///
     ///     // Read just the first key
-    ///
     ///     iter.seek_to_first();
     ///
     ///     if iter.valid() {
@@ -252,6 +265,8 @@ impl DBRawIterator {
     ///     } else {
     ///         // There are no keys in the database
     ///     }
+    /// }
+    /// let _ = DB::destroy(&Options::default(), path);
     /// ```
     pub fn seek_to_first(&mut self) {
         unsafe {
@@ -264,23 +279,22 @@ impl DBRawIterator {
     /// # Examples
     ///
     /// ```rust
-    /// use rocksdb::DB;
+    /// use rocksdb::{DB, Options};
     ///
-    /// let mut db = DB::open_default("path/for/rocksdb/storage6").unwrap();
+    /// let path = "_path_for_rocksdb_storage6";
+    /// {
+    ///     let db = DB::open_default(path).unwrap();
     ///     let mut iter = db.raw_iterator();
     ///
     ///     // Iterate all keys from the end in reverse lexicographic order
-    ///
     ///     iter.seek_to_last();
     ///
     ///     while iter.valid() {
     ///         println!("{:?} {:?}", iter.key(), iter.value());
-    ///
     ///         iter.prev();
     ///     }
     ///
     ///     // Read just the last key
-    ///
     ///     iter.seek_to_last();
     ///
     ///     if iter.valid() {
@@ -288,6 +302,8 @@ impl DBRawIterator {
     ///     } else {
     ///         // There are no keys in the database
     ///     }
+    /// }
+    /// let _ = DB::destroy(&Options::default(), path);
     /// ```
     pub fn seek_to_last(&mut self) {
         unsafe {
@@ -303,13 +319,14 @@ impl DBRawIterator {
     /// # Examples
     ///
     /// ```rust
-    /// use rocksdb::DB;
+    /// use rocksdb::{DB, Options};
     ///
-    /// let mut db = DB::open_default("path/for/rocksdb/storage7").unwrap();
+    /// let path = "_path_for_rocksdb_storage7";
+    /// {
+    ///     let db = DB::open_default(path).unwrap();
     ///     let mut iter = db.raw_iterator();
     ///
     ///     // Read the first key that starts with 'a'
-    ///
     ///     iter.seek(b"a");
     ///
     ///     if iter.valid() {
@@ -317,6 +334,8 @@ impl DBRawIterator {
     ///     } else {
     ///         // There are no keys in the database
     ///     }
+    /// }
+    /// let _ = DB::destroy(&Options::default(), path);
     /// ```
     pub fn seek(&mut self, key: &[u8]) {
         unsafe {
@@ -337,13 +356,14 @@ impl DBRawIterator {
     /// # Examples
     ///
     /// ```rust
-    /// use rocksdb::DB;
+    /// use rocksdb::{DB, Options};
     ///
-    /// let mut db = DB::open_default("path/for/rocksdb/storage8").unwrap();
+    /// let path = "_path_for_rocksdb_storage8";
+    /// {
+    ///     let db = DB::open_default(path).unwrap();
     ///     let mut iter = db.raw_iterator();
     ///
     ///     // Read the last key that starts with 'a'
-    ///
     ///     iter.seek_for_prev(b"b");
     ///
     ///     if iter.valid() {
@@ -351,6 +371,9 @@ impl DBRawIterator {
     ///     } else {
     ///         // There are no keys in the database
     ///     }
+    /// }
+    /// let _ = DB::destroy(&Options::default(), path);
+    /// ```
     pub fn seek_for_prev(&mut self, key: &[u8]) {
         unsafe {
             ffi::rocksdb_iter_seek_for_prev(
@@ -640,9 +663,7 @@ impl DB {
 
         if let Err(e) = fs::create_dir_all(&path) {
             return Err(Error::new(format!(
-                "Failed to create RocksDB\
-                 directory: `{:?}`.",
-                e
+                "Failed to create RocksDB directory: `{:?}`.", e
             )));
         }
 
