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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
extern crate proc_macro;
extern crate proc_macro2;
#[macro_use] extern crate quote;
extern crate syn;
extern crate walkdir;
use std::env;
use std::fs::File;
use std::io::BufReader;
use std::io::prelude::*;
#[allow(unused)]
use std::path::{Path, PathBuf};
use proc_macro::TokenStream;
use proc_macro2::{TokenTree, TokenNode, Delimiter, Span};
use syn::{Lit, LitStr, Meta, MetaNameValue, NestedMeta, MetaList };
use quote::{Tokens, ToTokens};
struct Asset(String, Bytes);
impl ToTokens for Asset {
fn to_tokens(&self, tokens: &mut Tokens) {
let &Asset(ref path, ref contents) = self;
let asset_tokens = quote!{ #path => Some(vec!#contents), }.into();
tokens.append(TokenTree {
span: Span::def_site(),
kind: TokenNode::Group(
Delimiter::None,
asset_tokens,
),
})
}
}
struct Bytes(Vec<u8>);
impl ToTokens for Bytes {
fn to_tokens(&self, tokens: &mut Tokens) {
let bytes = &self.0;
let byte_tokens = quote!{ #(#bytes),* }.into();
tokens.append(TokenTree {
span: Span::def_site(),
kind: TokenNode::Group(
Delimiter::Bracket,
byte_tokens,
),
});
}
}
#[allow(unused)]
fn read_bytes(filename: &Path) -> Asset {
match File::open(filename) {
Ok(file) => {
let mut reader = BufReader::new(file);
let mut contents = Vec::new();
let _ = reader.read_to_end(&mut contents);
Asset(filename.to_str().unwrap().to_owned(), Bytes(contents))
},
Err(error) => {
panic!(format!("could not open {:?}: {}", filename, error));
}
}
}
fn abs_path(path: String) -> PathBuf {
let current = env::current_dir().unwrap();
let mut path: PathBuf = path.into();
if path.is_relative() {
path = current.join(path)
}
path
}
fn relativize_path(path: PathBuf) -> String {
let current = env::current_dir().unwrap();
let path = match path.strip_prefix(¤t) {
Ok(path) => path,
Err(_) => &path,
};
path.to_str().unwrap().to_string()
}
fn walk(path: PathBuf) -> Vec<Asset> {
let entries = walkdir::WalkDir::new(path.clone()).into_iter();
entries.filter_map(|e| e.ok() )
.filter(|e| e.file_type().is_file())
.map(|f| read_bytes(f.path()))
.map(|Asset(path, contents)| Asset(relativize_path(path.into()), contents))
.collect()
}
#[proc_macro_derive(BinDataImpl, attributes(BinDataImplContent))]
pub fn bindata_impl(input: TokenStream) -> TokenStream {
fn parse_meta_list(m: Meta) -> Option<MetaList> {
match m {
Meta::List(meta) => Some(meta),
_ => None,
}
}
fn parse_meta_namevalue(m: Meta) -> Option<MetaNameValue> {
match m {
Meta::NameValue(namevalue) => Some(namevalue),
_ => None,
}
}
fn parse_nestedmeta_meta(m: NestedMeta) -> Option<Meta> {
match m {
NestedMeta::Meta(meta) => Some(meta),
_ => None
}
}
fn parse_string_literal(l: Lit) -> Option<LitStr> {
match l {
Lit::Str(string) => Some(string),
_ => None,
}
}
let input: syn::DeriveInput = syn::parse(input).unwrap();
let ident = input.ident;
let values: Vec<Asset> = input.attrs.iter()
.filter_map(|a| a.interpret_meta())
.filter(|m| m.name() == "BinDataImplContent")
.filter_map(parse_meta_list)
.flat_map(|bindata|
bindata.nested.into_iter()
.filter_map(parse_nestedmeta_meta)
.filter_map(parse_meta_namevalue)
.map(|nv| nv.lit)
.filter_map(parse_string_literal))
.map(|l| l.value())
.flat_map(|path| walk(abs_path(path)))
.collect();
let expanded = quote! {
impl #ident {
fn get(&self, key: &str) -> Option<Vec<u8>> {
match key {
#(#values)*
_ => None,
}
}
}
};
expanded.into()
}