Implement CodeCache

1 files changed, 402 insertions, 0 deletions

diff --git a/src/deno_dir.rs b/src/deno_dir.rs
new file mode 100644
index 000000000..ba25c1d8e
--- /dev/null
+++ b/src/deno_dir.rs
@@ -0,0 +1,402 @@
+// Copyright 2018 the Deno authors. All rights reserved. MIT license.
+use fs;
+use sha1;
+use std;
+use std::error::Error;
+use std::fs::File;
+use std::io::Write;
+use std::path::Path;
+use std::path::PathBuf;
+use std::result::Result;
+use url;
+use url::Url;
+
+#[cfg(test)]
+use tempfile::TempDir;
+
+pub struct DenoDir {
+  // Example: /Users/rld/.deno/
+  pub root: PathBuf,
+  // In the Go code this was called SrcDir.
+  // This is where we cache http resources. Example:
+  // /Users/rld/.deno/deps/github.com/ry/blah.js
+  pub gen: PathBuf,
+  // In the Go code this was called CacheDir.
+  // This is where we cache compilation outputs. Example:
+  // /Users/rld/.deno/gen/f39a473452321cacd7c346a870efb0e3e1264b43.js
+  pub deps: PathBuf,
+}
+
+impl DenoDir {
+  // Must be called before using any function from this module.
+  // https://github.com/ry/deno/blob/golang/deno_dir.go#L99-L111
+  pub fn new(custom_root: Option<&Path>) -> std::io::Result<DenoDir> {
+    // Only setup once.
+    let home_dir = std::env::home_dir().expect("Could not get home directory.");
+    let default = home_dir.join(".deno");
+
+    let root: PathBuf = match custom_root {
+      None => default,
+      Some(path) => path.to_path_buf(),
+    };
+    let gen = root.as_path().join("gen");
+    let deps = root.as_path().join("deps");
+
+    let deno_dir = DenoDir { root, gen, deps };
+    fs::mkdir(deno_dir.gen.as_ref())?;
+    fs::mkdir(deno_dir.deps.as_ref())?;
+
+    debug!("root {}", deno_dir.root.display());
+    debug!("gen {}", deno_dir.gen.display());
+    debug!("deps {}", deno_dir.deps.display());
+
+    Ok(deno_dir)
+  }
+
+  // https://github.com/ry/deno/blob/golang/deno_dir.go#L32-L35
+  pub fn cache_path(
+    self: &DenoDir,
+    filename: &str,
+    source_code: &str,
+  ) -> PathBuf {
+    let cache_key = source_code_hash(filename, source_code);
+    self.gen.join(cache_key + ".js")
+  }
+
+  fn load_cache(
+    self: &DenoDir,
+    filename: &str,
+    source_code: &str,
+  ) -> std::io::Result<String> {
+    let path = self.cache_path(filename, source_code);
+    debug!("load_cache {}", path.display());
+    fs::read_file_sync(&path)
+  }
+
+  pub fn code_cache(
+    self: &DenoDir,
+    filename: &str,
+    source_code: &str,
+    output_code: &str,
+  ) -> std::io::Result<()> {
+    let cache_path = self.cache_path(filename, source_code);
+    // TODO(ry) This is a race condition w.r.t to exists() -- probably should
+    // create the file in exclusive mode. A worry is what might happen is there
+    // are two processes and one reads the cache file while the other is in the
+    // midst of writing it.
+    if cache_path.exists() {
+      Ok(())
+    } else {
+      let mut file = File::create(cache_path)?;
+      file.write_all(output_code.as_bytes())?;
+      Ok(())
+    }
+  }
+
+  pub fn code_fetch(
+    self: &DenoDir,
+    module_specifier: &str,
+    containing_file: &str,
+  ) -> Result<CodeFetchOutput, Box<Error>> {
+    let (module_name, filename) =
+      self.resolve_module(module_specifier, containing_file)?;
+
+    debug!(
+            "code_fetch. module_name = {} module_specifier = {} containing_file = {} filename = {}",
+            module_name, module_specifier, containing_file, filename
+        );
+
+    let out = get_source_code(module_name.as_str(), filename.as_str())
+      .and_then(|source_code| {
+        Ok(CodeFetchOutput {
+          module_name,
+          filename,
+          source_code,
+          maybe_output_code: None,
+        })
+      })?;
+
+    let result =
+      self.load_cache(out.filename.as_str(), out.source_code.as_str());
+    match result {
+      Err(err) => {
+        if err.kind() == std::io::ErrorKind::NotFound {
+          Ok(out)
+        } else {
+          Err(err.into())
+        }
+      }
+      Ok(output_code) => Ok(CodeFetchOutput {
+        module_name: out.module_name,
+        filename: out.filename,
+        source_code: out.source_code,
+        maybe_output_code: Some(output_code),
+      }),
+    }
+  }
+
+  // Prototype: https://github.com/ry/deno/blob/golang/os.go#L56-L68
+  #[allow(dead_code)]
+  fn src_file_to_url<P: AsRef<Path>>(self: &DenoDir, filename: P) -> String {
+    let filename = filename.as_ref().to_path_buf();
+    if filename.starts_with(&self.deps) {
+      let rest = filename.strip_prefix(&self.deps).unwrap();
+      "http://".to_string() + rest.to_str().unwrap()
+    } else {
+      String::from(filename.to_str().unwrap())
+    }
+  }
+
+  // Prototype: https://github.com/ry/deno/blob/golang/os.go#L70-L98
+  // Returns (module name, local filename)
+  fn resolve_module(
+    self: &DenoDir,
+    module_specifier: &str,
+    containing_file: &str,
+  ) -> Result<(String, String), url::ParseError> {
+    debug!(
+      "resolve_module before module_specifier {} containing_file {}",
+      module_specifier, containing_file
+    );
+
+    //let module_specifier = src_file_to_url(module_specifier);
+    //let containing_file = src_file_to_url(containing_file);
+    //let base_url = Url::parse(&containing_file)?;
+
+    let j: Url =
+      if containing_file == "." || Path::new(module_specifier).is_absolute() {
+        Url::from_file_path(module_specifier).unwrap()
+      } else if containing_file.ends_with("/") {
+        let base = Url::from_directory_path(&containing_file).unwrap();
+        base.join(module_specifier)?
