begin the rocket framework implementation, based on the aquatic-crawler fs

src/feed.rs

@@ -0,0 +1,140 @@
+use crate::format;
+use std::collections::HashSet;
+use url::Url;
+
+/// Export crawl index to the RSS file
+pub struct Feed {
+    description: Option<String>,
+    link: Option<String>,
+    title: String,
+    /// Valid, parsed from Url, ready-to-use address string donor
+    trackers: Option<HashSet<String>>,
+}
+
+impl Feed {
+    pub fn init(
+        title: String,
+        description: Option<String>,
+        link: Option<Url>,
+        trackers: Option<HashSet<Url>>,
+    ) -> Self {
+        Self {
+            description: description.map(escape),
+            link: link.map(|s| escape(s.to_string())),
+            title: escape(title),
+            trackers: trackers.map(|v| v.into_iter().map(|u| u.to_string()).collect()),
+        }
+    }
+
+    pub fn transaction(&self, capacity: usize) -> String {
+        let t = chrono::Utc::now().to_rfc2822();
+        let mut b = String::with_capacity(capacity);
+
+        b.push_str("<?xml version=\"1.0\" encoding=\"UTF-8\"?><rss version=\"2.0\"><channel>");
+
+        b.push_str("<pubDate>");
+        b.push_str(&t);
+        b.push_str("</pubDate>");
+
+        b.push_str("<lastBuildDate>");
+        b.push_str(&t);
+        b.push_str("</lastBuildDate>");
+
+        b.push_str("<title>");
+        b.push_str(&self.title);
+        b.push_str("</title>");
+
+        if let Some(ref description) = self.description {
+            b.push_str("<description>");
+            b.push_str(description);
+            b.push_str("</description>")
+        }
+
+        if let Some(ref link) = self.link {
+            b.push_str("<link>");
+            b.push_str(link);
+            b.push_str("</link>")
+        }
+        b
+    }
+
+    /// Append `item` to the feed `channel`
+    pub fn push(&self, buffer: &mut String, torrent: crate::storage::Torrent) {
+        buffer.push_str(&format!(
+            "<item><guid>{}</guid><title>{}</title><link>{}</link>",
+            &torrent.info_hash,
+            escape(
+                torrent
+                    .name
+                    .as_ref()
+                    .map(|b| b.to_string())
+                    .unwrap_or("?".into()) // @TODO
+            ),
+            escape(self.magnet(&torrent.info_hash))
+        ));
+
+        if let Some(d) = item_description(torrent.length, torrent.files) {
+            buffer.push_str("<description>");
+            buffer.push_str(&escape(d));
+            buffer.push_str("</description>")
+        }
+
+        buffer.push_str("<pubDate>");
+        buffer.push_str(&torrent.time.to_rfc2822());
+        buffer.push_str("</pubDate>");
+
+        buffer.push_str("</item>")
+    }
+
+    /// Write final bytes
+    pub fn commit(&self, mut buffer: String) -> String {
+        buffer.push_str("</channel></rss>");
+        buffer
+    }
+
+    // Tools
+
+    fn magnet(&self, info_hash: &str) -> String {
+        let mut b = if info_hash.len() == 40 {
+            format!("magnet:?xt=urn:btih:{info_hash}")
+        } else {
+            todo!("info-hash v2 is not supported by librqbit")
+        };
+        if let Some(ref trackers) = self.trackers {
+            for tracker in trackers {
+                b.push_str("&tr=");
+                b.push_str(&urlencoding::encode(tracker))
+            }
+        }
+        b
+    }
+}
+
+fn escape(subject: String) -> String {
+    subject
+        .replace('&', "&amp;")
+        .replace('<', "&lt;")
+        .replace('>', "&gt;")
+        .replace('"', "&quot;")
+        .replace("'", "&apos;")
+}
+
+fn item_description(size: Option<u64>, list: Option<Vec<crate::storage::File>>) -> Option<String> {
+    if size.is_none() && list.is_none() {
+        return None;
+    }
+    let mut b = Vec::with_capacity(list.as_ref().map(|l| l.len()).unwrap_or_default() + 1);
+    if let Some(s) = size {
+        b.push(format::bytes(s))
+    }
+    if let Some(files) = list {
+        for file in files {
+            b.push(format!(
+                "{} ({})",
+                file.name.as_deref().unwrap_or("?"), // @TODO invalid encoding
+                format::bytes(file.length)
+            ))
+        }
+    }
+    Some(b.join("\n"))
+}