xds module : fix minor issue with timing ctx resulting in missing xds data in output

Author: vatsalkeshav

src/rust/src/libccxr_exports/time.rs

@@ -138,7 +138,7 @@ pub unsafe extern "C" fn ccxr_millis_to_time(
 /// # Safety
 ///
 /// `ctx` should not be null.
-unsafe fn generate_timing_context(ctx: *const ccx_common_timing_ctx) -> TimingContext {
+pub unsafe fn generate_timing_context(ctx: *const ccx_common_timing_ctx) -> TimingContext {
     let pts_set = match (*ctx).pts_set {
         0 => PtsSet::No,
         1 => PtsSet::Received,

src/rust/src/xds/handlers.rs

@@ -87,19 +87,20 @@ pub unsafe fn write_xds_string(
     let data_element = &mut *new_data.add(sub.nb_data as usize);
     let c_str = CString::new(p).map_err(|_| XDSError::Err)?;
 
-    let len = c_str.as_bytes_with_nul().len();
-    let ptr = unsafe { malloc(len) as *mut i8 }; // fixing c/rust mem mismatch
+    let len = c_str.as_bytes().len(); // length w/o null terminator - matching C's vsnprintf return
+    let alloc_len = len + 1; // allocate space for null terminator
+    let ptr = unsafe { malloc(alloc_len) as *mut i8 }; // fixing c/rust mem mismatch
     if ptr.is_null() {
         return Err(XDSError::Err);
     }
     unsafe {
-        std::ptr::copy_nonoverlapping(c_str.as_ptr(), ptr, len); // fixing c/rust mem mismatch
+        std::ptr::copy_nonoverlapping(c_str.as_ptr(), ptr, alloc_len); // copy including null terminator
     }
 
     data_element.format = 2;
     data_element.start_time = ts_start_of_xds;
     if let Some(timing) = ctx.timing.as_mut() {
-        data_element.end_time = get_fts(timing, CaptionField::Cea708).millis();
+        data_element.end_time = get_fts(timing, CaptionField::Field2).millis();
     }
     data_element.xds_str = ptr;
     data_element.xds_len = len;
@@ -179,15 +180,15 @@ impl CcxDecodersXdsContext<'_> {
             for i in 0..NUM_XDS_BUFFERS {
                 if self.xds_buffers[i].in_use != 0
                     && self.xds_buffers[i]
-                        .xds_class
-                        .map(|c| c.to_c_int())
-                        .unwrap_or(-1)
-                        == xds_class
+                    .xds_class
+                    .map(|c| c.to_c_int())
+                    .unwrap_or(-1)
+                    == xds_class
                     && self.xds_buffers[i]
-                        .xds_type
-                        .map(|t| t.to_c_int())
-                        .unwrap_or(-1)
-                        == lo as i32
+                    .xds_type
+                    .map(|t| t.to_c_int())
+                    .unwrap_or(-1)
+                    == lo as i32
                 {
                     matching_buf = i as i32;
                     break;

src/rust/src/xds/mod.rs

@@ -17,6 +17,7 @@ pub mod types;
 
 use crate::bindings::*;
 use crate::ctorust::FromCType;
+use crate::libccxr_exports::time::generate_timing_context;
 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;
@@ -47,6 +48,15 @@ pub unsafe extern "C" fn ccxr_do_end_of_xds(
         None => return,
     };
 
+    // populate timing from the C ctx's timing ptr
+    let c_timing_ptr = (*ctx).timing;
+    let mut timing_ctx = if !c_timing_ptr.is_null() {
+        Some(generate_timing_context(c_timing_ptr))
+    } else {
+        None
+    };
+    rust_ctx.timing = timing_ctx.as_mut();
+
     // Call the Rust implementation
     do_end_of_xds(&mut *sub, &mut rust_ctx, expected_checksum);
 

src/rust/src/xds/types.rs

@@ -503,6 +503,7 @@ pub unsafe fn copy_xds_context_from_rust_to_c(
     if bitstream_ptr.is_null() {
         return;
     }
+    let original_timing = (*bitstream_ptr).timing;
     let output = ccx_decoders_xds_context {
         current_xds_min: rust_ctx.current_xds_min,
         current_xds_hour: rust_ctx.current_xds_hour,
@@ -522,7 +523,7 @@ pub unsafe fn copy_xds_context_from_rust_to_c(
         cur_xds_payload: rust_ctx.cur_xds_payload,
         cur_xds_payload_length: rust_ctx.cur_xds_payload_length,
         cur_xds_packet_type: rust_ctx.cur_xds_packet_type,
-        timing: null_mut(),
+        timing: original_timing,
         current_ar_start: rust_ctx.current_ar_start,
         current_ar_end: rust_ctx.current_ar_end,
         xds_write_to_file: if rust_ctx.xds_write_to_file { 1 } else { 0 },