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authorNadrieril2020-11-01 18:50:09 +0000
committerGitHub2020-11-01 18:50:09 +0000
commit2ae979a22ee4b79590f74110d61164383c7b5182 (patch)
tree5286606d6d59f5d5d4b9ecb7f651c97d201a092e /dhall/src
parent48037367933085ca9c1c67c8c59f311e2b21be6d (diff)
parente5381c9b76f1d88dedb4a453cd026c8e98be5533 (diff)
Merge pull request #192 from Nadrieril/rework-caching
Diffstat (limited to 'dhall/src')
-rw-r--r--dhall/src/error/mod.rs4
-rw-r--r--dhall/src/lib.rs5
-rw-r--r--dhall/src/semantics/parse.rs7
-rw-r--r--dhall/src/semantics/resolve/cache.rs658
-rw-r--r--dhall/src/semantics/resolve/env.rs90
-rw-r--r--dhall/src/semantics/resolve/resolve.rs131
-rw-r--r--dhall/src/syntax/ast/expr.rs5
-rw-r--r--dhall/src/syntax/ast/import.rs2
-rw-r--r--dhall/src/syntax/binary/decode.rs2
-rw-r--r--dhall/src/syntax/text/parser.rs2
-rw-r--r--dhall/src/utils.rs17
11 files changed, 220 insertions, 703 deletions
diff --git a/dhall/src/error/mod.rs b/dhall/src/error/mod.rs
index d533264..800b8c1 100644
--- a/dhall/src/error/mod.rs
+++ b/dhall/src/error/mod.rs
@@ -1,6 +1,6 @@
use std::io::Error as IOError;
-use crate::semantics::resolve::{ImportLocation, ImportStack};
+use crate::semantics::resolve::{CyclesStack, ImportLocation};
use crate::syntax::{Import, ParseError};
mod builder;
@@ -31,7 +31,7 @@ pub enum ImportError {
MissingEnvVar,
SanityCheck,
UnexpectedImport(Import<()>),
- ImportCycle(ImportStack, ImportLocation),
+ ImportCycle(CyclesStack, ImportLocation),
Url(url::ParseError),
}
diff --git a/dhall/src/lib.rs b/dhall/src/lib.rs
index 87c461b..f9d259c 100644
--- a/dhall/src/lib.rs
+++ b/dhall/src/lib.rs
@@ -13,6 +13,7 @@ pub mod error;
pub mod operations;
pub mod semantics;
pub mod syntax;
+pub mod utils;
use std::fmt::Display;
use std::path::Path;
@@ -37,8 +38,8 @@ pub struct Resolved(Hir);
/// A typed expression
#[derive(Debug, Clone)]
pub struct Typed {
- hir: Hir,
- ty: Type,
+ pub hir: Hir,
+ pub ty: Type,
}
/// A normalized expression.
diff --git a/dhall/src/semantics/parse.rs b/dhall/src/semantics/parse.rs
index 82396e0..a770c15 100644
--- a/dhall/src/semantics/parse.rs
+++ b/dhall/src/semantics/parse.rs
@@ -1,5 +1,3 @@
-use std::fs::File;
-use std::io::Read;
use std::path::Path;
use url::Url;
@@ -36,9 +34,8 @@ pub fn parse_binary(data: &[u8]) -> Result<Parsed, Error> {
}
pub fn parse_binary_file(f: &Path) -> Result<Parsed, Error> {
- let mut buffer = Vec::new();
- File::open(f)?.read_to_end(&mut buffer)?;
- let expr = binary::decode(&buffer)?;
+ let data = crate::utils::read_binary_file(f)?;
+ let expr = binary::decode(&data)?;
let root = ImportLocation::Local(f.to_owned());
Ok(Parsed(expr, root))
}
diff --git a/dhall/src/semantics/resolve/cache.rs b/dhall/src/semantics/resolve/cache.rs
index 164baea..7763f18 100644
--- a/dhall/src/semantics/resolve/cache.rs
+++ b/dhall/src/semantics/resolve/cache.rs
@@ -2,13 +2,10 @@ use std::env;
use std::io::Write;
use std::path::{Path, PathBuf};
-use crate::error::{CacheError, Error, ErrorKind};
-use crate::parse::parse_binary_file;
-use crate::semantics::{Import, TypedHir};
-use crate::syntax::Hash;
-use crate::syntax::{binary, Expr};
-use crate::Parsed;
-use std::env::VarError;
+use crate::error::{CacheError, Error};
+use crate::parse::parse_binary;
+use crate::syntax::{binary, Hash};
+use crate::Typed;
use std::ffi::OsStr;
use std::fs::File;
@@ -20,634 +17,97 @@ const ALTERNATE_CACHE_ENV_VAR: &str = "HOME";
const ALTERNATE_CACHE_ENV_VAR: &str = "LOCALAPPDATA";
#[cfg(any(unix, windows))]
-fn load_cache_dir(
- env_provider: impl Fn(&str) -> Result<String, VarError> + Copy,
-) -> Result<PathBuf, CacheError> {
- let env_provider = |s| {
- env_provider(s)
- .map(PathBuf::from)
- .map_err(|_| CacheError::MissingConfiguration)
+fn default_cache_dir() -> Result<PathBuf, CacheError> {
+ let cache_base_path = match env::var(OsStr::new(CACHE_ENV_VAR)) {
+ Ok(path) => PathBuf::from(path),
+ Err(_) => match env::var(OsStr::new(ALTERNATE_CACHE_ENV_VAR)) {
+ Ok(path) => PathBuf::from(path).join(".cache"),
+ Err(_) => return Err(CacheError::MissingConfiguration),
+ },
};
- let cache_base_path = env_provider(CACHE_ENV_VAR).or_else(|_| {
- env_provider(ALTERNATE_CACHE_ENV_VAR).map(|path| path.join(".cache"))
