Merge branch 'master' into iter-from-result

.appveyor.yml

@@ -0,0 +1,24 @@
+environment:
+  matrix:
+    - TARGET: x86_64-pc-windows-msvc
+    - TARGET: i686-pc-windows-msvc
+    - TARGET: x86_64-pc-windows-gnu
+      MSYS_BITS: 64
+    - TARGET: i686-pc-windows-gnu
+      MSYS_BITS: 32
+
+install:
+  - ps: Start-FileDownload "https://static.rust-lang.org/dist/rust-nightly-${env:TARGET}.exe"
+  - rust-nightly-%TARGET%.exe /VERYSILENT /NORESTART /DIR="C:\Program Files (x86)\Rust"
+  - set PATH=%PATH%;C:\Program Files (x86)\Rust\bin
+  - if defined MSYS_BITS set PATH=%PATH%;C:\msys64\mingw%MSYS_BITS%\bin
+  - rustc -V
+  - cargo -V
+
+build_script:
+  - git submodule -q update --init
+  - cargo build --target %TARGET% --all -v
+
+test_script:
+  - SET RUST_BACKTRACE=1
+  - cargo test --target %TARGET% --all -v

.rustfmt.toml

@@ -0,0 +1 @@
+disable_all_formatting = true

.travis.yml

@@ -1,30 +1,21 @@
 language: rust
+dist: trusty
 sudo: false
 
-rust:
+cache: cargo
-- 1.2.0
-- nightly
 
 os:
   - linux
   - osx
 
-before_script:
+rust:
-  - pip install 'travis-cargo<0.2' --user
+- 1.20.0
-  - export PATH=$HOME/.local/bin:$PATH              # Linux
+- stable
-  - export PATH=$HOME/Library/Python/2.7/bin:$PATH  # OS X
+- nightly
 
 script:
-  - |
+  - cargo build --verbose
-      travis-cargo build &&
+  - if [[ $TRAVIS_RUST_VERSION = nightly* ]]; then
-      travis-cargo --only nightly test &&
+      env RUST_BACKTRACE=1 cargo test --all -v;
-      travis-cargo bench &&
+      env RUST_BACKTRACE=1 cargo test --all -v --release;
-      travis-cargo --only nightly doc
+    fi
-
-after_success:
-  - travis-cargo --only nightly doc-upload
-
-env:
-  global:
-    - TRAVIS_CARGO_NIGHTLY_FEATURE=""
-    - secure: "BCsYNBS56hCKCMBZFLYDxKk3+UbFkAt+JRpPG9aiQyTVGkVqXNm4jPhiNSc4/JMuxoBVne+EzUrKVgdv3D7jTOx0sPsWEiE/oFK1K+6xusvsA87ZdDBC0hTRMiEHaufgtaGFJNwWW2tLzwlcdzvGUPVGYogao2MAxl1xlpppvso="

Cargo.toml

@@ -1,24 +1,33 @@
 [package]
 
 name = "lmdb"
-version = "0.5.0"
+# NB: When modifying, also modify html_root_url in lib.rs
+version = "0.8.0"
 authors = ["Dan Burkert <dan@danburkert.com>"]
 license = "Apache-2.0"
 
 description = "Idiomatic and safe LMDB wrapper."
 repository = "https://github.com/danburkert/lmdb-rs.git"
 readme = "README.md"
+documentation = "https://docs.rs/lmdb"
 keywords = ["LMDB", "database", "storage-engine", "bindings", "library"]
-documentation = "http://danburkert.github.io/lmdb-rs/lmdb/index.html"
+categories = ["database"]
 
-[dependencies.lmdb-sys]
+[badges]
-path = "lmdb-sys"
+travis-ci = { repository = "danburkert/lmdb-rs" }
-version = "0.5.0"
+appveyor = { repository = "danburkert/lmdb-rs" }
+
+[workspace]
+members = [
+  "lmdb-sys",
+]
 
 [dependencies]
-bitflags = "0.4"
+bitflags = "1"
 libc = "0.2"
+lmdb-sys = { version = "0.8.0", path = "lmdb-sys" }
 
 [dev-dependencies]
-rand = "0.3"
+rand = "0.4"
 tempdir = "0.3"
+byteorder = "1.0"

README.md

@@ -1,8 +1,7 @@
 [![Build Status](https://travis-ci.org/danburkert/lmdb-rs.svg?branch=master)](https://travis-ci.org/danburkert/lmdb-rs)
-
+[![Windows Build Status](https://ci.appveyor.com/api/projects/status/0bw21yfqsrsv3soh/branch/master?svg=true)](https://ci.appveyor.com/project/danburkert/lmdb-rs/branch/master)
-[Documentation](http://danburkert.github.io/lmdb-rs/lmdb/index.html)
+[![Documentation](https://docs.rs/lmdb/badge.svg)](https://docs.rs/lmdb/)
-
+[![Crate](https://img.shields.io/crates/v/lmdb.svg)](https://crates.io/crates/lmdb)
-[Cargo](https://crates.io/crates/lmdb)
 
