1 files changed, 268 insertions, 0 deletions
diff --git a/cli/npm/cache_dir.rs b/cli/npm/cache_dir.rs
new file mode 100644
index 000000000..b0d049047
--- /dev/null
+++ b/cli/npm/cache_dir.rs
@@ -0,0 +1,268 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+use std::path::Path;
+use std::path::PathBuf;
+
+use deno_ast::ModuleSpecifier;
+use deno_core::anyhow::Context;
+use deno_core::error::AnyError;
+use deno_core::url::Url;
+use deno_npm::NpmPackageCacheFolderId;
+use deno_semver::package::PackageNv;
+use deno_semver::Version;
+
+use crate::util::fs::canonicalize_path;
+use crate::util::path::root_url_to_safe_local_dirname;
+
+/// The global cache directory of npm packages.
+#[derive(Clone, Debug)]
+pub struct NpmCacheDir {
+  root_dir: PathBuf,
+  // cached url representation of the root directory
+  root_dir_url: Url,
+}
+
+impl NpmCacheDir {
+  pub fn new(root_dir: PathBuf) -> Self {
+    fn try_get_canonicalized_root_dir(
+      root_dir: &Path,
+    ) -> Result<PathBuf, AnyError> {
+      if !root_dir.exists() {
+        std::fs::create_dir_all(root_dir)
+          .with_context(|| format!("Error creating {}", root_dir.display()))?;
+      }
+      Ok(canonicalize_path(root_dir)?)
+    }
+
+    // this may fail on readonly file systems, so just ignore if so
+    let root_dir =
+      try_get_canonicalized_root_dir(&root_dir).unwrap_or(root_dir);
+    let root_dir_url = Url::from_directory_path(&root_dir).unwrap();
+    Self {
+      root_dir,
+      root_dir_url,
+    }
+  }
+
+  pub fn root_dir_url(&self) -> &Url {
+    &self.root_dir_url
+  }
+
+  pub fn package_folder_for_id(
+    &self,
+    folder_id: &NpmPackageCacheFolderId,
+    registry_url: &Url,
+  ) -> PathBuf {
+    if folder_id.copy_index == 0 {
+      self.package_folder_for_name_and_version(&folder_id.nv, registry_url)
+    } else {
+      self
+        .package_name_folder(&folder_id.nv.name, registry_url)
+        .join(format!("{}_{}", folder_id.nv.version, folder_id.copy_index))
+    }
+  }
+
+  pub fn package_folder_for_name_and_version(
+    &self,
+    package: &PackageNv,
+    registry_url: &Url,
+  ) -> PathBuf {
+    self
+      .package_name_folder(&package.name, registry_url)
+      .join(package.version.to_string())
+  }
+
+  pub fn package_name_folder(&self, name: &str, registry_url: &Url) -> PathBuf {
+    let mut dir = self.registry_folder(registry_url);
+    if name.to_lowercase() != name {
+      let encoded_name = mixed_case_package_name_encode(name);
+      // Using the encoded directory may have a collision with an actual package name
+      // so prefix it with an underscore since npm packages can't start with that
+      dir.join(format!("_{encoded_name}"))
+    } else {
+      // ensure backslashes are used on windows
+      for part in name.split('/') {
+        dir = dir.join(part);
+      }
+      dir
+    }
+  }
+
+  pub fn registry_folder(&self, registry_url: &Url) -> PathBuf {
+    self
+      .root_dir
+      .join(root_url_to_safe_local_dirname(registry_url))
+  }
+
+  pub fn resolve_package_folder_id_from_specifier(
+    &self,
+    specifier: &ModuleSpecifier,
+    registry_url: &Url,
+  ) -> Option<NpmPackageCacheFolderId> {
+    let registry_root_dir = self
+      .root_dir_url
+      .join(&format!(
+        "{}/",
+        root_url_to_safe_local_dirname(registry_url)
+          .to_string_lossy()
+          .replace('\\', "/")
+      ))
+      // this not succeeding indicates a fatal issue, so unwrap
+      .unwrap();
+    let mut relative_url = registry_root_dir.make_relative(specifier)?;
+    if relative_url.starts_with("../") {
+      return None;
+    }
+
+    // base32 decode the url if it starts with an underscore
+    // * Ex. _{base32(package_name)}/
+    if let Some(end_url) = relative_url.strip_prefix('_') {
+      let mut parts = end_url
+        .split('/')
+        .map(ToOwned::to_owned)
+        .collect::<Vec<_>>();
+      match mixed_case_package_name_decode(&parts[0]) {
+        Some(part) => {
+          parts[0] = part;
+        }
+        None => return None,
+      }
+      relative_url = parts.join("/");
+    }
+
+    // examples:
+    // * chalk/5.0.1/
+    // * @types/chalk/5.0.1/
+    // * some-package/5.0.1_1/ -- where the `_1` (/_\d+/) is a copy of the folder for peer deps
+    let is_scoped_package = relative_url.starts_with('@');
+    let mut parts = relative_url
+      .split('/')
+      .enumerate()
+      .take(if is_scoped_package { 3 } else { 2 })
+      .map(|(_, part)| part)
+      .collect::<Vec<_>>();
+    if parts.len() < 2 {
+      return None;
+    }
+    let version_part = parts.pop().unwrap();
+    let name = parts.join("/");
+    let (version, copy_index) =
+      if let Some((version, copy_count)) = version_part.split_once('_') {
+        (version, copy_count.parse::<u8>().ok()?)
