add duplicate iterators

lmdb-sys/Cargo.toml

@@ -13,7 +13,7 @@ build = "build.rs"
 name = "lmdb-sys"
 
 [dependencies.rust-bindgen]
-git = "https://github.com/crabtw/rust-bindgen.git"
+path = "../../rust-bindgen"
 
 [build-dependencies.pkg-config]
 pkg-config = "*"

src/cursor.rs

@@ -18,7 +18,7 @@ pub trait Cursor<'txn> {
 }
 
 /// Cursor extension methods.
-pub trait CursorExt<'txn> : Cursor<'txn> {
+pub trait CursorExt<'txn> : Cursor<'txn> + Sized {
 
     /// Retrieves a key/data pair from the cursor. Depending on the cursor op, the current key may
     /// be returned.
@@ -47,30 +47,47 @@ pub trait CursorExt<'txn> : Cursor<'txn> {
     ///
     /// For databases with duplicate data items (`DatabaseFlags::DUP_SORT`), the duplicate data
     /// items of each key will be returned before moving on to the next key.
-    fn iter(&mut self) -> Items<'txn> {
-        Items::new(self, ffi::MDB_NEXT, ffi::MDB_NEXT)
+    fn iter(&mut self) -> Iter<'txn> {
+        Iter::new(self.cursor(), ffi::MDB_NEXT, ffi::MDB_NEXT)
     }
 
     /// Iterate over database items starting from the beginning of the database.
     ///
     /// For databases with duplicate data items (`DatabaseFlags::DUP_SORT`), the duplicate data
     /// items of each key will be returned before moving on to the next key.
-    fn iter_start(&mut self) -> Items<'txn> {
+    fn iter_start(&mut self) -> Iter<'txn> {
         self.get(None, None, ffi::MDB_FIRST).unwrap();
-        Items::new(self, ffi::MDB_GET_CURRENT, ffi::MDB_NEXT)
+        Iter::new(self.cursor(), ffi::MDB_GET_CURRENT, ffi::MDB_NEXT)
     }
 
     /// Iterate over database items starting from the given key.
     ///
     /// For databases with duplicate data items (`DatabaseFlags::DUP_SORT`), the duplicate data
     /// items of each key will be returned before moving on to the next key.
-    fn iter_from(&mut self, key: &[u8]) -> Items<'txn> {
+    fn iter_from(&mut self, key: &[u8]) -> Iter<'txn> {
         self.get(Some(key), None, ffi::MDB_SET_RANGE).unwrap();
-        Items::new(self, ffi::MDB_GET_CURRENT, ffi::MDB_NEXT)
+        Iter::new(self.cursor(), ffi::MDB_GET_CURRENT, ffi::MDB_NEXT)
     }
 
-    fn iter_dup(&mut self) -> Items<'txn> {
-        Items::new(self, ffi::MDB_NEXT_DUP, ffi::MDB_NEXT_DUP)
+    /// Iterate over duplicate database items. The iterator will begin with the item next after the
+    /// cursor, and continue until the end of the database. Each item will be returned as an
+    /// iterator of its duplicates.
+    fn iter_dup(&mut self) -> IterDup<'txn> {
+        IterDup::new(self.cursor(), ffi::MDB_NEXT)
+    }
+
+    /// Iterate over duplicate database items starting from the beginning of the database. Each item
+    /// will be returned as an iterator of its duplicates.
+    fn iter_dup_start(&mut self) -> IterDup<'txn> {
+        self.get(None, None, ffi::MDB_FIRST).unwrap();
+        IterDup::new(self.cursor(), ffi::MDB_GET_CURRENT)
+    }
+
+    /// Iterate over duplicate items in the database starting from the given key. Each item will be
+    /// returned as an iterator of its duplicates.
+    fn iter_dup_from(&mut self, key: &[u8]) -> IterDup<'txn> {
+        self.get(Some(key), None, ffi::MDB_SET_RANGE).unwrap();
+        IterDup::new(self.cursor(), ffi::MDB_GET_CURRENT)
     }
 }
 
@@ -199,21 +216,23 @@ unsafe fn val_to_slice<'a>(val: ffi::MDB_val) -> &'a [u8] {
     })
 }
 
-pub struct Items<'txn> {
+pub struct Iter<'txn> {
     cursor: *mut ffi::MDB_cursor,
     op: c_uint,
     next_op: c_uint,
 }
 
