bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/proc-macro-api/src/transport/codec/json.rs')
-rw-r--r--crates/proc-macro-api/src/transport/codec/json.rs58
1 files changed, 58 insertions, 0 deletions
diff --git a/crates/proc-macro-api/src/transport/codec/json.rs b/crates/proc-macro-api/src/transport/codec/json.rs
new file mode 100644
index 0000000000..96db802e0b
--- /dev/null
+++ b/crates/proc-macro-api/src/transport/codec/json.rs
@@ -0,0 +1,58 @@
+//! Protocol functions for json.
+use std::io::{self, BufRead, Write};
+
+use serde::{Serialize, de::DeserializeOwned};
+
+use crate::{Codec, transport::framing::Framing};
+
+pub struct JsonProtocol;
+
+impl Framing for JsonProtocol {
+ type Buf = String;
+
+ fn read<'a, R: BufRead + ?Sized>(
+ inp: &mut R,
+ buf: &'a mut String,
+ ) -> io::Result<Option<&'a mut String>> {
+ loop {
+ buf.clear();
+
+ inp.read_line(buf)?;
+ buf.pop(); // Remove trailing '\n'
+
+ if buf.is_empty() {
+ return Ok(None);
+ }
+
+ // Some ill behaved macro try to use stdout for debugging
+ // We ignore it here
+ if !buf.starts_with('{') {
+ tracing::error!("proc-macro tried to print : {}", buf);
+ continue;
+ }
+
+ return Ok(Some(buf));
+ }
+ }
+
+ fn write<W: Write + ?Sized>(out: &mut W, buf: &String) -> io::Result<()> {
+ tracing::debug!("> {}", buf);
+ out.write_all(buf.as_bytes())?;
+ out.write_all(b"\n")?;
+ out.flush()
+ }
+}
+
+impl Codec for JsonProtocol {
+ fn encode<T: Serialize>(msg: &T) -> io::Result<String> {
+ Ok(serde_json::to_string(msg)?)
+ }
+
+ fn decode<T: DeserializeOwned>(buf: &mut String) -> io::Result<T> {
+ let mut deserializer = serde_json::Deserializer::from_str(buf);
+ // Note that some proc-macro generate very deep syntax tree
+ // We have to disable the current limit of serde here
+ deserializer.disable_recursion_limit();
+ Ok(T::deserialize(&mut deserializer)?)
+ }
+}