- })?;
Ok(cache_base_path.join("dhall"))
}
+
#[cfg(not(any(unix, windows)))]
-fn load_cache_dir(
- _provider: impl Fn(&str) -> Result<String, VarError> + Copy,
-) -> Result<PathBuf, CacheError> {
+fn default_cache_dir() -> Result<PathBuf, CacheError> {
Err(CacheError::MissingConfiguration)
}
-#[derive(Debug, PartialEq)]
+#[derive(Debug, Clone, PartialEq)]
pub struct Cache {
- cache_dir: Option<PathBuf>,
+ cache_dir: PathBuf,
}
impl Cache {
- fn new_with_provider(
- provider: impl Fn(&str) -> Result<String, VarError> + Copy,
- ) -> Cache {
- // Should warn that we can't initialize cache on error
- let cache_dir = load_cache_dir(provider).and_then(|path| {
- if !path.exists() {
- std::fs::create_dir_all(path.as_path())
- .map(|_| path)
- .map_err(|e| CacheError::InitialisationError { cause: e })
- } else {
- Ok(path)
- }
- });
- Cache {
- cache_dir: cache_dir.ok(),
+ pub fn new() -> Result<Cache, Error> {
+ let cache_dir = default_cache_dir()?;
+ if !cache_dir.exists() {
+ std::fs::create_dir_all(&cache_dir)
+ .map_err(|e| CacheError::InitialisationError { cause: e })?;
}
+ Ok(Cache { cache_dir })
}
- pub fn new() -> Cache {
- Cache::new_with_provider(|name| env::var(OsStr::new(name)))
- }
-}
-
-impl Cache {
- fn cache_file(&self, import: &Import) -> Option<PathBuf> {
- self.cache_dir
- .as_ref()
- .and_then(|cache_dir| {
- import.hash.as_ref().map(|hash| (cache_dir, hash))
- })
- .map(|(cache_dir, hash)| cache_dir.join(cache_filename(hash)))
+ fn entry_path(&self, hash: &Hash) -> PathBuf {
+ self.cache_dir.join(filename_for_hash(hash))
}
- fn search_cache_file(&self, import: &Import) -> Option<PathBuf> {
- self.cache_file(import)
- .filter(|cache_file| cache_file.exists())
+ pub fn get(&self, hash: &Hash) -> Result<Typed, Error> {
+ let path = self.entry_path(hash);
+ let res = read_cache_file(&path, hash);
+ if let Err(_) = res {
+ if path.exists() {
+ // Delete cache file since it's invalid. We ignore the error.
+ let _ = std::fs::remove_file(&path);
+ }
+ }
+ res
}
- fn search_cache(&self, import: &Import) -> Option<Result<Parsed, Error>> {
- self.search_cache_file(import)
- .map(|cache_file| parse_binary_file(cache_file.as_path()))
+ pub fn insert(&self, hash: &Hash, expr: &Typed) -> Result<(), Error> {
+ let path = self.entry_path(hash);
+ write_cache_file(&path, expr)
}
+}
- // Side effect since we don't use the result
- fn delete_cache(&self, import: &Import) {
- self.search_cache_file(import)
- .map(|cache_file| std::fs::remove_file(cache_file.as_path()));
- }
+/// Read a file from the cache, also checking that its hash is valid.
+fn read_cache_file(path: &Path, hash: &Hash) -> Result<Typed, Error> {
+ let data = crate::utils::read_binary_file(path)?;
- // Side effect since we don't use the result
- fn save_expr(&self, import: &Import, expr: &Expr) {
- self.cache_file(import)
- .map(|cache_file| save_expr(cache_file.as_path(), expr));
+ match hash {
+ Hash::SHA256(hash) => {
+ let actual_hash = crate::utils::sha256_hash(&data);
+ if hash[..] != actual_hash[..] {
+ return Err(CacheError::CacheHashInvalid.into());
+ }
+ }
}
- pub fn caching_import<F, R>(
- &self,
- import: &Import,
- fetcher: F,
- mut resolver: R,
- ) -> Result<TypedHir, Error>
- where
- F: FnOnce() -> Result<Parsed, Error>,
- R: FnMut(Parsed) -> Result<TypedHir, Error>,
- {
- // Lookup the cache
- self.search_cache(import)
- // On cache found
- .and_then(|cache_result| {
- // Try to resolve the cache imported content
- match cache_result.and_then(|parsed| resolver(parsed)).and_then(
- |typed_hir| {
- check_hash(import.hash.as_ref().unwrap(), typed_hir)
- },
- ) {
- // Cache content is invalid (can't be parsed / can't be resolved / content sha invalid )
- Err(_) => {
- // Delete cache file since it's invalid
- self.delete_cache(import);
- // Result as there were no cache
- None
- }
- // Cache valid
- r => Some(r),
- }
- })
- .unwrap_or_else(|| {
- // Fetch and resolve as provided
- let imported = fetcher().and_then(resolver);
- // Save in cache the result if ok
- let _ = imported.as_ref().map(|(hir, _)| {
- self.save_expr(import, &hir.to_expr_noopts())
- });
- imported
- })
- }
+ Ok(parse_binary(&data)?.skip_resolve()?.typecheck()?)