+      } else {
+        let base = Url::from_file_path(&containing_file).unwrap();
+        base.join(module_specifier)?
+      };
+
+    let mut p = j.to_file_path()
+      .unwrap()
+      .into_os_string()
+      .into_string()
+      .unwrap();
+
+    if cfg!(target_os = "windows") {
+      // On windows, replace backward slashes to forward slashes.
+      // TODO(piscisaureus): This may not me be right, I just did it to make
+      // the tests pass.
+      p = p.replace("\\", "/");
+    }
+
+    let module_name = p.to_string();
+    let filename = p.to_string();
+
+    Ok((module_name, filename))
+  }
+}
+
+#[derive(Debug)]
+pub struct CodeFetchOutput {
+  pub module_name: String,
+  pub filename: String,
+  pub source_code: String,
+  pub maybe_output_code: Option<String>,
+}
+
+#[cfg(test)]
+pub fn test_setup() -> (TempDir, DenoDir) {
+  let temp_dir = TempDir::new().expect("tempdir fail");
+  let deno_dir = DenoDir::new(Some(temp_dir.path())).expect("setup fail");
+  (temp_dir, deno_dir)
+}
+
+#[test]
+fn test_cache_path() {
+  let (temp_dir, deno_dir) = test_setup();
+  assert_eq!(
+    temp_dir
+      .path()
+      .join("gen/a3e29aece8d35a19bf9da2bb1c086af71fb36ed5.js"),
+    deno_dir.cache_path("hello.ts", "1+2")
+  );
+}
+
+#[test]
+fn test_code_cache() {
+  let (_temp_dir, deno_dir) = test_setup();
+
+  let filename = "hello.js";
+  let source_code = "1+2";
+  let output_code = "1+2 // output code";
+  let cache_path = deno_dir.cache_path(filename, source_code);
+  assert!(
+    cache_path.ends_with("gen/e8e3ee6bee4aef2ec63f6ec3db7fc5fdfae910ae.js")
+  );
+
+  let r = deno_dir.code_cache(filename, source_code, output_code);
+  r.expect("code_cache error");
+  assert!(cache_path.exists());
+  assert_eq!(output_code, fs::read_file_sync(&cache_path).unwrap());
+}
+
+// https://github.com/ry/deno/blob/golang/deno_dir.go#L25-L30
+fn source_code_hash(filename: &str, source_code: &str) -> String {
+  let mut m = sha1::Sha1::new();
+  m.update(filename.as_bytes());
+  m.update(source_code.as_bytes());
+  m.digest().to_string()
+}
+
+#[test]
+fn test_source_code_hash() {
+  assert_eq!(
+    "a3e29aece8d35a19bf9da2bb1c086af71fb36ed5",
+    source_code_hash("hello.ts", "1+2")
+  );
+  // Different source_code should result in different hash.
+  assert_eq!(
+    "914352911fc9c85170908ede3df1128d690dda41",
+    source_code_hash("hello.ts", "1")
+  );
+  // Different filename should result in different hash.
+  assert_eq!(
+    "2e396bc66101ecc642db27507048376d972b1b70",
+    source_code_hash("hi.ts", "1+2")
+  );
+}
+
+// The `add_root` macro prepends "C:" to a string if on windows; on posix
+// systems it returns the input string untouched. This is necessary because
+// `Url::from_file_path()` fails if the input path isn't an absolute path.