-impl <'txn> Items<'txn> {
+impl <'txn> Iter<'txn> {
 
     /// Creates a new iterator backed by the given cursor.
-    fn new<'t>(cursor: &mut Cursor<'t>, op: c_uint, next_op: c_uint) -> Items<'t> {
-        Items { cursor: cursor.cursor(), op: op, next_op: next_op }
+    fn new<'t>(cursor: *mut ffi::MDB_cursor, op: c_uint, next_op: c_uint) -> Iter<'t> {
+        Iter { cursor: cursor, op: op, next_op: next_op }
     }
 }
 
-impl <'txn> Iterator<(&'txn [u8], &'txn [u8])> for Items<'txn> {
+impl <'txn> Iterator for Iter<'txn> {
+
+    type Item = (&'txn [u8], &'txn [u8]);
 
     fn next(&mut self) -> Option<(&'txn [u8], &'txn [u8])> {
         let mut key = ffi::MDB_val { mv_size: 0, mv_data: ptr::null_mut() };
@@ -237,40 +256,37 @@ impl <'txn> Iterator<(&'txn [u8], &'txn [u8])> for Items<'txn> {
     }
 }
 
-pub struct Items<'txn> {
+pub struct IterDup<'txn> {
     cursor: *mut ffi::MDB_cursor,
+    op: c_uint,
 }
 
-impl <'txn> DupItems<'txn> {
+impl <'txn> IterDup<'txn> {
 
     /// Creates a new iterator backed by the given cursor.
-    fn new<'t>(cursor: &mut Cursor<'t>) -> DupItems<'t> {
-        DupItems { cursor: cursor.cursor() }
+    fn new<'t>(cursor: *mut ffi::MDB_cursor, op: c_uint) -> IterDup<'t> {
+        IterDup { cursor: cursor, op: op}
     }
 }
 
-impl <'txn> Iterator<Items<'txn>> for DupItems<'txn> {
+impl <'txn> Iterator for IterDup<'txn> {
+
+    type Item = Iter<'txn>;
 
-    fn next(&mut self) -> Option<Items<'txn>> {
+    fn next(&mut self) -> Option<Iter<'txn>> {
         let mut key = ffi::MDB_val { mv_size: 0, mv_data: ptr::null_mut() };
         let mut data = ffi::MDB_val { mv_size: 0, mv_data: ptr::null_mut() };
+        let err_code = unsafe {
+            ffi::mdb_cursor_get(self.cursor, &mut key, &mut data, self.op)
+        };
 
-        unsafe {
-            let err_code = ffi::mdb_cursor_get(self.cursor, &mut key, &mut data, self.op);
-            // Set the operation for the next get
-            self.op = self.next_op;
         if err_code == ffi::MDB_SUCCESS {
-                Some((val_to_slice(key), val_to_slice(data)))
+            self.op = ffi::MDB_NEXT;
+            Some(Iter::new(self.cursor, ffi::MDB_GET_CURRENT, ffi::MDB_NEXT_DUP))
         } else {
-                // The documentation for mdb_cursor_get specifies that it may fail with MDB_NOTFOUND
-                // and MDB_EINVAL (and we shouldn't be passing in invalid parameters).
-                // TODO: validate that these are the only failures possible.
-                debug_assert!(err_code == ffi::MDB_NOTFOUND,
-                              "Unexpected LMDB error {}.", LmdbError::from_err_code(err_code));
             None
         }
     }
-    }
 }
 
 #[cfg(test)]
@@ -443,17 +459,20 @@ mod test {
 
         let txn = env.begin_ro_txn().unwrap();
         let mut cursor = txn.open_ro_cursor(db).unwrap();
-        assert_eq!(items, cursor.iter_dup().collect::<Vec<_>>());
+        assert_eq!(items, cursor.iter_dup().flat_map(|x| x).collect::<Vec<_>>());
 
-        //cursor.get(Some(b"b"), None, MDB_SET).unwrap();
-        //assert_eq!(items.clone().into_iter().skip(4).collect::<Vec<(&[u8], &[u8])>>(),
-                   //cursor.iter().collect::<Vec<_>>());
+        cursor.get(Some(b"b"), None, MDB_SET).unwrap();
+        assert_eq!(items.clone().into_iter().skip(4).collect::<Vec<(&[u8], &[u8])>>(),
+                   cursor.iter_dup().flat_map(|x| x).collect::<Vec<_>>());
 