}
-fn save_expr(file_path: &Path, expr: &Expr) -> Result<(), Error> {
- File::create(file_path)?.write_all(binary::encode(expr)?.as_slice())?;
+/// Write a file to the cache.
+fn write_cache_file(path: &Path, expr: &Typed) -> Result<(), Error> {
+ let data = binary::encode(&expr.to_expr())?;
+ File::create(path)?.write_all(data.as_slice())?;
Ok(())
}
-fn check_hash(hash: &Hash, typed_hir: TypedHir) -> Result<TypedHir, Error> {
- if hash.as_ref()[..] != typed_hir.0.to_expr_alpha().hash()?[..] {
- Err(Error::new(ErrorKind::Cache(CacheError::CacheHashInvalid)))
- } else {
- Ok(typed_hir)
- }
-}
-
-fn cache_filename<A: AsRef<[u8]>>(v: A) -> String {
- format!("1220{}", hex::encode(v.as_ref()))
-}
-
-impl AsRef<[u8]> for Hash {
- fn as_ref(&self) -> &[u8] {
- match self {
- Hash::SHA256(sha) => sha.as_slice(),
- }
+fn filename_for_hash(hash: &Hash) -> String {
+ match hash {
+ Hash::SHA256(sha) => format!("1220{}", hex::encode(&sha)),
}
}
#[cfg(test)]
mod test {
use super::*;
- use crate::semantics::parse::parse_str;
- use crate::syntax::{
- parse_expr, ExprKind, ImportMode, ImportTarget, NumKind, Span,
- };
- use rand::distributions::Alphanumeric;
- use rand::Rng;
- use std::env::temp_dir;
-
- #[cfg(any(unix, windows))]
- #[test]
- fn load_cache_dir_should_result_xdg_cache_first() {
- let actual = load_cache_dir(|var| match var {
- CACHE_ENV_VAR => Ok("/home/user/custom".to_string()),
- _ => Err(VarError::NotPresent),
- });
- assert_eq!(actual.unwrap(), PathBuf::from("/home/user/custom/dhall"));
- }
-
- #[cfg(unix)]
- #[test]
- fn load_cache_dir_should_result_alternate() {
- let actual = load_cache_dir(|var| match var {
- ALTERNATE_CACHE_ENV_VAR => Ok("/home/user".to_string()),
- _ => Err(VarError::NotPresent),
- });
- assert_eq!(actual.unwrap(), PathBuf::from("/home/user/.cache/dhall"));
- }
-
- #[test]
- fn load_cache_dir_should_result_none() {
- let actual = load_cache_dir(|_| Err(VarError::NotPresent));
- assert!(matches!(
- actual.unwrap_err(),
- CacheError::MissingConfiguration
- ));
- }
-
- #[test]
- fn new_with_provider_should_create_cache_folder() {
- let test_id = rand::thread_rng()
- .sample_iter(Alphanumeric)
- .take(36)
- .collect::<String>();
- let dir = temp_dir().join(test_id);
-
- std::fs::create_dir_all(dir.as_path()).unwrap();
-
- let actual = Cache::new_with_provider(|_| {
- Ok(dir.clone().to_str().map(String::from).unwrap())
- });
- assert_eq!(
- actual,
- Cache {
- cache_dir: Some(dir.join("dhall"))
- }
- );
- assert!(dir.join("dhall").exists());
- std::fs::remove_dir_all(dir.as_path()).unwrap();
- }
-
- #[test]
- fn new_with_provider_should_return_cache_for_existing_folder() {
- let test_id = rand::thread_rng()
- .sample_iter(Alphanumeric)
- .take(36)
- .collect::<String>();
- let dir = temp_dir().join(test_id);
-
- std::fs::create_dir_all(dir.as_path()).unwrap();
- File::create(dir.join("dhall")).unwrap();
-
- assert!(dir.join("dhall").exists());
-
- let actual = Cache::new_with_provider(|_| {
- Ok(dir.clone().to_str().map(String::from).unwrap())
- });
- assert_eq!(
- actual,
- Cache {
- cache_dir: Some(dir.join("dhall"))
- }
- );
- std::fs::remove_dir_all(dir.as_path()).unwrap();
- }
-
- #[test]
- fn caching_import_should_load_cache() -> Result<(), Error> {
- let test_id = rand::thread_rng()
- .sample_iter(Alphanumeric)
- .take(36)
- .collect::<String>();
- let dir = temp_dir().join(test_id);
-
- std::fs::create_dir_all(dir.as_path())?;
-
- let cache = Cache::new_with_provider(|_| {
- Ok(dir.clone().to_str().map(String::from).unwrap())
- });
-
- // Create cache file
- let expr =
- Expr::new(ExprKind::Num(NumKind::Natural(1)), Span::Artificial);
- File::create(dir.join("dhall").join("1220d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15"))?
