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// Copyright 2018-2020 Georges Racinet <georges.racinet@octobus.net>
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// and Mercurial contributors
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//
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// This software may be used and distributed according to the terms of the
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// GNU General Public License version 2 or any later version.
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//! Indexing facilities for fast retrieval of `Revision` from `Node`
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//!
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//! This provides a variation on the 16-ary radix tree that is
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//! provided as "nodetree" in revlog.c, ready for append-only persistence
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//! on disk.
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//!
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//! Following existing implicit conventions, the "nodemap" terminology
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//! is used in a more abstract context.
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use super::{
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node::NULL_NODE, Node, NodePrefix, Revision, RevlogIndex, NULL_REVISION,
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};
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use bytes_cast::{unaligned, BytesCast};
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use std::cmp::max;
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use std::fmt;
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use std::mem::{self, align_of, size_of};
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use std::ops::Deref;
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use std::ops::Index;
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#[derive(Debug, PartialEq)]
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pub enum NodeMapError {
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MultipleResults,
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/// A `Revision` stored in the nodemap could not be found in the index
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RevisionNotInIndex(Revision),
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}
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/// Mapping system from Mercurial nodes to revision numbers.
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///
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/// ## `RevlogIndex` and `NodeMap`
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///
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/// One way to think about their relationship is that
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/// the `NodeMap` is a prefix-oriented reverse index of the `Node` information
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/// carried by a [`RevlogIndex`].
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///
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/// Many of the methods in this trait take a `RevlogIndex` argument
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/// which is used for validation of their results. This index must naturally
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/// be the one the `NodeMap` is about, and it must be consistent.
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///
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/// Notably, the `NodeMap` must not store
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/// information about more `Revision` values than there are in the index.
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/// In these methods, an encountered `Revision` is not in the index, a
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/// [`RevisionNotInIndex`] error is returned.
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///
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/// In insert operations, the rule is thus that the `NodeMap` must always
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/// be updated after the `RevlogIndex`
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/// be updated first, and the `NodeMap` second.
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///
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/// [`RevisionNotInIndex`]: enum.NodeMapError.html#variant.RevisionNotInIndex
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/// [`RevlogIndex`]: ../trait.RevlogIndex.html
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pub trait NodeMap {
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/// Find the unique `Revision` having the given `Node`
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///
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/// If no Revision matches the given `Node`, `Ok(None)` is returned.
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fn find_node(
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&self,
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index: &impl RevlogIndex,
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node: &Node,
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) -> Result<Option<Revision>, NodeMapError> {
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self.find_bin(index, node.into())
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}
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/// Find the unique Revision whose `Node` starts with a given binary prefix
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///
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/// If no Revision matches the given prefix, `Ok(None)` is returned.
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///
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/// If several Revisions match the given prefix, a [`MultipleResults`]
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/// error is returned.
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fn find_bin<'a>(
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&self,
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idx: &impl RevlogIndex,
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prefix: NodePrefix,
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) -> Result<Option<Revision>, NodeMapError>;
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/// Give the size of the shortest node prefix that determines
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/// the revision uniquely.
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///
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/// From a binary node prefix, if it is matched in the node map, this
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/// returns the number of hexadecimal digits that would had sufficed
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/// to find the revision uniquely.
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///
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/// Returns `None` if no `Revision` could be found for the prefix.
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///
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/// If several Revisions match the given prefix, a [`MultipleResults`]
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/// error is returned.
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fn unique_prefix_len_bin<'a>(
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&self,
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idx: &impl RevlogIndex,
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node_prefix: NodePrefix,
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) -> Result<Option<usize>, NodeMapError>;
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/// Same as `unique_prefix_len_bin`, with a full `Node` as input
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fn unique_prefix_len_node(
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&self,
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idx: &impl RevlogIndex,
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node: &Node,
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) -> Result<Option<usize>, NodeMapError> {
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self.unique_prefix_len_bin(idx, node.into())
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}
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}
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pub trait MutableNodeMap: NodeMap {
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fn insert<I: RevlogIndex>(
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&mut self,
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index: &I,
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node: &Node,
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rev: Revision,
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) -> Result<(), NodeMapError>;
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}
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/// Low level NodeTree [`Blocks`] elements
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///
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/// These are exactly as for instance on persistent storage.