 # lmdb-rs
 
@@ -17,10 +16,10 @@ cd lmdb-rs
 cargo build
 ```
 
-## TODO
+## Features
 
 * [x] lmdb-sys.
 * [x] Cursors.
 * [x] Zero-copy put API.
-* [ ] Nested transactions.
+* [x] Nested transactions.
-* [ ] Database statistics.
+* [x] Database statistics.

lmdb-sys/Cargo.toml

@@ -1,13 +1,17 @@
 [package]
 
 name = "lmdb-sys"
-version = "0.5.0"
+# NB: When modifying, also modify html_root_url in lib.rs
+version = "0.8.0"
 authors = ["Dan Burkert <dan@danburkert.com>"]
 license = "Apache-2.0"
+
 description = "Rust bindings for liblmdb."
 repository = "https://github.com/danburkert/lmdb-rs.git"
 readme = "../README.md"
-documentation = "http://danburkert.github.io/lmdb-rs/lmdb_sys/index.html"
+documentation = "https://docs.rs/lmdb-sys"
+keywords = ["LMDB", "database", "storage-engine", "bindings", "library"]
+categories = ["database", "external-ffi-bindings"]
 
 build = "build.rs"
 
@@ -16,4 +20,4 @@ libc = "0.2"
 
 [build-dependencies]
 pkg-config = "0.3"
-gcc = "0.3"
+cc = "1"

lmdb-sys/build.rs

@@ -1,25 +1,21 @@
 extern crate pkg_config;
-extern crate gcc;
+extern crate cc;
 
 use std::env;
 use std::path::PathBuf;
 
 fn main() {
-
     let mut lmdb: PathBuf = PathBuf::from(&env::var("CARGO_MANIFEST_DIR").unwrap());
     lmdb.push("lmdb");
     lmdb.push("libraries");
     lmdb.push("liblmdb");
 
-    let mut mdb: PathBuf = lmdb.clone();
-    let mut midl: PathBuf = lmdb.clone();
-
-    mdb.push("mdb.c");
-    midl.push("midl.c");
-
     if !pkg_config::find_library("liblmdb").is_ok() {
-        gcc::compile_library("liblmdb.a",
+        cc::Build::new()
-                             &[(*mdb).to_str().unwrap(),
+                    .file(lmdb.join("mdb.c"))
-                               (*midl).to_str().unwrap()]);
+                    .file(lmdb.join("midl.c"))
+                    // https://github.com/LMDB/lmdb/blob/LMDB_0.9.21/libraries/liblmdb/Makefile#L25
+                    .opt_level(2)
+                    .compile("liblmdb.a")
     }
 }

lmdb-sys/lmdb

@@ -1 +1 @@
-Subproject commit ad8488cfac644d7a289e428ab3c403c859d844cb
+Subproject commit 60d500206a108b2c64ca7e36b0113b2cd3711b98

lmdb-sys/src/ffi.rs

@@ -62,7 +62,7 @@ extern "C" {
     pub fn mdb_version(major: *mut ::libc::c_int, minor: *mut ::libc::c_int, patch: *mut ::libc::c_int) -> *mut ::libc::c_char;
     pub fn mdb_strerror(err: ::libc::c_int) -> *mut ::libc::c_char;
     pub fn mdb_env_create(env: *mut *mut MDB_env) -> ::libc::c_int;
-    pub fn mdb_env_open(env: *mut MDB_env, path: *const ::libc::c_char, flags: ::libc::c_uint, mode: ::libc::mode_t) -> ::libc::c_int;
+    pub fn mdb_env_open(env: *mut MDB_env, path: *const ::libc::c_char, flags: ::libc::c_uint, mode: super::mode_t) -> ::libc::c_int;
     pub fn mdb_env_copy(env: *mut MDB_env, path: *const ::libc::c_char) -> ::libc::c_int;
     pub fn mdb_env_copyfd(env: *mut MDB_env, fd: ::libc::c_int) -> ::libc::c_int;
     pub fn mdb_env_copy2(env: *mut MDB_env, path: *const ::libc::c_char, flags: ::libc::c_uint) -> ::libc::c_int;

lmdb-sys/src/lib.rs

@@ -1,7 +1,16 @@
 #![allow(non_camel_case_types)]
+#![deny(warnings)]
+#![doc(html_root_url = "https://docs.rs/lmdb-sys/0.8.0")]
 
 extern crate libc;
 
+#[cfg(unix)]
+#[allow(non_camel_case_types)]
+pub type mode_t = ::libc::mode_t;
+#[cfg(windows)]
+#[allow(non_camel_case_types)]
+pub type mode_t = ::libc::c_int;
+
 pub use constants::*;
 pub use ffi::*;
 

src/cursor.rs

@@ -1,5 +1,5 @@
 use libc::{c_void, size_t, c_uint};
-use std::{ptr, slice};
+use std::{fmt, ptr, result, slice};
 use std::marker::PhantomData;
 
 use database::Database;
@@ -28,7 +28,7 @@ pub trait Cursor<'txn> {
             let mut key_val = slice_to_val(key);
             let mut data_val = slice_to_val(data);
             let key_ptr = key_val.mv_data;
-            try!(lmdb_result(ffi::mdb_cursor_get(self.cursor(), &mut key_val, &mut data_val, op)));
+            lmdb_result(ffi::mdb_cursor_get(self.cursor(), &mut key_val, &mut data_val, op))?;
             let key_out = if key_ptr != key_val.mv_data { Some(val_to_slice(key_val)) } else { None };
             let data_out = val_to_slice(data_val);
             Ok((key_out, data_out))
@@ -91,7 +91,7 @@ pub trait Cursor<'txn> {
     /// key.
     fn iter_dup_of<K>(&mut self, key: &K) -> Result<Iter<'txn>> where K:
         AsRef<[u8]> {
-        try!(self.get(Some(key.as_ref()), None, ffi::MDB_SET));
+        self.get(Some(key.as_ref()), None, ffi::MDB_SET)?;
         Ok(Iter::new(self.cursor(), ffi::MDB_GET_CURRENT, ffi::MDB_NEXT_DUP))
     }
 }
@@ -108,6 +108,12 @@ impl <'txn> Cursor<'txn> for RoCursor<'txn> {
     }
 }
 
+impl <'txn> fmt::Debug for RoCursor<'txn> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("RoCursor").finish()
+    }
+}
+
 impl <'txn> Drop for RoCursor<'txn> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_cursor_close(self.cursor) }
@@ -118,10 +124,9 @@ impl <'txn> RoCursor<'txn> {
 
     /// Creates a new read-only cursor in the given database and transaction.
     /// Prefer using `Transaction::open_cursor`.
-    #[doc(hidden)]
+    pub(crate) fn new<T>(txn: &'txn T, db: Database) -> Result<RoCursor<'txn>> where T: Transaction {
-    pub fn new<T>(txn: &'txn T, db: Database) -> Result<RoCursor<'txn>> where T: Transaction {
         let mut cursor: *mut ffi::MDB_cursor = ptr::null_mut();
-        unsafe { try!(lmdb_result(ffi::mdb_cursor_open(txn.txn(), db.dbi(), &mut cursor))); }