+#[cfg(test)]
+macro_rules! add_root {
+  ($path:expr) => {
+    if cfg!(target_os = "windows") {
+      concat!("C:", $path)
+    } else {
+      $path
+    }
+  };
+}
+
+#[test]
+fn test_code_fetch() {
+  let (_temp_dir, deno_dir) = test_setup();
+
+  let cwd = std::env::current_dir().unwrap();
+  let cwd_string = String::from(cwd.to_str().unwrap()) + "/";
+
+  // Test failure case.
+  let module_specifier = "hello.ts";
+  let containing_file = add_root!("/baddir/badfile.ts");
+  let r = deno_dir.code_fetch(module_specifier, containing_file);
+  assert!(r.is_err());
+
+  // Assuming cwd is the deno repo root.
+  let module_specifier = "./js/main.ts";
+  let containing_file = cwd_string.as_str();
+  let r = deno_dir.code_fetch(module_specifier, containing_file);
+  assert!(r.is_ok());
+  //let code_fetch_output = r.unwrap();
+  //println!("code_fetch_output {:?}", code_fetch_output);
+}
+
+#[test]
+fn test_src_file_to_url() {
+  let (_temp_dir, deno_dir) = test_setup();
+  assert_eq!("hello", deno_dir.src_file_to_url("hello"));
+  assert_eq!("/hello", deno_dir.src_file_to_url("/hello"));
+  let x = String::from(deno_dir.deps.join("hello/world.txt").to_str().unwrap());
+  assert_eq!("http://hello/world.txt", deno_dir.src_file_to_url(x));
+}
+
+// https://github.com/ry/deno/blob/golang/os_test.go#L16-L87
+#[test]
+fn test_resolve_module() {
+  let (_temp_dir, deno_dir) = test_setup();
+
+  let test_cases = [
+    (
+      "./subdir/print_hello.ts",
+      add_root!(
+        "/Users/rld/go/src/github.com/ry/deno/testdata/006_url_imports.ts"
+      ),
+      add_root!(
+        "/Users/rld/go/src/github.com/ry/deno/testdata/subdir/print_hello.ts"
+      ),
+      add_root!(
+        "/Users/rld/go/src/github.com/ry/deno/testdata/subdir/print_hello.ts"
+      ),
+    ),
+    (
+      "testdata/001_hello.js",
+      add_root!("/Users/rld/go/src/github.com/ry/deno/"),
+      add_root!("/Users/rld/go/src/github.com/ry/deno/testdata/001_hello.js"),
+      add_root!("/Users/rld/go/src/github.com/ry/deno/testdata/001_hello.js"),
+    ),
+    (
+      add_root!("/Users/rld/src/deno/hello.js"),
+      ".",
+      add_root!("/Users/rld/src/deno/hello.js"),
+      add_root!("/Users/rld/src/deno/hello.js"),
+    ),
+    (
+      add_root!("/this/module/got/imported.js"),
+      add_root!("/that/module/did/it.js"),
+      add_root!("/this/module/got/imported.js"),
+      add_root!("/this/module/got/imported.js"),
+    ),
+    /*
+        (
+            "http://localhost:4545/testdata/subdir/print_hello.ts",
+            add_root!("/Users/rld/go/src/github.com/ry/deno/testdata/006_url_imports.ts"),
+            "http://localhost:4545/testdata/subdir/print_hello.ts",
+            path.Join(SrcDir, "localhost:4545/testdata/subdir/print_hello.ts"),
+        ),
+        (
+            path.Join(SrcDir, "unpkg.com/liltest@0.0.5/index.ts"),
+            ".",
+            "http://unpkg.com/liltest@0.0.5/index.ts",
+            path.Join(SrcDir, "unpkg.com/liltest@0.0.5/index.ts"),
+        ),
+        (
+            "./util",
+            path.Join(SrcDir, "unpkg.com/liltest@0.0.5/index.ts"),
+            "http://unpkg.com/liltest@0.0.5/util",
+            path.Join(SrcDir, "unpkg.com/liltest@0.0.5/util"),
+        ),
+        */
+  ];
+  for &test in test_cases.iter() {
+    let module_specifier = String::from(test.0);
+    let containing_file = String::from(test.1);
+    let (module_name, filename) = deno_dir
+      .resolve_module(&module_specifier, &containing_file)
+      .unwrap();
+    assert_eq!(module_name, test.2);
+    assert_eq!(filename, test.3);
+  }
+}
+
+const ASSET_PREFIX: &str = "/$asset$/";
+
+fn is_remote(_module_name: &str) -> bool {
+  false
+}
+
+fn get_source_code(
+  module_name: &str,
+  filename: &str,
+) -> std::io::Result<String> {
+  if is_remote(module_name) {
+    unimplemented!();
+  } else if module_name.starts_with(ASSET_PREFIX) {
+    assert!(false, "Asset resolution should be done in JS, not Rust.");
+    unimplemented!();
+  } else {
+    assert!(
+      module_name == filename,
+      "if a module isn't remote, it should have the same filename"
+    );
+    fs::read_file_sync(Path::new(filename))
+  }
+}