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type RawElement = unaligned::I32Be;
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/// High level representation of values in NodeTree
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/// [`Blocks`](struct.Block.html)
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///
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/// This is the high level representation that most algorithms should
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/// use.
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#[derive(Clone, Debug, Eq, PartialEq)]
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enum Element {
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Rev(Revision),
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Block(usize),
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None,
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}
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impl From<RawElement> for Element {
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/// Conversion from low level representation, after endianness conversion.
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///
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/// See [`Block`](struct.Block.html) for explanation about the encoding.
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fn from(raw: RawElement) -> Element {
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let int = raw.get();
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if int >= 0 {
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Element::Block(int as usize)
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} else if int == -1 {
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Element::None
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} else {
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Element::Rev(-int - 2)
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}
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}
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}
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impl From<Element> for RawElement {
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fn from(element: Element) -> RawElement {
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RawElement::from(match element {
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Element::None => 0,
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Element::Block(i) => i as i32,
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Element::Rev(rev) => -rev - 2,
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})
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}
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}
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/// A logical block of the `NodeTree`, packed with a fixed size.
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///
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/// These are always used in container types implementing `Index<Block>`,
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/// such as `&Block`
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///
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/// As an array of integers, its ith element encodes that the
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/// ith potential edge from the block, representing the ith hexadecimal digit
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/// (nybble) `i` is either:
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///
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/// - absent (value -1)
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/// - another `Block` in the same indexable container (value ≥ 0)
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/// - a `Revision` leaf (value ≤ -2)
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///
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/// Endianness has to be fixed for consistency on shared storage across
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/// different architectures.
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///
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/// A key difference with the C `nodetree` is that we need to be
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/// able to represent the [`Block`] at index 0, hence -1 is the empty marker
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/// rather than 0 and the `Revision` range upper limit of -2 instead of -1.
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///
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/// Another related difference is that `NULL_REVISION` (-1) is not
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/// represented at all, because we want an immutable empty nodetree
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/// to be valid.
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const ELEMENTS_PER_BLOCK: usize = 16; // number of different values in a nybble
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#[derive(Copy, Clone, BytesCast, PartialEq)]
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#[repr(transparent)]
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pub struct Block([RawElement; ELEMENTS_PER_BLOCK]);
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impl Block {
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fn new() -> Self {
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let absent_node = RawElement::from(-1);
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Block([absent_node; ELEMENTS_PER_BLOCK])
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}
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fn get(&self, nybble: u8) -> Element {
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self.0[nybble as usize].into()
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}
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fn set(&mut self, nybble: u8, element: Element) {
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self.0[nybble as usize] = element.into()
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}
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}
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impl fmt::Debug for Block {
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/// sparse representation for testing and debugging purposes
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fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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f.debug_map()
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.entries((0..16).filter_map(|i| match self.get(i) {
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Element::None => None,
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element => Some((i, element)),
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}))
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.finish()
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}
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}
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/// A mutable 16-radix tree with the root block logically at the end
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///
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/// Because of the append only nature of our node trees, we need to
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/// keep the original untouched and store new blocks separately.
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///
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/// The mutable root `Block` is kept apart so that we don't have to rebump
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/// it on each insertion.
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pub struct NodeTree {
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readonly: Box<dyn Deref<Target = [Block]> + Send>,
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growable: Vec<Block>,
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root: Block,
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masked_inner_blocks: usize,
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}
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impl Index<usize> for NodeTree {
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type Output = Block;
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fn index(&self, i: usize) -> &Block {
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let ro_len = self.readonly.len();
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if i < ro_len {
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&self.readonly[i]
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} else if i == ro_len + self.growable.len() {
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&self.root
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} else {
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&self.growable[i - ro_len]
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}
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}
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}
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/// Return `None` unless the `Node` for `rev` has given prefix in `index`.