+        unsafe { lmdb_result(ffi::mdb_cursor_open(txn.txn(), db.dbi(), &mut cursor))?; }
         Ok(RoCursor {
             cursor: cursor,
             _marker: PhantomData,
@@ -129,7 +134,7 @@ impl <'txn> RoCursor<'txn> {
     }
 }
 
-/// A read-only cursor for navigating items within a database.
+/// A read-write cursor for navigating items within a database.
 pub struct RwCursor<'txn> {
     cursor: *mut ffi::MDB_cursor,
     _marker: PhantomData<fn() -> &'txn ()>,
@@ -141,6 +146,12 @@ impl <'txn> Cursor<'txn> for RwCursor<'txn> {
     }
 }
 
+impl <'txn> fmt::Debug for RwCursor<'txn> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("RwCursor").finish()
+    }
+}
+
 impl <'txn> Drop for RwCursor<'txn> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_cursor_close(self.cursor) }
@@ -151,10 +162,9 @@ impl <'txn> RwCursor<'txn> {
 
     /// Creates a new read-only cursor in the given database and transaction.
     /// Prefer using `RwTransaction::open_rw_cursor`.
-    #[doc(hidden)]
+    pub(crate) fn new<T>(txn: &'txn T, db: Database) -> Result<RwCursor<'txn>> where T: Transaction {
-    pub fn new<T>(txn: &'txn T, db: Database) -> Result<RwCursor<'txn>> where T: Transaction {
         let mut cursor: *mut ffi::MDB_cursor = ptr::null_mut();
-        unsafe { try!(lmdb_result(ffi::mdb_cursor_open(txn.txn(), db.dbi(), &mut cursor))); }
+        unsafe { lmdb_result(ffi::mdb_cursor_open(txn.txn(), db.dbi(), &mut cursor))?; }
         Ok(RwCursor { cursor: cursor, _marker: PhantomData })
     }
 
@@ -202,6 +212,7 @@ unsafe fn val_to_slice<'a>(val: ffi::MDB_val) -> &'a [u8] {
     slice::from_raw_parts(val.mv_data as *const u8, val.mv_size as usize)
 }
 
+/// An iterator over the values in an LMDB database.
 pub struct Iter<'txn> {
     cursor: *mut ffi::MDB_cursor,
     op: c_uint,
@@ -217,6 +228,12 @@ impl <'txn> Iter<'txn> {
     }
 }
 
+impl <'txn> fmt::Debug for Iter<'txn> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("Iter").finish()
+    }
+}
+
 impl <'txn> Iterator for Iter<'txn> {
 
     type Item = (&'txn [u8], &'txn [u8]);
@@ -243,6 +260,10 @@ impl <'txn> Iterator for Iter<'txn> {
     }
 }
 
+/// An iterator over the keys and duplicate values in an LMDB database.
+///
+/// The yielded items of the iterator are themselves iterators over the duplicate values for a
+/// specific key.
 pub struct IterDup<'txn> {
     cursor: *mut ffi::MDB_cursor,
     op: c_uint,
@@ -257,6 +278,12 @@ impl <'txn> IterDup<'txn> {
     }
 }
 
+impl <'txn> fmt::Debug for IterDup<'txn> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("IterDup").finish()
+    }
+}
+
 impl <'txn> Iterator for IterDup<'txn> {
 
     type Item = Iter<'txn>;
@@ -290,7 +317,6 @@ mod test {
     use flags::*;
     use super::*;
     use test_utils::*;
-    use transaction::*;
 
     #[test]
     fn test_get() {
@@ -326,7 +352,7 @@ mod test {
     fn test_get_dup() {
         let dir = TempDir::new("test").unwrap();
         let env = Environment::new().open(dir.path()).unwrap();
-        let db = env.create_db(None, DUP_SORT).unwrap();
+        let db = env.create_db(None, DatabaseFlags::DUP_SORT).unwrap();
 
         let mut txn = env.begin_rw_txn().unwrap();
         txn.put(db, b"key1", b"val1", WriteFlags::empty()).unwrap();
@@ -372,7 +398,7 @@ mod test {
     fn test_get_dupfixed() {
         let dir = TempDir::new("test").unwrap();
         let env = Environment::new().open(dir.path()).unwrap();
-        let db = env.create_db(None, DUP_SORT | DUP_FIXED).unwrap();
+        let db = env.create_db(None, DatabaseFlags::DUP_SORT | DatabaseFlags::DUP_FIXED).unwrap();
 
         let mut txn = env.begin_rw_txn().unwrap();
         txn.put(db, b"key1", b"val1", WriteFlags::empty()).unwrap();
@@ -428,7 +454,7 @@ mod test {
     fn test_iter_dup() {
         let dir = TempDir::new("test").unwrap();
         let env = Environment::new().open(dir.path()).unwrap();
-        let db = env.create_db(None, DUP_SORT).unwrap();
+        let db = env.create_db(None, DatabaseFlags::DUP_SORT).unwrap();
 
         let items: Vec<(&[u8], &[u8])> = vec!((b"a", b"1"),
                                               (b"a", b"2"),

src/database.rs

@@ -20,15 +20,14 @@ impl Database {
     ///
     /// Prefer using `Environment::open_db`, `Environment::create_db`, `TransactionExt::open_db`,
     /// or `RwTransaction::create_db`.
-    #[doc(hidden)]
+    pub(crate) unsafe fn new(txn: *mut ffi::MDB_txn,
-    pub unsafe fn new(txn: *mut ffi::MDB_txn,
                              name: Option<&str>,
                              flags: c_uint)
                              -> Result<Database> {
         let c_name = name.map(|n| CString::new(n).unwrap());
         let name_ptr = if let Some(ref c_name) = c_name { c_name.as_ptr() } else { ptr::null() };
         let mut dbi: ffi::MDB_dbi = 0;
-        try!(lmdb_result(ffi::mdb_dbi_open(txn, name_ptr, flags, &mut dbi)));
+        lmdb_result(ffi::mdb_dbi_open(txn, name_ptr, flags, &mut dbi))?;
         Ok(Database { dbi: dbi })
     }
 

src/environment.rs

@@ -1,8 +1,11 @@
-use libc::{c_uint, size_t, mode_t};
+use libc::{c_uint, size_t};
+use std::{fmt, ptr, result, mem};
 use std::ffi::CString;
+#[cfg(unix)]
 use std::os::unix::ffi::OsStrExt;
+#[cfg(windows)]
+use std::ffi::OsStr;
 use std::path::Path;
-use std::ptr;
 use std::sync::Mutex;
 
 use ffi;
@@ -12,6 +15,18 @@ use database::Database;
 use transaction::{RoTransaction, RwTransaction, Transaction};
