Export links to custom binary format

brood/src/data.rs

@@ -1,3 +1,5 @@
+use std::io::{self, Read, Write};
+
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -20,3 +22,89 @@ pub struct AdjacencyList {
     pub pages: Vec<Page>,
     pub links: Vec<Link>,
 }
+
+impl AdjacencyList {
+    pub fn write<W: Write>(&self, mut to: W) -> io::Result<()> {
+        let n_pages: u32 = self.pages.len() as u32;
+        to.write_all(&n_pages.to_le_bytes())?;
+
+        let n_links: u32 = self.links.len() as u32;
+        to.write_all(&n_links.to_le_bytes())?;
+
+        for page in &self.pages {
+            to.write_all(&page.link_idx.to_le_bytes())?;
+            to.write_all(&page.id.to_le_bytes())?;
+            to.write_all(&[if page.redirect { 1 } else { 0 }])?;
+
+            let title_len: u16 = page.title.len() as u16;
+            to.write_all(&title_len.to_le_bytes())?;
+            to.write_all(page.title.as_bytes())?;
+        }
+
+        for link in &self.links {
+            to.write_all(&link.to.to_le_bytes())?;
+            to.write_all(&link.start.to_le_bytes())?;
+            to.write_all(&link.end.to_le_bytes())?;
+        }
+
+        Ok(())
+    }
+
+    pub fn read<R: Read>(mut from: R) -> io::Result<Self> {
+        let mut result = Self {
+            pages: vec![],
+            links: vec![],
+        };
+
+        let mut u8_buf = [0_u8; 1];
+        let mut u16_buf = [0_u8; 2];
+        let mut u32_buf = [0_u8; 4];
+
+        from.read_exact(&mut u32_buf)?;
+        let n_pages = u32::from_le_bytes(u32_buf);
+
+        from.read_exact(&mut u32_buf)?;
+        let n_links = u32::from_le_bytes(u32_buf);
+
+        for _ in 0..n_pages {
+            from.read_exact(&mut u32_buf)?;
+            let link_idx = u32::from_le_bytes(u32_buf);
+
+            from.read_exact(&mut u32_buf)?;
+            let id = u32::from_le_bytes(u32_buf);
+
+            from.read_exact(&mut u8_buf)?;
+            let redirect = u8_buf[0] != 0;
+
+            from.read_exact(&mut u16_buf)?;
+            let title_len = u16::from_le_bytes(u16_buf);
+            let mut title_bytes = vec![0_u8; title_len as usize];
+            from.read_exact(&mut title_bytes)?;
+            let title = String::from_utf8(title_bytes).unwrap();
+
+            let page = Page {
+                link_idx,
+                id,
+                title,
+                redirect,
+            };
+            result.pages.push(page);
+        }
+
+        for _ in 0..n_links {
+            from.read_exact(&mut u32_buf)?;
+            let to = u32::from_le_bytes(u32_buf);
+
+            from.read_exact(&mut u32_buf)?;
+            let start = u32::from_le_bytes(u32_buf);
+
+            from.read_exact(&mut u32_buf)?;
+            let end = u32::from_le_bytes(u32_buf);
+
+            let link = Link { to, start, end };
+            result.links.push(link);
+        }
+
+        Ok(result)
+    }
+}