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extern crate jq_sys;
#[cfg(test)]
#[macro_use]
extern crate serde_json;
use jq::JqState;
use std::ffi::CString;
mod jq {
use jq_sys::{
self, jq_next, jv_copy, jv_dump_string, jv_invalid_get_msg, jv_parser_next, jv_string_value,
};
use std::ffi::{CStr, CString};
use std::os::raw::c_char;
pub type JqValue = ::jq_sys::jv;
pub type JqState = ::jq_sys::jq_state;
mod jv {
use super::JqValue;
use jq_sys;
pub fn value_is_valid(value: JqValue) -> bool {
unsafe { jq_sys::jv_get_kind(value) != jq_sys::jv_kind_JV_KIND_INVALID }
}
pub fn invalid_has_msg(value: JqValue) -> bool {
unsafe { jq_sys::jv_invalid_has_msg(value) == 1 }
}
}
pub fn init() -> *mut JqState {
unsafe { jq_sys::jq_init() }
}
pub fn teardown(state: *mut *mut JqState) {
unsafe { jq_sys::jq_teardown(state) }
}
pub fn load_string(state: *mut *mut JqState, buf: CString) -> Result<String, String> {
unsafe {
let parser = jq_sys::jv_parser_new(0);
let len = buf.as_bytes().len() as i32;
jq_sys::jv_parser_set_buf(parser, buf.as_ptr(), len, 0);
let res = parse(state, parser);
jq_sys::jv_parser_free(parser);
res
}
}
unsafe fn get_string_value(value: *const c_char) -> Result<String, ::std::str::Utf8Error> {
let s = CStr::from_ptr(value).to_str()?;
Ok(s.to_owned())
}
unsafe fn check(value: JqValue) -> Result<(), String> {
if jv::invalid_has_msg(jv_copy(value)) {
let msg = jv_invalid_get_msg(value);
let reason = format!(
"parse error: {}",
get_string_value(jv_string_value(msg)).unwrap_or_else(|_| "unknown".into())
);
let ret = Err(reason);
jq_sys::jv_free(msg);
return ret;
} else {
jq_sys::jv_free(value);
}
Ok(())
}
unsafe fn dump(
state: *mut *mut JqState,
initial_value: JqValue,
buf: &mut String,
) -> Result<(), String> {
let mut value = initial_value;
while jv::value_is_valid(value) {
let dumped = jv_dump_string(value, 0);
match get_string_value(jv_string_value(dumped)) {
Ok(s) => buf.push_str(&s),
Err(e) => return Err(format!("parse error: {}", e)),
};
value = jq_next(*state);
}
check(value)
}
unsafe fn parse(
state: *mut *mut JqState,
parser: *mut jq_sys::jv_parser,
) -> Result<String, String> {
let mut buf = String::new();
let mut value = jv_parser_next(parser);
while jv::value_is_valid(value) {
jq_sys::jq_start(*state, value, 0);
if let Err(reason) = dump(state, jq_next(*state), &mut buf) {
jq_sys::jv_free(value);
return Err(reason);
}
value = jv_parser_next(parser);
}
check(value)?;
Ok(buf)
}
pub fn compile_program(state: *mut *mut JqState, program: CString) -> Result<(), String> {
unsafe {
if jq_sys::jq_compile(*state, program.as_ptr()) == 0 {
Err("syntax error: JQ Program failed to compile.".into())
} else {
Ok(())
}
}
}
}
pub fn run(program: &str, data: &str) -> Result<String, String> {
let mut state = jq::init();
let buf = CString::new(data).map_err(|_| "unable to convert data to c string.".to_string())?;
let prog =
CString::new(program).map_err(|_| "unable to convert data to c string.".to_string())?;
jq::compile_program(&mut state, prog)?;
let res = jq::load_string(&mut state, buf);
jq::teardown(&mut state);
res
}
pub struct JqProgram {
state: *mut JqState,
}
impl JqProgram {
pub fn run(&mut self, data: &str) -> Result<String, String> {
let buf =
CString::new(data).map_err(|_| "unable to convert data to c string.".to_string())?;
let res = jq::load_string(&mut self.state, buf);
res
}
}
impl Drop for JqProgram {
fn drop(&mut self) {
jq::teardown(&mut self.state);
}
}
pub fn compile(program: &str) -> Result<JqProgram, String> {
let mut state = jq::init();
let prog =
CString::new(program).map_err(|_| "unable to convert data to c string.".to_string())?;
jq::compile_program(&mut state, prog)?;
Ok(JqProgram { state })
}
#[cfg(test)]
mod test {
use super::{compile, run};
use serde_json;
#[test]
fn reuse_compiled_program() {
let query = r#"if . == 0 then "zero" elif . == 1 then "one" else "many" end"#;
let mut prog = compile(&query).unwrap();
assert_eq!(prog.run("2").unwrap(), r#""many""#);
assert_eq!(prog.run("1").unwrap(), r#""one""#);
assert_eq!(prog.run("0").unwrap(), r#""zero""#);
}
#[test]
fn jq_state_is_not_global() {
let input = r#"{"id": 123, "name": "foo"}"#;
let query1 = r#".name"#;
let query2 = r#".id"#;
let mut prog1 = compile(&query1).unwrap();
let mut prog2 = compile(&query2).unwrap();
assert_eq!(prog1.run(input).unwrap(), r#""foo""#);
assert_eq!(prog2.run(input).unwrap(), r#"123"#);
assert_eq!(prog1.run(input).unwrap(), r#""foo""#);
assert_eq!(prog2.run(input).unwrap(), r#"123"#);
}
fn get_movies() -> serde_json::Value {
json!({
"movies": [
{ "title": "Coraline", "year": 2009 },
{ "title": "ParaNorman", "year": 2012 },
{ "title": "Boxtrolls", "year": 2014 },
{ "title": "Kubo and the Two Strings", "year": 2016 },
{ "title": "Missing Link", "year": 2019 }
]
})
}
#[test]
fn identity_nothing() {
assert_eq!(run(".", ""), Ok("".to_string()));
}
#[test]
fn identity_empty() {
assert_eq!(run(".", "{}"), Ok("{}".to_string()));
}
#[test]
fn extract_dates() {
let data = get_movies();
let query = "[.movies[].year]";
let output = run(query, &data.to_string()).unwrap();
let parsed: Vec<i64> = serde_json::from_str(&output).unwrap();
assert_eq!(vec![2009, 2012, 2014, 2016, 2019], parsed);
}
#[test]
fn extract_name() {
let res = run(".name", r#"{"name": "test"}"#);
assert_eq!(res, Ok(r#""test""#.to_string()));
}
#[test]
fn compile_error() {
let res = run(". aa12312me dsaafsdfsd", "{\"name\": \"test\"}");
assert!(res.is_err());
}
#[test]
fn parse_error() {
let res = run(".", "{1233 invalid json ahoy : est\"}");
assert!(res.is_err());
}
#[test]
fn just_open_brace() {
let res = run(".", "{");
assert!(res.is_err());
}
#[test]
fn just_close_brace() {
let res = run(".", "}");
assert!(res.is_err());
}
#[test]
fn total_garbage() {
let data = r#"
{
moreLike: "an object literal but also bad"
loveToDangleComma: true,
}"#;
let res = run(".", data);
assert!(res.is_err());
}
}