Remove PageIdx and LinkIdx again

I don't think the type safety is worth the effort right now.

brood/src/commands/ingest.rs

@@ -7,9 +7,7 @@ use std::u32;
 use rustc_hash::FxHashMap;
 use serde::Deserialize;
 
-use crate::data::adjacency_list::{
+use crate::data::adjacency_list::{AdjacencyList, Page};
-    AdjacencyList, Link, LinkIdx, Page, PageIdx, SENTINEL_PAGE_MARKER,
-};
 use crate::data::info::{LinkInfo, PageInfo};
 use crate::data::store;
 use crate::util;
@@ -74,29 +72,20 @@ fn first_stage() -> io::Result<(AdjacencyList<PageInfo, LinkInfo>, Titles)> {
     for (i, line) in stdin.lines().enumerate() {
         let json_page = serde_json::from_str::<JsonPage>(&line?).unwrap();
 
-        result.pages.push(Page {
+        result.push_page(PageInfo {
-            start: LinkIdx(result.links.len() as u32),
+            id: json_page.id,
-            data: PageInfo {
+            length: json_page.length,
-                id: json_page.id,
+            redirect: json_page.redirect.is_some(),
-                length: json_page.length,
+            title: json_page.title,
-                redirect: json_page.redirect.is_some(),
-                title: json_page.title,
-            },
         });
 
         if let Some(to) = json_page.redirect {
             let to = titles.insert(util::normalize_link(&to));
-            result.links.push(Link {
+            result.push_link(to, LinkInfo::default());
-                to: PageIdx(to),
-                data: LinkInfo::default(),
-            });
         } else {
             for (to, start, len, flags) in json_page.links {
                 let to = titles.insert(util::normalize_link(&to));
-                result.links.push(Link {
+                result.push_link(to, LinkInfo { start, len, flags });
-                    to: PageIdx(to),
-                    data: LinkInfo { start, len, flags },
-                });
             }
         }
 
@@ -110,16 +99,6 @@ fn first_stage() -> io::Result<(AdjacencyList<PageInfo, LinkInfo>, Titles)> {
     eprintln!("Titles: {}", titles.titles.len());
     eprintln!("Title map entries: {}", titles.map.len());
 
-    result.pages.push(Page {
-        start: LinkIdx(result.links.len() as u32),
-        data: PageInfo {
-            id: u32::MAX,
-            length: 0,
-            redirect: false,
-            title: SENTINEL_PAGE_MARKER.to_string(),
-        },
-    });
-
     Ok((result, titles))
 }
 
@@ -151,26 +130,19 @@ fn second_stage(
     let pages_map = initialize_pages_map(&first_stage.pages);
     let mut result = AdjacencyList::default();
 
-    for page_idx in 0..first_stage.pages.len() - 1 {
+    for (page_idx, page) in first_stage.pages() {
-        let mut page = first_stage.pages[page_idx].clone();
+        result.push_page(page.data.clone());
-        let start_link_idx = page.start;
-        let end_link_idx = first_stage.pages[page_idx + 1].start;
 
-        page.start.0 = result.links.len() as u32;
+        for (_, link) in first_stage.links(page_idx) {
-        result.pages.push(page);
+            let title = util::normalize_link(titles.get(link.to));
-
-        for link_idx in start_link_idx.0..end_link_idx.0 {
-            let mut link = first_stage.links[link_idx as usize];
-            let title = util::normalize_link(titles.get(link.to.0));
             if let Some(to) = pages_map.get(&title) {
                 // The link points to an existing article, we should keep it
-                link.to.0 = *to;
+                result.push_link(*to, link.data);
-                result.links.push(link);
             }
         }
 
         if (page_idx + 1) % 100_000 == 0 {
-            eprintln!("{} pages processed", page_idx + 1)
+            eprintln!("{} pages imported", page_idx + 1)
         }
     }
 
@@ -178,10 +150,6 @@ fn second_stage(
     eprintln!("Links: {}", result.links.len());
     eprintln!("Page map entries: {}", pages_map.len());
 
-    let mut sentinel = first_stage.pages.last().unwrap().clone();
-    sentinel.start.0 = result.links.len() as u32;
-    result.pages.push(sentinel);
-
     result
 }
 

brood/src/commands/list_pages.rs

@@ -2,15 +2,13 @@ use std::fs::File;
 use std::io::{self, BufReader};
 use std::path::Path;
 
-use crate::data::adjacency_list::PageIdx;
 use crate::data::store;
 
 pub fn run(datafile: &Path) -> io::Result<()> {
     let mut databuf = BufReader::new(File::open(datafile)?);
     let data = store::read_adjacency_list(&mut databuf)?;
 
