Mercurial > hg
view rust/hg-core/src/revlog/nodemap.rs @ 46033:88e741bf2d93
rust: use NodePrefix::from_hex instead of hex::decode directly
This adds support for prefixes with an odd number of hex digits.
Differential Revision: https://phab.mercurial-scm.org/D9490
author | Simon Sapin <simon-commits@exyr.org> |
---|---|
date | Wed, 02 Dec 2020 15:00:49 +0100 |
parents | 26114bd6ec60 |
children | 0800aa42bb4c |
line wrap: on
line source
// Copyright 2018-2020 Georges Racinet <georges.racinet@octobus.net> // and Mercurial contributors // // This software may be used and distributed according to the terms of the // GNU General Public License version 2 or any later version. //! Indexing facilities for fast retrieval of `Revision` from `Node` //! //! This provides a variation on the 16-ary radix tree that is //! provided as "nodetree" in revlog.c, ready for append-only persistence //! on disk. //! //! Following existing implicit conventions, the "nodemap" terminology //! is used in a more abstract context. use super::{ node::NULL_NODE, Node, NodeError, NodePrefix, NodePrefixRef, Revision, RevlogIndex, NULL_REVISION, }; use std::cmp::max; use std::fmt; use std::mem; use std::ops::Deref; use std::ops::Index; use std::slice; #[derive(Debug, PartialEq)] pub enum NodeMapError { MultipleResults, InvalidNodePrefix(NodeError), /// A `Revision` stored in the nodemap could not be found in the index RevisionNotInIndex(Revision), } impl From<NodeError> for NodeMapError { fn from(err: NodeError) -> Self { NodeMapError::InvalidNodePrefix(err) } } /// Mapping system from Mercurial nodes to revision numbers. /// /// ## `RevlogIndex` and `NodeMap` /// /// One way to think about their relationship is that /// the `NodeMap` is a prefix-oriented reverse index of the `Node` information /// carried by a [`RevlogIndex`]. /// /// Many of the methods in this trait take a `RevlogIndex` argument /// which is used for validation of their results. This index must naturally /// be the one the `NodeMap` is about, and it must be consistent. /// /// Notably, the `NodeMap` must not store /// information about more `Revision` values than there are in the index. /// In these methods, an encountered `Revision` is not in the index, a /// [`RevisionNotInIndex`] error is returned. /// /// In insert operations, the rule is thus that the `NodeMap` must always /// be updated after the `RevlogIndex` /// be updated first, and the `NodeMap` second. /// /// [`RevisionNotInIndex`]: enum.NodeMapError.html#variant.RevisionNotInIndex /// [`RevlogIndex`]: ../trait.RevlogIndex.html pub trait NodeMap { /// Find the unique `Revision` having the given `Node` /// /// If no Revision matches the given `Node`, `Ok(None)` is returned. fn find_node( &self, index: &impl RevlogIndex, node: &Node, ) -> Result<Option<Revision>, NodeMapError> { self.find_bin(index, node.into()) } /// Find the unique Revision whose `Node` starts with a given binary prefix /// /// If no Revision matches the given prefix, `Ok(None)` is returned. /// /// If several Revisions match the given prefix, a [`MultipleResults`] /// error is returned. fn find_bin<'a>( &self, idx: &impl RevlogIndex, prefix: NodePrefixRef<'a>, ) -> Result<Option<Revision>, NodeMapError>; /// Find the unique Revision whose `Node` hexadecimal string representation /// starts with a given prefix /// /// If no Revision matches the given prefix, `Ok(None)` is returned. /// /// If several Revisions match the given prefix, a [`MultipleResults`] /// error is returned. fn find_hex( &self, idx: &impl RevlogIndex, prefix: &str, ) -> Result<Option<Revision>, NodeMapError> { self.find_bin(idx, NodePrefix::from_hex(prefix)?.borrow()) } /// Give the size of the shortest node prefix that determines /// the revision uniquely. /// /// From a binary node prefix, if it is matched in the node map, this /// returns the number of hexadecimal