state functions moved to features

Cargo.toml

@@ -54,8 +54,8 @@ once_cell = { version = "1.19.0", optional = true }
 parking_lot = { version = "0.12.3", optional = true }
 parking_lot_rt = { version = "0.12.1", optional = true }
 quanta = { version = "=0.12.3", optional = true }
-serde_json = "1.0.134"
-rmp-serde = "1.3.0"
+serde_json = { version = "1.0.134", optional = true }
+rmp-serde = { version = "1.3.0", optional = true }
 
 [target.'cfg(windows)'.dependencies]
 parking_lot_rt = { version = "0.12.1" }
@@ -69,12 +69,15 @@ modbus = ["rmodbus"]
 openssl-vendored = ["busrt/openssl-vendored", "eva-common/openssl-vendored"]
 metrics = ["dep:metrics", "metrics-exporter-prometheus", "metrics-exporter-scope", "tokio", "quanta"]
 async = ["dep:parking_lot_rt"]
-full = ["eapi", "modbus", "metrics", "pipe", "rvideo", "rflow", "async"]
+full = ["eapi", "modbus", "metrics", "pipe", "rvideo", "rflow", "async", "json", "msgpack"]
 
 locking-default = ["dep:parking_lot", "rtsc/parking_lot", "rvideo?/locking-default", "rflow?/locking-default"]
 locking-rt = ["dep:parking_lot_rt", "rvideo?/locking-rt", "rflow?/locking-rt"]
 locking-rt-safe = ["rvideo?/locking-rt-safe", "rflow?/locking-rt-safe"]
 
+json = ["serde_json"]
+msgpack = ["rmp-serde"]
+
 default = ["locking-default"]
 
 [dev-dependencies]

src/lib.rs

@@ -108,6 +108,7 @@ pub mod supervisor;
 pub mod thread_rt;
 
 /// State helper functions
+#[cfg(any(feature = "json", feature = "msgpack"))]
 pub mod state;
 
 /// The crate result type

src/state.rs

@@ -5,42 +5,55 @@ use serde::{de::DeserializeOwned, Serialize};
 use crate::{Error, Result};
 
 enum Format {
+    #[cfg(feature = "json")]
     Json,
+    #[cfg(feature = "msgpack")]
     Msgpack,
 }
 
 impl Format {
-    fn from_path<P: AsRef<Path>>(path: P) -> Self {
+    fn from_path<P: AsRef<Path>>(path: P) -> Result<Self> {
         match path
             .as_ref()
             .extension()
             .map_or("", |ext| ext.to_str().unwrap())
         {
-            "json" => Self::Json,
-            _ => Self::Msgpack,
+            #[cfg(feature = "json")]
+            "json" => Ok(Self::Json),
+            #[cfg(not(feature = "json"))]
+            "json" => Err(Error::Unimplemented),
+            #[cfg(feature = "msgpack")]
+            _ => Ok(Self::Msgpack),
+            #[cfg(not(feature = "msgpack"))]
+            _ => Err(Error::Unimplemented),
         }
     }
 }
 
-/// Load the state from a file. If "json" extension is specified, the state is loaded in JSON
-/// format. All errors, including missing state file, must be handled by the caller.
+/// Load the state from a file. If "json" extension is specified, the state is loaded from JSON
+/// format (requires crate 'json' feature), otherwise from MessagePack (requires crate 'msgpack'
+/// feature). All errors, including missing state file, must be handled by the caller.
 pub fn load<S: DeserializeOwned, P: AsRef<Path>>(path: P) -> Result<S> {
-    let format = Format::from_path(&path);
+    let format = Format::from_path(&path)?;
     let file = File::open(&path)?;
     let data = match format {
+        #[cfg(feature = "json")]
         Format::Json => serde_json::from_reader(file).map_err(Error::failed)?,
+        #[cfg(feature = "msgpack")]
         Format::Msgpack => rmp_serde::from_read(file).map_err(Error::failed)?,
     };
     Ok(data)
 }
 
-/// Save the state to a file. If "json" extension is specified, the state is saved in JSON
-/// format. Otherwise it is saved in MessagePack format.
+/// Save the state to a file. If "json" extension is specified, the state is saved in JSON format
+/// (requires crate 'json' feature), otherwise in MessagePack (requires crate 'msgpack' feature).
 pub fn save<S: Serialize, P: AsRef<Path>>(path: P, state: &S) -> Result<()> {
-    let format = Format::from_path(&path);
+    let format = Format::from_path(&path)?;
     let mut file = File::create(&path)?;
     let data = match format {
+        #[cfg(feature = "json")]
         Format::Json => serde_json::to_vec(state).map_err(Error::failed)?,
+        #[cfg(feature = "msgpack")]
         Format::Msgpack => rmp_serde::to_vec_named(state).map_err(Error::failed)?,
     };
     file.write_all(&data)?;