- .write_all(binary::encode(&expr)?.as_ref())?;
-
- let import = Import {
- mode: ImportMode::Code,
- location: ImportTarget::Missing,
- hash: Some(Hash::SHA256(hex::decode("d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15").unwrap())),
- };
-
- let mut resolve_counter = 0;
-
- let result = cache.caching_import(
- &import,
- || panic!("Should not fetch import"),
- |parsed| {
- resolve_counter += 1;
- let result = parsed.resolve()?.typecheck()?;
- Ok((result.normalize().to_hir(), result.ty))
- },
- );
-
- assert!(result.is_ok());
- assert_eq!(resolve_counter, 1);
-
- std::fs::remove_dir_all(dir.as_path()).unwrap();
- Ok(())
- }
-
- #[test]
- fn caching_import_should_skip_cache_if_missing_cache_folder(
- ) -> Result<(), Error> {
- let cache = Cache::new_with_provider(|_| Err(VarError::NotPresent));
-
- let import = Import {
- mode: ImportMode::Code,
- location: ImportTarget::Missing,
- hash: Some(Hash::SHA256(hex::decode("d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15").unwrap())),
- };
-
- let mut resolve_counter = 0;
- let mut fetcher_counter = 0;
-
- let result = cache.caching_import(
- &import,
- || {
- fetcher_counter += 1;
- parse_str("1")
- },
- |parsed| {
- resolve_counter += 1;
- let result = parsed.resolve()?.typecheck()?;
- Ok((result.normalize().to_hir(), result.ty))
- },
- );
-
- assert!(result.is_ok(), "caching_import Should be valid");
- assert_eq!(resolve_counter, 1);
- assert_eq!(fetcher_counter, 1);
- Ok(())
- }
-
- #[test]
- fn caching_import_should_skip_cache_on_no_hash_import() -> Result<(), Error>
- {
- let cache = Cache::new_with_provider(|_| Err(VarError::NotPresent));
-
- let import = Import {
- mode: ImportMode::Code,
- location: ImportTarget::Missing,
- hash: None,
- };
-
- let mut resolve_counter = 0;
- let mut fetcher_counter = 0;
-
- let result = cache.caching_import(
- &import,
- || {
- fetcher_counter += 1;
- parse_str("1")
- },
- |parsed| {
- resolve_counter += 1;
- let result = parsed.resolve()?.typecheck()?;
- Ok((result.normalize().to_hir(), result.ty))
- },
- );
-
- assert!(result.is_ok(), "caching_import Should be valid");
- assert_eq!(resolve_counter, 1);
- assert_eq!(fetcher_counter, 1);
- Ok(())
- }
-
- #[test]
- fn caching_import_should_fetch_import_if_no_cache() -> Result<(), Error> {
- let test_id = rand::thread_rng()
- .sample_iter(Alphanumeric)
- .take(36)
- .collect::<String>();
- let dir = temp_dir().join(test_id);
-
- std::fs::create_dir_all(dir.as_path())?;
-
- let cache = Cache::new_with_provider(|_| {
- Ok(dir.clone().to_str().map(String::from).unwrap())
- });
-
- let import = Import {
- mode: ImportMode::Code,
- location: ImportTarget::Missing,
- hash: Some(Hash::SHA256(hex::decode("d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15").unwrap())),
- };
-
- let mut fetcher_counter = 0;
- let mut resolve_counter = 0;
-
- let result = cache.caching_import(
- &import,
- || {
- fetcher_counter += 1;
- parse_str("1")
- },
- |parsed| {
- resolve_counter += 1;
- let result = parsed.resolve()?.typecheck()?;
- Ok((result.normalize().to_hir(), result.ty))
- },
- );
-
- assert!(result.is_ok(), "caching_import Should be valid");
- assert_eq!(resolve_counter, 1);
- assert_eq!(fetcher_counter, 1);
-
- std::fs::remove_dir_all(dir.as_path()).unwrap();
- Ok(())
- }
-
- #[test]
- fn caching_import_should_fetch_import_on_cache_parsed_error(
- ) -> Result<(), Error> {
- let test_id = rand::thread_rng()
- .sample_iter(Alphanumeric)
- .take(36)
- .collect::<String>();
- let dir = temp_dir().join(test_id);
-
- std::fs::create_dir_all(dir.as_path())?;
-
- let cache = Cache::new_with_provider(|_| {
- Ok(dir.clone().to_str().map(String::from).unwrap())
- });
-
- File::create(dir.join("dhall").join("1220d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15"))?
- .write_all("Invalid content".as_bytes())?;
-
- let import = Import {
- mode: ImportMode::Code,
- location: ImportTarget::Missing,
- hash: Some(Hash::SHA256(hex::decode("d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15").unwrap())),
- };
-
- let mut fetcher_counter = 0;
- let mut resolve_counter = 0;
-
- let result = cache.caching_import(
- &import,
- || {
- fetcher_counter += 1;
- parse_str("1")
- },
- |parsed| {
- resolve_counter += 1;
- let result = parsed.resolve()?.typecheck()?;
- Ok((result.normalize().to_hir(), result.ty))
- },
- );
-
- assert!(result.is_ok(), "caching_import Should be valid");
- assert_eq!(fetcher_counter, 1, "Should fetch since cache is invalid");
- assert_eq!(
- resolve_counter, 1,
- "Should resolve only 1 time because cache can't be parsed"
- );
-
- std::fs::remove_dir_all(dir.as_path()).unwrap();
- Ok(())
- }
-
- #[test]
- fn caching_import_should_fetch_import_on_cache_resolve_error(
- ) -> Result<(), Error> {
- let test_id = rand::thread_rng()
- .sample_iter(Alphanumeric)
- .take(36)
- .collect::<String>();
- let dir = temp_dir().join(test_id);
-
- std::fs::create_dir_all(dir.as_path())?;
-
- let cache = Cache::new_with_provider(|_| {
- Ok(dir.clone().to_str().map(String::from).unwrap())
- });
-
- let expr =
- Expr::new(ExprKind::Num(NumKind::Natural(2)), Span::Artificial);
- File::create(dir.join("dhall").join("1220d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15"))?
