proxmox-backup/src/server/config.rs
Dominik Csapak 2ab5acac5a server/config: add mechanism to update template
instead of exposing handlebars itself, offer a register_template and
a render_template ourselves.

render_template checks if the template file was modified since
the last render and reloads it when necessary

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
2020-07-23 11:55:00 +02:00

122 lines
3.7 KiB
Rust

use std::collections::HashMap;
use std::path::PathBuf;
use std::time::SystemTime;
use std::fs::metadata;
use std::sync::RwLock;
use anyhow::{bail, Error, format_err};
use hyper::Method;
use handlebars::Handlebars;
use serde::Serialize;
use proxmox::api::{ApiMethod, Router, RpcEnvironmentType};
pub struct ApiConfig {
basedir: PathBuf,
router: &'static Router,
aliases: HashMap<String, PathBuf>,
env_type: RpcEnvironmentType,
templates: RwLock<Handlebars<'static>>,
template_files: RwLock<HashMap<String, (SystemTime, PathBuf)>>,
}
impl ApiConfig {
pub fn new<B: Into<PathBuf>>(basedir: B, router: &'static Router, env_type: RpcEnvironmentType) -> Result<Self, Error> {
Ok(Self {
basedir: basedir.into(),
router,
aliases: HashMap::new(),
env_type,
templates: RwLock::new(Handlebars::new()),
template_files: RwLock::new(HashMap::new()),
})
}
pub fn find_method(
&self,
components: &[&str],
method: Method,
uri_param: &mut HashMap<String, String>,
) -> Option<&'static ApiMethod> {
self.router.find_method(components, method, uri_param)
}
pub fn find_alias(&self, components: &[&str]) -> PathBuf {
let mut prefix = String::new();
let mut filename = self.basedir.clone();
let comp_len = components.len();
if comp_len >= 1 {
prefix.push_str(components[0]);
if let Some(subdir) = self.aliases.get(&prefix) {
filename.push(subdir);
for i in 1..comp_len { filename.push(components[i]) }
} else {
for i in 0..comp_len { filename.push(components[i]) }
}
}
filename
}
pub fn add_alias<S, P>(&mut self, alias: S, path: P)
where S: Into<String>,
P: Into<PathBuf>,
{
self.aliases.insert(alias.into(), path.into());
}
pub fn env_type(&self) -> RpcEnvironmentType {
self.env_type
}
pub fn register_template<P>(&self, name: &str, path: P) -> Result<(), Error>
where
P: Into<PathBuf>
{
if self.template_files.read().unwrap().contains_key(name) {
bail!("template already registered");
}
let path: PathBuf = path.into();
let metadata = metadata(&path)?;
let mtime = metadata.modified()?;
self.templates.write().unwrap().register_template_file(name, &path)?;
self.template_files.write().unwrap().insert(name.to_string(), (mtime, path));
Ok(())
}
/// Checks if the template was modified since the last rendering
/// if yes, it loads a the new version of the template
pub fn render_template<T>(&self, name: &str, data: &T) -> Result<String, Error>
where
T: Serialize,
{
let path;
let mtime;
{
let template_files = self.template_files.read().unwrap();
let (old_mtime, old_path) = template_files.get(name).ok_or_else(|| format_err!("template not found"))?;
mtime = metadata(old_path)?.modified()?;
if mtime <= *old_mtime {
return self.templates.read().unwrap().render(name, data).map_err(|err| format_err!("{}", err));
}
path = old_path.to_path_buf();
}
{
let mut template_files = self.template_files.write().unwrap();
let mut templates = self.templates.write().unwrap();
templates.register_template_file(name, &path)?;
template_files.insert(name.to_string(), (mtime, path));
templates.render(name, data).map_err(|err| format_err!("{}", err))
}
}
}