rust: ability to convert to common serde map structure

rust/sbp/src/json/convert.rs

@@ -0,0 +1,40 @@
+use std::convert::TryFrom;
+
+use bytes::BytesMut;
+
+use crate::Sbp;
+
+use super::{JsonError, JsonOutput};
+
+/// A JSON map holding all the fields and metadata of the
+/// SBP message.  This is format used by the output of the
+/// `sbp2json` tool, for example:
+///
+/// {
+///   "crc": 49084,
+///   "length": 52,
+///   "msg_type": 1025,
+///   "msg_name": "MSG_LOG",
+///   "payload": "BHNicCBuZXcgY2xpZW50IGNvbm5lY3Rpb24gOjpmZmZmOjE5Mi4xNjguMC4xMDo2MTQ1MA==",
+///   "preamble": 85,
+///   "sender": 4096,
+///   "level": 4,
+///   "text": "sbp new client connection ::ffff:192.168.0.10:61450"
+/// }
+pub type JsonMap = serde_json::Map<String, serde_json::Value>;
+
+impl TryFrom<crate::Sbp> for JsonMap {
+    type Error = JsonError;
+
+    fn try_from(msg: Sbp) -> Result<Self, Self::Error> {
+        let mut frame = BytesMut::with_capacity(crate::BUFLEN);
+        let mut payload = String::with_capacity(crate::BUFLEN);
+        let output = JsonOutput {
+            common: super::ser::get_common_fields(&mut payload, &mut frame, &msg)?,
+            msg: &msg,
+        };
+        let output = serde_json::to_value(output)?;
+        let output: serde_json::Map<String, serde_json::Value> = serde_json::from_value(output)?;
+        Ok(output)
+    }
+}

rust/sbp/src/json/mod.rs

@@ -1,5 +1,6 @@
 //! Encode/decode SBP messages as JSON.
 
+mod convert;
 mod de;
 mod ser;
 
@@ -17,6 +18,8 @@ pub use de::{iter_json2json_messages, iter_messages, iter_messages_from_fields};
 
 pub use ser::{to_vec, to_writer, Json2JsonEncoder, JsonEncoder};
 
+pub use convert::JsonMap;
+
 #[derive(Debug, Deserialize)]
 #[serde(untagged)]
 enum JsonInput {

rust/sbp/src/json/ser.rs

@@ -5,10 +5,11 @@ use dencode::{Encoder, FramedWrite, IterSinkExt};
 use serde::Serialize;
 use serde_json::{ser::Formatter, Serializer};
 
-use super::{JsonError, JsonOutput};
-
 use crate::{
-    json::{CommonJson, HaskellishFloatFormatter, Json2JsonInput, Json2JsonOutput},
+    json::{
+        CommonJson, HaskellishFloatFormatter, Json2JsonInput, Json2JsonOutput, JsonError,
+        JsonOutput,
+    },
     messages::Sbp,
     SbpMessage, BUFLEN, CRC_LEN, HEADER_LEN, PREAMBLE,
 };
@@ -212,7 +213,7 @@ impl<F: Formatter + Clone> Encoder<Json2JsonInput> for Json2JsonEncoderInner<F>
     }
 }
 
-fn get_common_fields<'a, M: SbpMessage>(
+pub(super) fn get_common_fields<'a, M: SbpMessage>(
     payload_buf: &'a mut String,
     frame_buf: &'a mut BytesMut,
     msg: &M,

test_data/benchmark_main.py

@@ -11,10 +11,10 @@
 
 # How much faster Rust should be than other implementations
 RATIOS_SBP2JSON = {
-    "haskell": 2.12,
-    "python": 17,
-    "kaitai_python": 3.7,
-    "kaitai_perl": 18,
+    "haskell"       : 3.01,
+    "python"        : 23.38,
+    "kaitai_python" : 5.00,
+    "kaitai_perl"   : 18,
 }
 
 RATIOS_JSON2SBP = {