refactoring report_block and impl unknown report block

Author: Rain Liu

src/extended_report/dlrr.rs

@@ -0,0 +1,81 @@
+use super::*;
+
+/// DLRRReportBlock encodes a DLRR Report Block as described in
+/// RFC 3611 section 4.5.
+///
+///  0                   1                   2                   3
+///  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+/// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+/// |     BT=5      |   reserved    |         block length          |
+/// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+/// |                 SSRC_1 (ssrc of first receiver)               | sub-
+/// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ block
+/// |                         last RR (LRR)                         |   1
+/// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+/// |                   delay since last RR (DLRR)                  |
+/// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+/// |                 SSRC_2 (ssrc of second receiver)              | sub-
+/// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ block
+/// :                               ...                             :   2
+/// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
+#[derive(Debug, Default, PartialEq, Clone)]
+pub struct DLRRReportBlock {
+    pub xr_header: XRHeader,
+    pub reports: Vec<DLRRReport>,
+}
+
+impl fmt::Display for DLRRReportBlock {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+/// DLRRReport encodes a single report inside a DLRRReportBlock.
+#[derive(Debug, Default, PartialEq, Clone)]
+pub struct DLRRReport {
+    pub ssrc: u32,
+    pub last_rr: u32,
+    pub dlrr: u32,
+}
+
+impl fmt::Display for DLRRReport {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+impl ReportBlock for DLRRReportBlock {
+    /// destination_ssrc returns an array of ssrc values that this report block refers to.
+    fn destination_ssrc(&self) -> Vec<u32> {
+        let mut ssrc = Vec::with_capacity(self.reports.len());
+        for r in &self.reports {
+            ssrc.push(r.ssrc);
+        }
+        ssrc
+    }
+
+    fn setup_block_header(&mut self) {
+        self.xr_header.block_type = ReportBlockType::DLRR;
+        self.xr_header.type_specific = 0;
+        self.xr_header.block_length = (self.raw_size() / 4 - 1) as u16;
+    }
+
+    fn unpack_block_header(&mut self) {}
+
+    fn raw_size(&self) -> usize {
+        4 + self.reports.len() * 4 * 3
+    }
+
+    fn as_any(&self) -> &(dyn Any + Send + Sync) {
+        self
+    }
+    fn equal(&self, other: &(dyn ReportBlock + Send + Sync)) -> bool {
+        other
+            .as_any()
+            .downcast_ref::<DLRRReportBlock>()
+            .map_or(false, |a| self == a)
+    }
+    fn cloned(&self) -> Box<dyn ReportBlock + Send + Sync> {
+        Box::new(self.clone())
+    }
+}