 use flags::{DatabaseFlags, EnvironmentFlags};
 
+#[cfg(windows)]
+/// Adding a 'missing' trait from windows OsStrExt
+trait OsStrExtLmdb {
+    fn as_bytes(&self) -> &[u8];
+}
+#[cfg(windows)]
+impl OsStrExtLmdb for OsStr {
+    fn as_bytes(&self) -> &[u8] {
+        &self.to_str().unwrap().as_bytes()
+    }
+}
+
 /// An LMDB environment.
 ///
 /// An environment supports multiple databases, all residing in the same shared-memory map.
@@ -56,9 +71,9 @@ impl Environment {
     /// The database name may not contain the null character.
     pub fn open_db<'env>(&'env self, name: Option<&str>) -> Result<Database> {
         let mutex = self.dbi_open_mutex.lock();
-        let txn = try!(self.begin_ro_txn());
+        let txn = self.begin_ro_txn()?;
-        let db = unsafe { try!(txn.open_db(name)) };
+        let db = unsafe { txn.open_db(name)? };
-        try!(txn.commit());
+        txn.commit()?;
         drop(mutex);
         Ok(db)
     }
@@ -82,18 +97,21 @@ impl Environment {
                            flags: DatabaseFlags)
                            -> Result<Database> {
         let mutex = self.dbi_open_mutex.lock();
-        let txn = try!(self.begin_rw_txn());
+        let txn = self.begin_rw_txn()?;
-        let db = unsafe { try!(txn.create_db(name, flags)) };
+        let db = unsafe { txn.create_db(name, flags)? };
-        try!(txn.commit());
+        txn.commit()?;
         drop(mutex);
         Ok(db)
     }
 
+    /// Retrieves the set of flags which the database is opened with.
+    ///
+    /// The database must belong to to this environment.
     pub fn get_db_flags<'env>(&'env self, db: Database) -> Result<DatabaseFlags> {
-        let txn = try!(self.begin_ro_txn());
+        let txn = self.begin_ro_txn()?;
         let mut flags: c_uint = 0;
         unsafe {
-            try!(lmdb_result(ffi::mdb_dbi_flags(txn.txn(), db.dbi(), &mut flags)));
+            lmdb_result(ffi::mdb_dbi_flags(txn.txn(), db.dbi(), &mut flags))?;
         }
         Ok(DatabaseFlags::from_bits(flags).unwrap())
     }
@@ -136,11 +154,69 @@ impl Environment {
     pub unsafe fn close_db(&mut self, db: Database) {
         ffi::mdb_dbi_close(self.env, db.dbi());
     }
+
+    /// Retrieves statistics about this environment.
+    pub fn stat(&self) -> Result<Stat> {
+        unsafe {
+            let mut stat = Stat(mem::zeroed());
+            lmdb_try!(ffi::mdb_env_stat(self.env(), &mut stat.0));
+            Ok(stat)
+        }
+    }
+}
+
+/// Environment statistics.
+///
+/// Contains information about the size and layout of an LMDB environment.
+pub struct Stat(ffi::MDB_stat);
+
+impl Stat {
+    /// Size of a database page. This is the same for all databases in the environment.
+    #[inline]
+    pub fn page_size(&self) -> u32 {
+        self.0.ms_psize
+    }
+
+    /// Depth (height) of the B-tree.
+    #[inline]
+    pub fn depth(&self) -> u32 {
+        self.0.ms_depth
+    }
+
+    /// Number of internal (non-leaf) pages.
+    #[inline]
+    pub fn branch_pages(&self) -> usize {
+        self.0.ms_branch_pages
+    }
+
+    /// Number of leaf pages.
+    #[inline]
+    pub fn leaf_pages(&self) -> usize {
+        self.0.ms_leaf_pages
+    }
+
+    /// Number of overflow pages.
+    #[inline]
+    pub fn overflow_pages(&self) -> usize {
+        self.0.ms_overflow_pages
+    }
+
+    /// Number of data items.
+    #[inline]
+    pub fn entries(&self) -> usize {
+        self.0.ms_entries
+    }
 }
 
 unsafe impl Send for Environment {}
 unsafe impl Sync for Environment {}
 
+impl fmt::Debug for Environment {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("Environment").finish()
+    }
+}
+
 impl Drop for Environment {
     fn drop(&mut self) {
         unsafe { ffi::mdb_env_close(self.env) }
@@ -176,7 +252,7 @@ impl EnvironmentBuilder {
     /// On Windows, the permissions will be ignored.
     ///
     /// The path may not contain the null character.
-    pub fn open_with_permissions(&self, path: &Path, mode: mode_t) -> Result<Environment> {
+    pub fn open_with_permissions(&self, path: &Path, mode: ffi::mode_t) -> Result<Environment> {
         let mut env: *mut ffi::MDB_env = ptr::null_mut();
         unsafe {
             lmdb_try!(ffi::mdb_env_create(&mut env));
@@ -192,16 +268,18 @@ impl EnvironmentBuilder {
                 lmdb_try_with_cleanup!(ffi::mdb_env_set_mapsize(env, map_size),
                                        ffi::mdb_env_close(env))
             }
-            lmdb_try_with_cleanup!(ffi::mdb_env_open(env,
+            let path = match CString::new(path.as_os_str().as_bytes()) {
-                                                     CString::new(path.as_os_str().as_bytes()).unwrap().as_ptr(),
+                Ok(path) => path,
-                                                     self.flags.bits(),
+                Err(..) => return Err(::Error::Invalid),
-                                                     mode),
+            };
+            lmdb_try_with_cleanup!(ffi::mdb_env_open(env, path.as_ptr(), self.flags.bits(), mode),
                                    ffi::mdb_env_close(env));
         }
         Ok(Environment { env: env, dbi_open_mutex: Mutex::new(()) })
 
     }
 
+    /// Sets the provided options in the environment.
     pub fn set_flags(&mut self, flags: EnvironmentFlags) -> &mut EnvironmentBuilder {
         self.flags = flags;
         self
@@ -252,7 +330,10 @@ impl EnvironmentBuilder {
 #[cfg(test)]
