Merge pull request #362 from blyxxyz/optimize-serde-json

Use serde-transcode to optimize JSON formatting

Cargo.toml

@@ -40,6 +40,7 @@ regex-lite = "0.1.5"
 roff = { version = "0.2.1", optional = true }
 rpassword = "7.2.0"
 serde = { version = "1.0", features = ["derive"] }
+serde-transcode = "1.1.1"
 serde_json = { version = "1.0", features = ["preserve_order"] }
 serde_urlencoded = "0.7.0"
 termcolor = "1.1.2"

src/decoder.rs

@@ -67,6 +67,7 @@ impl<R: Read> InnerReader<R> {
 
 impl<R: Read> Read for InnerReader<R> {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.has_errored = false;
         match self.reader.read(buf) {
             Ok(0) => Ok(0),
             Ok(len) => {
@@ -176,4 +177,27 @@ mod tests {
             }
         }
     }
+
+    #[test]
+    fn interrupts_are_handled_gracefully() {
+        struct InterruptedReader {
+            init: bool,
+        }
+        impl Read for InterruptedReader {
+            fn read(&mut self, _buf: &mut [u8]) -> io::Result<usize> {
+                if !self.init {
+                    self.init = true;
+                    Err(io::Error::new(io::ErrorKind::Interrupted, "interrupted"))
+                } else {
+                    Ok(0)
+                }
+            }
+        }
+
+        let mut base_reader = InterruptedReader { init: false };
+        let mut reader = decompress(&mut base_reader, Some(CompressionType::Gzip));
+        let mut buffer = Vec::new();
+        reader.read_to_end(&mut buffer).unwrap();
+        assert_eq!(buffer, b"");
+    }
 }

src/formatting.rs

@@ -1,6 +1,5 @@
 use std::io::{self, Write};
 
-use serde::Serialize;
 use syntect::dumps::from_binary;
 use syntect::easy::HighlightLines;
 use syntect::highlighting::ThemeSet;
@@ -18,12 +17,16 @@ pub fn get_json_formatter(indent_level: usize) -> jsonxf::Formatter {
     fmt
 }
 
+/// Format a JSON value using serde. Unlike jsonxf this decodes escaped Unicode values.
+///
+/// Note that if parsing fails this function will stop midway through and return an error.
+/// It should only be used with known-valid JSON.
 pub fn serde_json_format(indent_level: usize, text: &str, write: impl Write) -> io::Result<()> {
     let indent = " ".repeat(indent_level);
     let formatter = serde_json::ser::PrettyFormatter::with_indent(indent.as_bytes());
-    let value = serde_json::from_str::<serde_json::Value>(text)?;
     let mut serializer = serde_json::Serializer::with_formatter(write, formatter);
-    value.serialize(&mut serializer)?;
+    let mut deserializer = serde_json::Deserializer::from_str(text);
+    serde_transcode::transcode(&mut deserializer, &mut serializer)?;
     Ok(())
 }