- .write_all(binary::encode(&expr)?.as_slice())?;
-
- let import = Import {
- mode: ImportMode::Code,
- location: ImportTarget::Missing,
- hash: Some(Hash::SHA256(hex::decode("d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15").unwrap())),
- };
-
- let mut fetcher_counter = 0;
- let mut resolve_counter = 0;
-
- let result = cache.caching_import(
- &import,
- || {
- fetcher_counter += 1;
- parse_str("1")
- },
- |parsed| {
- resolve_counter += 1;
- match resolve_counter {
- 1 => Err(Error::new(ErrorKind::Cache(
- CacheError::CacheHashInvalid,
- ))),
- _ => {
- let result = parsed.resolve()?.typecheck()?;
- Ok((result.normalize().to_hir(), result.ty))
- }
- }
- },
- );
-
- assert!(result.is_ok(), "caching_import Should be valid");
- assert_eq!(fetcher_counter, 1, "Should fetch since cache is invalid");
- assert_eq!(
- resolve_counter, 2,
- "Should resolve 2 time (one for cache that fail, one for fetch)"
- );
-
- std::fs::remove_dir_all(dir.as_path()).unwrap();
- Ok(())
- }
-
- #[test]
- fn caching_import_should_fetch_import_on_invalid_hash_cache_content(
- ) -> Result<(), Error> {
- let test_id = rand::thread_rng()
- .sample_iter(Alphanumeric)
- .take(36)
- .collect::<String>();
- let dir = temp_dir().join(test_id);
-
- std::fs::create_dir_all(dir.as_path())?;
-
- let cache = Cache::new_with_provider(|_| {
- Ok(dir.clone().to_str().map(String::from).unwrap())
- });
-
- let expr =
- Expr::new(ExprKind::Num(NumKind::Natural(2)), Span::Artificial);
- File::create(dir.join("dhall").join("1220d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15"))?
- .write_all(binary::encode(&expr)?.as_slice())?;
-
- let import = Import {
- mode: ImportMode::Code,
- location: ImportTarget::Missing,
- hash: Some(Hash::SHA256(hex::decode("d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15").unwrap())),
- };
-
- let mut fetcher_counter = 0;
- let mut resolve_counter = 0;
-
- let result = cache.caching_import(
- &import,
- || {
- fetcher_counter += 1;
- parse_str("1")
- },
- |parsed| {
- resolve_counter += 1;
- let result = parsed.resolve()?.typecheck()?;
- Ok((result.normalize().to_hir(), result.ty))
- },
- );
-
- assert!(result.is_ok(), "caching_import Should be valid");
- assert_eq!(fetcher_counter, 1, "Should fetch since cache is invalid");
- assert_eq!(
- resolve_counter, 2,
- "Should resolve 2 time (one for cache, one for fetch)"
- );
-
- std::fs::remove_dir_all(dir.as_path()).unwrap();
- Ok(())
- }
-
- #[test]
- fn caching_import_should_save_import_if_missing() -> Result<(), Error> {
- let test_id = rand::thread_rng()
- .sample_iter(Alphanumeric)
- .take(36)
- .collect::<String>();
- let dir = temp_dir().join(test_id);
-
- std::fs::create_dir_all(dir.as_path())?;
-
- let cache = Cache::new_with_provider(|_| {
- Ok(dir.clone().to_str().map(String::from).unwrap())
- });
- let import = Import {
- mode: ImportMode::Code,
- location: ImportTarget::Missing,
- hash: Some(Hash::SHA256(hex::decode("d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15").unwrap())),
- };
-
- let mut fetcher_counter = 0;
- let mut resolve_counter = 0;
-
- let result = cache.caching_import(
- &import,
- || {
- fetcher_counter += 1;
- parse_str("1")
- },
- |parsed| {
- resolve_counter += 1;
- let result = parsed.resolve()?.typecheck()?;
- Ok((result.normalize().to_hir(), result.ty))
- },
- );
-
- assert!(result.is_ok(), "caching_import Should be valid");
- assert_eq!(fetcher_counter, 1, "Should fetch since cache is mising");
- assert_eq!(resolve_counter, 1, "Should resolve 1 time");
-
- let cache_file = dir.join("dhall").join("1220d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15");
- assert!(cache_file.exists());
-
- std::fs::remove_dir_all(dir.as_path()).unwrap();
- Ok(())
- }
+ use crate::syntax::parse_expr;
#[test]
- fn cache_filename_should_result_for_hash() {
+ fn filename_for_hash_should_work() {
let hash =
- Hash::SHA256(parse_expr("1").unwrap().hash().unwrap().into_vec());
- assert_eq!("1220d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15".to_string(), cache_filename(hash));
- }
-
- #[test]