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fn has_prefix_or_none(
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idx: &impl RevlogIndex,
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prefix: NodePrefix,
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rev: Revision,
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) -> Result<Option<Revision>, NodeMapError> {
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idx.node(rev)
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.ok_or_else(|| NodeMapError::RevisionNotInIndex(rev))
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.map(|node| {
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if prefix.is_prefix_of(node) {
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Some(rev)
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} else {
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None
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}
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})
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}
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/// validate that the candidate's node starts indeed with given prefix,
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/// and treat ambiguities related to `NULL_REVISION`.
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///
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/// From the data in the NodeTree, one can only conclude that some
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/// revision is the only one for a *subprefix* of the one being looked up.
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fn validate_candidate(
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idx: &impl RevlogIndex,
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prefix: NodePrefix,
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candidate: (Option<Revision>, usize),
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) -> Result<(Option<Revision>, usize), NodeMapError> {
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let (rev, steps) = candidate;
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if let Some(nz_nybble) = prefix.first_different_nybble(&NULL_NODE) {
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rev.map_or(Ok((None, steps)), |r| {
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has_prefix_or_none(idx, prefix, r)
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.map(|opt| (opt, max(steps, nz_nybble + 1)))
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})
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} else {
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// the prefix is only made of zeros; NULL_REVISION always matches it
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// and any other *valid* result is an ambiguity
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match rev {
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None => Ok((Some(NULL_REVISION), steps + 1)),
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Some(r) => match has_prefix_or_none(idx, prefix, r)? {
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None => Ok((Some(NULL_REVISION), steps + 1)),
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_ => Err(NodeMapError::MultipleResults),
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},
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}
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}
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}
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impl NodeTree {
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/// Initiate a NodeTree from an immutable slice-like of `Block`
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///
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/// We keep `readonly` and clone its root block if it isn't empty.
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fn new(readonly: Box<dyn Deref<Target = [Block]> + Send>) -> Self {
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let root = readonly.last().cloned().unwrap_or_else(Block::new);
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NodeTree {
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readonly,
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growable: Vec::new(),
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root,
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masked_inner_blocks: 0,
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}
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}
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/// Create from an opaque bunch of bytes
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///
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/// The created `NodeTreeBytes` from `buffer`,
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/// of which exactly `amount` bytes are used.
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///
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/// - `buffer` could be derived from `PyBuffer` and `Mmap` objects.
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/// - `offset` allows for the final file format to include fixed data
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/// (generation number, behavioural flags)
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/// - `amount` is expressed in bytes, and is not automatically derived from
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/// `bytes`, so that a caller that manages them atomically can perform
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/// temporary disk serializations and still rollback easily if needed.
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/// First use-case for this would be to support Mercurial shell hooks.
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///
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/// panics if `buffer` is smaller than `amount`
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pub fn load_bytes(
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bytes: Box<dyn Deref<Target = [u8]> + Send>,
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amount: usize,
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) -> Self {
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NodeTree::new(Box::new(NodeTreeBytes::new(bytes, amount)))
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}
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/// Retrieve added `Block` and the original immutable data
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pub fn into_readonly_and_added(
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self,
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) -> (Box<dyn Deref<Target = [Block]> + Send>, Vec<Block>) {
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let mut vec = self.growable;
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let readonly = self.readonly;
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if readonly.last() != Some(&self.root) {
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vec.push(self.root);
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}
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(readonly, vec)
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}
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/// Retrieve added `Blocks` as bytes, ready to be written to persistent
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/// storage
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pub fn into_readonly_and_added_bytes(
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self,
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) -> (Box<dyn Deref<Target = [Block]> + Send>, Vec<u8>) {
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let (readonly, vec) = self.into_readonly_and_added();
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// Prevent running `v`'s destructor so we are in complete control
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// of the allocation.
