test_encoding/
test_encoding.rs

1// SPDX-License-Identifier: Apache-2.0 OR MIT
2// Copyright (c) 2025-2026 naskel.com
3
4// Test RTPS encoding to verify correct bytes
5// Run with: cargo run --example test_encoding
6
7use hdds_micro::cdr::CdrEncoder;
8use hdds_micro::core::{MicroParticipant, MicroWriter};
9use hdds_micro::rtps::{EntityId, Locator};
10use hdds_micro::transport::NullTransport;
11
12fn main() {
13    println!("=== HDDS Micro Encoding Test ===\n");
14
15    // Create a null transport (captures sent data)
16    let transport = NullTransport::default();
17
18    // Create participant
19    let mut participant = MicroParticipant::new(0, transport).unwrap();
20    let guid_prefix = participant.guid_prefix();
21    let entity_id = participant.allocate_entity_id(true);
22
23    println!("GUID Prefix: {:02X?}", guid_prefix.as_bytes());
24    println!("Entity ID: {:02X?}", entity_id.as_bytes());
25
26    // Create writer (for demonstration, not used in this encoding test)
27    let dest = Locator::udpv4([239, 255, 0, 1], 7400);
28    let _writer = MicroWriter::new(guid_prefix, entity_id, "test/topic", dest).unwrap();
29
30    // Encode temperature-like payload: sensor_id(4) + value(4) + timestamp(8)
31    let mut buf = [0u8; 32];
32    let mut encoder = CdrEncoder::new(&mut buf);
33    encoder.encode_u32(0x42).unwrap(); // sensor_id
34    encoder.encode_f32(25.5).unwrap(); // temperature
35    encoder.encode_u64(12345678).unwrap(); // timestamp
36    let payload = encoder.finish();
37
38    println!("Payload ({} bytes): {:02X?}", payload.len(), payload);
39
40    // Build the packet manually to inspect bytes
41    let mut packet = [0u8; 256];
42
43    // RTPS Header (20 bytes)
44    let header = hdds_micro::rtps::RtpsHeader::new(
45        hdds_micro::rtps::ProtocolVersion::RTPS_2_5,
46        hdds_micro::rtps::VendorId::HDDS,
47        guid_prefix,
48    );
49    let header_len = header.encode(&mut packet).unwrap();
50
51    // DATA submessage
52    let data = hdds_micro::rtps::submessages::Data::new(
53        EntityId::UNKNOWN,
54        entity_id,
55        hdds_micro::rtps::SequenceNumber::new(1),
56    );
57    let data_len = data.encode_header(&mut packet[header_len..]).unwrap();
58
59    // Copy payload
60    let payload_offset = header_len + data_len;
61    packet[payload_offset..payload_offset + payload.len()].copy_from_slice(payload);
62
63    let total_len = payload_offset + payload.len();
64
65    // Update octets_to_next
66    let octets_to_next = (20 + payload.len()) as u16;
67    packet[header_len + 2] = (octets_to_next & 0xff) as u8;
68    packet[header_len + 3] = ((octets_to_next >> 8) & 0xff) as u8;
69
70    println!("\n=== Complete RTPS Packet ({} bytes) ===", total_len);
71
72    // Print in rows of 16
73    for i in (0..total_len).step_by(16) {
74        print!("{:04X}  ", i);
75        for &byte in &packet[i..std::cmp::min(i + 16, total_len)] {
76            print!("{:02X} ", byte);
77        }
78        println!();
79    }
80
81    println!("\n=== Key Bytes Analysis ===");
82    println!(
83        "Bytes 0-3 (RTPS magic): {:02X} {:02X} {:02X} {:02X} = '{}'",
84        packet[0],
85        packet[1],
86        packet[2],
87        packet[3],
88        std::str::from_utf8(&packet[0..4]).unwrap_or("???")
89    );
90    println!("Bytes 4-5 (version): {:02X} {:02X}", packet[4], packet[5]);
91    println!("Bytes 6-7 (vendor): {:02X} {:02X}", packet[6], packet[7]);
92    println!("Bytes 8-19 (GUID prefix): {:02X?}", &packet[8..20]);
93    println!(
94        "Byte 20 (submsg kind): {:02X} (expected: 0x15 for DATA)",
95        packet[20]
96    );
97    println!(
98        "Byte 21 (submsg flags): {:02X} (expected: 0x05)",
99        packet[21]
100    );
101    println!(
102        "Bytes 22-23 (octetsToNext): {:02X} {:02X} = {} bytes",
103        packet[22],
104        packet[23],
105        u16::from_le_bytes([packet[22], packet[23]])
106    );
107
108    // Verify
109    if packet[20] == 0x15 {
110        println!("\n✓ Submessage kind is correct (0x15)");
111    } else {
112        println!(
113            "\n✗ ERROR: Submessage kind is wrong: 0x{:02X} instead of 0x15",
114            packet[20]
115        );
116    }
117}
test_encoding/test_encoding.rs

test_encoding/
test_encoding.rs
