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use std::cell::RefCell; use std::collections::HashMap; use std::fs::File; use std::marker::PhantomData; use std::ops::{Deref, DerefMut}; use std::pin::Pin; use crate::cursor::{Cursor, PageNode, PageNodeID}; use crate::data::{BucketData, Data, KVPair, Ref}; use crate::errors::{Error, Result}; use crate::node::{Branch, Node, NodeData, NodeID}; use crate::page::{Page, PageID}; use crate::ptr::Ptr; use crate::transaction::TransactionInner; /// A collection of data /// /// Buckets contain a collection of data, sorted by key. /// The data can either be key / value pairs, or nested buckets. /// You can use buckets to [`get`](#method.get) and [`put`](#method.put) data, /// as well as [`get`](#method.get_bucket) and [`create`](#method.create_bucket) /// nested buckets. /// /// You can use a [`Cursor`] to iterate over all the data in a bucket. /// /// Buckets have an inner auto-incremented counter that keeps track /// of how many unique keys have been inserted into the bucket. /// You can access that using the [`next_int()`](#method.next_int) function. /// /// # Examples /// /// ```no_run /// use jammdb::{DB, Data}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(true)?; /// /// // create a root-level bucket /// let bucket = tx.create_bucket("my-bucket")?; /// /// // create nested bucket /// bucket.create_bucket("nested-bucket")?; /// /// // insert a key / value pair (using &str) /// bucket.put("key", "value"); /// /// // insert a key / value pair (using [u8]) /// bucket.put([1,2,3], [4,5,6]); /// /// for data in bucket.cursor() { /// match &*data { /// Data::Bucket(b) => println!("found a bucket with the name {:?}", b.name()), /// Data::KeyValue(kv) => println!("found a kv pair {:?} {:?}", kv.key(), kv.value()), /// } /// } /// /// println!("Bucket next_int {:?}", bucket.next_int()); /// # Ok(()) /// # } /// ``` pub struct Bucket { inner: RefCell<BucketInner>, } impl Bucket { pub(crate) fn root(tx: Ptr<TransactionInner>) -> Bucket { let meta = tx.meta.root; Bucket::new(BucketInner { tx, meta, root: PageNodeID::Page(meta.root_page), dirty: false, buckets: HashMap::new(), nodes: Vec::new(), page_node_ids: HashMap::new(), page_parents: HashMap::new(), }) } pub(crate) fn new(inner: BucketInner) -> Bucket { Bucket { inner: RefCell::new(inner), } } /// Adds to or replaces key / value data in the bucket. /// Returns an error if the key currently exists but is a bucket instead of a key / value pair. /// /// # Examples /// /// ```no_run /// use jammdb::{DB}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(true)?; /// /// // create a root-level bucket /// let bucket = tx.create_bucket("my-bucket")?; /// /// // insert data /// bucket.put("123", "456")?; /// /// // update data /// bucket.put("123", "789")?; /// /// bucket.create_bucket("nested-bucket")?; /// /// assert!(bucket.put("nested-bucket", "data").is_err()); /// /// # Ok(()) /// # } /// ``` pub fn put<T: AsRef<[u8]>, S: AsRef<[u8]>>( &self, key: T, value: S, ) -> Result<Option<Ref<KVPair>>> { Ok(self.inner.borrow_mut().put(key, value)?.map(Ref::new)) } /// Get a cursor to iterate over the bucket. /// /// /// # Examples /// /// ```no_run /// use jammdb::{DB, Data}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(false)?; /// /// let bucket = tx.get_bucket("my-bucket")?; /// /// for data in bucket.cursor() { /// match &*data { /// Data::Bucket(b) => println!("found a bucket with the name {:?}", b.name()), /// Data::KeyValue(kv) => println!("found a kv pair {:?} {:?