[c] Support vector search materialized read in C FFI bindings (#537)

Author: JunRuiLee

bindings/c/Cargo.toml

@@ -35,3 +35,9 @@ futures = "0.3"
 arrow = { workspace = true }
 arrow-array = { workspace = true }
 arrow-schema = { workspace = true }
+
+[dev-dependencies]
+# Test-only: the vector-search integration tests build a real primary-key vindex
+# IVF-flat ANN segment fixture in-process. Versions match crates/paimon.
+bytes = "1.7.1"
+paimon-vindex-core = "0.2.0"

bindings/c/src/lib.rs

@@ -27,6 +27,7 @@ mod table;
 #[cfg(test)]
 mod tests;
 mod types;
+mod vector_search;
 mod write;
 
 use std::sync::OnceLock;

bindings/c/src/result.rs

@@ -78,6 +78,12 @@ pub struct paimon_result_next_batch {
     pub error: *mut paimon_error,
 }
 
+#[repr(C)]
+pub struct paimon_result_vector_search_builder {
+    pub builder: *mut paimon_vector_search_builder,
+    pub error: *mut paimon_error,
+}
+
 // === Write/Commit result types ===
 
 #[repr(C)]

bindings/c/src/table.rs

@@ -658,7 +658,8 @@ pub unsafe extern "C" fn paimon_record_batch_reader_next(
 /// Free a paimon_record_batch_reader.
 ///
 /// # Safety
-/// Only call with a reader returned from `paimon_table_read_to_arrow`.
+/// Only call with a reader returned from `paimon_table_read_to_arrow` or
+/// `paimon_vector_search_builder_execute_read`.
 #[no_mangle]
 pub unsafe extern "C" fn paimon_record_batch_reader_free(reader: *mut paimon_record_batch_reader) {
     if !reader.is_null() {