- fn check_hash_should_be_ok_for_same_hash() -> Result<(), Error> {
- let typed = parse_str("1")?.resolve()?.typecheck()?;
- let hash = Hash::SHA256(parse_expr("1")?.hash()?.into_vec());
-
- let expected = (typed.normalize().to_hir(), typed.ty);
- let actual = check_hash(&hash, expected.clone());
- assert_eq!(actual.unwrap(), expected);
- Ok(())
- }
-
- #[test]
- fn check_hash_should_be_ok_for_unmatching_hash() -> Result<(), Error> {
- let typed = parse_str("1")?.resolve()?.typecheck()?;
- let hash = Hash::SHA256(parse_expr("2")?.hash()?.into_vec());
-
- let expected = (typed.normalize().to_hir(), typed.ty);
- let actual = check_hash(&hash, expected);
- assert!(actual.is_err());
- Ok(())
+ Hash::SHA256(parse_expr("1").unwrap().sha256_hash().unwrap());
+ assert_eq!("1220d60d8415e36e86dae7f42933d3b0c4fe3ca238f057fba206c7e9fbf5d784fe15".to_string(), filename_for_hash(&hash));
}
}
diff --git a/dhall/src/semantics/resolve/env.rs b/dhall/src/semantics/resolve/env.rs
index 6346a6d..29dd16b 100644
--- a/dhall/src/semantics/resolve/env.rs
+++ b/dhall/src/semantics/resolve/env.rs
@@ -1,8 +1,9 @@
use std::collections::HashMap;
use crate::error::{Error, ImportError};
-use crate::semantics::{AlphaVar, ImportLocation, TypedHir, VarEnv};
-use crate::syntax::{Label, V};
+use crate::semantics::{AlphaVar, Cache, ImportLocation, VarEnv};
+use crate::syntax::{Hash, Label, V};
+use crate::Typed;
/// Environment for resolving names.
#[derive(Debug, Clone, Default)]
@@ -10,14 +11,15 @@ pub struct NameEnv {
names: Vec<Label>,
}
-pub type ImportCache = HashMap<ImportLocation, TypedHir>;
-pub type ImportStack = Vec<ImportLocation>;
+pub type MemCache = HashMap<ImportLocation, Typed>;
+pub type CyclesStack = Vec<ImportLocation>;
/// Environment for resolving imports
-#[derive(Debug, Clone, Default)]
+#[derive(Debug)]
pub struct ImportEnv {
- cache: ImportCache,
- stack: ImportStack,
+ disk_cache: Option<Cache>, // Missing if it failed to initialize
+ mem_cache: MemCache,
+ stack: CyclesStack,
}
impl NameEnv {
@@ -66,38 +68,62 @@ impl NameEnv {
impl ImportEnv {
pub fn new() -> Self {
- ImportEnv::default()
+ ImportEnv {
+ disk_cache: Cache::new().ok(),
+ mem_cache: Default::default(),
+ stack: Default::default(),
+ }
+ }
+
+ pub fn get_from_mem_cache(
+ &mut self,
+ location: &ImportLocation,
+ ) -> Option<Typed> {
+ Some(self.mem_cache.get(location)?.clone())
+ }
+
+ pub fn get_from_disk_cache(
+ &mut self,
+ hash: &Option<Hash>,
+ ) -> Option<Typed> {
+ let hash = hash.as_ref()?;
+ let expr = self.disk_cache.as_ref()?.get(hash).ok()?;
+ Some(expr)
+ }
+
+ pub fn write_to_mem_cache(
+ &mut self,
+ location: ImportLocation,
+ expr: Typed,
+ ) {
+ self.mem_cache.insert(location, expr);
}
- pub fn handle_import(
+ pub fn write_to_disk_cache(&mut self, hash: &Option<Hash>, expr: &Typed) {
+ if let Some(disk_cache) = self.disk_cache.as_ref() {
+ if let Some(hash) = hash {
+ let _ = disk_cache.insert(hash, &expr);
+ }
+ }
+ }
+
+ pub fn with_cycle_detection(
&mut self,
- mut location: ImportLocation,
- do_resolve: impl FnOnce(&mut Self) -> Result<TypedHir, Error>,
- ) -> Result<TypedHir, Error> {
+ location: ImportLocation,
+ do_resolve: impl FnOnce(&mut Self) -> Result<Typed, Error>,
+ ) -> Result<Typed, Error> {
if self.stack.contains(&location) {
return Err(
ImportError::ImportCycle(self.stack.clone(), location).into()
);
}
- Ok(match self.cache.get(&location) {
- Some(expr) => expr.clone(),
- None => {
- let expr = {
- // Push the current location on the stack
- self.stack.push(location);
- // Resolve the import recursively
- // WARNING: do not propagate errors here or the stack will get messed up.
- let result = do_resolve(self);
- // Remove location from the stack.
- location = self.stack.pop().unwrap();
- result
- }?;
-
- // Add the resolved import to the cache
- self.cache.insert(location, expr.clone());
-
- expr
- }
- })
+ // Push the current location on the stack
+ self.stack.push(location);
+ // Resolve the import recursively
+ // WARNING: do not propagate errors here or the stack will get messed up.
+ let result = do_resolve(self);
+ // Remove location from the stack.