}", kv.key(), kv.value()), /// } /// } /// /// # Ok(()) /// # } /// ``` pub fn cursor(&self) -> Cursor { Cursor::new(Ptr::new(&self.inner.borrow())) } /// Gets an already created bucket. /// /// Returns an error if /// 1. the given key does not exist /// 2. the key is for key / value data, not a bucket /// /// # Examples /// /// ```no_run /// use jammdb::{DB}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(false)?; /// /// // get a root-level bucket /// let bucket = tx.get_bucket("my-bucket")?; /// /// // get nested bucket /// let mut sub_bucket = bucket.get_bucket("nested-bucket")?; /// /// // get nested bucket /// let sub_sub_bucket = sub_bucket.get_bucket("double-nested-bucket")?; /// /// # Ok(()) /// # } /// ``` pub fn get_bucket<T: AsRef<[u8]>>(&self, name: T) -> Result<BucketRef> { let mut inner = self.inner.borrow_mut(); let r = inner.bucket_getter(name.as_ref(), false, false)?; Ok(BucketRef::new(unsafe { &*r.bucket })) } /// Deletes a key / value pair from the bucket /// /// # Examples /// /// ```no_run /// use jammdb::{DB}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(false)?; /// /// let bucket = tx.get_bucket("my-bucket")?; /// // check if data is there /// assert!(bucket.get_kv("some-key").is_some()); /// // delete the key / value pair /// bucket.delete("some-key")?; /// // data should no longer exist /// assert!(bucket.get_kv("some-key").is_none()); /// /// # Ok(()) /// # } /// ``` pub fn delete<T: AsRef<[u8]>>(&self, key: T) -> Result<Ref<KVPair>> { Ok(Ref::new(self.inner.borrow_mut().delete(key)?)) } /// Creates a new bucket. /// /// Returns an error if /// 1. the given key already exists /// 2. It is in a read-only transaction /// /// # Examples /// /// ```no_run /// use jammdb::{DB}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(true)?; /// /// // create a root-level bucket /// let bucket = tx.create_bucket("my-bucket")?; /// /// // create nested bucket /// let mut sub_bucket = bucket.create_bucket("nested-bucket")?; /// /// // create nested bucket /// let mut sub_sub_bucket = sub_bucket.create_bucket("double-nested-bucket")?; /// /// # Ok(()) /// # } /// ``` pub fn create_bucket<T: AsRef<[u8]>>(&self, name: T) -> Result<BucketRef> { let mut inner = self.inner.borrow_mut(); let r = inner.create_bucket(name)?; Ok(BucketRef::new(unsafe { &*r.bucket })) } /// Creates a new bucket if it doesn't exist /// /// Returns an error if /// 1. It is in a read-only transaction /// /// # Examples /// /// ```no_run /// use jammdb::{DB}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// { /// let mut tx = db.tx(true)?; /// // create a root-level bucket /// let bucket = tx.get_or_create_bucket("my-bucket")?; /// tx.commit()?; /// } /// { /// let mut tx = db.tx(true)?; /// // get the existing a root-level bucket /// let bucket = tx.get_or_create_bucket("my-bucket")?; /// } /// /// # Ok(()) /// # } /// ``` pub fn get_or_create_bucket<T: AsRef<[u8]>>(&self, name: T) -> Result<BucketRef> { let mut inner = self.inner.borrow_mut(); let r = inner.get_or_create_bucket(name)?; Ok(BucketRef::new(unsafe { &*r.bucket })) } /// Deletes an bucket. /// /// Returns an error if /// 1. the given key does not exist /// 2. the key is for key / value data, not a bucket /// 3. It is in a read-only transaction /// /// # Examples /// /// ```no_run /// use jammdb::{DB}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(true)?; /// /// // get a root-level bucket /// let bucket = tx.get_bucket("my-bucket")?; /// /// // delete nested bucket /// bucket.delete_bucket("nested-bucket")?; /// /// # Ok(()) /// # } /// ``` pub fn delete_bucket<T: AsRef<[u8]>>(&self, name: T) -> Result<()> { self.inner.borrow_mut().delete_bucket(name) } /// Returns the next integer for the bucket. /// The integer is automatically incremented each time a new key is added to the bucket. /// You can it as a unique key for the bucket, since it will increment each time you add something new. /// It will not increment if you [`put`](#method.put) a key that already exists /// /// # Examples /// /// ```no_run /// use jammdb::{DB}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(true)?; /// /// // create a root-level bucket /// let bucket = tx.create_bucket("my-bucket")?; /// // starts at 0 /// assert_eq!