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use std::io;
use std::process;
#[macro_use]
extern crate log;
pub type Error = io::Error;
pub type Result<T> = io::Result<T>;
fn err_other<T>(s: &str) -> Result<T> {
Err(Error::new(io::ErrorKind::Other, s.to_owned()))
}
#[derive(Default)]
pub struct Args<'a> {
pub lang: &'a str,
pub out_dir: &'a str,
pub plugin: Option<&'a str>,
pub includes: &'a [&'a str],
pub input: &'a [&'a str],
}
#[derive(Debug)]
pub struct DescriptorSetOutArgs<'a> {
pub out: &'a str,
pub includes: &'a [&'a str],
pub input: &'a [&'a str],
pub include_imports: bool,
}
pub struct Protoc {
exec: String,
}
impl Protoc {
pub fn from_env_path() -> Protoc {
Protoc { exec: "protoc".to_owned() }
}
pub fn from_path(path: &str) -> Protoc {
Protoc { exec: path.to_owned() }
}
pub fn check(&self) -> Result<()> {
self.version().map(|_| ())
}
pub fn version(&self) -> Result<Version> {
let child = process::Command::new(&self.exec)
.stdin(process::Stdio::null())
.stdout(process::Stdio::piped())
.stderr(process::Stdio::piped())
.args(&["--version"])
.spawn()?;
let output = child.wait_with_output()?;
if !output.status.success() {
return err_other("protoc failed with error");
}
let output = String::from_utf8(output.stdout)
.map_err(|e| Error::new(io::ErrorKind::Other, e))?;
let output = match output.lines().next() {
None => return err_other("output is empty"),
Some(line) => line,
};
let prefix = "libprotoc ";
if !output.starts_with(prefix) {
return err_other("output does not start with prefix");
}
let output = &output[prefix.len()..];
if output.is_empty() {
return err_other("version is empty");
}
let first = output.chars().next().unwrap();
if !first.is_digit(10) {
return err_other("version does not start with digit");
}
Ok(Version { version: output.to_owned() })
}
fn run_with_args(&self, args: Vec<String>) -> Result<()> {
let mut cmd = process::Command::new(&self.exec);
cmd.stdin(process::Stdio::null());
cmd.args(args);
info!("spawning command {:?}", cmd);
let mut child = cmd.spawn()?;
if !child.wait()?.success() {
return err_other("protoc exited with non-zero exit code");
}
Ok(())
}
pub fn run(&self, args: Args) -> Result<()> {
let mut cmd_args: Vec<String> = Vec::new();
if args.out_dir.is_empty() {
return err_other("out_dir is empty");
}
if args.lang.is_empty() {
return err_other("lang is empty");
}
cmd_args.push(format!("--{}_out={}", args.lang, args.out_dir));
if args.input.is_empty() {
return err_other("input is empty");
}
cmd_args.extend(args.input.into_iter().map(|a| String::from(*a)));
if let Some(plugin) = args.plugin {
cmd_args.push(format!("--plugin={}", plugin));
}
for include in args.includes {
cmd_args.push(format!("-I{}", include));
}
self.run_with_args(cmd_args)
}
pub fn write_descriptor_set(&self, args: DescriptorSetOutArgs) -> Result<()> {
let mut cmd_args: Vec<String> = Vec::new();
for include in args.includes {
cmd_args.push(format!("-I{}", include));
}
if args.out.is_empty() {
return err_other("out is empty");
}
cmd_args.push(format!("--descriptor_set_out={}", args.out));
if args.include_imports {
cmd_args.push("--include_imports".to_owned());
}
if args.input.is_empty() {
return err_other("input is empty");
}
cmd_args.extend(args.input.into_iter().map(|a| String::from(*a)));
self.run_with_args(cmd_args)
}
}
pub fn run(args: Args) -> Result<()> {
let protoc = Protoc::from_env_path();
protoc.check()?;
protoc.run(args)
}
pub struct Version {
version: String,
}
impl Version {
pub fn is_3(&self) -> bool {
self.version.starts_with("3")
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn version() {
Protoc::from_env_path().version().expect("version");
}
}