fork of https://github.com/rustwasm/wasm-pack for the needs of NextGraph.org
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//! Utilities for finding and installing binaries that we depend on.
extern crate curl;
#[macro_use]
extern crate failure;
extern crate dirs;
extern crate flate2;
extern crate hex;
extern crate is_executable;
extern crate siphasher;
extern crate tar;
extern crate zip;
use failure::{Error, ResultExt};
use siphasher::sip::SipHasher13;
use std::collections::HashSet;
use std::env;
use std::ffi;
use std::fs;
use std::hash::{Hash, Hasher};
use std::io;
use std::path::{Path, PathBuf};
/// Global cache for wasm-pack, currently containing binaries downloaded from
/// urls like wasm-bindgen and such.
pub struct Cache {
destination: PathBuf,
}
/// Representation of a downloaded tarball/zip
pub struct Download {
root: PathBuf,
}
impl Cache {
/// Returns the global cache directory, as inferred from env vars and such.
///
/// This function may return an error if a cache directory cannot be
/// determined.
pub fn new(name: &str) -> Result<Cache, Error> {
let cache_name = format!(".{}", name);
let destination = dirs::cache_dir()
.map(|p| p.join(&cache_name))
.or_else(|| {
let home = dirs::home_dir()?;
Some(home.join(&cache_name))
})
.ok_or_else(|| format_err!("couldn't find your home directory, is $HOME not set?"))?;
Ok(Cache::at(&destination))
}
/// Creates a new cache specifically at a particular directory, useful in
/// testing and such.
pub fn at(path: &Path) -> Cache {
Cache {
destination: path.to_path_buf(),
}
}
/// Joins a path to the destination of this cache, returning the result
pub fn join(&self, path: &Path) -> PathBuf {
self.destination.join(path)
}
/// Downloads a tarball or zip file from the specified url, extracting it
/// locally and returning the directory that the contents were extracted
/// into.
///
/// Note that this function requries that the contents of `url` never change
/// as the contents of the url are globally cached on the system and never
/// invalidated.
///
/// The `name` is a human-readable name used to go into the folder name of
/// the destination, and `binaries` is a list of binaries expected to be at
/// the url. If the URL's extraction doesn't contain all the binaries this
/// function will return an error.
pub fn download(
&self,
install_permitted: bool,
name: &str,
binaries: &[&str],
url: &str,
) -> Result<Option<Download>, Error> {
let mut hasher = SipHasher13::new();
url.hash(&mut hasher);
let result = hasher.finish();
let hex = hex::encode(&[
(result >> 0) as u8,
(result >> 8) as u8,
(result >> 16) as u8,
(result >> 24) as u8,
(result >> 32) as u8,
(result >> 40) as u8,
(result >> 48) as u8,
(result >> 56) as u8,
]);
let dirname = format!("{}-{}", name, hex);
let destination = self.destination.join(&dirname);
if destination.exists() {
return Ok(Some(Download { root: destination }));
}
if !install_permitted {
return Ok(None);
}
let data = curl(&url).with_context(|_| format!("failed to download from {}", url))?;
// Extract everything in a temporary directory in case we're ctrl-c'd.
// Don't want to leave around corrupted data!
let temp = self.destination.join(&format!(".{}", dirname));
drop(fs::remove_dir_all(&temp));
fs::create_dir_all(&temp)?;
if url.ends_with(".tar.gz") {
self.extract_tarball(&data, &temp, binaries)
.with_context(|_| format!("failed to extract tarball from {}", url))?;
} else if url.ends_with(".zip") {
self.extract_zip(&data, &temp, binaries)
.with_context(|_| format!("failed to extract zip from {}", url))?;
} else {
// panic instead of runtime error as it's a static violation to
// download a different kind of url, all urls should be encoded into
// the binary anyway
panic!("don't know how to extract {}", url)
}
// Now that everything is ready move this over to our destination and
// we're good to go.
fs::rename(&temp, &destination)?;
Ok(Some(Download { root: destination }))
}
fn extract_tarball(&self, tarball: &[u8], dst: &Path, binaries: &[&str]) -> Result<(), Error> {
let mut binaries: HashSet<_> = binaries.into_iter().map(ffi::OsStr::new).collect();
let mut archive = tar::Archive::new(flate2::read::GzDecoder::new(tarball));
for entry in archive.entries()? {
let mut entry = entry?;
let dest = match entry.path()?.file_stem() {
Some(f) if binaries.contains(f) => {
binaries.remove(f);
dst.join(entry.path()?.file_name().unwrap())
}
_ => continue,
};
entry.unpack(dest)?;
}
if !binaries.is_empty() {
bail!(
"the tarball was missing expected executables: {}",
binaries
.into_iter()
.map(|s| s.to_string_lossy())
.collect::<Vec<_>>()
.join(", "),
)
}
Ok(())
}
fn extract_zip(&self, zip: &[u8], dst: &Path, binaries: &[&str]) -> Result<(), Error> {
let mut binaries: HashSet<_> = binaries.into_iter().map(ffi::OsStr::new).collect();
let data = io::Cursor::new(zip);
let mut zip = zip::ZipArchive::new(data)?;
for i in 0..zip.len() {
let mut entry = zip.by_index(i).unwrap();
let entry_path = entry.sanitized_name();
match entry_path.file_stem() {
Some(f) if binaries.contains(f) => {
binaries.remove(f);
let mut dest = bin_open_options()
.write(true)
.create_new(true)
.open(dst.join(entry_path.file_name().unwrap()))?;
io::copy(&mut entry, &mut dest)?;
}
_ => continue,
};
}
if !binaries.is_empty() {
bail!(
"the zip was missing expected executables: {}",
binaries
.into_iter()
.map(|s| s.to_string_lossy())
.collect::<Vec<_>>()
.join(", "),
)
}
return Ok(());
#[cfg(unix)]
fn bin_open_options() -> fs::OpenOptions {
use std::os::unix::fs::OpenOptionsExt;
let mut opts = fs::OpenOptions::new();
opts.mode(0o755);
opts
}
#[cfg(not(unix))]
fn bin_open_options() -> fs::OpenOptions {
fs::OpenOptions::new()
}
}
}
impl Download {
/// Manually constructs a download at the specified path
pub fn at(path: &Path) -> Download {
Download {
root: path.to_path_buf(),
}
}
/// Returns the path to the binary `name` within this download
pub fn binary(&self, name: &str) -> Result<PathBuf, Error> {
use is_executable::IsExecutable;
let ret = self
.root
.join(name)
.with_extension(env::consts::EXE_EXTENSION);
if !ret.is_file() {
bail!("{} binary does not exist", ret.display());
}
if !ret.is_executable() {
bail!("{} is not executable", ret.display());
}
Ok(ret)
}
}
fn curl(url: &str) -> Result<Vec<u8>, Error> {
let mut data = Vec::new();
let mut easy = curl::easy::Easy::new();
easy.follow_location(true)?;
easy.url(url)?;
easy.get(true)?;
{
let mut transfer = easy.transfer();
transfer.write_function(|part| {
data.extend_from_slice(part);
Ok(part.len())
})?;
transfer.perform()?;
}
let status_code = easy.response_code()?;
if 200 <= status_code && status_code < 300 {
Ok(data)
} else {
bail!(
"received a bad HTTP status code ({}) when requesting {}",
status_code,
url
)
}
}