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let vec = mem::ManuallyDrop::new(vec);
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// Transmute the `Vec<Block>` to a `Vec<u8>`. Blocks are contiguous
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// bytes, so this is perfectly safe.
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let bytes = unsafe {
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// Check for compatible allocation layout.
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// (Optimized away by constant-folding + dead code elimination.)
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assert_eq!(size_of::<Block>(), 64);
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assert_eq!(align_of::<Block>(), 1);
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// /!\ Any use of `vec` after this is use-after-free.
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// TODO: use `into_raw_parts` once stabilized
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Vec::from_raw_parts(
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vec.as_ptr() as *mut u8,
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vec.len() * size_of::<Block>(),
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vec.capacity() * size_of::<Block>(),
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)
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};
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(readonly, bytes)
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}
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/// Total number of blocks
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fn len(&self) -> usize {
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self.readonly.len() + self.growable.len() + 1
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}
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/// Implemented for completeness
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///
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/// A `NodeTree` always has at least the mutable root block.
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#[allow(dead_code)]
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fn is_empty(&self) -> bool {
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false
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}
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/// Main working method for `NodeTree` searches
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///
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/// The first returned value is the result of analysing `NodeTree` data
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/// *alone*: whereas `None` guarantees that the given prefix is absent
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/// from the `NodeTree` data (but still could match `NULL_NODE`), with
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/// `Some(rev)`, it is to be understood that `rev` is the unique `Revision`
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/// that could match the prefix. Actually, all that can be inferred from
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/// the `NodeTree` data is that `rev` is the revision with the longest
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/// common node prefix with the given prefix.
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///
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/// The second returned value is the size of the smallest subprefix
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/// of `prefix` that would give the same result, i.e. not the
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/// `MultipleResults` error variant (again, using only the data of the
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/// `NodeTree`).
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fn lookup(
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&self,
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prefix: NodePrefix,
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) -> Result<(Option<Revision>, usize), NodeMapError> {
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for (i, visit_item) in self.visit(prefix).enumerate() {
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if let Some(opt) = visit_item.final_revision() {
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return Ok((opt, i + 1));
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}
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}
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Err(NodeMapError::MultipleResults)
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}
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fn visit(&self, prefix: NodePrefix) -> NodeTreeVisitor {
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NodeTreeVisitor {
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nt: self,
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prefix,
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visit: self.len() - 1,
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nybble_idx: 0,
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done: false,
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}
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}
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/// Return a mutable reference for `Block` at index `idx`.
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///
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/// If `idx` lies in the immutable area, then the reference is to
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/// a newly appended copy.
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///
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/// Returns (new_idx, glen, mut_ref) where
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///
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/// - `new_idx` is the index of the mutable `Block`
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/// - `mut_ref` is a mutable reference to the mutable Block.
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/// - `glen` is the new length of `self.growable`
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///
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/// Note: the caller wouldn't be allowed to query `self.growable.len()`
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/// itself because of the mutable borrow taken with the returned `Block`
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|
|
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 / size_of::<Block>();
|
|
|
NodeTreeBytes {
|
|
|
buffer,
|
|
|
len_in_blocks,
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
impl Deref for NodeTreeBytes {
|
|
|
type Target = [Block];
|
|
|
|
|
|
fn deref(&self) -> &[Block] {
|
|
|
Block::slice_from_bytes(&self.buffer, self.len_in_blocks)
|
|
|
// `NodeTreeBytes::new` already asserted that `self.buffer` is
|
|
|
// large enough.