-    for (page_idx, page) in data.pages.iter().enumerate() {
+    for (page_idx, page) in data.pages() {
-        let page_idx = PageIdx(page_idx as u32);
         if page.data.redirect {
             for link_idx in data.link_range(page_idx) {
                 let target_page = data.page(data.link(link_idx).to);

brood/src/commands/longest_shortest_path.rs

@@ -3,14 +3,15 @@ use std::fs::File;
 use std::io::{self, BufReader};
 use std::path::Path;
 
-use crate::data::adjacency_list::{AdjacencyList, PageIdx};
+use crate::data::adjacency_list::AdjacencyList;
 use crate::data::info::{LinkInfo, PageInfo};
 use crate::data::store;
 use crate::util;
 
 struct DijkstraPageInfo {
     cost: u32,
-    prev: PageIdx,
+    /// Index of the previous page.
+    prev: u32,
     redirect: bool,
 }
 
@@ -18,7 +19,7 @@ impl DijkstraPageInfo {
     fn from_page_info(info: PageInfo) -> Self {
         Self {
             cost: u32::MAX,
-            prev: PageIdx::MAX,
+            prev: u32::MAX,
             redirect: info.redirect,
         }
     }
@@ -42,12 +43,12 @@ impl DijkstraLinkInfo {
 #[derive(Clone, Copy, PartialEq, Eq)]
 struct Entry {
     cost: u32,
-    idx: PageIdx,
+    page_idx: u32,
 }
 
 impl Entry {
-    pub fn new(cost: u32, idx: PageIdx) -> Self {
+    pub fn new(cost: u32, page_idx: u32) -> Self {
-        Self { cost, idx }
+        Self { cost, page_idx }
     }
 }
 
@@ -57,7 +58,7 @@ impl Ord for Entry {
         other
             .cost
             .cmp(&self.cost)
-            .then_with(|| self.idx.cmp(&other.idx))
+            .then_with(|| self.page_idx.cmp(&other.page_idx))
     }
 }
 
@@ -70,22 +71,18 @@ impl PartialOrd for Entry {
 /// Closely matches the dijkstra example in [std::collections::binary_heap].
 fn full_dijkstra(
     data: AdjacencyList<PageInfo, LinkInfo>,
-    from_idx: PageIdx,
+    from: u32,
 ) -> AdjacencyList<DijkstraPageInfo, DijkstraLinkInfo> {
     println!("> Prepare state");
     let mut data = data
         .change_page_data(DijkstraPageInfo::from_page_info)
         .change_link_data(DijkstraLinkInfo::from_link_info);
     let mut queue = BinaryHeap::new();
-    data.page_mut(from_idx).data.cost = 0;
+    data.page_mut(from).data.cost = 0;
-    queue.push(Entry::new(0, from_idx));
+    queue.push(Entry::new(0, from));
 
     println!("> Run dijkstra");
-    while let Some(Entry {
+    while let Some(Entry { cost, page_idx }) = queue.pop() {
-        cost,
-        idx: page_idx,
-    }) = queue.pop()
-    {
         let page = data.page(page_idx);
         if cost > page.data.cost {
             // This queue entry is outdated
@@ -98,7 +95,7 @@ fn full_dijkstra(
 
             let next = Entry {
                 cost: cost + if redirect { 0 } else { link.data.cost },
-                idx: link.to,
+                page_idx: link.to,
             };
 
             let target_page = data.page_mut(link.to);
@@ -115,23 +112,22 @@ fn full_dijkstra(
 
 fn find_longest_shortest_path(
     data: AdjacencyList<DijkstraPageInfo, DijkstraLinkInfo>,
-    from: PageIdx,
+    from: u32,
-) -> Option<Vec<PageIdx>> {
+) -> Option<Vec<u32>> {
-    let to = PageIdx(
+    let to = data
-        data.pages
+        .pages
-            .iter()
+        .iter()
-            .enumerate()
+        .enumerate()
-            .filter(|(_, p)| p.data.cost != u32::MAX)
+        .filter(|(_, p)| p.data.cost != u32::MAX)
-            .max_by_key(|(_, p)| p.data.cost)?
+        .max_by_key(|(_, p)| p.data.cost)?
-            .0 as u32,
+        .0 as u32;
-    );
 
     let mut steps = vec![];
     let mut at = to;
     loop {
         steps.push(at);
         at = data.page(at).data.prev;
-        if at == PageIdx::MAX {
+        if at == u32::MAX {
             break;
         };
     }
@@ -162,7 +158,7 @@ pub fn run(datafile: &Path, from: &str) -> io::Result<()> {
     if let Some(path) = path {
         println!("Path found:");
         for page_idx in path {
-            let page = &pages[page_idx.0 as usize];
+            let page = &pages[page_idx as usize];
             if page.data.redirect {
                 println!(" v {:?}", page.data.title);
             } else {

brood/src/commands/path.rs

@@ -3,14 +3,14 @@ use std::fs::File;
 use std::io::{self, BufReader};
 use std::path::Path;
 
