Split updater into module.

1 files changed, 161 insertions, 0 deletions

diff --git a/src/manager/updater.rs b/src/manager/updater.rs
new file mode 100644
index 0000000..0de675c
--- /dev/null
+++ b/src/manager/updater.rs
@@ -0,0 +1,161 @@
+// Copyright 2019 Hristo Venev
+//
+// See COPYING.
+
+use super::{load_file, update_file, Source};
+use crate::{config, proto};
+use std::ffi::{OsStr, OsString};
+use std::path::PathBuf;
+use std::time::{Duration, Instant};
+use std::{fs, io};
+
+pub(super) struct Updater {
+    config: config::UpdaterConfig,
+}
+
+impl Updater {
+    pub fn new(config: config::UpdaterConfig) -> Self {
+        Self { config }
+    }
+
+    fn cache_path(&self, s: &Source) -> Option<PathBuf> {
+        if let Some(ref dir) = self.config.cache_directory {
+            let mut p = dir.clone();
+            p.push(&s.name);
+            Some(p)
+        } else {
+            None
+        }
+    }
+
+    fn cache_update(&self, src: &Source) {
+        let path = if let Some(path) = self.cache_path(src) {
+            path
+        } else {
+            return;
+        };
+
+        let data = serde_json::to_vec(&src.data).unwrap();
+        match update_file(&path, &data) {
+            Ok(()) => {}
+            Err(e) => {
+                eprintln!("<4>Failed to cache [{}]: {}", &src.name, e);
+            }
+        }
+    }
+
+    pub fn cache_load(&self, src: &mut Source) -> bool {
+        let path = if let Some(path) = self.cache_path(src) {
+            path
+        } else {
+            return false;
+        };
+
+        let data = match load_file(&path) {
+            Ok(Some(data)) => data,
+            Ok(None) => {
+                return false;
+            }
+            Err(e) => {
+                eprintln!("<3>Failed to read [{}] from cache: {}", &src.name, e);
+                return false;
+            }
+        };
+
+        let mut de = serde_json::Deserializer::from_slice(&data);
+        src.data = match serde::Deserialize::deserialize(&mut de) {
+            Ok(r) => r,
+            Err(e) => {
+                eprintln!("<3>Failed to load [{}] from cache: {}", &src.name, e);
+                return false;
+            }
+        };
+
+        true
+    }
+
+    pub fn update(&self, src: &mut Source) -> (bool, Instant) {
+        let refresh = self.refresh_time();
+
+        let r = fetch_source(&src.config.url);
+        let now = Instant::now();
+        let r = match r {
+            Ok(r) => {
+                eprintln!("<6>Updated [{}]", &src.config.url);
+                src.data = r;
+                src.backoff = None;
+                src.next_update = now + refresh;
+                self.cache_update(src);
+                return (true, now);
+            }
+            Err(r) => r,
+        };
+
+        let b = src
+            .backoff
+            .unwrap_or_else(|| Duration::from_secs(10).min(refresh / 10));
+        src.next_update = now + b;
+        src.backoff = Some((b + b / 3).min(refresh / 3));
+        eprintln!(
+            "<3>Failed to update [{}], retrying after {:.1?}: {}",
+            &src.config.url, b, &r
+        );
+        (false, now)
+    }
+
+    pub fn refresh_time(&self) -> Duration {
+        Duration::from_secs(u64::from(self.config.refresh_sec))
+    }
+}
+
+fn fetch_source(url: &str) -> io::Result<proto::Source> {
+    use std::env;
+    use std::process::{Command, Stdio};
+
+    let curl = match env::var_os("CURL") {
+        None => OsString::new(),
+        Some(v) => v,
+    };
+    let mut proc = Command::new(if curl.is_empty() {
+        OsStr::new("curl")
+    } else {
+        curl.as_os_str()
+    });
+
+    proc.stdin(Stdio::null());
+    proc.stdout(Stdio::piped());
+    proc.stderr(Stdio::piped());
+    proc.arg("-gsSfL");
+    proc.arg("--fail-early");
+    proc.arg("--max-time");
+    proc.arg("10");
+    proc.arg("--max-filesize");
+    proc.arg("1M");
+    proc.arg("--");
+    proc.arg(url);
+
+    let out = proc.output()?;
+
+    if !out.status.success() {
+        let msg = String::from_utf8_lossy(&out.stderr);
+        let msg = msg.replace('\n', "; ");
+        return Err(io::Error::new(io::ErrorKind::Other, msg));
+    }
+
+    let mut de = serde_json::Deserializer::from_slice(&out.stdout);
+    let r = serde::Deserialize::deserialize(&mut de)?;
+    Ok(r)
+}
+
+pub fn load_source(path: &OsStr) -> io::Result<proto::Source> {
+    let mut data = Vec::new();
+    {
+        use std::io::Read;
+        let mut f = fs::File::open(&path)?;
+        f.read_to_end(&mut data)?;
+    }
+
+    let mut de = serde_json::Deserializer::from_slice(&data);
+    let r = serde::Deserialize::deserialize(&mut de)?;
+    Ok(r)
+}