git.delta.rocks / jrsonnet / refs/commits / d13245aaf3fc

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}44impl Default for Box<dyn ImportResolver> {45	fn default() -> Self {46		Box::new(DummyImportResolver)47	}48}4950/// File resolver, can load file from both FS and library paths51#[derive(Default)]52pub struct FileImportResolver {53	/// Library directories to search for file.54	/// Referred to as `jpath` in original jsonnet implementation.55	pub library_paths: Vec<PathBuf>,56}57impl ImportResolver for FileImportResolver {58	fn resolve_file(&self, from: &PathBuf, path: &PathBuf) -> Result<Rc<PathBuf>> {59		let mut new_path = from.clone();60		new_path.push(path);61		if new_path.exists() {62			Ok(Rc::new(new_path))63		} else {64			for library_path in self.library_paths.iter() {65				let mut cloned = library_path.clone();66				cloned.push(path);67				if cloned.exists() {68					return Ok(Rc::new(cloned));69				}70			}71			throw!(ImportFileNotFound(from.clone(), path.clone()))72		}73	}74	fn load_file_contents(&self, id: &PathBuf) -> Result<Rc<str>> {75		let mut file = File::open(id).map_err(|_e| ResolvedFileNotFound(id.clone()))?;76		let mut out = String::new();77		file.read_to_string(&mut out)78			.map_err(|_e| ImportBadFileUtf8(id.clone()))?;79		Ok(out.into())80	}81	unsafe fn as_any(&self) -> &dyn Any {82		panic!("this resolver can't be used as any")83	}84}8586type ResolutionData = (PathBuf, PathBuf);8788/// Caches results of the underlying resolver89pub struct CachingImportResolver {90	resolution_cache: RefCell<HashMap<ResolutionData, Result<Rc<PathBuf>>>>,91	loading_cache: RefCell<HashMap<PathBuf, Result<Rc<str>>>>,92	inner: Box<dyn ImportResolver>,93}94impl ImportResolver for CachingImportResolver {95	fn resolve_file(&self, from: &PathBuf, path: &PathBuf) -> Result<Rc<PathBuf>> {96		self.resolution_cache97			.borrow_mut()98			.entry((from.clone(), path.clone()))99			.or_insert_with(|| self.inner.resolve_file(from, path))100			.clone()101	}102103	fn load_file_contents(&self, resolved: &PathBuf) -> Result<Rc<str>> {104		self.loading_cache105			.borrow_mut()106			.entry(resolved.clone())107			.or_insert_with(|| self.inner.load_file_contents(resolved))108			.clone()109	}110	unsafe fn as_any(&self) -> &dyn Any {111		panic!("this resolver can't be used as any")112	}113}