@@ -1395,6 +1416,39 @@ impl DBVector {
     }
 }
 
+/// Retrieves a list of column families names from a given path.
+pub fn get_cf_names<P: AsRef<Path>>(path: P) -> Result<Vec<String>, Error> {
+    let opts = Options::default();
+    let cpath = to_cpath(path)?;
+    let result: Vec<String>;
+
+    unsafe {
+        let mut cflen: size_t = 0;
+        let column_fams_raw = ffi_try!(ffi::rocksdb_list_column_families(
+            opts.inner,
+            cpath.as_ptr() as *const _,
+            &mut cflen,
+        ));
+        let column_fams = slice::from_raw_parts(column_fams_raw, cflen as usize);
+        result = column_fams
+            .iter()
+            .map(|cf| CStr::from_ptr(*cf).to_string_lossy().into_owned())
+            .collect();
+        ffi::rocksdb_list_column_families_destroy(column_fams_raw, cflen);
+    }
+
+    Ok(result)
+}
+
+fn to_cpath<P: AsRef<Path>>(path: P) -> Result<CString, Error> {
+    match CString::new(path.as_ref().to_string_lossy().as_bytes()) {
+        Ok(c) => Ok(c),
+        Err(_) => Err(Error::new(
+            "Failed to convert path to CString when opening DB.".to_owned(),
+        )),
+    }
+}
+
 #[test]
 fn test_db_vector() {
     use std::mem;
@@ -1425,6 +1479,7 @@ fn external() {
 #[test]
 fn errors_do_stuff() {
     let path = "_rust_rocksdb_error";
+    {
         let _db = DB::open_default(path).unwrap();
         let opts = Options::default();
         // The DB will still be open when we try to destroy it and the lock should fail.
@@ -1437,6 +1492,10 @@ fn errors_do_stuff() {
             Ok(_) => panic!("should fail"),
         }
     }
+    let opts = Options::default();
+    let result = DB::destroy(&opts, path);
+    assert!(result.is_ok());
+}
 
 #[test]
 fn writebatch_works() {
@@ -1562,4 +1621,31 @@ fn set_option_test() {
         ];
         db.set_options(&multiple_options).unwrap();
     }
+    assert!(DB::destroy(&Options::default(), path).is_ok());
+}
+
+#[test]
+fn get_cf_names_test() {
+    let path = "_rust_rocksdb_get_cf_names";
+    let opts = Options::default();
+    {
+        let db = DB::open_default(path).unwrap();
+        let cf_one = db.create_cf("one", &opts).unwrap();
+        let result = db.put_cf(cf_one, b"1", b"1");
+        assert!(result.is_ok());
+        let cf_two = db.create_cf("two", &opts).unwrap();
+        let result = db.put_cf(cf_two, b"2", b"2");
+        assert!(result.is_ok());
+    }
+    {
+        let cf_names = get_cf_names(path).unwrap();
+        let cfs = cf_names.iter().map(String::as_str).collect::<Vec<_>>();
+        assert_eq!(cfs, vec!["default", "one", "two"]);
+        let db = DB::open_cf(&opts, path, cfs.as_slice()).unwrap();
+        let cf_one = db.cf_handle("one").unwrap();
+        assert_eq!(db.get_cf(cf_one, b"1").unwrap().unwrap().as_ref(), b"1");
+        let cf_two = db.cf_handle("two").unwrap();
+        assert_eq!(db.get_cf(cf_two, b"2").unwrap().unwrap().as_ref(), b"2");
+    }
+    assert!(DB::destroy(&opts, path).is_ok());
 }

