Put metadata-related code into submodule

Author: alexdewar

src/output.rs

@@ -14,12 +14,12 @@ use std::fs;
 use std::fs::File;
 use std::path::{Path, PathBuf};
 
+pub mod metadata;
+use metadata::write_metadata;
+
 /// The root folder in which model-specific output folders will be created
 const OUTPUT_DIRECTORY_ROOT: &str = "muse2_results";
 
-/// The output file name for metadata
-const METADATA_FILE_NAME: &str = "metadata.toml";
-
 /// The output file name for commodity flows
 const COMMODITY_FLOWS_FILE_NAME: &str = "commodity_flows.csv";
 
@@ -66,72 +66,6 @@ pub fn create_output_directory(output_dir: &Path) -> Result<()> {
     Ok(())
 }
 
-#[derive(Serialize, Default)]
-struct Metadata<'a> {
-    program: ProgramMetadata<'a>,
-}
-
-/// Information about the version and build of MUSE
-#[derive(Serialize)]
-struct ProgramMetadata<'a> {
-    /// The program name
-    name: &'a str,
-    /// The program version as specified in Cargo.toml
-    version: &'a str,
-    /// The target architecture for the build (e.g. x86_64-unknown-linux-gnu)
-    target: &'a str,
-    /// Whether it is a debug build
-    is_debug: bool,
-    /// The version of rustc used to compile MUSE
-    rustc_version: &'a str,
-    /// When MUSE was built
-    build_time_utc: &'a str,
-    /// The git commit hash for the version of MUSE (if known)
-    git_commit_hash: String,
-}
-
-/// Information about the program build via `built` crate
-mod built_info {
-    // The file has been placed there by the build script.
-    include!(concat!(env!("OUT_DIR"), "/built.rs"));
-}
-
-/// Get information about program version from git
-fn get_git_hash() -> String {
-    let Some(hash) = built_info::GIT_COMMIT_HASH_SHORT else {
-        return "unknown".into();
-    };
-
-    if built_info::GIT_DIRTY == Some(true) {
-        format!("{hash}-dirty")
-    } else {
-        hash.into()
-    }
-}
-
-impl Default for ProgramMetadata<'_> {
-    fn default() -> Self {
-        Self {
-            name: built_info::PKG_NAME,
-            version: built_info::PKG_VERSION,
-            target: built_info::TARGET,
-            is_debug: built_info::DEBUG,
-            rustc_version: built_info::RUSTC_VERSION,
-            build_time_utc: built_info::BUILT_TIME_UTC,
-            git_commit_hash: get_git_hash(),
-        }
-    }
-}
-
-/// Write metadata to the specified output path in TOML format
-fn write_metadata(output_path: &Path) -> Result<()> {
-    let metadata = Metadata::default();
-    let file_path = output_path.join(METADATA_FILE_NAME);
-    fs::write(&file_path, toml::to_string(&metadata)?)?;
-
-    Ok(())
-}
-
 /// Used to represent assets in assets output CSV file and other output files.
 ///
 /// NB: It may be better to represent assets in these other files with IDs instead, see

src/output/metadata.rs

@@ -0,0 +1,74 @@
+//! Code for writing metadata to file
+use anyhow::Result;
+use serde::Serialize;
+use std::fs;
+use std::path::Path;
+
+/// The output file name for metadata
+const METADATA_FILE_NAME: &str = "metadata.toml";
+
+/// Information about the program build via `built` crate
+mod built_info {
+    // The file has been placed there by the build script.
+    include!(concat!(env!("OUT_DIR"), "/built.rs"));
+}
+
+/// Get information about program version from git
+fn get_git_hash() -> String {
+    let Some(hash) = built_info::GIT_COMMIT_HASH_SHORT else {
+        return "unknown".into();
+    };
+
+    if built_info::GIT_DIRTY == Some(true) {
+        format!("{hash}-dirty")
+    } else {
+        hash.into()
+    }
+}
+
+#[derive(Serialize, Default)]
+struct Metadata<'a> {
+    program: ProgramMetadata<'a>,
+}
+
+/// Information about the version and build of MUSE
+#[derive(Serialize)]
+struct ProgramMetadata<'a> {
+    /// The program name
+    name: &'a str,
+    /// The program version as specified in Cargo.toml
+    version: &'a str,
+    /// The target architecture for the build (e.g. x86_64-unknown-linux-gnu)
+    target: &'a str,
+    /// Whether it is a debug build
+    is_debug: bool,
+    /// The version of rustc used to compile MUSE
+    rustc_version: &'a str,
+    /// When MUSE was built
+    build_time_utc: &'a str,
+    /// The git commit hash for the version of MUSE (if known)
+    git_commit_hash: String,
+}
+
+impl Default for ProgramMetadata<'_> {
+    fn default() -> Self {
+        Self {
+            name: built_info::PKG_NAME,
+            version: built_info::PKG_VERSION,
+            target: built_info::TARGET,
+            is_debug: built_info::DEBUG,
+            rustc_version: built_info::RUSTC_VERSION,
+            build_time_utc: built_info::BUILT_TIME_UTC,
+            git_commit_hash: get_git_hash(),
+        }
+    }
+}
+
+/// Write metadata to the specified output path in TOML format
+pub fn write_metadata(output_path: &Path) -> Result<()> {
+    let metadata = Metadata::default();
+    let file_path = output_path.join(METADATA_FILE_NAME);
+    fs::write(&file_path, toml::to_string(&metadata)?)?;
+
+    Ok(())
+}