 mod test {
 
+    extern crate byteorder;
+
     use tempdir::TempDir;
+    use self::byteorder::{ByteOrder, LittleEndian};
 
     use flags::*;
 
@@ -263,7 +344,7 @@ mod test {
         let dir = TempDir::new("test").unwrap();
 
         // opening non-existent env with read-only should fail
-        assert!(Environment::new().set_flags(READ_ONLY)
+        assert!(Environment::new().set_flags(EnvironmentFlags::READ_ONLY)
                                   .open(dir.path())
                                   .is_err());
 
@@ -271,7 +352,7 @@ mod test {
         assert!(Environment::new().open(dir.path()).is_ok());
 
         // opening env with read-only should succeed
-        assert!(Environment::new().set_flags(READ_ONLY)
+        assert!(Environment::new().set_flags(EnvironmentFlags::READ_ONLY)
                                   .open(dir.path())
                                   .is_ok());
     }
@@ -288,7 +369,7 @@ mod test {
         }
 
         { // read-only environment
-            let env = Environment::new().set_flags(READ_ONLY)
+            let env = Environment::new().set_flags(EnvironmentFlags::READ_ONLY)
                                         .open(dir.path())
                                         .unwrap();
 
@@ -338,10 +419,45 @@ mod test {
             let env = Environment::new().open(dir.path()).unwrap();
             assert!(env.sync(true).is_ok());
         } {
-            let env = Environment::new().set_flags(READ_ONLY)
+            let env = Environment::new().set_flags(EnvironmentFlags::READ_ONLY)
                                         .open(dir.path())
                                         .unwrap();
             assert!(env.sync(true).is_err());
         }
     }
+
+    #[test]
+    fn test_stat() {
+        let dir = TempDir::new("test").unwrap();
+        let env = Environment::new().open(dir.path()).unwrap();
+
+        // Stats should be empty initially.
+        let stat = env.stat().unwrap();
+        assert_eq!(stat.page_size(), 4096);
+        assert_eq!(stat.depth(), 0);
+        assert_eq!(stat.branch_pages(), 0);
+        assert_eq!(stat.leaf_pages(), 0);
+        assert_eq!(stat.overflow_pages(), 0);
+        assert_eq!(stat.entries(), 0);
+
+        let db = env.open_db(None).unwrap();
+
+        // Write a few small values.
+        for i in 0..64 {
+            let mut value = [0u8; 8];
+            LittleEndian::write_u64(&mut value, i);
+            let mut tx = env.begin_rw_txn().expect("begin_rw_txn");
+            tx.put(db, &value, &value, WriteFlags::default()).expect("tx.put");
+            tx.commit().expect("tx.commit")
+        }
+
+        // Stats should now reflect inserted values.
+        let stat = env.stat().unwrap();
+        assert_eq!(stat.page_size(), 4096);
+        assert_eq!(stat.depth(), 1);
+        assert_eq!(stat.branch_pages(), 0);
+        assert_eq!(stat.leaf_pages(), 1);
+        assert_eq!(stat.overflow_pages(), 0);
+        assert_eq!(stat.entries(), 64);
+    }
 }

src/error.rs

@@ -1,10 +1,12 @@
 use libc::c_int;
 use std::error::Error as StdError;
 use std::ffi::CStr;
+use std::os::raw::c_char;
 use std::{fmt, result, str};
 
 use ffi;
 
+/// An LMDB error kind.
 #[derive(Debug, Eq, PartialEq, Copy, Clone)]
 pub enum Error {
     /// key/data pair already exists.
@@ -52,6 +54,8 @@ pub enum Error {
 }
 
 impl Error {
+
+    /// Converts a raw error code to an `Error`.
     pub fn from_err_code(err_code: c_int) -> Error {
         match err_code {
             ffi::MDB_KEYEXIST         => Error::KeyExist,
@@ -78,6 +82,7 @@ impl Error {
         }
     }
 
+    /// Converts an `Error` to the raw error code.
     pub fn to_err_code(&self) -> c_int {
         match *self {
             Error::KeyExist        => ffi::MDB_KEYEXIST,
@@ -115,12 +120,13 @@ impl StdError for Error {
     fn description(&self) -> &str {
         unsafe {
             // This is safe since the error messages returned from mdb_strerror are static.
-            let err: *const i8 = ffi::mdb_strerror(self.to_err_code()) as *const i8;
+            let err: *const c_char = ffi::mdb_strerror(self.to_err_code()) as *const c_char;
             str::from_utf8_unchecked(CStr::from_ptr(err).to_bytes())
         }
     }
 }
 
+/// An LMDB result.
 pub type Result<T> = result::Result<T, Error>;
 
 pub fn lmdb_result(err_code: c_int) -> Result<()> {
@@ -145,5 +151,4 @@ mod test {
         assert_eq!("MDB_NOTFOUND: No matching key/data pair found",
                    Error::NotFound.description());
     }
-
 }

src/flags.rs

@@ -3,8 +3,9 @@ use libc::c_uint;
 use ffi::*;
 
 bitflags! {
-    #[doc="Environment Options"]
+    #[doc="Environment options."]
-    flags EnvironmentFlags: c_uint {
+    #[derive(Default)]
+    pub struct EnvironmentFlags: c_uint {
 
         #[doc="Use a fixed address for the mmap region. This flag must be specified"]
         #[doc="when creating the environment, and is stored persistently in the environment."]
@@ -13,25 +14,25 @@ bitflags! {
         #[doc="across multiple invocations. This option may not always work, depending on"]
         #[doc="how the operating system has allocated memory to shared libraries and other uses."]
         #[doc="The feature is highly experimental."]
-        const FIXED_MAP = MDB_FIXEDMAP,
+        const FIXED_MAP = MDB_FIXEDMAP;
 
         #[doc="By default, LMDB creates its environment in a directory whose pathname is given in"]
