xds module : add setter function for TS_START_OF_XDS from C code

Author: vatsalkeshav

src/lib_ccx/ccx_decoders_xds.c

@@ -16,6 +16,9 @@ extern void ccxr_do_end_of_xds(
     struct ccx_decoders_xds_context *ctx,
     unsigned char expected_checksum);
 
+// declare setter function for TS_START_OF_XDS from C code
+extern void ccxr_set_ts_start_of_xds(long long value);
+
 LLONG ts_start_of_xds = -1; // Time at which we switched to XDS mode, =-1 hasn't happened yet
 
 static const char *XDSclasses[] =
@@ -907,6 +910,7 @@ int xds_do_misc(struct ccx_decoders_xds_context *ctx)
 void do_end_of_xds(struct cc_subtitle *sub, struct ccx_decoders_xds_context *ctx, unsigned char expected_checksum)
 {
 #ifndef DISABLE_RUST
+	ccxr_set_ts_start_of_xds(ts_start_of_xds);
 	ccxr_do_end_of_xds(sub, ctx, expected_checksum); // use the rust implementation
 	return;
 #endif

src/rust/src/xds/handlers.rs

@@ -51,10 +51,10 @@ use libc::malloc;
 
 use crate::xds::types::*;
 
-static TS_START_OF_XDS: AtomicI64 = AtomicI64::new(-1); // Time at which we switched to XDS mode, =-1 hasn't happened yet
-                                                        // Usage example:
-                                                        // TS_START_OF_XDS.store(new_value, Ordering::SeqCst);
-                                                        // let value = TS_START_OF_XDS.load(Ordering::SeqCst);
+pub static TS_START_OF_XDS: AtomicI64 = AtomicI64::new(-1); // Time at which we switched to XDS mode, =-1 hasn't happened yet
+                                                            // Usage example:
+                                                            // TS_START_OF_XDS.store(new_value, Ordering::SeqCst);
+                                                            // let value = TS_START_OF_XDS.load(Ordering::SeqCst);
 
 /// Represents failures during XDS string writing or processing.
 pub enum XDSError {

src/rust/src/xds/mod.rs

@@ -17,9 +17,10 @@ pub mod types;
 
 use crate::bindings::*;
 use crate::ctorust::FromCType;
-use crate::xds::handlers::do_end_of_xds;
+use crate::xds::handlers::{do_end_of_xds, TS_START_OF_XDS};
 use crate::xds::types::{copy_xds_context_from_rust_to_c, CcxDecodersXdsContext};
 use std::os::raw::c_int;
+use std::sync::atomic::Ordering;
 
 /// FFI wrapper for `do_end_of_xds`.
 ///
@@ -82,3 +83,9 @@ pub unsafe extern "C" fn ccxr_process_xds_bytes(
     // Write changes back to C
     copy_xds_context_from_rust_to_c(ctx, &rust_ctx);
 }
+
+/// setter function for TS_START_OF_XDS from C code
+#[no_mangle]
+pub extern "C" fn ccxr_set_ts_start_of_xds(value: i64) {
+    TS_START_OF_XDS.store(value, Ordering::SeqCst);
+}