digits that would had sufficed /// to find the revision uniquely. /// /// Returns `None` if no `Revision` could be found for the prefix. /// /// If several Revisions match the given prefix, a [`MultipleResults`] /// error is returned. fn unique_prefix_len_bin<'a>( &self, idx: &impl RevlogIndex, node_prefix: NodePrefixRef<'a>, ) -> Result<Option<usize>, NodeMapError>; /// Same as `unique_prefix_len_bin`, with the hexadecimal representation /// of the prefix as input. fn unique_prefix_len_hex( &self, idx: &impl RevlogIndex, prefix: &str, ) -> Result<Option<usize>, NodeMapError> { self.unique_prefix_len_bin(idx, NodePrefix::from_hex(prefix)?.borrow()) } /// Same as `unique_prefix_len_bin`, with a full `Node` as input fn unique_prefix_len_node( &self, idx: &impl RevlogIndex, node: &Node, ) -> Result<Option<usize>, NodeMapError> { self.unique_prefix_len_bin(idx, node.into()) } } pub trait MutableNodeMap: NodeMap { fn insert<I: RevlogIndex>( &mut self, index: &I, node: &Node, rev: Revision, ) -> Result<(), NodeMapError>; } /// Low level NodeTree [`Blocks`] elements /// /// These are exactly as for instance on persistent storage. type RawElement = i32; /// High level representation of values in NodeTree /// [`Blocks`](struct.Block.html) /// /// This is the high level representation that most algorithms should /// use. #[derive(Clone, Debug, Eq, PartialEq)] enum Element { Rev(Revision), Block(usize), None, } impl From<RawElement> for Element { /// Conversion from low level representation, after endianness conversion. /// /// See [`Block`](struct.Block.html) for explanation about the encoding. fn from(raw: RawElement) -> Element { if raw >= 0 { Element::Block(raw as usize) } else if raw == -1 { Element::None } else { Element::Rev(-raw - 2) } } } impl From<Element> for RawElement { fn from(element: Element) -> RawElement { match element { Element::None => 0, Element::Block(i) => i as RawElement, Element::Rev(rev) => -rev - 2, } } } /// A logical block of the `NodeTree`, packed with a fixed size. /// /// These are always used in container types implementing `Index<Block>`, /// such as `&Block` /// /// As an array of integers, its ith element encodes that the /// ith potential edge from the block, representing the ith hexadecimal digit /// (nybble) `i` is either: /// /// - absent (value -1) /// - another `Block` in the same indexable container (value ≥ 0) /// - a `Revision` leaf (value ≤ -2) /// /// Endianness has to be fixed for consistency on shared storage across /// different architectures. /// /// A key difference with the C `nodetree` is that we need to be /// able to represent the [`Block`] at index 0, hence -1 is the empty marker /// rather than 0 and the `Revision` range upper limit of -2 instead of -1. /// /// Another related difference is that `NULL_REVISION` (-1) is not /// represented at all, because we want an immutable empty nodetree /// to be valid. #[derive(Copy, Clone)] pub struct Block([u8; BLOCK_SIZE]); /// Not derivable for arrays of length >32 until const generics are stable impl PartialEq for Block { fn eq(&self, other: &Self) -> bool { self.0[..] == other.0[..] } } pub const BLOCK_SIZE: usize = 64; impl Block { fn new() -> Self { // -1 in 2's complement to create an absent node let byte: u8 = 255; Block([byte; BLOCK_SIZE]) } fn get(&self, nybble: u8) -> Element { let index = nybble as usize * mem::size_of::<RawElement>(); Element::from(RawElement::from_be_bytes([ self.0[index], self.0[index + 1], self.0[index + 2], self.0[index + 3], ])) } fn set(&mut self, nybble: u8, element: Element) { let values = RawElement::to_be_bytes(element.into()); let index = nybble as usize * mem::size_of::<RawElement>(); self.0[index] = values[0]; self.0[index + 1] = values[1]; self.0[index + 2] = values[2]; self.0[index + 3] = values[3]; } } impl fmt::Debug for Block { /// sparse representation