added str and bytes mode

This commit is contained in:
Niklas Kapelle 2025-07-28 20:44:32 +02:00
parent 41ec4d31a4
commit d025c3c120
Signed by: niklas
GPG Key ID: 4EB651B36D841D16
2 changed files with 79 additions and 24 deletions

View File

@ -6,32 +6,41 @@ use syn::{Attribute, DeriveInput, Expr, Ident, Lit, Meta, parse_macro_input};
use std::fs;
use std::path::{Path, PathBuf};
#[proc_macro_derive(Embed, attributes(dir))]
#[derive(Debug, Clone, Copy)]
enum EmbedMode {
Bytes,
Str,
}
#[proc_macro_derive(Embed, attributes(dir,mode))]
pub fn embed(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
let input = parse_macro_input!(input as DeriveInput);
let struct_name = &input.ident;
let attr = input
let dir_attr = input
.attrs
.iter()
.find(|e| e.path().is_ident("dir"))
.expect("No #[dir = \"...\"] attribute found");
let base_path = PathBuf::from(extract_dir_path(attr));
let mode_attr = input.attrs.iter().find(|e| e.path().is_ident("mode"));
let mode = mode_attr.map(extract_mode).unwrap_or(EmbedMode::Bytes);
let base_path = PathBuf::from(extract_dir_path(dir_attr));
let source_file = PathBuf::from(input.span().unwrap().file());
let source_dir = if let Some(parent) = source_file.parent() {
parent
} else {
// HACK: when running in rust-analyzer i can't seem to get the parent dir.
return TokenStream::from(generate_impl(struct_name, Vec::new(), Vec::new()));
return TokenStream::from(generate_byte_impl(struct_name, Vec::new()));
};
let absolue_path = source_dir.join(&base_path);
let mut match_arms = Vec::new();
let mut entries = Vec::new();
for entry in collect_files(&absolue_path) {
let rel_path = entry
@ -42,18 +51,20 @@ pub fn embed(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
.replace("\\", "/");
let include_path = base_path.join(&rel_path);
let include_string = include_path.to_str();
let include_string = include_path.to_str().unwrap();
match_arms.push(quote! {
#rel_path => Some(include_bytes!(#include_string) as &'static [u8]),
});
let arm = match mode {
EmbedMode::Bytes => generate_byte_arm(&rel_path, include_string),
EmbedMode::Str => generate_str_arm(&rel_path, include_string),
};
entries.push(quote! {
(#rel_path, include_bytes!(#include_string) as &'static [u8])
});
match_arms.push(arm);
}
let expanded = generate_impl(struct_name, match_arms, entries);
let expanded = match mode {
EmbedMode::Bytes => generate_byte_impl(struct_name, match_arms),
EmbedMode::Str => generate_str_impl(struct_name, match_arms),
};
proc_macro::TokenStream::from(expanded)
}
@ -88,10 +99,36 @@ fn extract_dir_path(attr: &Attribute) -> String {
}
}
fn generate_impl(
fn extract_mode(attr: &Attribute) -> EmbedMode {
let meta = match &attr.meta {
Meta::NameValue(meta) => meta,
_ => panic!("Expected #[mode = \"bytes\"|\"str\"] as a name-value attribute."),
};
let expr_lit = match &meta.value {
Expr::Lit(expr_lit) => expr_lit,
_ => panic!("Expected #[mode = \"bytes\"|\"str\"] with a string literal."),
};
match &expr_lit.lit {
Lit::Str(str) => match str.value().as_str() {
"bytes" => EmbedMode::Bytes,
"str" => EmbedMode::Str,
other => panic!("Unknown mode: {other}. Use `bytes` or `str`."),
},
_ => panic!("Expected #[mode = \"bytes\"|\"str\"] to be a string."),
}
}
fn generate_byte_arm(rel: &str, include: &str) -> proc_macro2::TokenStream {
quote! {
#rel => Some(include_bytes!(#include)),
}
}
fn generate_byte_impl(
struct_name: &Ident,
match_arms: Vec<proc_macro2::TokenStream>,
entries: Vec<proc_macro2::TokenStream>,
) -> proc_macro2::TokenStream {
quote! {
impl #struct_name {
@ -101,9 +138,27 @@ fn generate_impl(
_ => None,
}
}
}
}
}
pub fn iter() -> impl Iterator<Item = (&'static str, &'static [u8])> {
[#(#entries),*].into_iter()
fn generate_str_arm(rel: &str, include: &str) -> proc_macro2::TokenStream {
quote! {
#rel => Some(include_str!(#include)),
}
}
fn generate_str_impl(
struct_name: &Ident,
match_arms: Vec<proc_macro2::TokenStream>,
) -> proc_macro2::TokenStream {
quote! {
impl #struct_name {
pub fn get(name: &str) -> Option<&'static str> {
match name {
#(#match_arms)*
_ => None,
}
}
}
}

View File

@ -2,27 +2,28 @@ use dir_embed::Embed;
#[derive(Embed)]
#[dir = "./../testdata/"]
#[mode = "bytes"]
pub struct Assets;
#[test]
fn get() {
fn byte_get() {
assert!(Assets::get("file1.txt").is_some());
}
#[test]
fn get_missing() {
fn byte_get_missing() {
assert!(Assets::get("missing.txt").is_none());
}
#[test]
fn read_content() {
fn byte_read_content() {
let content_should = "file1".as_bytes();
let content_is = Assets::get("file1.txt").unwrap();
assert_eq!(*content_is, *content_should);
}
#[test]
fn parse_string() {
fn byte_parse_string() {
let file: &[u8] = Assets::get("file1.txt").expect("Can't find file");
let string = str::from_utf8(file).expect("Failed to parse file");
@ -31,14 +32,13 @@ fn parse_string() {
}
#[test]
fn sub_directories_get() {
fn byte_sub_directories_get() {
assert!(Assets::get("sub/file2.txt").is_some());
}
#[test]
fn sub_directories_content() {
fn byte_sub_directories_content() {
let content_should = "file2".as_bytes();
let content_is = Assets::get("sub/file2.txt").unwrap();
assert_eq!(*content_is, *content_should);
}