rust-embed v8.11.0

#rust#proc-macro#http

git clone https://git.pyrossh.dev/rust-embed

rust macro which loads files into the rust binary at compile time during release and loads the file from the fs during dev.

6679d58 — pyrossh 2026-06-27T18:15:10+05:30 
Fix rust-embed-utils is built twice when cross-compiling
Files changed (4) hide show
  1. Cargo.toml +1 -1
  2. impl/Cargo.toml +6 -1
  3. impl/src/lib.rs +24 -8
  4. utils/src/lib.rs +7 -24
Cargo.toml CHANGED
@@ -93,7 +93,7 @@ sha2 = "0.10"
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  debug-embed = ["rust-embed-impl/debug-embed", "rust-embed-utils/debug-embed"]
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  interpolate-folder-path = ["rust-embed-impl/interpolate-folder-path"]
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  compression = ["rust-embed-impl/compression", "include-flate"]
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- mime-guess = ["rust-embed-impl/mime-guess", "rust-embed-utils/mime-guess"]
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+ mime-guess = ["rust-embed-utils/mime-guess"]
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  include-exclude = [
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  "rust-embed-impl/include-exclude",
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  "rust-embed-utils/include-exclude",
impl/Cargo.toml CHANGED
@@ -17,6 +17,12 @@ proc-macro = true
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  [dependencies]
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  rust-embed-utils = { version = "8.11.0", path = "../utils" }
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+ # Unconditional (host-only, this is a proc-macro crate) so that the `__mimetype_of`
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+ # proc macro can always compute a mimetype regardless of how the `mime-guess`
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+ # feature resolves for the host. Whether the result is actually used is decided
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+ # target-side by the `__rust_embed_metadata!` macro in `rust-embed-utils`.
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+ mime_guess = "2.0.4"
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+
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  syn = { version = "2", default-features = false, features = [
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  "derive",
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  "parsing",
@@ -35,6 +41,5 @@ optional = true
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  debug-embed = []
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  interpolate-folder-path = ["shellexpand"]
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  compression = []
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- mime-guess = ["rust-embed-utils/mime-guess"]
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  include-exclude = ["rust-embed-utils/include-exclude"]
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  deterministic-timestamps = []
impl/src/lib.rs CHANGED
@@ -276,13 +276,6 @@ fn embed_file(
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  };
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  (last_modified, created)
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  };
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- // Always compute and emit the mimetype, without branching on this crate's own
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- // `mime-guess` feature. This crate is a proc-macro compiled for the host, so
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- // its features are resolved independently of the target the generated code is
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- // compiled into. The decision of whether to keep the mimetype is made
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- // target-side by the `__rust_embed_metadata!` macro in `rust-embed-utils`.
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- let mimetype = rust_embed_utils::_mimetype_of(Path::new(full_canonical_path));
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-
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  let embedding_code = if metadata_only {
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  quote! {
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  const BYTES: &'static [u8] = &[];
@@ -311,7 +304,12 @@ fn embed_file(
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  #crate_path::EmbeddedFile {
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  data: ::std::borrow::Cow::Borrowed(&BYTES),
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+ // The mimetype is computed by a proc macro (so it does not depend
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+ // on the host's `mime-guess` feature) and passed as the final
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+ // argument. `__rust_embed_metadata!` is selected target-side: when
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+ // the target lacks `mime-guess` it drops this argument without ever
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+ // expanding the `__mimetype_of!` call.
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- metadata: #crate_path::utils::__rust_embed_metadata!([#(#hash),*], #last_modified, #created, #mimetype)
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+ metadata: #crate_path::utils::__rust_embed_metadata!([#(#hash),*], #last_modified, #created, #crate_path::__mimetype_of!(#full_canonical_path))
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  }
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  }
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  })
@@ -449,3 +447,21 @@ pub fn derive_input_object(input: TokenStream) -> TokenStream {
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  Err(e) => e.to_compile_error().into(),
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  }
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  }
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+
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+ /// Expands to a string literal containing the mimetype of the file at the given
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+ /// path, guessed from its extension.
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+ ///
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+ /// This lives in the proc-macro crate (which depends on `mime_guess`
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+ /// unconditionally) rather than being computed inside the derive's host-side
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+ /// logic: the derive must emit tokens that do not depend on the *host*'s
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+ /// `mime-guess` feature, and this proc macro is invoked only from the
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+ /// target-side `__rust_embed_metadata!` macro. When the target has `mime-guess`
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+ /// disabled, the invocation generated by the derive is discarded by that macro
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+ /// without ever being expanded.
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+ #[doc(hidden)]
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+ #[proc_macro]
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+ pub fn __mimetype_of(input: TokenStream) -> TokenStream {
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+ let path = parse_macro_input!(input as syn::LitStr).value();
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+ let mimetype = mime_guess::from_path(&path).first_or_octet_stream().to_string();
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+ quote! { #mimetype }.into()
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+ }
utils/src/lib.rs CHANGED
@@ -60,10 +60,10 @@ pub struct Metadata {
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  /// compiled for the *host*, where its `mime-guess` feature is resolved
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  /// independently of the *target* that the generated code is compiled into. It
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  /// must not branch on its own `#[cfg(feature = "mime-guess")]`, since that
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- /// reflects the host rather than the target. Instead it unconditionally emits
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+ /// reflects the host rather than the target. Instead it unconditionally emits a
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- /// all four arguments (including a mimetype string) and defers to this macro,
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+ /// `__mimetype_of!(...)` call as the final argument and defers to this macro,
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- /// which *is* compiled for the target and so discards the mimetype when
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+ /// which *is* compiled for the target. This variant (target has `mime-guess`)
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- /// `mime-guess` is disabled there.
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+ /// forwards the argument, expanding the proc macro to the real mimetype.
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  #[cfg(feature = "mime-guess")]
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  #[doc(hidden)]
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  #[macro_export]
@@ -73,7 +73,9 @@ macro_rules! __rust_embed_metadata {
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  };
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  }
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- /// See the `mime-guess` variant above. This variant drops the mimetype token.
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+ /// See the `mime-guess` variant above. This variant (target lacks `mime-guess`)
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+ /// drops the final argument, so the `__mimetype_of!` call it contains is never
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+ /// expanded.
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  #[cfg(not(feature = "mime-guess"))]
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  #[doc(hidden)]
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  #[macro_export]
@@ -83,25 +85,6 @@ macro_rules! __rust_embed_metadata {
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  };
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  }
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- /// Computes the mimetype of a file at build time.
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- ///
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- /// This is always available (regardless of the `mime-guess` feature) so that
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- /// the derive macro can unconditionally produce a mimetype token without using
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- /// `#[cfg(…)]`. The token is only ever used by [`__rust_embed_metadata`] when
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- /// the target enables `mime-guess`; otherwise the empty string returned here is
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- /// discarded by the macro.
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- #[doc(hidden)]
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- pub fn _mimetype_of(_path: &Path) -> String {
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- #[cfg(feature = "mime-guess")]
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- {
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- mime_guess::from_path(_path).first_or_octet_stream().to_string()
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- }
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- #[cfg(not(feature = "mime-guess"))]
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- {
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- String::new()
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- }
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- }
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-
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  impl Metadata {
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  #[doc(hidden)]
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  pub const fn __rust_embed_new(