+      } else {
+        (version_part, 0)
+      };
+    Some(NpmPackageCacheFolderId {
+      nv: PackageNv {
+        name,
+        version: Version::parse_from_npm(version).ok()?,
+      },
+      copy_index,
+    })
+  }
+
+  pub fn get_cache_location(&self) -> PathBuf {
+    self.root_dir.clone()
+  }
+}
+
+pub fn mixed_case_package_name_encode(name: &str) -> String {
+  // use base32 encoding because it's reversible and the character set
+  // only includes the characters within 0-9 and A-Z so it can be lower cased
+  base32::encode(
+    base32::Alphabet::RFC4648 { padding: false },
+    name.as_bytes(),
+  )
+  .to_lowercase()
+}
+
+pub fn mixed_case_package_name_decode(name: &str) -> Option<String> {
+  base32::decode(base32::Alphabet::RFC4648 { padding: false }, name)
+    .and_then(|b| String::from_utf8(b).ok())
+}
+
+#[cfg(test)]
+mod test {
+  use deno_core::url::Url;
+  use deno_semver::package::PackageNv;
+  use deno_semver::Version;
+
+  use super::NpmCacheDir;
+  use crate::npm::cache_dir::NpmPackageCacheFolderId;
+
+  #[test]
+  fn should_get_package_folder() {
+    let deno_dir = crate::cache::DenoDir::new(None).unwrap();
+    let root_dir = deno_dir.npm_folder_path();
+    let cache = NpmCacheDir::new(root_dir.clone());
+    let registry_url = Url::parse("https://registry.npmjs.org/").unwrap();
+
+    assert_eq!(
+      cache.package_folder_for_id(
+        &NpmPackageCacheFolderId {
+          nv: PackageNv {
+            name: "json".to_string(),
+            version: Version::parse_from_npm("1.2.5").unwrap(),
+          },
+          copy_index: 0,
+        },
+        &registry_url,
+      ),
+      root_dir
+        .join("registry.npmjs.org")
+        .join("json")
+        .join("1.2.5"),
+    );
+
+    assert_eq!(
+      cache.package_folder_for_id(
+        &NpmPackageCacheFolderId {
+          nv: PackageNv {
+            name: "json".to_string(),
+            version: Version::parse_from_npm("1.2.5").unwrap(),
+          },
+          copy_index: 1,
+        },
+        &registry_url,
+      ),
+      root_dir
+        .join("registry.npmjs.org")
+        .join("json")
+        .join("1.2.5_1"),
+    );
+
+    assert_eq!(
+      cache.package_folder_for_id(
+        &NpmPackageCacheFolderId {
+          nv: PackageNv {
+            name: "JSON".to_string(),
+            version: Version::parse_from_npm("2.1.5").unwrap(),
+          },
+          copy_index: 0,
+        },
+        &registry_url,
+      ),
+      root_dir
+        .join("registry.npmjs.org")
+        .join("_jjju6tq")
+        .join("2.1.5"),
+    );
+
+    assert_eq!(
+      cache.package_folder_for_id(
+        &NpmPackageCacheFolderId {
+          nv: PackageNv {
+            name: "@types/JSON".to_string(),
+            version: Version::parse_from_npm("2.1.5").unwrap(),
+          },
+          copy_index: 0,
+        },
+        &registry_url,
+      ),
+      root_dir
+        .join("registry.npmjs.org")
+        .join("_ib2hs4dfomxuuu2pjy")
+        .join("2.1.5"),
+    );
+  }
+}