for testing and debugging purposes fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { f.debug_map() .entries((0..16).filter_map(|i| match self.get(i) { Element::None => None, element => Some((i, element)), })) .finish() } } /// A mutable 16-radix tree with the root block logically at the end /// /// Because of the append only nature of our node trees, we need to /// keep the original untouched and store new blocks separately. /// /// The mutable root `Block` is kept apart so that we don't have to rebump /// it on each insertion. pub struct NodeTree { readonly: Box<dyn Deref<Target = [Block]> + Send>, growable: Vec<Block>, root: Block, masked_inner_blocks: usize, } impl Index<usize> for NodeTree { type Output = Block; fn index(&self, i: usize) -> &Block { let ro_len = self.readonly.len(); if i < ro_len { &self.readonly[i] } else if i == ro_len + self.growable.len() { &self.root } else { &self.growable[i - ro_len] } } } /// Return `None` unless the `Node` for `rev` has given prefix in `index`. fn has_prefix_or_none( idx: &impl RevlogIndex, prefix: NodePrefixRef, rev: Revision, ) -> Result<Option<Revision>, NodeMapError> { idx.node(rev) .ok_or_else(|| NodeMapError::RevisionNotInIndex(rev)) .map(|node| { if prefix.is_prefix_of(node) { Some(rev) } else { None } }) } /// validate that the candidate's node starts indeed with given prefix, /// and treat ambiguities related to `NULL_REVISION`. /// /// From the data in the NodeTree, one can only conclude that some /// revision is the only one for a *subprefix* of the one being looked up. fn validate_candidate( idx: &impl RevlogIndex, prefix: NodePrefixRef, candidate: (Option<Revision>, usize), ) -> Result<(Option<Revision>, usize), NodeMapError> { let (rev, steps) = candidate; if let Some(nz_nybble) = prefix.first_different_nybble(&NULL_NODE) { rev.map_or(Ok((None, steps)), |r| { has_prefix_or_none(idx, prefix, r) .map(|opt| (opt, max(steps, nz_nybble + 1))) }) } else { // the prefix is only made of zeros; NULL_REVISION always matches it // and any other *valid* result is an ambiguity match rev { None => Ok((Some(NULL_REVISION), steps + 1)), Some(r) => match has_prefix_or_none(idx, prefix, r)? { None => Ok((Some(NULL_REVISION), steps + 1)), _ => Err(NodeMapError::MultipleResults), }, } } } impl NodeTree { /// Initiate a NodeTree from an immutable slice-like of `Block` /// /// We keep `readonly` and clone its root block if it isn't empty. fn new(readonly: Box<dyn Deref<Target = [Block]> + Send>) -> Self { let root = readonly.last().cloned().unwrap_or_else(Block::new); NodeTree { readonly, growable: Vec::new(), root, masked_inner_blocks: 0, } } /// Create from an opaque bunch of bytes /// /// The created `NodeTreeBytes` from `buffer`, /// of which exactly `amount` bytes are used. /// /// - `buffer` could be derived from `PyBuffer` and `Mmap` objects. /// - `offset` allows for the final file format to include fixed data /// (generation number, behavioural flags) /// - `amount` is expressed in bytes, and is not automatically derived from /// `bytes`, so that a caller that manages them atomically can perform /// temporary disk serializations and still rollback easily if needed. /// First use-case for this would be to support Mercurial shell hooks. /// /// panics if `buffer` is smaller than `amount` pub fn load_bytes( bytes: Box<dyn Deref<Target = [u8]> + Send>, amount: usize, ) -> Self { NodeTree::new(Box::new(NodeTreeBytes::new(bytes, amount))) } /// Retrieve added `Block` and the original immutable data pub fn into_readonly_and_added( self, ) -> (Box<dyn Deref<Target = [Block]> + Send>, Vec<Block>) { let mut vec = self.growable; let readonly = self.readonly; if readonly.last() != Some(&self.root) { vec.push(self.root); } (readonly, vec) } /// Retrieve added `Blocks` as bytes, ready to be written to persistent /// storage pub fn into_readonly_and_added_bytes( self, ) -> (Box<dyn Deref<Target = [Block]> + Send>, Vec<u8>) { let (readonly, vec) = self.into_readonly_and_added(); // Prevent running `v`'s destructor so we are in complete control // of the allocation. let vec = mem::ManuallyDrop::new(vec); // Transmute the `Vec<Block>` to a `Vec<u8>`. Blocks are contiguous // bytes, so this is perfectly safe. let bytes = unsafe { // Assert that `Block` hasn't been changed and has no padding let _: [u8; 4 * BLOCK_SIZE] = std::mem::transmute([Block::new(); 4]); // /!