1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

#![recursion_limit = "1024"]
extern crate proc_macro;
#[macro_use]
extern crate quote;
extern crate syn;

extern crate walkdir;

use proc_macro::TokenStream;
use quote::Tokens;
use std::path::Path;
use syn::*;

mod utils;

#[cfg(all(debug_assertions, not(feature = "debug-embed")))]
fn generate_assets(ident: &syn::Ident, folder_path: String) -> quote::Tokens {
  quote! {      
      impl #ident {
          pub fn get(file_path: &str) -> Option<std::borrow::Cow<'static, [u8]>> {
              use std::fs::File;
              use std::io::Read;
              use std::path::Path;

              let file_path = Path::new(#folder_path).join(file_path);
              let mut file = match File::open(file_path) {
                  Ok(mut file) => file,
                  Err(_e) => {
                      return None
                  }
              };
              let mut data: Vec<u8> = Vec::new();
              match file.read_to_end(&mut data) {
                  Ok(_) => Some(std::borrow::Cow::from(data)),
                  Err(_e) =>  {
                      return None
                  }
              }
          }

          pub fn iter() -> impl Iterator<Item = std::borrow::Cow<'static, str>> {
              use std::path::Path;
              use rust_embed::utils::get_files;
              get_files(String::from(#folder_path)).map(|e| std::borrow::Cow::from(e.rel_path))
          }
      }
  }
}

#[cfg(any(not(debug_assertions), feature = "debug-embed"))]
fn generate_assets(ident: &syn::Ident, folder_path: String) -> quote::Tokens {
  use utils::{get_files, FileEntry};

  let mut match_values = Vec::<Tokens>::new();
  let mut list_values = Vec::<String>::new();

  for FileEntry { rel_path, full_canonical_path } in get_files(folder_path) {
    match_values.push(quote! {
      #rel_path => {
          let bytes = &include_bytes!(#full_canonical_path)[..];
          Some(std::borrow::Cow::from(bytes))
      },
    });
    list_values.push(rel_path);
  }

  let array_len = list_values.len();

  quote! {      
      impl #ident {
          pub fn get(file_path: &str) -> Option<std::borrow::Cow<'static, [u8]>> {
              match file_path {
                  #(#match_values)*
                  _ => None,
              }
          }

          pub fn iter() -> impl Iterator<Item = std::borrow::Cow<'static, str>> {
              static items: [&str; #array_len] = [#(#list_values),*];
              items.iter().map(|x| std::borrow::Cow::from(*x))
          }
      }
  }
}

fn help() -> ! {
  panic!("#[derive(RustEmbed)] should contain one attribute like this #[folder = \"examples/public/\"]");
}

fn impl_rust_embed(ast: &syn::DeriveInput) -> Tokens {
  match ast.body {
    Body::Enum(_) => help(),
    Body::Struct(ref data) => match data {
      &VariantData::Struct(_) => help(),
      _ => {}
    },
  };

  let attribute = ast.attrs
      .iter()
      .map(|attr| &attr.value)
      .find(|value| value.name() == "folder");
  let literal_value = match attribute {
    Some(&MetaItem::NameValue(_, ref literal)) => literal,
    _ => help()
  };
  let folder_path = match literal_value {
    &Lit::Str(ref val, _) => val.clone(),
    _ => {
      panic!("#[derive(RustEmbed)] attribute value must be a string literal");
    }
  };

  if !Path::new(&folder_path).exists() {
    panic!(
      "#[derive(RustEmbed)] folder '{}' does not exist. cwd: '{}'",
      folder_path,
      std::env::current_dir().unwrap().to_str().unwrap()
    );
  };

  generate_assets(&ast.ident, folder_path)
}

#[proc_macro_derive(RustEmbed, attributes(folder))]
pub fn derive_input_object(input: TokenStream) -> TokenStream {
  let s = input.to_string();
  let ast = syn::parse_derive_input(&s).unwrap();
  let gen = impl_rust_embed(&ast);
  gen.parse().unwrap()
}