feat: add Config control

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- Add `zarrs{Get,Set}GlobalConfig`
+
 ### Changed
 - Bump `zarrs` to 0.22.8
 

src/config.rs

@@ -0,0 +1,62 @@
+use std::ffi::{c_char, CString};
+
+use ffi_support::FfiStr;
+
+use crate::{ZarrsResult, LAST_ERROR};
+
+/// Get the global zarrs configuration as a JSON string.
+///
+/// # Safety
+/// The caller must free the returned string with `zarrsStringFree`.
+///
+/// # Errors
+/// Returns `ZARRS_ERROR_CONFIG` if serialization fails.
+#[no_mangle]
+pub unsafe extern "C" fn zarrsGetGlobalConfig(pJsonString: *mut *mut c_char) -> ZarrsResult {
+    if pJsonString.is_null() {
+        *LAST_ERROR.lock().unwrap() = "pJsonString is null".to_string();
+        return ZarrsResult::ZARRS_ERROR_NULL_PTR;
+    }
+
+    let config = zarrs::config::global_config();
+
+    match serde_json::to_string_pretty(&*config) {
+        Ok(json_str) => match CString::new(json_str) {
+            Ok(cstring) => {
+                *pJsonString = cstring.into_raw();
+                ZarrsResult::ZARRS_SUCCESS
+            }
+            Err(e) => {
+                *LAST_ERROR.lock().unwrap() = format!("Failed to create C string: {e}");
+                ZarrsResult::ZARRS_ERROR_CONFIG
+            }
+        },
+        Err(e) => {
+            *LAST_ERROR.lock().unwrap() = format!("Failed to serialize config: {e}");
+            ZarrsResult::ZARRS_ERROR_CONFIG
+        }
+    }
+}
+
+/// Set the global zarrs configuration from a JSON string.
+///
+/// # Safety
+/// The caller must provide a valid JSON string representing a zarrs Config.
+///
+/// # Errors
+/// Returns `ZARRS_ERROR_CONFIG` if deserialization fails or the JSON is invalid.
+#[no_mangle]
+pub unsafe extern "C" fn zarrsSetGlobalConfig(jsonString: FfiStr) -> ZarrsResult {
+    let json_str = jsonString.as_str();
+
+    match serde_json::from_str::<zarrs::config::Config>(json_str) {
+        Ok(config) => {
+            *zarrs::config::global_config_mut() = config;
+            ZarrsResult::ZARRS_SUCCESS
+        }
+        Err(e) => {
+            *LAST_ERROR.lock().unwrap() = format!("Failed to deserialize config: {e}");
+            ZarrsResult::ZARRS_ERROR_CONFIG
+        }
+    }
+}

src/lib.rs

@@ -12,13 +12,15 @@ use once_cell::sync::Lazy;
 extern crate zarrs;
 
 mod array;
+mod config;
 mod group;
 mod storage;
 mod version;
 
 pub use array::{
     array_read::*, array_read_write::*, array_sharded::*, array_write::*, data_type::*, *,
 };
+pub use config::*;
 pub use group::{group_write::*, *};
 pub use storage::*;
 pub use version::*;
@@ -41,6 +43,7 @@ pub enum ZarrsResult {
     ZARRS_ERROR_UNSUPPORTED_DATA_TYPE = -12,
     ZARRS_ERROR_GROUP = -13,
     ZARRS_ERROR_INCOMPATIBLE_DIMENSIONALITY = -14,
+    ZARRS_ERROR_CONFIG = -15,
 }
 
 static LAST_ERROR: Lazy<Mutex<String>> = Lazy::new(|| Mutex::new("".to_string()));

zarrs.h

@@ -38,6 +38,7 @@ enum ZarrsResult
   ZARRS_ERROR_UNSUPPORTED_DATA_TYPE = -12,
   ZARRS_ERROR_GROUP = -13,
   ZARRS_ERROR_INCOMPATIBLE_DIMENSIONALITY = -14,
+  ZARRS_ERROR_CONFIG = -15,
 };
 #ifndef __cplusplus
 typedef int32_t ZarrsResult;
@@ -537,6 +538,17 @@ ZarrsResult zarrsDestroyStorage(ZarrsStorage storage);
  */
 ZarrsResult zarrsFreeString(char *string);
 
+/**
+ * Get the global zarrs configuration as a JSON string.
+ *
+ * # Safety
+ * The caller must free the returned string with `zarrsStringFree`.
+ *
+ * # Errors
+ * Returns `ZARRS_ERROR_CONFIG` if serialization fails.
+ */
+ZarrsResult zarrsGetGlobalConfig(char **pJsonString);
+
 /**
  * Get the group attributes as a JSON string.
  *
@@ -597,6 +609,17 @@ ZarrsResult zarrsOpenArrayRW(ZarrsStorage storage, const char* path, ZarrsArray
  */
 ZarrsResult zarrsOpenGroupRW(ZarrsStorage storage, const char* path, ZarrsGroup *pGroup);
 
+/**
+ * Set the global zarrs configuration from a JSON string.
+ *
+ * # Safety
+ * The caller must provide a valid JSON string representing a zarrs Config.
+ *
+ * # Errors
+ * Returns `ZARRS_ERROR_CONFIG` if deserialization fails or the JSON is invalid.
+ */
+ZarrsResult zarrsSetGlobalConfig(const char* jsonString);
+
 /**
  * Get the zarrs version.
  *