\ Any use of `vec` after this is use-after-free. // TODO: use `into_raw_parts` once stabilized Vec::from_raw_parts( vec.as_ptr() as *mut u8, vec.len() * BLOCK_SIZE, vec.capacity() * BLOCK_SIZE, ) }; (readonly, bytes) } /// Total number of blocks fn len(&self) -> usize { self.readonly.len() + self.growable.len() + 1 } /// Implemented for completeness /// /// A `NodeTree` always has at least the mutable root block. #[allow(dead_code)] fn is_empty(&self) -> bool { false } /// Main working method for `NodeTree` searches /// /// The first returned value is the result of analysing `NodeTree` data /// *alone*: whereas `None` guarantees that the given prefix is absent /// from the `NodeTree` data (but still could match `NULL_NODE`), with /// `Some(rev)`, it is to be understood that `rev` is the unique `Revision` /// that could match the prefix. Actually, all that can be inferred from /// the `NodeTree` data is that `rev` is the revision with the longest /// common node prefix with the given prefix. /// /// The second returned value is the size of the smallest subprefix /// of `prefix` that would give the same result, i.e. not the /// `MultipleResults` error variant (again, using only the data of the /// `NodeTree`). fn lookup( &self, prefix: NodePrefixRef, ) -> Result<(Option<Revision>, usize), NodeMapError> { for (i, visit_item) in self.visit(prefix).enumerate() { if let Some(opt) = visit_item.final_revision() { return Ok((opt, i + 1)); } } Err(NodeMapError::MultipleResults) } fn visit<'n, 'p>( &'n self, prefix: NodePrefixRef<'p>, ) -> NodeTreeVisitor<'n, 'p> { NodeTreeVisitor { nt: self, prefix, visit: self.len() - 1, nybble_idx: 0, done: false, } } /// Return a mutable reference for `Block` at index `idx`. /// /// If `idx` lies in the immutable area, then the reference is to /// a newly appended copy. /// /// Returns (new_idx, glen, mut_ref) where /// /// - `new_idx` is the index of the mutable `Block` /// - `mut_ref` is a mutable reference to the mutable Block. /// - `glen` is the new length of `self.growable` /// /// Note: the caller wouldn't be allowed to query `self.growable.len()` /// itself because of the mutable borrow taken with the returned `Block` fn mutable_block(&mut self, idx: usize) -> (usize, &mut Block, usize) { let ro_blocks = &self.readonly; let ro_len = ro_blocks.len(); let glen = self.growable.len(); if idx < ro_len { self.masked_inner_blocks += 1; self.growable.push(ro_blocks[idx]); (glen + ro_len, &mut self.growable[glen], glen + 1) } else if glen + ro_len == idx { (idx, &mut self.root, glen) } else { (idx, &mut self.growable[idx - ro_len], glen) } } /// Main insertion method /// /// This will dive in the node tree to find the deepest `Block` for /// `node`, split it as much as needed and record `node` in there. /// The method then backtracks, updating references in all the visited /// blocks from the root. /// /// All the mutated `Block` are copied first to the growable part if /// needed. That happens for those in the immutable part except the root. pub fn insert<I: RevlogIndex>( &mut self, index: &I, node: &Node, rev: Revision, ) -> Result<(), NodeMapError> { let ro_len = &self.readonly.len(); let mut visit_steps: Vec<_> = self.visit(node.into()).collect(); let read_nybbles = visit_steps.len(); // visit_steps cannot be empty, since we always visit the root block let deepest = visit_steps.pop().unwrap(); let (mut block_idx, mut block, mut glen) = self.mutable_block(deepest.block_idx); if let Element::Rev(old_rev) = deepest.element { let old_node = index .node(old_rev) .ok_or_else(|| NodeMapError::RevisionNotInIndex(old_rev))?; if old_node == node { return Ok(()); // avoid creating lots of useless blocks } // Looping over the tail of nybbles in both nodes, creating // new blocks until we find the difference let mut new_block_idx = ro_len + glen; let mut nybble = deepest.nybble; for nybble_pos in read_nybbles..node.nybbles_len() { block.set(nybble, Element::Block(new_block_idx)); let new_nybble = node.get_nybble(nybble_pos); let old_nybble = old_node.get_nybble(nybble_pos); if old_nybble == new_nybble { self.growable.push(Block::new()); block = &mut self.growable[glen]; glen += 1; new_block_idx += 1; nybble = new_nybble; } else { let mut new_block = Block::new(); new_block.set(old_nybble, Element::Rev(old_rev)); new_block.set(new_nybble, Element::Rev(rev)); self.growable.push(new_block); break; } } } else { // Free slot in the deepest block: no splitting has to be done block.set(deepest.nybble, Element::Rev(rev)); } // Backtrack over visit steps to update references while let Some(visited) = visit_steps.pop() { let to_write = Element::Block(block_idx); if visit_steps.is_empty() { self.root.set(visited.nybble, to_write); break; } let (new_idx, block, _) = self.mutable_block(visited.block_idx); if block.get(visited.nybble) == to_write { break; } block.set(visited.nybble, to_write); block_idx = new_idx; } Ok(()) } /// Make the whole `NodeTree` logically empty, without touching the /// immutable part. pub fn invalidate_all(&mut self) { self.root = Block::new(); self.growable = Vec::new(); self.masked_inner_blocks = self.readonly.len(); } /// Return the number of blocks in the readonly part that are currently /// masked in the mutable part. /// /// The `NodeTree` structure has no efficient way to know how many blocks /// are already unreachable in the readonly part. /// /// After a call to `invalidate_all()`, the returned number can be actually /// bigger than the whole readonly part, a conventional way to mean that /// all the readonly blocks have been masked. This is what is really /// useful to the caller and does not require to know how many were /// actually unreachable to begin with. pub fn masked_readonly_blocks(&self) -> usize { if let Some(readonly_root) = self.readonly.last() { if readonly_root == &self.root { return 0; } } else { return 0; } self.masked_inner_blocks + 1 } } pub struct NodeTreeBytes { buffer: Box<dyn Deref<Target = [u8]> + Send>, len_in_blocks: usize, } impl NodeTreeBytes { fn new( buffer: Box<dyn Deref<Target = [u8]> + Send>, amount: usize, ) -> Self { assert!(buffer.len() >= amount); let len_in_blocks = amount / BLOCK_SIZE; NodeTreeBytes { buffer, len_in_blocks, } } } impl Deref for NodeTreeBytes { type Target = [Block]; fn deref(&self) -> &[Block] { unsafe { slice::from_raw_parts( (&self.buffer).as_ptr() as *const Block, self.len_in_blocks, ) } } } struct NodeTreeVisitor<'n, 'p> { nt: &'n NodeTree, prefix: NodePrefixRef<'p>, visit: usize, nybble_idx: usize, done: bool, } #[derive(Debug, PartialEq, Clone)] struct NodeTreeVisitItem { block_idx: usize, nybble: u8, element: Element, } impl<'n, 'p> Iterator for NodeTreeVisitor<'n, 'p> { type Item = NodeTreeVisitItem; fn next(&mut self) -> Option<Self::Item> { if self.done || self.nybble_idx >= self.prefix.len() { return None; } let nybble = self.prefix.get_nybble(self.nybble_idx); self.nybble_idx += 1; let visit = self.visit; let element = self.nt[visit].get(nybble); if let Element::Block(idx) = element { self.visit = idx; } else { self.done = true; } Some(NodeTreeVisitItem { block_idx: visit, nybble, element, }) } } impl NodeTreeVisitItem { // Return `Some(opt)` if this item is final, with `opt` being the // `Revision` that it may represent. // // If the item is not terminal, return `None` fn final_revision(&self) -> Option<Option<Revision>> { match self.element { Element::Block(_) => None, Element::Rev(r) => Some(Some(r)), Element::None => Some(None), } } } impl From<Vec<Block>> for NodeTree { fn from(vec: Vec<Block>) -> Self { Self::new(Box::new(vec)) } } impl fmt::Debug for NodeTree { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { let readonly: &[Block] = &*self.readonly; write!