openethereum/dapps/js-glue/src/codegen.rs

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2016-12-11 19:30:54 +01:00
// Copyright 2015, 2016 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
extern crate aster;
extern crate glob;
extern crate mime_guess;
use self::mime_guess::guess_mime_type;
use std::path::{self, Path, PathBuf};
use std::ops::Deref;
use syntax::ast::{MetaItem, Item};
use syntax::ast;
use syntax::attr;
use syntax::codemap::Span;
use syntax::ext::base::{Annotatable, ExtCtxt};
use syntax::ptr::P;
use syntax::print::pprust::{lit_to_string};
use syntax::parse::token::{InternedString};
pub fn expand_webapp_implementation(
cx: &mut ExtCtxt,
span: Span,
meta_item: &MetaItem,
annotatable: &Annotatable,
push: &mut FnMut(Annotatable)
) {
let item = match *annotatable {
Annotatable::Item(ref item) => item,
_ => {
cx.span_err(meta_item.span, "`#[derive(WebAppFiles)]` may only be applied to struct implementations");
return;
},
};
let builder = aster::AstBuilder::new().span(span);
implement_webapp(cx, &builder, &item, push);
}
fn implement_webapp(cx: &ExtCtxt, builder: &aster::AstBuilder, item: &Item, push: &mut FnMut(Annotatable)) {
let static_files_dir = extract_path(cx, item);
let src = Path::new("src");
let static_files = {
let mut buf = src.to_path_buf();
buf.push(static_files_dir.deref());
buf
};
let search_location = {
let mut buf = static_files.to_path_buf();
buf.push("**");
buf.push("*");
buf
};
let files = glob::glob(search_location.to_str().expect("Valid UTF8 path"))
.expect("The sources directory is missing.")
.collect::<Result<Vec<PathBuf>, glob::GlobError>>()
.expect("There should be no error when reading a list of files.");
let statements = files
.iter()
.filter(|path_buf| path_buf.is_file())
.map(|path_buf| {
let path = path_buf.as_path();
let filename = path.file_name().and_then(|s| s.to_str()).expect("Only UTF8 paths.");
let mime_type = guess_mime_type(filename).to_string();
let file_path = as_uri(path.strip_prefix(&static_files).ok().expect("Prefix is always there, cause it's absolute path;qed"));
let file_path_in_source = path.to_str().expect("Only UTF8 paths.");
let path_lit = builder.expr().str(file_path.as_str());
let mime_lit = builder.expr().str(mime_type.as_str());
let web_path_lit = builder.expr().str(file_path_in_source);
let separator_lit = builder.expr().str(path::MAIN_SEPARATOR.to_string().as_str());
let concat_id = builder.id("concat!");
let env_id = builder.id("env!");
let macro_id = builder.id("include_bytes!");
let content = quote_expr!(
cx,
$macro_id($concat_id($env_id("CARGO_MANIFEST_DIR"), $separator_lit, $web_path_lit))
);
quote_stmt!(
cx,
files.insert($path_lit, File { path: $path_lit, content_type: $mime_lit, content: $content });
).expect("The statement is always ok, because it just uses literals.")
}).collect::<Vec<ast::Stmt>>();
let type_name = item.ident;
let files_impl = quote_item!(cx,
impl $type_name {
fn files() -> ::std::collections::HashMap<&'static str, File> {
let mut files = ::std::collections::HashMap::new();
$statements
files
}
}
).unwrap();
push(Annotatable::Item(files_impl));
}
fn extract_path(cx: &ExtCtxt, item: &Item) -> String {
for meta_items in item.attrs().iter().filter_map(webapp_meta_items) {
for meta_item in meta_items {
match meta_item.node {
ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"path" => {
if let Some(s) = get_str_from_lit(cx, name, lit) {
return s.deref().to_owned();
}
},
_ => {},
}
}
}
// default
"web".to_owned()
}
fn get_str_from_lit(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Option<InternedString> {
match lit.node {
ast::LitKind::Str(ref s, _) => Some(s.clone()),
_ => {
cx.span_err(
lit.span,
&format!("webapp annotation `{}` must be a string, not `{}`",
name,
lit_to_string(lit)
)
);
return None;
}
}
}
fn webapp_meta_items(attr: &ast::Attribute) -> Option<&[P<ast::MetaItem>]> {
match attr.node.value.node {
ast::MetaItemKind::List(ref name, ref items) if name == &"webapp" => {
attr::mark_used(&attr);
Some(items)
}
_ => None
}
}
fn as_uri(path: &Path) -> String {
let mut s = String::new();
for component in path.iter() {
s.push_str(component.to_str().expect("Only UTF-8 filenames are supported."));
s.push('/');
}
s[0..s.len()-1].into()
}
#[test]
fn should_convert_path_separators_on_all_platforms() {
// given
let p = {
let mut p = PathBuf::new();
p.push("web");
p.push("src");
p.push("index.html");
p
};
// when
let path = as_uri(&p);
// then
assert_eq!(path, "web/src/index.html".to_owned());
}