-use crate::data::adjacency_list::{AdjacencyList, PageIdx};
+use crate::data::adjacency_list::AdjacencyList;
 use crate::data::info::{LinkInfo, PageInfo};
 use crate::data::store;
 use crate::util;
 
 struct DijkstraPageInfo {
     cost: u32,
-    prev: PageIdx,
+    prev: u32,
     redirect: bool,
 }
 
@@ -18,7 +18,7 @@ impl DijkstraPageInfo {
     fn from_page_info(info: PageInfo) -> Self {
         Self {
             cost: u32::MAX,
-            prev: PageIdx::MAX,
+            prev: u32::MAX,
             redirect: info.redirect,
         }
     }
@@ -42,12 +42,12 @@ impl DijkstraLinkInfo {
 #[derive(Clone, Copy, PartialEq, Eq)]
 struct Entry {
     cost: u32,
-    idx: PageIdx,
+    page_idx: u32,
 }
 
 impl Entry {
-    pub fn new(cost: u32, idx: PageIdx) -> Self {
+    pub fn new(cost: u32, page_idx: u32) -> Self {
-        Self { cost, idx }
+        Self { cost, page_idx }
     }
 }
 
@@ -57,7 +57,7 @@ impl Ord for Entry {
         other
             .cost
             .cmp(&self.cost)
-            .then_with(|| self.idx.cmp(&other.idx))
+            .then_with(|| self.page_idx.cmp(&other.page_idx))
     }
 }
 
@@ -68,11 +68,7 @@ impl PartialOrd for Entry {
 }
 
 /// Closely matches the dijkstra example in [std::collections::binary_heap].
-fn dijkstra(
+fn dijkstra(data: AdjacencyList<PageInfo, LinkInfo>, from: u32, to: u32) -> Option<Vec<u32>> {
-    data: AdjacencyList<PageInfo, LinkInfo>,
-    from: PageIdx,
-    to: PageIdx,
-) -> Option<Vec<PageIdx>> {
     println!("> Prepare state");
     let mut data = data
         .change_page_data(DijkstraPageInfo::from_page_info)
@@ -82,11 +78,7 @@ fn dijkstra(
     queue.push(Entry::new(0, from));
 
     println!("> Run dijkstra");
-    while let Some(Entry {
+    while let Some(Entry { cost, page_idx }) = queue.pop() {
-        cost,
-        idx: page_idx,
-    }) = queue.pop()
-    {
         if page_idx == to {
             // We've found the shortest path to our target
             break;
@@ -104,7 +96,7 @@ fn dijkstra(
 
             let next = Entry {
                 cost: cost + if redirect { 0 } else { link.data.cost },
-                idx: link.to,
+                page_idx: link.to,
             };
 
             let target_page = data.page_mut(link.to);
@@ -122,7 +114,7 @@ fn dijkstra(
     loop {
         steps.push(at);
         at = data.page(at).data.prev;
-        if at == PageIdx::MAX {
+        if at == u32::MAX {
             break;
         };
     }
@@ -152,7 +144,7 @@ pub fn path(datafile: &Path, from: &str, to: &str) -> io::Result<()> {
     if let Some(path) = path {
         println!("Path found:");
         for page_idx in path {
-            let page = &pages[page_idx.0 as usize];
+            let page = &pages[page_idx as usize];
             if page.data.redirect {
                 println!(" v {:?}", page.data.title);
             } else {

brood/src/data/adjacency_list.rs

@@ -1,20 +1,11 @@
+use std::ops::Range;
+
 use super::info::{LinkInfo, PageInfo};
 
-pub const SENTINEL_PAGE_MARKER: &str = "Q2AKO3OYzyitmCJURghJ";
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct PageIdx(pub u32);
-
-impl PageIdx {
-    pub const MAX: PageIdx = PageIdx(u32::MAX);
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct LinkIdx(pub u32);
-
 #[derive(Debug, Clone, Copy)]
 pub struct Page<P> {
-    pub start: LinkIdx,
+    /// Index of the first link belonging to this page.
+    pub start: u32,
     pub data: P,
 }
 