( f, "readonly: {:?}, growable: {:?}, root: {:?}", readonly, self.growable, self.root ) } } impl Default for NodeTree { /// Create a fully mutable empty NodeTree fn default() -> Self { NodeTree::new(Box::new(Vec::new())) } } impl NodeMap for NodeTree { fn find_bin<'a>( &self, idx: &impl RevlogIndex, prefix: NodePrefixRef<'a>, ) -> Result<Option<Revision>, NodeMapError> { validate_candidate(idx, prefix.clone(), self.lookup(prefix)?) .map(|(opt, _shortest)| opt) } fn unique_prefix_len_bin<'a>( &self, idx: &impl RevlogIndex, prefix: NodePrefixRef<'a>, ) -> Result<Option<usize>, NodeMapError> { validate_candidate(idx, prefix.clone(), self.lookup(prefix)?) .map(|(opt, shortest)| opt.map(|_rev| shortest)) } } #[cfg(test)] mod tests { use super::NodeMapError::*; use super::*; use crate::revlog::node::{hex_pad_right, Node}; use std::collections::HashMap; /// Creates a `Block` using a syntax close to the `Debug` output macro_rules! block { {$($nybble:tt : $variant:ident($val:tt)),*} => ( { let mut block = Block::new(); $(block.set($nybble, Element::$variant($val)));*; block } ) } #[test] fn test_block_debug() { let mut block = Block::new(); block.set(1, Element::Rev(3)); block.set(10, Element::Block(0)); assert_eq!(format!("{:?}", block), "{1: Rev(3), 10: Block(0)}"); } #[test] fn test_block_macro() { let block = block! {5: Block(2)}; assert_eq!(format!("{:?}", block), "{5: Block(2)}"); let block = block! {13: Rev(15), 5: Block(2)}; assert_eq!(format!("{:?}", block), "{5: Block(2), 13: Rev(15)}"); } #[test] fn test_raw_block() { let mut raw = [255u8; 64]; let mut counter = 0; for val in [0, 15, -2, -1, -3].iter() { for byte in RawElement::to_be_bytes(*val).iter() { raw[counter] = *byte; counter += 1; } } let block = Block(raw); assert_eq!(block.get(0), Element::Block(0)); assert_eq!(block.get(1), Element::Block(15)); assert_eq!(block.get(3), Element::None); assert_eq!(block.get(2), Element::Rev(0)); assert_eq!(block.get(4), Element::Rev(1)); } type TestIndex = HashMap<Revision, Node>; impl RevlogIndex for TestIndex { fn node(&self, rev: Revision) -> Option<&Node> { self.get(&rev) } fn len(&self) -> usize { self.len() } } /// Pad hexadecimal Node prefix with zeros on the right /// /// This avoids having to repeatedly write very long hexadecimal /// strings for test data, and brings actual hash size independency. #[cfg(test)] fn pad_node(hex: &str) -> Node { Node::from_hex(&hex_pad_right(hex)).unwrap() } /// Pad hexadecimal Node prefix with zeros on the right, then insert fn pad_insert(idx: &mut TestIndex, rev: Revision, hex: &str) { idx.insert(rev, pad_node(hex)); } fn sample_nodetree() -> NodeTree { NodeTree::from(vec![ block![0: Rev(9)], block![0: Rev(0), 1: Rev(9)], block![0: Block(1), 1:Rev(1)], ]) } #[test] fn test_nt_debug() { let nt = sample_nodetree(); assert_eq!( format!("{:?}", nt), "readonly: \ [{0: Rev(9)}, {0: Rev(0), 1: Rev(9)}, {0: Block(1), 1: Rev(1)}], \ growable: [], \ root: {0: Block(1), 1: Rev(1)}", ); } #[test] fn test_immutable_find_simplest() -> Result<(), NodeMapError> { let mut idx: TestIndex = HashMap::new(); pad_insert(&mut idx, 1, "1234deadcafe"); let nt = NodeTree::from(vec![block! {1: Rev(1)}]); assert_eq!(nt.find_hex(&idx, "1")?, Some(1)); assert_eq!(nt.find_hex(&idx, "12")?, Some(1)); assert_eq!(nt.find_hex(&idx, "1234de")?, Some(1)); assert_eq!(nt.find_hex(&idx, "1a")?, None); assert_eq!