src/lib.rs

@@ -18,9 +18,11 @@
 //! # Examples
 //!
 //! ```
-//!  use rocksdb::DB;
+//! use rocksdb::{DB, Options};
 //! // NB: db is automatically closed at end of lifetime
-//!  let db = DB::open_default("path/for/rocksdb/storage").unwrap();
+//! let path = "_path_for_rocksdb_storage";
+//! {
+//!    let db = DB::open_default(path).unwrap();
 //!    db.put(b"my key", b"my value");
 //!    match db.get(b"my key") {
 //!        Ok(Some(value)) => println!("retrieved value {}", value.to_utf8().unwrap()),
@@ -28,12 +30,16 @@
 //!        Err(e) => println!("operational problem encountered: {}", e),
 //!    }
 //!    db.delete(b"my key").unwrap();
+//! }
+//! let _ = DB::destroy(&Options::default(), path);
 //! ```
 //!
 //! Opening a database and a single column family with custom options:
 //!
 //! ```
 //! use rocksdb::{DB, ColumnFamilyDescriptor, Options};
+//!
+//! let path = "_path_for_rocksdb_storage_with_cfs";
 //! let mut cf_opts = Options::default();
 //! cf_opts.set_max_write_buffer_number(16);
 //! let cf = ColumnFamilyDescriptor::new("cf1", cf_opts);
@@ -41,8 +47,10 @@
 //! let mut db_opts = Options::default();
 //! db_opts.create_missing_column_families(true);
 //! db_opts.create_if_missing(true);
-//!
-//! let db = DB::open_cf_descriptors(&db_opts, "path/for/rocksdb/storage_with_cfs", vec![cf]).unwrap();
+//! {
+//!     let db = DB::open_cf_descriptors(&db_opts, path, vec![cf]).unwrap();
+//! }
+//! let _ = DB::destroy(&db_opts, path);
 //! ```
 //!
 
@@ -63,7 +71,7 @@ mod slice_transform;
 
 pub use compaction_filter::Decision as CompactionDecision;
 pub use db::{
-    new_bloom_filter, DBCompactionStyle, DBCompressionType, DBIterator, DBRawIterator,
+    get_cf_names, new_bloom_filter, DBCompactionStyle, DBCompressionType, DBIterator, DBRawIterator,
     DBRecoveryMode, DBVector, Direction, IteratorMode, ReadOptions, Snapshot, WriteBatch,
 };
 
@@ -211,10 +219,11 @@ pub struct Options {
 /// Making an unsafe write of a batch:
 ///
 /// ```
-/// use rocksdb::{DB, WriteBatch, WriteOptions};
-///
-/// let db = DB::open_default("path/for/rocksdb/storageY").unwrap();
+/// use rocksdb::{DB, Options, WriteBatch, WriteOptions};
 ///
+/// let path = "_path_for_rocksdb_storageY";
+/// {
+///     let db = DB::open_default(path).unwrap();
 ///     let mut batch = WriteBatch::default();
 ///     batch.put(b"my key", b"my value");
 ///     batch.put(b"key2", b"value2");
@@ -225,6 +234,8 @@ pub struct Options {
 ///     write_options.disable_wal(true);
 ///
 ///     db.write_opt(batch, &write_options);
+/// }
+/// let _ = DB::destroy(&Options::default(), path);
 /// ```
 pub struct WriteOptions {
     inner: *mut ffi::rocksdb_writeoptions_t,

src/merge_operator.rs

@@ -38,10 +38,11 @@
 //! }
 //!
 //! fn main() {
-//!    let path = "path/to/rocksdb";
+//!    let path = "_rust_path_to_rocksdb";
 //!    let mut opts = Options::default();
 //!    opts.create_if_missing(true);
 //!    opts.set_merge_operator("test operator", concat_merge, None);
+//!    {
 //!        let db = DB::open(&opts, path).unwrap();
 //!         let p = db.put(b"k1", b"a");
 //!         db.merge(b"k1", b"b");
@@ -51,6 +52,8 @@
 //!         let r = db.get(b"k1");
 //!         assert!(r.unwrap().unwrap().to_utf8().unwrap() == "abcdefg");
 //!    }
+//!    let _ = DB::destroy(&opts, path);
+//! }
 //! ```
 
 use libc::{self, c_char, c_int, c_void, size_t};