@@ -29,7 +20,8 @@ impl<P> Page<P> {
 
 #[derive(Debug, Clone, Copy)]
 pub struct Link<L> {
-    pub to: PageIdx,
+    /// Index of the page this link points to.
+    pub to: u32,
     pub data: L,
 }
 
@@ -57,40 +49,57 @@ impl<P, L> Default for AdjacencyList<P, L> {
 }
 
 impl<P, L> AdjacencyList<P, L> {
-    pub fn page(&self, idx: PageIdx) -> &Page<P> {
+    pub fn push_page(&mut self, data: P) {
-        &self.pages[idx.0 as usize]
+        self.pages.push(Page {
+            start: self.links.len() as u32,
+            data,
+        });
     }
 
-    pub fn page_mut(&mut self, idx: PageIdx) -> &mut Page<P> {
+    pub fn push_link(&mut self, to: u32, data: L) {
-        &mut self.pages[idx.0 as usize]
+        self.links.push(Link { to, data })
     }
 
-    pub fn pages_range(&self) -> impl DoubleEndedIterator<Item = PageIdx> {
+    pub fn page(&self, page_idx: u32) -> &Page<P> {
-        (0..self.pages.len() as u32 - 1).map(PageIdx)
+        &self.pages[page_idx as usize]
     }
 
-    pub fn link_range(&self, idx: PageIdx) -> impl DoubleEndedIterator<Item = LinkIdx> {
+    pub fn page_mut(&mut self, page_idx: u32) -> &mut Page<P> {
-        let start_idx = self.page(idx).start;
+        &mut self.pages[page_idx as usize]
-        let end_idx = self.page(PageIdx(idx.0 + 1)).start;
-        (start_idx.0..end_idx.0).map(LinkIdx)
     }
 
-    pub fn link_redirect(&self, idx: PageIdx) -> Option<LinkIdx> {
+    pub fn pages(&self) -> impl Iterator<Item = (u32, &Page<P>)> {
-        let start_idx = self.page(idx).start;
+        self.pages.iter().enumerate().map(|(i, p)| (i as u32, p))
-        let end_idx = self.page(PageIdx(idx.0 + 1)).start;
+    }
-        if start_idx == end_idx {
+
+    pub fn link(&self, link_idx: u32) -> &Link<L> {
+        &self.links[link_idx as usize]
+    }
+
+    pub fn link_mut(&mut self, link_idx: u32) -> &mut Link<L> {
+        &mut self.links[link_idx as usize]
+    }
+
+    pub fn link_range(&self, page_idx: u32) -> Range<u32> {
+        let start_idx = self.pages[page_idx as usize].start;
+        let end_idx = match self.pages.get(page_idx as usize + 1) {
+            Some(page) => page.start,
+            None => self.links.len() as u32,
+        };
+        start_idx..end_idx
+    }
+
+    pub fn link_redirect(&self, page_idx: u32) -> Option<u32> {
+        let range = self.link_range(page_idx);
+        if range.is_empty() {
             None
         } else {
-            Some(start_idx)
+            Some(range.start)
         }
     }
 
-    pub fn link(&self, idx: LinkIdx) -> &Link<L> {
+    pub fn links(&self, page_idx: u32) -> impl Iterator<Item = (u32, &Link<L>)> {
-        &self.links[idx.0 as usize]
+        self.link_range(page_idx).map(|i| (i, self.link(i)))
-    }
-
-    pub fn link_mut(&mut self, idx: LinkIdx) -> &mut Link<L> {
-        &mut self.links[idx.0 as usize]
     }
 
     pub fn change_page_data<P2>(self, page_f: impl Fn(P) -> P2 + Copy) -> AdjacencyList<P2, L> {
@@ -122,14 +131,6 @@ impl<P, L> AdjacencyList<P, L> {
 
 impl AdjacencyList<PageInfo, LinkInfo> {
     pub fn check_consistency(&self) {
-        // Check that we have a sentinel page
-        let sentinel = self.pages.last().expect("no sentinel page");
-        assert!(sentinel.data.id == u32::MAX, "unmarked sentinel page");
-        assert!(
-            sentinel.data.title.contains(SENTINEL_PAGE_MARKER),
-            "unmarked sentinel page"
-        );
-
         // Check that all types are large enough
         assert!(self.pages.len() < u32::MAX as usize, "too many pages");
         assert!(self.links.len() < u32::MAX as usize, "too many links");
@@ -142,18 +143,17 @@ impl AdjacencyList<PageInfo, LinkInfo> {
 
         // Check that all links contain valid indices. Links must not link to
         // the sentinel page.
-        let range = 0..self.pages.len() as u32 - 1;
+        let range = 0..self.pages.len() as u32;
         for link in &self.links {
-            assert!(range.contains(&link.to.0), "invalid link");
+            assert!(range.contains(&link.to), "invalid link");
         }
 
