git.delta.rocks / jrsonnet / refs/commits / bc97bc99f5fd

1use crate::{2	error::{Error::*, Result},3	throw,4};5use fs::File;6use std::fs;7use std::io::Read;8use std::{any::Any, cell::RefCell, collections::HashMap, path::PathBuf, rc::Rc};910/// Implements file resolution logic for `import` and `importStr`11pub trait ImportResolver {12	/// Resolves real file path, e.g. `(/home/user/manifests, b.libjsonnet)` can correspond13	/// both to `/home/user/manifests/b.libjsonnet` and to `/home/user/${vendor}/b.libjsonnet`14	/// where `${vendor}` is a library path.15	fn resolve_file(&self, from: &PathBuf, path: &PathBuf) -> Result<Rc<PathBuf>>;1617	/// Reads file from filesystem, should be used only with path received from `resolve_file`18	fn load_file_contents(&self, resolved: &PathBuf) -> Result<Rc<str>>;1920	/// # Safety21	///22	/// For use only in bindings, should not be used elsewhere.23	/// Implementations which are not intended to be used in bindings24	/// should panic on call to this method.25	unsafe fn as_any(&self) -> &dyn Any;26}2728/// Dummy resolver, can't resolve/load any file29pub struct DummyImportResolver;30impl ImportResolver for DummyImportResolver {31	fn resolve_file(&self, from: &PathBuf, path: &PathBuf) -> Result<Rc<PathBuf>> {32		throw!(ImportNotSupported(from.clone(), path.clone()))33	}3435	fn load_file_contents(&self, _resolved: &PathBuf) -> Result<Rc<str>> {36		// Can be only caused by library direct consumer, not by supplied jsonnet37		panic!("dummy resolver can't load any file")38	}3940	unsafe fn as_any(&self) -> &dyn Any {41		panic!("`as_any($self)` is not supported by dummy resolver")42	}43}44#[allow(clippy::use_self)]45impl Default for Box<dyn ImportResolver> {46	fn default() -> Self {47		Box::new(DummyImportResolver)48	}49}5051/// File resolver, can load file from both FS and library paths52#[derive(Default)]53pub struct FileImportResolver {54	/// Library directories to search for file.55	/// Referred to as `jpath` in original jsonnet implementation.56	pub library_paths: Vec<PathBuf>,57}58impl ImportResolver for FileImportResolver {59	fn resolve_file(&self, from: &PathBuf, path: &PathBuf) -> Result<Rc<PathBuf>> {60		let mut new_path = from.clone();61		new_path.push(path);62		if new_path.exists() {63			Ok(Rc::new(new_path))64		} else {65			for library_path in self.library_paths.iter() {66				let mut cloned = library_path.clone();67				cloned.push(path);68				if cloned.exists() {69					return Ok(Rc::new(cloned));70				}71			}72			throw!(ImportFileNotFound(from.clone(), path.clone()))73		}74	}75	fn load_file_contents(&self, id: &PathBuf) -> Result<Rc<str>> {76		let mut file = File::open(id).map_err(|_e| ResolvedFileNotFound(id.clone()))?;77		let mut out = String::new();78		file.read_to_string(&mut out)79			.map_err(|_e| ImportBadFileUtf8(id.clone()))?;80		Ok(out.into())81	}82	unsafe fn as_any(&self) -> &dyn Any {83		panic!("this resolver can't be used as any")84	}85}8687type ResolutionData = (PathBuf, PathBuf);8889/// Caches results of the underlying resolver90pub struct CachingImportResolver {91	resolution_cache: RefCell<HashMap<ResolutionData, Result<Rc<PathBuf>>>>,92	loading_cache: RefCell<HashMap<PathBuf, Result<Rc<str>>>>,93	inner: Box<dyn ImportResolver>,94}95impl ImportResolver for CachingImportResolver {96	fn resolve_file(&self, from: &PathBuf, path: &PathBuf) -> Result<Rc<PathBuf>> {97		self.resolution_cache98			.borrow_mut()99			.entry((from.clone(), path.clone()))100			.or_insert_with(|| self.inner.resolve_file(from, path))101			.clone()102	}103104	fn load_file_contents(&self, resolved: &PathBuf) -> Result<Rc<str>> {105		self.loading_cache106			.borrow_mut()107			.entry(resolved.clone())108			.or_insert_with(|| self.inner.load_file_contents(resolved))109			.clone()110	}111	unsafe fn as_any(&self) -> &dyn Any {112		panic!("this resolver can't be used as any")113	}114}