(nt.find_hex(&idx, "ab")?, None); // and with full binary Nodes assert_eq!(nt.find_node(&idx, idx.get(&1).unwrap())?, Some(1)); let unknown = Node::from_hex(&hex_pad_right("3d")).unwrap(); assert_eq!(nt.find_node(&idx, &unknown)?, None); Ok(()) } #[test] fn test_immutable_find_one_jump() { let mut idx = TestIndex::new(); pad_insert(&mut idx, 9, "012"); pad_insert(&mut idx, 0, "00a"); let nt = sample_nodetree(); assert_eq!(nt.find_hex(&idx, "0"), Err(MultipleResults)); assert_eq!(nt.find_hex(&idx, "01"), Ok(Some(9))); assert_eq!(nt.find_hex(&idx, "00"), Err(MultipleResults)); assert_eq!(nt.find_hex(&idx, "00a"), Ok(Some(0))); assert_eq!(nt.unique_prefix_len_hex(&idx, "00a"), Ok(Some(3))); assert_eq!(nt.find_hex(&idx, "000"), Ok(Some(NULL_REVISION))); } #[test] fn test_mutated_find() -> Result<(), NodeMapError> { let mut idx = TestIndex::new(); pad_insert(&mut idx, 9, "012"); pad_insert(&mut idx, 0, "00a"); pad_insert(&mut idx, 2, "cafe"); pad_insert(&mut idx, 3, "15"); pad_insert(&mut idx, 1, "10"); let nt = NodeTree { readonly: sample_nodetree().readonly, growable: vec![block![0: Rev(1), 5: Rev(3)]], root: block![0: Block(1), 1:Block(3), 12: Rev(2)], masked_inner_blocks: 1, }; assert_eq!(nt.find_hex(&idx, "10")?, Some(1)); assert_eq!(nt.find_hex(&idx, "c")?, Some(2)); assert_eq!(nt.unique_prefix_len_hex(&idx, "c")?, Some(1)); assert_eq!(nt.find_hex(&idx, "00"), Err(MultipleResults)); assert_eq!(nt.find_hex(&idx, "000")?, Some(NULL_REVISION)); assert_eq!(nt.unique_prefix_len_hex(&idx, "000")?, Some(3)); assert_eq!(nt.find_hex(&idx, "01")?, Some(9)); assert_eq!(nt.masked_readonly_blocks(), 2); Ok(()) } struct TestNtIndex { index: TestIndex, nt: NodeTree, } impl TestNtIndex { fn new() -> Self { TestNtIndex { index: HashMap::new(), nt: NodeTree::default(), } } fn insert( &mut self, rev: Revision, hex: &str, ) -> Result<(), NodeMapError> { let node = pad_node(hex); self.index.insert(rev, node.clone()); self.nt.insert(&self.index, &node, rev)?; Ok(()) } fn find_hex( &self, prefix: &str, ) -> Result<Option<Revision>, NodeMapError> { self.nt.find_hex(&self.index, prefix) } fn unique_prefix_len_hex( &self, prefix: &str, ) -> Result<Option<usize>, NodeMapError> { self.nt.unique_prefix_len_hex(&self.index, prefix) } /// Drain `added` and restart a new one fn commit(self) -> Self { let mut as_vec: Vec<Block> = self.nt.readonly.iter().map(|block| block.clone()).collect(); as_vec.extend(self.nt.growable); as_vec.push(self.nt.root); Self { index: self.index, nt: NodeTree::from(as_vec).into(), } } } #[test] fn test_insert_full_mutable() -> Result<(), NodeMapError> { let mut idx = TestNtIndex::new(); idx.insert(0, "1234")?; assert_eq!(idx.find_hex("1")?, Some(0)); assert_eq!(idx.find_hex("12")?, Some(0)); // let's trigger a simple split idx.insert(1, "1a34")?; assert_eq!(idx.nt.growable.len(), 1); assert_eq!(idx.find_hex("12")?, Some(0)); assert_eq!(idx.find_hex("1a")?, Some(1)); // reinserting is a no_op idx.insert(1, "1a34")?; assert_eq!(idx.nt.growable.len(), 1); assert_eq!(idx.find_hex("12")?, Some(0)); assert_eq!(idx.find_hex("1a")?, Some(1)); idx.insert(2, "1a01")?; assert_eq!(idx.nt.growable.len(), 2); assert_eq!(idx.find_hex("1a"), Err(NodeMapError::MultipleResults)); assert_eq!(idx.find_hex("12")?, Some(0)); assert_eq!(idx.find_hex("1a3")?, Some(1)); assert_eq!(idx.find_hex("1a0")?, Some(2)); assert_eq!(idx.find_hex("1a12")?, None); // now let's make it split and create more than one additional block idx.insert(3, "1a345")?; assert_eq!(idx.nt.growable.len(), 4); assert_eq!(idx.find_hex("1a340")?, Some(1)); assert_eq!(idx.find_hex("1a345")?, Some(3)); assert_eq!(idx.find_hex("1a341")?, None); // there's no readonly block to mask assert_eq!(idx.nt.masked_readonly_blocks(), 0); Ok(()) } #[test] fn test_unique_prefix_len_zero_prefix() { let mut idx = TestNtIndex::new(); idx.insert(0, "00000abcd").unwrap(); assert_eq!