         #[doc="`path`, and creates its data and lock files under that directory. With this option,"]
         #[doc="`path` is used as-is for the database main data file. The database lock file is the"]
         #[doc="`path` with `-lock` appended."]
-        const NO_SUB_DIR = MDB_NOSUBDIR,
+        const NO_SUB_DIR = MDB_NOSUBDIR;
 
         #[doc="Use a writeable memory map unless `READ_ONLY` is set. This is faster and uses"]
         #[doc="fewer mallocs, but loses protection from application bugs like wild pointer writes"]
         #[doc="and other bad updates into the database. Incompatible with nested transactions."]
         #[doc="Processes with and without `WRITE_MAP` on the same environment do not cooperate"]
         #[doc="well."]
-        const WRITE_MAP = MDB_WRITEMAP,
+        const WRITE_MAP = MDB_WRITEMAP;
 
         #[doc="Open the environment in read-only mode. No write operations will be allowed."]
         #[doc="When opening an environment, LMDB will still modify the lock file - except on"]
         #[doc="read-only filesystems, where LMDB does not use locks."]
-        const READ_ONLY = MDB_RDONLY,
+        const READ_ONLY = MDB_RDONLY;
 
         #[doc="Flush system buffers to disk only once per transaction, omit the metadata flush."]
         #[doc="Defer that until the system flushes files to disk, or next non-`READ_ONLY` commit"]
@@ -39,7 +40,7 @@ bitflags! {
         #[doc="system crash may undo the last committed transaction. I.e. it preserves the ACI"]
         #[doc="(atomicity, consistency, isolation) but not D (durability) database property."]
         #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."]
-        const NO_META_SYNC = MDB_NOMETASYNC,
+        const NO_META_SYNC = MDB_NOMETASYNC;
 
         #[doc="Don't flush system buffers to disk when committing a transaction. This optimization"]
         #[doc="means a system crash can corrupt the database or lose the last transactions if"]
@@ -52,36 +53,36 @@ bitflags! {
         #[doc="system with no hint for when to write transactions to disk, unless"]
         #[doc="`Environment::sync` is called. (`MAP_ASYNC | WRITE_MAP`) may be preferable."]
         #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."]
-        const NO_SYNC = MDB_NOSYNC,
+        const NO_SYNC = MDB_NOSYNC;
 
         #[doc="When using `WRITE_MAP`, use asynchronous flushes to disk. As with `NO_SYNC`, a"]
         #[doc="system crash can then corrupt the database or lose the last transactions. Calling"]
         #[doc="`Environment::sync` ensures on-disk database integrity until next commit."]
         #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."]
-        const MAP_ASYNC = MDB_MAPASYNC,
+        const MAP_ASYNC = MDB_MAPASYNC;
 
         #[doc="Don't use thread-local storage. Tie reader locktable slots to transaction objects"]
-        #[doc="instead of to threads. I.e. `RoTransaction::reset` keeps the slot reseved for the"]
+        #[doc="instead of to threads. I.e. `RoTransaction::reset` keeps the slot reserved for the"]
         #[doc="transaction object. A thread may use parallel read-only transactions. A read-only"]
         #[doc="transaction may span threads if the user synchronizes its use. Applications that"]
         #[doc="multiplex many the user synchronizes its use. Applications that multiplex many user"]
         #[doc="threads over individual OS threads need this option. Such an application must also"]
         #[doc="serialize the write transactions in an OS thread, since LMDB's write locking is"]
         #[doc="unaware of the user threads."]
-        const NO_TLS = MDB_NOTLS,
+        const NO_TLS = MDB_NOTLS;
 
         #[doc="Do not do any locking. If concurrent access is anticipated, the caller must manage"]
         #[doc="all concurrency themself. For proper operation the caller must enforce"]
         #[doc="single-writer semantics, and must ensure that no readers are using old"]
         #[doc="transactions while a writer is active. The simplest approach is to use an exclusive"]
         #[doc="lock so that no readers may be active at all when a writer begins."]
-        const NO_LOCK = MDB_NOLOCK,
+        const NO_LOCK = MDB_NOLOCK;
 
         #[doc="Turn off readahead. Most operating systems perform readahead on read requests by"]
         #[doc="default. This option turns it off if the OS supports it. Turning it off may help"]
         #[doc="random read performance when the DB is larger than RAM and system RAM is full."]
         #[doc="The option is not implemented on Windows."]
-        const NO_READAHEAD = MDB_NORDAHEAD,
+        const NO_READAHEAD = MDB_NORDAHEAD;
 
         #[doc="Do not initialize malloc'd memory before writing to unused spaces in the data file."]
         #[doc="By default, memory for pages written to the data file is obtained using malloc."]
@@ -98,73 +99,75 @@ bitflags! {
         #[doc="with reserve; the caller is expected to overwrite all of the memory that was"]
         #[doc="reserved in that case."]
         #[doc="\n\nThis flag may be changed at any time using `Environment::set_flags`."]
-        const NO_MEM_INIT = MDB_NOMEMINIT,
+        const NO_MEM_INIT = MDB_NOMEMINIT;
     }
 }
 
 bitflags! {
-    #[doc="Database Options"]
+    #[doc="Database options."]
-    flags DatabaseFlags: c_uint {
+    #[derive(Default)]
+    pub struct DatabaseFlags: c_uint {
 
