Refactor binary download logic in build.rs to check for existing SHERPA_LIB_PATH before downloading. This change ensures that libraries are only fetched if the environment variable is not set, improving efficiency and preventing unnecessary downloads. Additionally, fallback handling for manual builds is maintained.

Author: BenLocal

crates/sherpa-rs-sys/build.rs

@@ -360,68 +360,70 @@ fn main() {
 
     #[cfg(feature = "download-binaries")]
     {
-        // Download libraries, cache and set SHERPA_LIB_PATH
-        use download_binaries::{extract_tbz, fetch_file, get_cache_dir, sha256, DIST_TABLE};
-        debug_log!("Download binaries enabled");
-        // debug_log!("Dist table: {:?}", DIST_TABLE.targets);
-        // Try download sherpa libs and set SHERPA_LIB_PATH
-        if let Some(dist) = DIST_TABLE.get(&target, &mut is_dynamic) {
-            debug_log!("is_dynamic after: {}", is_dynamic);
-            optional_dist = Some(dist.clone());
-            let mut cache_dir = if let Some(dir) = get_cache_dir() {
-                dir.join(target.clone()).join(&dist.checksum)
-            } else {
-                println!("cargo:warning=Could not determine cache directory, using OUT_DIR");
-                PathBuf::from(env::var("OUT_DIR").unwrap())
-            };
-            if fs::create_dir_all(&cache_dir).is_err() {
-                println!("cargo:warning=Could not create cache directory, using OUT_DIR");
-                cache_dir = env::var("OUT_DIR").unwrap().into();
-            }
-            debug_log!("Cache dir: {}", cache_dir.display());
-
-            let lib_dir = cache_dir.join(&dist.name);
-
-            // if is mobile then check if cache dir not empty
-            // Sherpa uses special directory structure for mobile
-            let cache_dir_empty = cache_dir
-                .read_dir()
-                .map(|mut entries| entries.next().is_none())
-                .unwrap_or(true);
-
-            if (is_mobile && cache_dir_empty) || (!is_mobile && !lib_dir.exists()) {
-                let downloaded_file = fetch_file(&dist.url);
-                let hash = sha256(&downloaded_file);
-                verify_checksum(&hash, &dist.checksum);
-                extract_tbz(&downloaded_file, &cache_dir);
-            } else {
-                debug_log!("Skip fetch file. Using cache from {}", lib_dir.display());
-            }
-
-            // In Android, we need to set SHERPA_LIB_PATH to the cache directory sincie it has jniLibs
-            if is_mobile {
-                env::set_var("SHERPA_LIB_PATH", &cache_dir);
-            } else {
-                env::set_var("SHERPA_LIB_PATH", cache_dir.join(&dist.name));
-            }
+        if let Err(_) = env::var("SHERPA_LIB_PATH") {
+            // Download libraries, cache and set SHERPA_LIB_PATH
+            use download_binaries::{extract_tbz, fetch_file, get_cache_dir, sha256, DIST_TABLE};
+            debug_log!("Download binaries enabled");
+            // debug_log!("Dist table: {:?}", DIST_TABLE.targets);
+            // Try download sherpa libs and set SHERPA_LIB_PATH
+            if let Some(dist) = DIST_TABLE.get(&target, &mut is_dynamic) {
+                debug_log!("is_dynamic after: {}", is_dynamic);
+                optional_dist = Some(dist.clone());
+                let mut cache_dir = if let Some(dir) = get_cache_dir() {
+                    dir.join(target.clone()).join(&dist.checksum)
+                } else {
+                    println!("cargo:warning=Could not determine cache directory, using OUT_DIR");
+                    PathBuf::from(env::var("OUT_DIR").unwrap())
+                };
+                if fs::create_dir_all(&cache_dir).is_err() {
+                    println!("cargo:warning=Could not create cache directory, using OUT_DIR");
+                    cache_dir = env::var("OUT_DIR").unwrap().into();
+                }
+                debug_log!("Cache dir: {}", cache_dir.display());
+
+                let lib_dir = cache_dir.join(&dist.name);
+
+                // if is mobile then check if cache dir not empty
+                // Sherpa uses special directory structure for mobile
+                let cache_dir_empty = cache_dir
+                    .read_dir()
+                    .map(|mut entries| entries.next().is_none())
+                    .unwrap_or(true);
+
+                if (is_mobile && cache_dir_empty) || (!is_mobile && !lib_dir.exists()) {
+                    let downloaded_file = fetch_file(&dist.url);
+                    let hash = sha256(&downloaded_file);
+                    verify_checksum(&hash, &dist.checksum);
+                    extract_tbz(&downloaded_file, &cache_dir);
+                } else {
+                    debug_log!("Skip fetch file. Using cache from {}", lib_dir.display());
+                }
 
-            debug_log!("dist libs: {:?}", dist.libs);
-            if let Some(libs) = dist.libs {
-                for lib in libs.iter() {
-                    let lib_path = cache_dir.join(lib);
-                    let lib_parent = lib_path.parent().unwrap();
-                    add_search_path(lib_parent);
+                // In Android, we need to set SHERPA_LIB_PATH to the cache directory sincie it has jniLibs
+                if is_mobile {
+                    env::set_var("SHERPA_LIB_PATH", &cache_dir);
+                } else {
+                    env::set_var("SHERPA_LIB_PATH", cache_dir.join(&dist.name));
                 }
 
-                sherpa_libs = libs
-                    .iter()
-                    .map(download_binaries::extract_lib_name)
-                    .collect();
+                debug_log!("dist libs: {:?}", dist.libs);
+                if let Some(libs) = dist.libs {
+                    for lib in libs.iter() {
+                        let lib_path = cache_dir.join(lib);
+                        let lib_parent = lib_path.parent().unwrap();
+                        add_search_path(lib_parent);
+                    }
+
+                    sherpa_libs = libs
+                        .iter()
+                        .map(download_binaries::extract_lib_name)
+                        .collect();
+                } else {
+                    sherpa_libs = extract_lib_names(&lib_dir, is_dynamic, &target_os);
+                }
             } else {
-                sherpa_libs = extract_lib_names(&lib_dir, is_dynamic, &target_os);
+                println!("cargo:warning=Failed to download binaries. fallback to manual build.");
             }
-        } else {
-            println!("cargo:warning=Failed to download binaries. fallback to manual build.");
         }
     }