(idx.find_hex("000"), Err(NodeMapError::MultipleResults)); // in the nodetree proper, this will be found at the first nybble // yet the correct answer for unique_prefix_len is not 1, nor 1+1, // but the first difference with `NULL_NODE` assert_eq!(idx.unique_prefix_len_hex("00000a"), Ok(Some(6))); assert_eq!(idx.unique_prefix_len_hex("00000ab"), Ok(Some(6))); // same with odd result idx.insert(1, "00123").unwrap(); assert_eq!(idx.unique_prefix_len_hex("001"), Ok(Some(3))); assert_eq!(idx.unique_prefix_len_hex("0012"), Ok(Some(3))); // these are unchanged of course assert_eq!(idx.unique_prefix_len_hex("00000a"), Ok(Some(6))); assert_eq!(idx.unique_prefix_len_hex("00000ab"), Ok(Some(6))); } #[test] fn test_insert_extreme_splitting() -> Result<(), NodeMapError> { // check that the splitting loop is long enough let mut nt_idx = TestNtIndex::new(); let nt = &mut nt_idx.nt; let idx = &mut nt_idx.index; let node0_hex = hex_pad_right("444444"); let mut node1_hex = hex_pad_right("444444").clone(); node1_hex.pop(); node1_hex.push('5'); let node0 = Node::from_hex(&node0_hex).unwrap(); let node1 = Node::from_hex(&node1_hex).unwrap(); idx.insert(0, node0.clone()); nt.insert(idx, &node0, 0)?; idx.insert(1, node1.clone()); nt.insert(idx, &node1, 1)?; assert_eq!(nt.find_bin(idx, (&node0).into())?, Some(0)); assert_eq!(nt.find_bin(idx, (&node1).into())?, Some(1)); Ok(()) } #[test] fn test_insert_partly_immutable() -> Result<(), NodeMapError> { let mut idx = TestNtIndex::new(); idx.insert(0, "1234")?; idx.insert(1, "1235")?; idx.insert(2, "131")?; idx.insert(3, "cafe")?; let mut idx = idx.commit(); assert_eq!(idx.find_hex("1234")?, Some(0)); assert_eq!(idx.find_hex("1235")?, Some(1)); assert_eq!(idx.find_hex("131")?, Some(2)); assert_eq!(idx.find_hex("cafe")?, Some(3)); // we did not add anything since init from readonly assert_eq!(idx.nt.masked_readonly_blocks(), 0); idx.insert(4, "123A")?; assert_eq!(idx.find_hex("1234")?, Some(0)); assert_eq!(idx.find_hex("1235")?, Some(1)); assert_eq!(idx.find_hex("131")?, Some(2)); assert_eq!(idx.find_hex("cafe")?, Some(3)); assert_eq!(idx.find_hex("123A")?, Some(4)); // we masked blocks for all prefixes of "123", including the root assert_eq!(idx.nt.masked_readonly_blocks(), 4); eprintln!("{:?}", idx.nt); idx.insert(5, "c0")?; assert_eq!(idx.find_hex("cafe")?, Some(3)); assert_eq!(idx.find_hex("c0")?, Some(5)); assert_eq!(idx.find_hex("c1")?, None); assert_eq!(idx.find_hex("1234")?, Some(0)); // inserting "c0" is just splitting the 'c' slot of the mutable root, // it doesn't mask anything assert_eq!(idx.nt.masked_readonly_blocks(), 4); Ok(()) } #[test] fn test_invalidate_all() -> Result<(), NodeMapError> { let mut idx = TestNtIndex::new(); idx.insert(0, "1234")?; idx.insert(1, "1235")?; idx.insert(2, "131")?; idx.insert(3, "cafe")?; let mut idx = idx.commit(); idx.nt.invalidate_all(); assert_eq!(idx.find_hex("1234")?, None); assert_eq!(idx.find_hex("1235")?, None); assert_eq!(idx.find_hex("131")?, None); assert_eq!(idx.find_hex("cafe")?, None); // all the readonly blocks have been masked, this is the // conventional expected response assert_eq!(idx.nt.masked_readonly_blocks(), idx.nt.readonly.len() + 1); Ok(()) } #[test] fn test_into_added_empty() { assert!(sample_nodetree().into_readonly_and_added().1.is_empty()); assert!(sample_nodetree() .into_readonly_and_added_bytes() .1 .is_empty()); } #[test] fn test_into_added_bytes() -> Result<(), NodeMapError> { let mut idx = TestNtIndex::new(); idx.insert(0, "1234")?; let mut idx = idx.commit(); idx.insert(4, "cafe")?; let (_, bytes) = idx.nt.into_readonly_and_added_bytes(); // only the root block has been changed assert_eq!(bytes.len(), BLOCK_SIZE); // big endian for -2 assert_eq!(&bytes[4..2 * 4], [255, 255, 255, 254]); // big endian for -6 assert_eq!(&bytes[12 * 4..13 * 4], [255, 255, 255, 250]); Ok(()) } }