+ self.stack.pop().unwrap();
+ result
}
}
diff --git a/dhall/src/semantics/resolve/resolve.rs b/dhall/src/semantics/resolve/resolve.rs
index 2b401dc..614ea22 100644
--- a/dhall/src/semantics/resolve/resolve.rs
+++ b/dhall/src/semantics/resolve/resolve.rs
@@ -10,20 +10,17 @@ use crate::builtins::Builtin;
use crate::error::ErrorBuilder;
use crate::error::{Error, ImportError};
use crate::operations::{BinOp, OpKind};
-use crate::semantics::{mkerr, Cache, Hir, HirKind, ImportEnv, NameEnv, Type};
+use crate::semantics::{mkerr, Hir, HirKind, ImportEnv, NameEnv, Type};
use crate::syntax;
use crate::syntax::{
Expr, ExprKind, FilePath, FilePrefix, Hash, ImportMode, ImportTarget,
Label, Span, UnspannedExpr, URL,
};
-use crate::{Parsed, Resolved};
+use crate::{Parsed, Resolved, Typed};
// TODO: evaluate import headers
pub type Import = syntax::Import<()>;
-/// Owned Hir with a type. Different from Tir because the Hir is owned.
-pub type TypedHir = (Hir, Type);
-
/// The location of some data, usually some dhall code.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum ImportLocation {
@@ -220,65 +217,55 @@ fn make_aslocation_uniontype() -> Expr {
mkexpr(ExprKind::UnionType(union))
}
+fn check_hash(import: &Import, typed: &Typed, span: Span) -> Result<(), Error> {
+ match (import.mode, &import.hash) {
+ (ImportMode::Code, Some(Hash::SHA256(hash))) => {
+ let actual_hash = typed.hir.to_expr_alpha().sha256_hash()?;
+ if hash[..] != actual_hash[..] {
+ mkerr(
+ ErrorBuilder::new("hash mismatch")
+ .span_err(span, "hash mismatch")
+ .note(format!("Expected sha256:{}", hex::encode(hash)))
+ .note(format!(
+ "Found sha256:{}",
+ hex::encode(actual_hash)
+ ))
+ .format(),
+ )?
+ }
+ }
+ _ => {}
+ }
+ Ok(())
+}
+
fn resolve_one_import(
env: &mut ImportEnv,
- cache: &Cache,
import: &Import,
- location: &ImportLocation,
+ location: ImportLocation,
span: Span,
-) -> Result<TypedHir, Error> {
- let do_sanity_check = import.mode != ImportMode::Location;
- let location = location.chain(&import.location, do_sanity_check)?;
- env.handle_import(location.clone(), |env| match import.mode {
+) -> Result<Typed, Error> {
+ let (hir, ty) = match import.mode {
ImportMode::Code => {
- let (hir, ty) = cache.caching_import(
- import,
- || location.fetch_dhall(),
- |parsed| {
- let typed =
- resolve_with_env(env, cache, parsed)?.typecheck()?;
- let hir = typed.normalize().to_hir();
- Ok((hir, typed.ty))
- },
- )?;
- match &import.hash {
- Some(Hash::SHA256(hash)) => {
- let actual_hash = hir.to_expr_alpha().hash()?;
- if hash[..] != actual_hash[..] {
- mkerr(
- ErrorBuilder::new("hash mismatch")
- .span_err(span, "hash mismatch")
- .note(format!(
- "Expected sha256:{}",
- hex::encode(hash)
- ))
- .note(format!(
- "Found sha256:{}",
- hex::encode(actual_hash)
- ))
- .format(),
- )?
- }
- }
- None => {}
- }
- Ok((hir, ty))
+ let parsed = location.fetch_dhall()?;
+ let typed = resolve_with_env(env, parsed)?.typecheck()?;
+ let hir = typed.normalize().to_hir();
+ (hir, typed.ty)
}
ImportMode::RawText => {
let text = location.fetch_text()?;
- let hir = Hir::new(
- HirKind::Expr(ExprKind::TextLit(text.into())),
- Span::Artificial,
- );
- Ok((hir, Type::from_builtin(Builtin::Text)))
+ let hir =
+ Hir::new(HirKind::Expr(ExprKind::TextLit(text.into())), span);
+ (hir, Type::from_builtin(Builtin::Text))
}
ImportMode::Location => {
let expr = location.into_location();
let hir = skip_resolve_expr(&expr)?;
let ty = hir.typecheck_noenv()?.ty().clone();
- Ok((hir, ty))
+ (hir, ty)
}
- })
+ };
+ Ok(Typed { hir, ty })
}
/// Desugar a `with` expression.
@@ -342,7 +329,7 @@ fn desugar(expr: &Expr) -> Cow<'_, Expr> {
fn traverse_resolve_expr(
name_env: &mut NameEnv,
expr: &Expr,
- f: &mut impl FnMut(Import, Span) -> Result<TypedHir, Error>,
+ f: &mut impl FnMut(Import, Span) -> Result<Typed, Error>,
) -> Result<Hir, Error> {
let expr = desugar(expr);
Ok(match expr.kind() {
@@ -382,7 +369,7 @@ fn traverse_resolve_expr(
// TODO: evaluate import headers
let import = import.traverse_ref(|_| Ok::<_, Error>(()))?;
let imported = f(import, expr.span())?;
- HirKind::Import(imported.0, imported.1)
+ HirKind::Import(imported.hir, imported.ty)
}
kind => HirKind::Expr(kind),
};
@@ -393,23 +380,53 @@ fn traverse_resolve_expr(
fn resolve_with_env(
env: &mut ImportEnv,
- cache: &Cache,
parsed: Parsed,
) -> Result<Resolved, Error> {
- let Parsed(expr, location) = parsed;
+ let Parsed(expr, base_location) = parsed;
let resolved = traverse_resolve_expr(
&mut NameEnv::new(),
&expr,
&mut |import, span| {
- resolve_one_import(env, cache, &import, &location, span)
+ let do_sanity_check = import.mode != ImportMode::Location;
+ let location =
+ base_location.chain(&import.location, do_sanity_check)?;
+
+ // If the import is in the in-memory cache, or the hash is in the on-disk cache, return
+ // the cached contents.