         #[doc="Keys are strings to be compared in reverse order, from the end of the strings"]
         #[doc="to the beginning. By default, Keys are treated as strings and compared from"]
         #[doc="beginning to end."]
-        const REVERSE_KEY = MDB_REVERSEKEY,
+        const REVERSE_KEY = MDB_REVERSEKEY;
 
         #[doc="Duplicate keys may be used in the database. (Or, from another perspective,"]
         #[doc="keys may have multiple data items, stored in sorted order.) By default"]
         #[doc="keys must be unique and may have only a single data item."]
-        const DUP_SORT = MDB_DUPSORT,
+        const DUP_SORT = MDB_DUPSORT;
 
         #[doc="Keys are binary integers in native byte order. Setting this option requires all"]
         #[doc="keys to be the same size, typically 32 or 64 bits."]
-        const INTEGER_KEY = MDB_INTEGERKEY,
+        const INTEGER_KEY = MDB_INTEGERKEY;
 
         #[doc="This flag may only be used in combination with `DUP_SORT`. This option tells"]
         #[doc="the library that the data items for this database are all the same size, which"]
         #[doc="allows further optimizations in storage and retrieval. When all data items are"]
         #[doc="the same size, the `GET_MULTIPLE` and `NEXT_MULTIPLE` cursor operations may be"]
         #[doc="used to retrieve multiple items at once."]
-        const DUP_FIXED = MDB_DUPFIXED,
+        const DUP_FIXED = MDB_DUPFIXED;
 
         #[doc="This option specifies that duplicate data items are also integers, and"]
         #[doc="should be sorted as such."]
-        const INTEGER_DUP = MDB_INTEGERDUP,
+        const INTEGER_DUP = MDB_INTEGERDUP;
 
         #[doc="This option specifies that duplicate data items should be compared as strings"]
         #[doc="in reverse order."]
-        const REVERSE_DUP = MDB_REVERSEDUP,
+        const REVERSE_DUP = MDB_REVERSEDUP;
     }
 }
 
 bitflags! {
-    #[doc="Write Options"]
+    #[doc="Write options."]
-    flags WriteFlags: c_uint {
+    #[derive(Default)]
+    pub struct WriteFlags: c_uint {
 
         #[doc="Insert the new item only if the key does not already appear in the database."]
         #[doc="The function will return `LmdbError::KeyExist` if the key already appears in the"]
         #[doc="database, even if the database supports duplicates (`DUP_SORT`)."]
-        const NO_OVERWRITE = MDB_NOOVERWRITE,
+        const NO_OVERWRITE = MDB_NOOVERWRITE;
 
         #[doc="Insert the new item only if it does not already appear in the database."]
         #[doc="This flag may only be specified if the database was opened with `DUP_SORT`."]
         #[doc="The function will return `LmdbError::KeyExist` if the item already appears in the"]
         #[doc="database."]
-        const NO_DUP_DATA = MDB_NODUPDATA,
+        const NO_DUP_DATA = MDB_NODUPDATA;
 
         #[doc="For `Cursor::put`. Replace the item at the current cursor position. The key"]
         #[doc="parameter must match the current position. If using sorted duplicates (`DUP_SORT`)"]
         #[doc="the data item must still sort into the same position. This is intended to be used"]
         #[doc="when the new data is the same size as the old. Otherwise it will simply perform a"]
         #[doc="delete of the old record followed by an insert."]
-        const CURRENT = MDB_CURRENT,
+        const CURRENT = MDB_CURRENT;
 
         #[doc="Append the given item to the end of the database. No key comparisons are performed."]
         #[doc="This option allows fast bulk loading when keys are already known to be in the"]
         #[doc="correct order. Loading unsorted keys with this flag will cause data corruption."]
-        const APPEND = MDB_APPEND,
+        const APPEND = MDB_APPEND;
 
         #[doc="Same as `APPEND`, but for sorted dup data."]
-        const APPEND_DUP = MDB_APPENDDUP,
+        const APPEND_DUP = MDB_APPENDDUP;
     }
 }

src/lib.rs

@@ -1,7 +1,9 @@
 //! Idiomatic and safe APIs for interacting with the
-//! [Symas Lightning Memory-Mapped Database (LMDB)](http://symas.com/mdb/).
+//! [Lightning Memory-mapped Database (LMDB)](https://symas.com/lmdb).
 
 #![cfg_attr(test, feature(test))]
+#![deny(missing_docs)]
+#![doc(html_root_url = "https://docs.rs/lmdb/0.8.0")]
 
 extern crate libc;
 extern crate lmdb_sys as ffi;
@@ -14,10 +16,12 @@ extern crate lmdb_sys as ffi;
 pub use cursor::{
     Cursor,
     RoCursor,
-    RwCursor
+    RwCursor,
+    Iter,
+    IterDup,
 };
 pub use database::Database;
-pub use environment::{Environment, EnvironmentBuilder};
+pub use environment::{Environment, Stat, EnvironmentBuilder};
 pub use error::{Error, Result};
 pub use flags::*;
 pub use transaction::{
@@ -58,6 +62,9 @@ mod transaction;
 #[cfg(test)]
 mod test_utils {
 
+    extern crate byteorder;
+
+    use self::byteorder::{ByteOrder, LittleEndian};
     use tempdir::TempDir;
 
     use super::*;
@@ -84,4 +91,33 @@ mod test_utils {
         }
         (dir, env)
     }
+
+    /// Regression test for https://github.com/danburkert/lmdb-rs/issues/21.
+    /// This test reliably segfaults when run against lmbdb compiled with opt level -O3 and newer
+    /// GCC compilers.
+    #[test]
+    fn issue_21_regression() {
+        const HEIGHT_KEY: [u8; 1] = [0];
+
+        let dir = TempDir::new("test").unwrap();
+
+        let env = {
+            let mut builder = Environment::new();
+            builder.set_max_dbs(2);
+            builder.set_map_size(1_000_000);
+            builder.open(dir.path()).expect("open lmdb env")