(bucket.next_int(), 0); /// /// let next_int = bucket.next_int(); /// bucket.put(next_int.to_be_bytes(), [0]); /// // auto-incremented after inserting a key / value pair /// assert_eq!(bucket.next_int(), 1); /// /// bucket.put(0_u64.to_be_bytes(), [0, 0]); /// // not incremented after updating a key / value pair /// assert_eq!(bucket.next_int(), 1); /// /// bucket.create_bucket("nested-bucket")?; /// // auto-incremented after creating a nested bucket /// assert_eq!(bucket.next_int(), 2); /// /// # Ok(()) /// # } /// ``` pub fn next_int(&self) -> u64 { self.inner.borrow().meta.next_int } pub(crate) fn rebalance(&mut self) -> Result<BucketMeta> { self.inner.borrow_mut().rebalance() } pub(crate) fn write(&mut self, file: &mut File) -> Result<()> { self.inner.borrow_mut().write(file) } #[doc(hidden)] #[cfg_attr(tarpaulin, skip)] pub(crate) fn print(&self) { self.inner.borrow().print() } pub(crate) fn meta(&self) -> BucketMeta { self.inner.borrow().meta } /// Gets [`Data`] from a bucket. /// /// Returns `None` if the key does not exist. Otherwise returns `Some(Data)` representing either a /// key / value pair or a nested-bucket. /// /// # Examples /// /// ```no_run /// use jammdb::{DB, Data}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(false)?; /// /// let bucket = tx.get_bucket("my-bucket")?; /// /// match bucket.get("some-key") { /// Some(data) => { /// match &*data { /// Data::Bucket(b) => println!("found a bucket with the name {:?}", b.name()), /// Data::KeyValue(kv) => println!("found a kv pair {:?} {:?}", kv.key(), kv.value()), /// } /// }, /// None => println!("Key does not exist"), /// } /// /// # Ok(()) /// # } /// ``` pub fn get<T: AsRef<[u8]>>(&self, key: T) -> Option<Ref<Data>> { let mut c = self.cursor(); let exists = c.seek(key); if exists { c.current().map(Ref::new) } else { None } } /// Gets a key / value pair from a bucket. /// /// Returns `None` if the key does not exist, or if the key is for a nested bucket. /// /// # Examples /// /// ```no_run /// use jammdb::{DB, Data}; /// # use jammdb::Error; /// /// # fn main() -> Result<(), Error> { /// let db = DB::open("my.db")?; /// let mut tx = db.tx(false)?; /// /// let bucket = tx.get_bucket("my-bucket")?; /// bucket.create_bucket("sub-bucket")?; /// bucket.put("some-key", "some-value")?; /// /// if let Some(kv) = bucket.get_kv("some-key") { /// assert_eq!(kv.value(), b"some-value"); /// } /// assert!(bucket.get("sub-bucket").is_some()); /// assert!(bucket.get_kv("sub-bucket").is_none()); /// /// # Ok(()) /// # } /// ``` pub fn get_kv<T: AsRef<[u8]>>(&self, key: T) -> Option<Ref<KVPair>> { match self.get(key) { Some(data) => match &*data { Data::KeyValue(kv) => Some(Ref::new(kv.clone())), _ => None, }, _ => None, } } } pub(crate) struct BucketInner { pub(crate) tx: Ptr<TransactionInner>, pub(crate) meta: BucketMeta, pub(crate) root: PageNodeID, dirty: bool, buckets: HashMap<Vec<u8>, Pin<Box<Bucket>>>, nodes: Vec<Pin<Box<Node>>>, page_node_ids: HashMap<PageID, NodeID>, page_parents: HashMap<PageID, PageID>, } impl BucketInner { fn new_child(&mut self, name: &[u8]) { let b = Bucket::new(BucketInner { tx: Ptr::new(&self.tx), meta: BucketMeta::default(), root: PageNodeID::Node(0), dirty: true, buckets: HashMap::new(), nodes: Vec::new(), page_node_ids: HashMap::new(), page_parents: HashMap::new(), }); self.buckets.insert(Vec::from(name), Pin::new(Box::new(b))); let b = self.buckets.get_mut(name).unwrap(); let mut b = b.inner.borrow_mut(); let n = Node::new(0, Page::TYPE_LEAF, Ptr::new(&b)); b.nodes.push(Pin::new(Box::new(n))); b.page_node_ids.insert(0, 0); } pub(crate) fn new_node(&mut self, data: NodeData) -> &mut Node { let node_id = self.nodes.len() as u64; let n = Node::with_data(node_id, data, Ptr::new(self)); self.nodes.push(Pin::new(Box::new(n))); self.nodes.get_mut(node_id as usize).unwrap() } fn from_meta(&self, meta: BucketMeta) -> BucketInner { BucketInner { tx: Ptr::new(&self.tx), meta, root: PageNodeID::Page(meta.root_page), dirty: false, buckets: HashMap::new(), nodes: Vec::new(), page_node_ids: HashMap::new(), page_parents: HashMap::new(), } } fn create_bucket<T: AsRef<[u8]>>(&mut self, name: T) -> Result<BucketRef> { if !self.tx.writable { return Err(Error::ReadOnlyTx); } self.bucket_getter(name.as_ref(), true, true) } fn get_bucket<T: AsRef<[u8]>>(&mut self, name: T) -> Result<BucketRef> { self.bucket_getter(name.as_ref(), false, false) } fn get_or_create_bucket<T: AsRef<[u8]>>(&mut self, name: T) -> Result<BucketRef> { if !self.tx.writable { return Err(Error::ReadOnlyTx); } self.bucket_getter(name.as_ref(), true, false) } fn bucket_getter( &mut self, name: &[u8], should_create: bool, must_create: bool, ) -> Result<BucketRef> { let key = Vec::from(name); if !self.buckets.contains_key(&key) { let mut c = self.cursor(); let exists = c.seek(name); let current_id = c.current_id(); if !exists { if should_create { self.meta.next_int += 1; let key = Vec::from(name); self.new_child(&key); let data = { let b = self.buckets.get(&key).unwrap(); let b = b.inner.borrow_mut(); let key = self.tx.copy_data(name); Data::Bucket(BucketData::from_meta(key, &b.meta)) }; let node = self.node(current_id); node.insert_data(data); } else { return Err(Error::BucketMissing); } } else { match c.current() { Some(data) => match data { Data::Bucket(data) => { if must_create { return Err(Error::BucketExists); } let mut b = self.from_meta(data.meta()); b.meta = data.meta(); b.dirty = false; self.buckets .insert(key.clone(), Pin::new(Box::new(Bucket::new(b)))); } _ => return Err(Error::IncompatibleValue), }, None => return Err(Error::BucketMissing), } } } else if must_create { return Err(Error::BucketExists); } Ok(BucketRef::new(self.buckets.get(&key).unwrap())) } fn delete_bucket<T: AsRef<[u8]>>(&mut self, name: T) -> Result<()> { if !self.tx.writable { return Err(Error::ReadOnlyTx); } // make sure the bucket is in our map self.get_bucket(&name)?; // remove the bucket from the map so it will be dropped at the end of this function let b = self.buckets.remove(&Vec::from(name.as_ref())).unwrap(); let b = Pin::into_inner(b); let b = b.inner.borrow_mut(); // check that the bucket wasn't just created and never comitted let mut remaining_pages = Vec::new(); if b.meta.root_page != 0 { // create a stack of pages to free and keep going until // we've freed every reachable page starting from this bucket's root page remaining_pages.push(b.meta.root_page); while !remaining_pages.is_empty() { let page_id = remaining_pages.pop().unwrap(); let page = self.tx.page(page_id); let num_pages = page.overflow + 1; match page.page_type { // every branch element's page much be freed Page::TYPE_BRANCH => { page.branch_elements() .iter() .for_each(|b| remaining_pages.push(b.page)); } Page::TYPE_LEAF => { // every nested bucket's pages must be freed page.leaf_elements().iter().for_each(|leaf| { if leaf.node_type == Node::TYPE_BUCKET { let bucket_data = BucketData::new(leaf.key(), leaf.value()); remaining_pages.push(bucket_data.meta().root_page); } }); } _ => (), } self.tx.free(page_id, num_pages); } } // delete the element from this bucket let mut c = self.cursor(); let exists = c.seek(&name); if exists { let data = c.current().unwrap(); let current_id = c.current_id(); let index = c.current_index(); if !data.is_kv() { self.dirty = true; let node = self.node(current_id); node.delete(index); Ok(()) } else { Err(Error::IncompatibleValue) } } else { Err(Error::KeyValueMissing) } } fn put<T: AsRef<[u8]>, S: AsRef<[u8]>>(&mut self, key: T, value: S) -> Result<Option<KVPair>> { if !self.tx.writable { return Err(Error::ReadOnlyTx); } let k = self.tx.copy_data(key.as_ref()); let v = self.tx.copy_data(value.as_ref()); match self.put_data(Data::KeyValue(KVPair::from_slice_parts(k, v)))? { Some(data) => match data { Data::KeyValue(kv) => Ok(Some(kv)), _ => panic!