|
|
|
.unwrap()
|
|
|
.0
|
|
|
}
|
|
|
}
|
|
|
|
|
|
struct NodeTreeVisitor<'n> {
|
|
|
nt: &'n NodeTree,
|
|
|
prefix: NodePrefix,
|
|
|
visit: usize,
|
|
|
nybble_idx: usize,
|
|
|
done: bool,
|
|
|
}
|
|
|
|
|
|
#[derive(Debug, PartialEq, Clone)]
|
|
|
struct NodeTreeVisitItem {
|
|
|
block_idx: usize,
|
|
|
nybble: u8,
|
|
|
element: Element,
|
|
|
}
|
|
|
|
|
|
impl<'n> Iterator for NodeTreeVisitor<'n> {
|
|
|
type Item = NodeTreeVisitItem;
|
|
|
|
|
|
fn next(&mut self) -> Option<Self::Item> {
|
|
|
if self.done || self.nybble_idx >= self.prefix.nybbles_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: NodePrefix,
|
|
|
) -> Result<Option<Revision>, NodeMapError> {
|
|
|
validate_candidate(idx, prefix, self.lookup(prefix)?)
|
|
|
.map(|(opt, _shortest)| opt)
|
|
|
}
|
|
|
|
|
|
fn unique_prefix_len_bin<'a>(
|
|
|
&self,
|
|
|
idx: &impl RevlogIndex,
|
|
|
prefix: NodePrefix,
|
|
|
) -> Result<Option<usize>, NodeMapError> {
|
|
|
validate_candidate(idx, prefix, 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_i32, 15, -2, -1, -3].iter() {
|
|
|
for byte in val.to_be_bytes().iter() {
|
|
|
raw[counter] = *byte;
|
|
|
counter += 1;
|
|
|
}
|
|
|
}
|
|
|
let (block, _) = Block::from_bytes(&raw).unwrap();
|
|
|
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)],
|
|
|
])
|
|
|
}
|
|
|
|
|
|
fn hex(s: &str) -> NodePrefix {
|
|
|
NodePrefix::from_hex(s).unwrap()
|
|
|
}
|
|
|
|
|
|
#[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_bin(&idx, hex("1"))?, Some(1));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("12"))?, Some(1));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("1234de"))?, Some(1));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("1a"))?, None);
|
|
|
assert_eq!(nt.find_bin(&idx, hex("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_bin(&idx, hex("0")), Err(MultipleResults));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("01")), Ok(Some(9)));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("00")), Err(MultipleResults));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("00a")), Ok(Some(0)));
|
|
|
assert_eq!(nt.unique_prefix_len_bin(&idx, hex("00a")), Ok(Some(3)));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("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_bin(&idx, hex("10"))?, Some(1));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("c"))?, Some(2));
|
|
|
assert_eq!(nt.unique_prefix_len_bin(&idx, hex("c"))?, Some(1));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("00")), Err(MultipleResults));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("000"))?, Some(NULL_REVISION));
|
|
|
assert_eq!(nt.unique_prefix_len_bin(&idx, hex("000"))?, Some(3));
|
|
|
assert_eq!(nt.find_bin(&idx, hex("01"))?, Some(9));
|
|
|
assert_eq!(nt.masked_readonly_blocks(), 2);
|
|
|
Ok(())
|
|
|
}
|
|
|
|
|
|
struct TestNtIndex {
|
|
|
index: TestIndex,
|
|
|
nt: NodeTree,
|
|
|
}
|
|
|
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impl TestNtIndex {
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fn new() -> Self {
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TestNtIndex {
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index: HashMap::new(),
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nt: NodeTree::default(),
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}
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}
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fn insert(
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&mut self,
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rev: Revision,
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hex: &str,
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) -> Result<(), NodeMapError> {
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let node = pad_node(hex);
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self.index.insert(rev, node.clone());
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self.nt.insert(&self.index, &node, rev)?;
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Ok(())
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}
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fn find_hex(
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&self,
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prefix: &str,
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) -> Result<Option<Revision>, NodeMapError> {
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self.nt.find_bin(&self.index, hex(prefix))
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}
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fn unique_prefix_len_hex(
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&self,
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prefix: &str,
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) -> Result<Option<usize>, NodeMapError> {
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self.nt.unique_prefix_len_bin(&self.index, hex(prefix))
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}
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/// Drain `added` and restart a new one
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fn commit(self) -> Self {
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let mut as_vec: Vec<Block> =
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self.nt.readonly.iter().map(|block| block.clone()).collect();
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as_vec.extend(self.nt.growable);
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as_vec.push(self.nt.root);
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Self {
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index: self.index,
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nt: NodeTree::from(as_vec).into(),
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}
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}
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}
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#[test]
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fn test_insert_full_mutable() -> Result<(), NodeMapError> {
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let mut idx = TestNtIndex::new();
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idx.insert(0, "1234")?;