-        //assert_eq!(items, cursor.iter_start().collect::<Vec<(&[u8], &[u8])>>());
+        assert_eq!(items,
+                   cursor.iter_dup_start().flat_map(|x| x).collect::<Vec<(&[u8], &[u8])>>());
 
-        //assert_eq!(items.clone().into_iter().skip(3).collect::<Vec<(&[u8], &[u8])>>(),
-                   //cursor.iter_from(b"b").collect::<Vec<_>>());
+        assert_eq!(items.clone().into_iter().skip(3).collect::<Vec<(&[u8], &[u8])>>(),
+                   cursor.iter_dup_from(b"b").flat_map(|x| x).collect::<Vec<_>>());
 
+        assert_eq!(items.clone().into_iter().skip(3).collect::<Vec<(&[u8], &[u8])>>(),
+                   cursor.iter_dup_from(b"ab").flat_map(|x| x).collect::<Vec<_>>());
     }
 
 

src/database.rs

@@ -1,4 +1,5 @@
 use libc::c_uint;
+use std::c_str::ToCStr;
 use std::ptr;
 
 use ffi;
@@ -8,7 +9,7 @@ use error::{LmdbResult, lmdb_result};
 /// A handle to an individual database in an environment.
 ///
 /// A database handle denotes the name and parameters of a database in an environment.
-#[deriving(Show, Clone, Copy, Eq, PartialEq)]
+#[derive(Show, Clone, Copy, Eq, PartialEq)]
 pub struct Database {
     dbi: ffi::MDB_dbi,
 }

src/environment.rs

@@ -1,4 +1,5 @@
 use libc::{c_uint, size_t, mode_t};
+use std::c_str::ToCStr;
 use std::io::FilePermission;
 use std::ptr;
 use std::sync::Mutex;
@@ -18,6 +19,9 @@ pub struct Environment {
     dbi_open_mutex: Mutex<()>,
 }
 
+unsafe impl Send for Environment {}
+unsafe impl Sync for Environment {}
+
 impl Environment {
 
     /// Creates a new builder for specifying options for opening an LMDB environment.
@@ -145,7 +149,7 @@ impl Drop for Environment {
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 /// Options for opening or creating an environment.
-#[deriving(Show, PartialEq, Eq, Copy, Clone)]
+#[derive(Show, PartialEq, Eq, Copy, Clone)]
 pub struct EnvironmentBuilder {
     flags: EnvironmentFlags,
     max_readers: Option<c_uint>,

src/error.rs

@@ -4,7 +4,7 @@ use std::str;
 
 use ffi;
 
-#[deriving(Show, Eq, PartialEq, Copy, Clone)]
+#[derive(Show, Eq, PartialEq, Copy, Clone)]
 pub enum LmdbError {
     /// key/data pair already exists.
     KeyExist,

src/flags.rs

@@ -4,7 +4,7 @@ use ffi::*;
 
 bitflags! {
     #[doc="Environment Options"]
-    #[deriving(Show)]
+    #[derive(Show)]
     flags EnvironmentFlags: c_uint {
 
         #[doc="Use a fixed address for the mmap region. This flag must be specified"]
@@ -105,7 +105,7 @@ bitflags! {
 
 bitflags! {
     #[doc="Database Options"]
-    #[deriving(Show)]
+    #[derive(Show)]
     flags DatabaseFlags: c_uint {
 
         #[doc="Keys are strings to be compared in reverse order, from the end of the strings"]
@@ -141,7 +141,7 @@ bitflags! {
 
 bitflags! {
     #[doc="Write Options"]
-    #[deriving(Show)]
+    #[derive(Show)]
     flags WriteFlags: c_uint {
 
         #[doc="Insert the new item only if the key does not already appear in the database."]

src/lib.rs

@@ -4,7 +4,7 @@
 //! Provides the minimal amount of abstraction necessary to interact with LMDB safely in Rust. In
 //! general, the API is very similar to the LMDB [C-API](http://symas.com/mdb/doc/).
 
-#![feature(phase, globs, macro_rules, unsafe_destructor)]
+#![feature(phase, globs, macro_rules, unsafe_destructor, associated_types)]
 
 #[phase(plugin, link)] extern crate log;
 extern crate libc;

src/transaction.rs

@@ -24,7 +24,7 @@ pub trait Transaction<'env> {
 }
 
 /// Transaction extension methods.
-pub trait TransactionExt<'env> : Transaction<'env> {
+pub trait TransactionExt<'env> : Transaction<'env> + Sized {
 
     /// Commits the transaction.
     ///