("Unexpected data"), }, None => Ok(None), } } fn delete<T: AsRef<[u8]>>(&mut self, key: T) -> Result<KVPair> { if !self.tx.writable { return Err(Error::ReadOnlyTx); } let mut c = self.cursor(); let exists = c.seek(key); if exists { let data = c.current().unwrap(); if data.is_kv() { let current_id = c.current_id(); let index = c.current_index(); self.dirty = true; let node = self.node(current_id); match node.delete(index) { Data::KeyValue(kv) => Ok(kv), _ => panic!("Unexpected data"), } } else { Err(Error::IncompatibleValue) } } else { Err(Error::KeyValueMissing) } } fn put_data(&mut self, data: Data) -> Result<Option<Data>> { let mut c = self.cursor(); let exists = c.seek(data.key()); let current_id = c.current_id(); let current_data = if exists { let current = c.current().unwrap(); if current.is_kv() != data.is_kv() { return Err(Error::IncompatibleValue); } Some(current) } else { self.meta.next_int += 1; None }; let node = self.node(current_id); node.insert_data(data); self.dirty = true; Ok(current_data) } fn cursor(&self) -> Cursor { Cursor::new(Ptr::new(self)) } pub(crate) fn page_node(&self, page: PageID) -> PageNode { if let Some(node_id) = self.page_node_ids.get(&page) { PageNode::Node(Ptr::new(self.nodes.get(*node_id as usize).unwrap())) } else { PageNode::Page(Ptr::new(self.tx.page(page))) } } pub(crate) fn add_page_parent(&mut self, page: PageID, parent: PageID) { debug_assert!(self.meta.root_page == parent || self.page_parents.contains_key(&parent)); self.page_parents.insert(page, parent); } pub(crate) fn node(&mut self, id: PageNodeID) -> &mut Node { let id: NodeID = match id { PageNodeID::Page(page_id) => { if let Some(node_id) = self.page_node_ids.get(&page_id) { return &mut self.nodes[*node_id as usize]; } debug_assert!( self.meta.root_page == page_id || self.page_parents.contains_key(&page_id) ); let node_id = self.nodes.len() as u64; self.page_node_ids.insert(page_id, node_id); let n: Node = Node::from_page(node_id, Ptr::new(self), self.tx.page(page_id)); self.nodes.push(Pin::new(Box::new(n))); if self.meta.root_page != page_id { let node_key = self.nodes[node_id as usize].data.key_parts(); let parent = self.node(PageNodeID::Page(self.page_parents[&page_id])); parent.insert_child(node_id, node_key); } node_id } PageNodeID::Node(id) => id, }; self.nodes.get_mut(id as usize).unwrap() } fn rebalance(&mut self) -> Result<BucketMeta> { let mut bucket_metas = HashMap::new(); for (key, b) in self.buckets.iter_mut() { let b = b.inner.get_mut(); if b.dirty { self.dirty = true; let bucket_meta = b.rebalance()?; bucket_metas.insert(key.clone(), bucket_meta); } } for (k, b) in bucket_metas { let name = self.tx.copy_data(&k[..]); let meta = self.tx.copy_data(b.as_ref()); self.put_data(Data::Bucket(BucketData::from_slice_parts(name, meta)))?; } if self.dirty { // merge emptyish nodes first { let mut root_node = self.node(self.root); let should_merge_root = root_node.merge(); // check if the root is a bucket and only has one node if should_merge_root && !root_node.leaf() && root_node.data.len() == 1 { // remove the branch and make the leaf node the root root_node.free_page(); root_node.deleted = true; let page_id = match &root_node.data { NodeData::Branches(branches) => branches[0].page, _ => panic!