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assert_eq!(idx.find_hex("1")?, Some(0));
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assert_eq!(idx.find_hex("12")?, Some(0));
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// let's trigger a simple split
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idx.insert(1, "1a34")?;
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assert_eq!(idx.nt.growable.len(), 1);
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assert_eq!(idx.find_hex("12")?, Some(0));
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assert_eq!(idx.find_hex("1a")?, Some(1));
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// reinserting is a no_op
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idx.insert(1, "1a34")?;
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assert_eq!(idx.nt.growable.len(), 1);
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assert_eq!(idx.find_hex("12")?, Some(0));
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assert_eq!(idx.find_hex("1a")?, Some(1));
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idx.insert(2, "1a01")?;
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assert_eq!(idx.nt.growable.len(), 2);
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assert_eq!(idx.find_hex("1a"), Err(NodeMapError::MultipleResults));
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assert_eq!(idx.find_hex("12")?, Some(0));
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assert_eq!(idx.find_hex("1a3")?, Some(1));
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assert_eq!(idx.find_hex("1a0")?, Some(2));
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assert_eq!(idx.find_hex("1a12")?, None);
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// now let's make it split and create more than one additional block
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idx.insert(3, "1a345")?;
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assert_eq!(idx.nt.growable.len(), 4);
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assert_eq!(idx.find_hex("1a340")?, Some(1));
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assert_eq!(idx.find_hex("1a345")?, Some(3));
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assert_eq!(idx.find_hex("1a341")?, None);
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// there's no readonly block to mask
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assert_eq!(idx.nt.masked_readonly_blocks(), 0);
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Ok(())
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}
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#[test]
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fn test_unique_prefix_len_zero_prefix() {
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let mut idx = TestNtIndex::new();
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idx.insert(0, "00000abcd").unwrap();
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assert_eq!(idx.find_hex("000"), Err(NodeMapError::MultipleResults));
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// in the nodetree proper, this will be found at the first nybble
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// yet the correct answer for unique_prefix_len is not 1, nor 1+1,
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// but the first difference with `NULL_NODE`
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assert_eq!(idx.unique_prefix_len_hex("00000a"), Ok(Some(6)));
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assert_eq!(idx.unique_prefix_len_hex("00000ab"), Ok(Some(6)));
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// same with odd result
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idx.insert(1, "00123").unwrap();
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assert_eq!(idx.unique_prefix_len_hex("001"), Ok(Some(3)));
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assert_eq!(idx.unique_prefix_len_hex("0012"), Ok(Some(3)));
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// these are unchanged of course
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assert_eq!(idx.unique_prefix_len_hex("00000a"), Ok(Some(6)));
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assert_eq!(idx.unique_prefix_len_hex("00000ab"), Ok(Some(6)));
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}
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#[test]
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fn test_insert_extreme_splitting() -> Result<(), NodeMapError> {
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// check that the splitting loop is long enough
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let mut nt_idx = TestNtIndex::new();
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let nt = &mut nt_idx.nt;
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let idx = &mut nt_idx.index;
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let node0_hex = hex_pad_right("444444");
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let mut node1_hex = hex_pad_right("444444").clone();
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node1_hex.pop();
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node1_hex.push('5');
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let node0 = Node::from_hex(&node0_hex).unwrap();
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let node1 = Node::from_hex(&node1_hex).unwrap();
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idx.insert(0, node0.clone());
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nt.insert(idx, &node0, 0)?;
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idx.insert(1, node1.clone());
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nt.insert(idx, &node1, 1)?;
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assert_eq!(nt.find_bin(idx, (&node0).into())?, Some(0));
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assert_eq!(nt.find_bin(idx, (&node1).into())?, Some(1));
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Ok(())
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}
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#[test]
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fn test_insert_partly_immutable() -> Result<(), NodeMapError> {