+ if let Some(typed) = env.get_from_mem_cache(&location) {
+ // The same location may be used with different or no hashes. Thus we need to check
+ // the hashes every time.
+ check_hash(&import, &typed, span)?;
+ env.write_to_disk_cache(&import.hash, &typed);
+ return Ok(typed);
+ }
+ if let Some(typed) = env.get_from_disk_cache(&import.hash) {
+ // No need to check the hash, it was checked before reading the file. We also don't
+ // write to the in-memory cache, because the location might be completely unrelated
+ // to the cached file (e.g. `missing sha256:...` is valid).
+ // This actually means that importing many times a same hashed import will take
+ // longer than importing many times a same non-hashed import.
+ return Ok(typed);
+ }
+
+ // Resolve this import, making sure that recursive imports don't cycle back to the
+ // current one.
+ let typed = env.with_cycle_detection(location.clone(), |env| {
+ resolve_one_import(env, &import, location.clone(), span.clone())
+ })?;
+
+ // Add the resolved import to the caches
+ check_hash(&import, &typed, span)?;
+ env.write_to_disk_cache(&import.hash, &typed);
+ env.write_to_mem_cache(location, typed.clone());
+ Ok(typed)
},
)?;
Ok(Resolved(resolved))
}
pub fn resolve(parsed: Parsed) -> Result<Resolved, Error> {
- let cache = Cache::new();
- resolve_with_env(&mut ImportEnv::new(), &cache, parsed)
+ resolve_with_env(&mut ImportEnv::new(), parsed)
}
pub fn skip_resolve_expr(expr: &Expr) -> Result<Hir, Error> {
diff --git a/dhall/src/syntax/ast/expr.rs b/dhall/src/syntax/ast/expr.rs
index b1a978f..eba2735 100644
--- a/dhall/src/syntax/ast/expr.rs
+++ b/dhall/src/syntax/ast/expr.rs
@@ -178,10 +178,9 @@ impl Expr {
}
// Compute the sha256 hash of the binary form of the expression.
- pub fn hash(&self) -> Result<Box<[u8]>, Error> {
- use sha2::Digest;
+ pub fn sha256_hash(&self) -> Result<Box<[u8]>, Error> {
let data = binary::encode(self)?;
- Ok(sha2::Sha256::digest(&data).as_slice().into())
+ Ok(crate::utils::sha256_hash(&data))
}
}
diff --git a/dhall/src/syntax/ast/import.rs b/dhall/src/syntax/ast/import.rs
index c45fe51..69f4021 100644
--- a/dhall/src/syntax/ast/import.rs
+++ b/dhall/src/syntax/ast/import.rs
@@ -52,7 +52,7 @@ pub enum ImportMode {
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum Hash {
- SHA256(Vec<u8>),
+ SHA256(Box<[u8]>),
}
/// Reference to an external resource
diff --git a/dhall/src/syntax/binary/decode.rs b/dhall/src/syntax/binary/decode.rs
index f4747d3..4ea7d98 100644
--- a/dhall/src/syntax/binary/decode.rs
+++ b/dhall/src/syntax/binary/decode.rs
@@ -290,7 +290,7 @@ fn cbor_value_to_dhall(data: &Value) -> Result<DecodedExpr, DecodeError> {
Null => None,
Bytes(bytes) => match bytes.as_slice() {
[18, 32, rest @ ..] => {
- Some(Hash::SHA256(rest.to_vec()))
+ Some(Hash::SHA256(rest.to_vec().into()))
}
_ => {
return Err(DecodeError::WrongFormatError(format!(
diff --git a/dhall/src/syntax/text/parser.rs b/dhall/src/syntax/text/parser.rs
index 37f28e5..07921b5 100644
--- a/dhall/src/syntax/text/parser.rs
+++ b/dhall/src/syntax/text/parser.rs
@@ -593,7 +593,7 @@ impl DhallParser {
input.error(format!("Unknown hashing protocol '{}'", protocol))
);
}
- Ok(Hash::SHA256(hex::decode(hash).unwrap()))
+ Ok(Hash::SHA256(hex::decode(hash).unwrap().into()))
}
fn import_hashed(
diff --git a/dhall/src/utils.rs b/dhall/src/utils.rs
new file mode 100644
index 0000000..d1e642a
--- /dev/null
+++ b/dhall/src/utils.rs
@@ -0,0 +1,17 @@
+use std::fs::File;
+use std::io::Read;
+use std::path::Path;
+
+use crate::error::Error;
+
+// Compute the sha256 hash of a bitstring.
+pub fn sha256_hash(data: &[u8]) -> Box<[u8]> {
+ use sha2::Digest;
+ sha2::Sha256::digest(data).as_slice().into()
+}
+
+pub fn read_binary_file(path: impl AsRef<Path>) -> Result<Box<[u8]>, Error> {
+ let mut buffer = Vec::new();
+ File::open(path)?.read_to_end(&mut buffer)?;
+ Ok(buffer.into())
+}