("uh wat"), }; self.meta.root_page = page_id; self.root = PageNodeID::Page(page_id); // if the new root hasn't been modified, no need to split it if !self.page_node_ids.contains_key(&page_id) { self.dirty = false; return Ok(self.meta); } // otherwise we'll continue to possibly split the new root // this could result in re-adding a branch root node, // but it's pretty unlikely! } } // split overflowing nodes { let mut root_node = self.node(self.root); while let Some(mut branches) = root_node.split() { branches.insert(0, Branch::from_node(root_node)); root_node = self.new_node(NodeData::Branches(branches)); } let page_id = root_node.page_id; self.root = PageNodeID::Node(root_node.page_id); self.meta.root_page = page_id; } } Ok(self.meta) } pub(crate) fn write(&mut self, file: &mut File) -> Result<()> { for (_, b) in self.buckets.iter_mut() { b.inner.get_mut().write(file)?; } if self.dirty { for node in self.nodes.iter_mut() { if !node.deleted { node.write(file)?; } } } Ok(()) } #[doc(hidden)] #[cfg_attr(tarpaulin, skip)] fn print(&self) { let page = self.tx.page(self.meta.root_page); page.print(&self.tx); } } pub struct BucketRef<'a> { bucket: *const Bucket, _phantom: PhantomData<&'a ()>, } impl<'a> BucketRef<'a> { pub(crate) fn new(b: &Bucket) -> BucketRef { BucketRef { bucket: b as *const Bucket, _phantom: PhantomData {}, } } } impl<'a> Deref for BucketRef<'a> { type Target = Bucket; fn deref(&self) -> &Self::Target { unsafe { &*self.bucket } } } impl<'a> DerefMut for BucketRef<'a> { fn deref_mut(&mut self) -> &mut Self::Target { unsafe { &mut *(self.bucket as *mut Bucket) } } } const META_SIZE: usize = std::mem::size_of::<BucketMeta>(); #[repr(C)] #[derive(Debug, Clone, Copy, Default)] pub(crate) struct BucketMeta { pub(crate) root_page: PageID, pub(crate) next_int: u64, } impl AsRef<[u8]> for BucketMeta { #[inline] fn as_ref(&self) -> &[u8] { let ptr = self as *const BucketMeta as *const u8; unsafe { std::slice::from_raw_parts(ptr, META_SIZE) } } } // #[cfg(test)] // mod tests { // use super::*; // use crate::db::DB; // use crate::testutil::RandomFile; // #[test] // fn test_incompatible_values() -> Result<()> { // let random_file = RandomFile::new(); // let db = DB::open(&random_file)?; // { // let tx = db.tx(true)?; // assert_eq!(tx.get_bucket("abc").err(), Some(Error::BucketMissing)); // let b = tx.create_bucket("abc")?; // b.put("key", "value")?; // assert_eq!(b.create_bucket("key").err(), Some(Error::IncompatibleValue)); // b.create_bucket("nested-bucket")?; // assert_eq!( // b.put("nested-bucket", "value"), // Err(Error::IncompatibleValue) // ); // assert_eq!( // b.create_bucket("nested-bucket").err(), // Some(Error::BucketExists) // ); // assert_eq!(b.delete("missing-key"), Err(Error::KeyValueMissing)); // tx.commit()?; // } // { // let tx = db.tx(true)?; // let b = tx.get_bucket("abc")?; // assert_eq!(b.create_bucket("key").err(), Some(Error::IncompatibleValue)); // assert_eq!( // b.put("nested-bucket", "value"), // Err(Error::IncompatibleValue) // ); // } // db.check() // } // #[test] // fn test_get_kv() -> Result<()> { // let random_file = RandomFile::new(); // let db = DB::open(&random_file)?; // { // let mut tx = db.tx(true)?; // let mut b = tx.create_bucket("abc")?; // b.create_bucket("nested-bucket")?; // b.put("key", "value")?; // assert_eq!(b.get_kv("key").unwrap().value(), b"value"); // assert!(b.get_kv("nested-bucket").is_none()); // assert!(b.get("nested-bucket").is_some()); // tx.commit()?; // } // { // let mut tx = db.tx(false)?; // let b = tx.get_bucket("abc")?; // assert_eq!(b.get_kv("key").unwrap().value(), b"value"); // assert!(b.get_kv("nested-bucket").is_none()); // assert!(b.get("nested-bucket").is_some()); // } // db.check() // } // }