         // Check that all redirect pages have at most one link
-        for page_idx in (0..self.pages.len() as u32 - 1).map(PageIdx) {
+        for (page_idx, page) in self.pages.iter().enumerate() {
-            let page = self.page(page_idx);
             if page.data.redirect {
-                let mut range = self.link_range(page_idx);
+                let range = self.link_range(page_idx as u32);
-                range.next(); // 0 or 1 links allowed
+                let amount = range.end - range.start;
-                assert!(range.next().is_none(), "too many redirect links");
+                assert!(amount <= 1, "too many redirect links");
             }
         }
     }

brood/src/data/store.rs

@@ -1,7 +1,7 @@
 use std::io::{self, Read, Write};
 
 use super::{
-    adjacency_list::{AdjacencyList, Link, LinkIdx, Page, PageIdx},
+    adjacency_list::{AdjacencyList, Link, Page},
     info::{LinkInfo, PageInfo},
 };
 
@@ -50,7 +50,7 @@ fn read_str<R: Read>(from: &mut R) -> io::Result<String> {
 }
 
 fn write_page<W: Write>(page: &Page<PageInfo>, to: &mut W) -> io::Result<()> {
-    write_u32(page.start.0, to)?;
+    write_u32(page.start, to)?;
     write_u32(page.data.id, to)?;
     write_u32(page.data.length, to)?;
     write_u8(if page.data.redirect { 1 } else { 0 }, to)?;
@@ -60,14 +60,14 @@ fn write_page<W: Write>(page: &Page<PageInfo>, to: &mut W) -> io::Result<()> {
 }
 
 pub fn read_page<R: Read>(from: &mut R) -> io::Result<Page<PageInfo>> {
-    let start = LinkIdx(read_u32(from)?);
+    let start_link_idx = read_u32(from)?;
     let id = read_u32(from)?;
     let length = read_u32(from)?;
     let redirect = read_u8(from)? != 0;
     let title = read_str(from)?;
 
     Ok(Page {
-        start,
+        start: start_link_idx,
         data: PageInfo {
             id,
             length,
@@ -78,7 +78,7 @@ pub fn read_page<R: Read>(from: &mut R) -> io::Result<Page<PageInfo>> {
 }
 
 fn write_link<W: Write>(link: &Link<LinkInfo>, to: &mut W) -> io::Result<()> {
-    write_u32(link.to.0, to)?;
+    write_u32(link.to, to)?;
     write_u32(link.data.start, to)?;
     write_u32(link.data.len, to)?;
     write_u8(link.data.flags, to)?;
@@ -87,13 +87,13 @@ fn write_link<W: Write>(link: &Link<LinkInfo>, to: &mut W) -> io::Result<()> {
 }
 
 fn read_link<R: Read>(from: &mut R) -> io::Result<Link<LinkInfo>> {
-    let to = PageIdx(read_u32(from)?);
+    let to_page_idx = read_u32(from)?;
     let start = read_u32(from)?;
     let len = read_u32(from)?;
     let flags = read_u8(from)?;
 
     Ok(Link {
-        to,
+        to: to_page_idx,
         data: LinkInfo { start, len, flags },
     })
 }

brood/src/util.rs

@@ -1,5 +1,5 @@
 use crate::data::{
-    adjacency_list::{AdjacencyList, Page, PageIdx},
+    adjacency_list::{AdjacencyList, Page},
     info::{LinkInfo, PageInfo},
 };
 
@@ -15,21 +15,17 @@ pub fn normalize_link(link: &str) -> String {
         .collect::<String>()
 }
 
-pub fn find_index_of_title(pages: &[Page<PageInfo>], title: &str) -> PageIdx {
+pub fn find_index_of_title(pages: &[Page<PageInfo>], title: &str) -> u32 {
     let title = normalize_link(title);
-    let idx = pages
+    pages
         .iter()
         .enumerate()
         .find(|(_, p)| normalize_link(&p.data.title) == title)
         .map(|(i, _)| i)
-        .expect("invalid title") as u32;
+        .expect("invalid title") as u32
-    PageIdx(idx)
 }
 
-pub fn resolve_redirects(
+pub fn resolve_redirects(data: &AdjacencyList<PageInfo, LinkInfo>, mut page_idx: u32) -> u32 {
-    data: &AdjacencyList<PageInfo, LinkInfo>,
-    mut page_idx: PageIdx,
-) -> PageIdx {
     loop {
         if data.page(page_idx).data.redirect {
             if let Some(link_idx) = data.link_redirect(page_idx) {