+        };
+        let index = env.create_db(None, DatabaseFlags::DUP_SORT).expect("open index db");
+
+        for height in 0..1000 {
+            let mut value = [0u8; 8];
+            LittleEndian::write_u64(&mut value, height);
+            let mut tx = env.begin_rw_txn().expect("begin_rw_txn");
+            tx.put(index,
+                   &HEIGHT_KEY,
+                   &value,
+                   WriteFlags::empty()).expect("tx.put");
+            tx.commit().expect("tx.commit")
+        }
+    }
 }

src/transaction.rs

@@ -1,5 +1,5 @@
 use libc::{c_uint, c_void, size_t};
-use std::{mem, ptr, slice};
+use std::{fmt, mem, ptr, result, slice};
 use std::marker::PhantomData ;
 
 use ffi;
@@ -98,7 +98,7 @@ pub trait Transaction : Sized {
     fn db_flags(&self, db: Database) -> Result<DatabaseFlags> {
         let mut flags: c_uint = 0;
         unsafe {
-            try!(lmdb_result(ffi::mdb_dbi_flags(self.txn(), db.dbi(), &mut flags)));
+            lmdb_result(ffi::mdb_dbi_flags(self.txn(), db.dbi(), &mut flags))?;
         }
         Ok(DatabaseFlags::from_bits_truncate(flags))
     }
@@ -110,6 +110,12 @@ pub struct RoTransaction<'env> {
     _marker: PhantomData<&'env ()>,
 }
 
+impl <'env> fmt::Debug for RoTransaction<'env> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("RoTransaction").finish()
+    }
+}
+
 impl <'env> Drop for RoTransaction<'env> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_txn_abort(self.txn) }
@@ -120,14 +126,10 @@ impl <'env> RoTransaction<'env> {
 
     /// Creates a new read-only transaction in the given environment. Prefer
     /// using `Environment::begin_ro_txn`.
-    #[doc(hidden)]
+    pub(crate) fn new(env: &'env Environment) -> Result<RoTransaction<'env>> {
-    pub fn new(env: &'env Environment) -> Result<RoTransaction<'env>> {
         let mut txn: *mut ffi::MDB_txn = ptr::null_mut();
         unsafe {
-            try!(lmdb_result(ffi::mdb_txn_begin(env.env(),
+            lmdb_result(ffi::mdb_txn_begin(env.env(), ptr::null_mut(), ffi::MDB_RDONLY, &mut txn))?;
-                                                ptr::null_mut(),
-                                                ffi::MDB_RDONLY,
-                                                &mut txn)));
             Ok(RoTransaction { txn: txn, _marker: PhantomData })
         }
     }
@@ -166,6 +168,12 @@ pub struct InactiveTransaction<'env> {
     _marker: PhantomData<&'env ()>,
 }
 
+impl <'env> fmt::Debug for InactiveTransaction<'env> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("InactiveTransaction").finish()
+    }
+}
+
 impl <'env> Drop for InactiveTransaction<'env> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_txn_abort(self.txn) }
@@ -183,7 +191,7 @@ impl <'env> InactiveTransaction<'env> {
         let txn = self.txn;
         unsafe {
             mem::forget(self);
-            try!(lmdb_result(ffi::mdb_txn_renew(txn)))
+            lmdb_result(ffi::mdb_txn_renew(txn))?
         };
         Ok(RoTransaction { txn: txn, _marker: PhantomData })
     }
@@ -195,6 +203,12 @@ pub struct RwTransaction<'env> {
     _marker: PhantomData<&'env ()>,
 }
 
+impl <'env> fmt::Debug for RwTransaction<'env> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("RwTransaction").finish()
+    }
+}
+
 impl <'env> Drop for RwTransaction<'env> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_txn_abort(self.txn) }
@@ -205,14 +219,13 @@ impl <'env> RwTransaction<'env> {
 
     /// Creates a new read-write transaction in the given environment. Prefer
     /// using `Environment::begin_ro_txn`.
-    #[doc(hidden)]
+    pub(crate) fn new(env: &'env Environment) -> Result<RwTransaction<'env>> {
-    pub fn new(env: &'env Environment) -> Result<RwTransaction<'env>> {
         let mut txn: *mut ffi::MDB_txn = ptr::null_mut();
         unsafe {
-            try!(lmdb_result(ffi::mdb_txn_begin(env.env(),
+            lmdb_result(ffi::mdb_txn_begin(env.env(),
                         ptr::null_mut(),
                         EnvironmentFlags::empty().bits(),
-                                                &mut txn)));
+                        &mut txn))?;
             Ok(RwTransaction { txn: txn, _marker: PhantomData })
         }
     }
@@ -229,7 +242,7 @@ impl <'env> RwTransaction<'env> {
     ///
     /// ## Safety
     ///
-    /// * This function (as well as `Environment::open_db`,
+    /// This function (as well as `Environment::open_db`,
     /// `Environment::create_db`, and `Database::open`) **must not** be called
     /// from multiple concurrent transactions in the same environment. A
     /// transaction which uses this function must finish (either commit or
@@ -287,11 +300,11 @@ impl <'env> RwTransaction<'env> {
         let mut data_val: ffi::MDB_val = ffi::MDB_val { mv_size: len,
                                                         mv_data: ptr::null_mut::<c_void>() };
         unsafe {
-            try!(lmdb_result(ffi::mdb_put(self.txn(),
+            lmdb_result(ffi::mdb_put(self.txn(),
                         database.dbi(),
                         &mut key_val,
                         &mut data_val,
-                                          flags.bits() | ffi::MDB_RESERVE)));
+                        flags.bits() | ffi::MDB_RESERVE))?;
             Ok(slice::from_raw_parts_mut(data_val.mv_data as *mut u8,
                                          data_val.mv_size as usize))
         }