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let mut idx = TestNtIndex::new();
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idx.insert(0, "1234")?;
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idx.insert(1, "1235")?;
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idx.insert(2, "131")?;
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idx.insert(3, "cafe")?;
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let mut idx = idx.commit();
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assert_eq!(idx.find_hex("1234")?, Some(0));
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assert_eq!(idx.find_hex("1235")?, Some(1));
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assert_eq!(idx.find_hex("131")?, Some(2));
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assert_eq!(idx.find_hex("cafe")?, Some(3));
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// we did not add anything since init from readonly
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assert_eq!(idx.nt.masked_readonly_blocks(), 0);
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idx.insert(4, "123A")?;
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assert_eq!(idx.find_hex("1234")?, Some(0));
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assert_eq!(idx.find_hex("1235")?, Some(1));
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assert_eq!(idx.find_hex("131")?, Some(2));
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assert_eq!(idx.find_hex("cafe")?, Some(3));
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assert_eq!(idx.find_hex("123A")?, Some(4));
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// we masked blocks for all prefixes of "123", including the root
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assert_eq!(idx.nt.masked_readonly_blocks(), 4);
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eprintln!("{:?}", idx.nt);
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idx.insert(5, "c0")?;
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assert_eq!(idx.find_hex("cafe")?, Some(3));
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assert_eq!(idx.find_hex("c0")?, Some(5));
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assert_eq!(idx.find_hex("c1")?, None);
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assert_eq!(idx.find_hex("1234")?, Some(0));
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// inserting "c0" is just splitting the 'c' slot of the mutable root,
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// it doesn't mask anything
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assert_eq!(idx.nt.masked_readonly_blocks(), 4);
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Ok(())
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}
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#[test]
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fn test_invalidate_all() -> Result<(), NodeMapError> {
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let mut idx = TestNtIndex::new();
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idx.insert(0, "1234")?;
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idx.insert(1, "1235")?;
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idx.insert(2, "131")?;
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idx.insert(3, "cafe")?;
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let mut idx = idx.commit();
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idx.nt.invalidate_all();
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assert_eq!(idx.find_hex("1234")?, None);
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assert_eq!(idx.find_hex("1235")?, None);
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assert_eq!(idx.find_hex("131")?, None);
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assert_eq!(idx.find_hex("cafe")?, None);
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// all the readonly blocks have been masked, this is the
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// conventional expected response
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assert_eq!(idx.nt.masked_readonly_blocks(), idx.nt.readonly.len() + 1);
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Ok(())
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}
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#[test]
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fn test_into_added_empty() {
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assert!(sample_nodetree().into_readonly_and_added().1.is_empty());
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assert!(sample_nodetree()
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.into_readonly_and_added_bytes()
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.1
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.is_empty());
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}
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#[test]
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fn test_into_added_bytes() -> Result<(), NodeMapError> {
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let mut idx = TestNtIndex::new();
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idx.insert(0, "1234")?;
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let mut idx = idx.commit();
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idx.insert(4, "cafe")?;
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let (_, bytes) = idx.nt.into_readonly_and_added_bytes();
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// only the root block has been changed
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assert_eq!(bytes.len(), size_of::<Block>());
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// big endian for -2
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assert_eq!(&bytes[4..2 * 4], [255, 255, 255, 254]);
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// big endian for -6
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assert_eq!(&bytes[12 * 4..13 * 4], [255, 255, 255, 250]);
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Ok(())
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}
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}
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