[feat](trx-server): gzip-compress history replay blob

Add flate2 dependency and a new AUDIO_MSG_HISTORY_COMPRESSED (0x0a)
wire type. The server gzip-compresses the full history blob before
sending; JSON history compresses ~10-20x so both transfer size and
client wait time drop significantly. The client decompresses and
dispatches sub-messages from the embedded framed stream. MAX_PAYLOAD_SIZE
is kept at 1 MB for normal messages; a separate 16 MB limit is applied
only to the compressed history type.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-client/Cargo.toml

@@ -8,6 +8,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+flate2 = { workspace = true }
 tokio = { workspace = true, features = ["full"] }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
@@ -27,4 +28,4 @@ trx-frontend-http-json = { path = "trx-frontend/trx-frontend-http-json" }
 trx-frontend-rigctl = { path = "trx-frontend/trx-frontend-rigctl" }
 
 [features]
-default = []
+default = []

src/trx-client/src/audio_client.rs

@@ -10,6 +10,8 @@ use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
 use bytes::Bytes;
+use flate2::read::GzDecoder;
+use std::io::Read as _;
 use tokio::io::BufReader;
 use tokio::net::TcpStream;
 use tokio::sync::{broadcast, mpsc, watch};
@@ -19,8 +21,9 @@ use trx_frontend::RemoteRigEntry;
 
 use trx_core::audio::{
     read_audio_msg, write_audio_msg, AudioStreamInfo, AUDIO_MSG_AIS_DECODE, AUDIO_MSG_APRS_DECODE,
-    AUDIO_MSG_CW_DECODE, AUDIO_MSG_FT8_DECODE, AUDIO_MSG_HF_APRS_DECODE, AUDIO_MSG_RX_FRAME,
-    AUDIO_MSG_STREAM_INFO, AUDIO_MSG_TX_FRAME, AUDIO_MSG_VDES_DECODE, AUDIO_MSG_WSPR_DECODE,
+    AUDIO_MSG_CW_DECODE, AUDIO_MSG_FT8_DECODE, AUDIO_MSG_HF_APRS_DECODE,
+    AUDIO_MSG_HISTORY_COMPRESSED, AUDIO_MSG_RX_FRAME, AUDIO_MSG_STREAM_INFO, AUDIO_MSG_TX_FRAME,
+    AUDIO_MSG_VDES_DECODE, AUDIO_MSG_WSPR_DECODE,
 };
 use trx_core::decode::DecodedMessage;
 
@@ -147,6 +150,34 @@ async fn handle_audio_connection(
                 Ok((AUDIO_MSG_RX_FRAME, payload)) => {
                     let _ = rx_tx.send(Bytes::from(payload));
                 }
+                Ok((AUDIO_MSG_HISTORY_COMPRESSED, payload)) => {
+                    // Decompress gzip blob, then iterate the embedded framed messages.
+                    let mut decompressed = Vec::new();
+                    if GzDecoder::new(payload.as_slice())
+                        .read_to_end(&mut decompressed)
+                        .is_ok()
+                    {
+                        let mut pos = 0;
+                        while pos + 5 <= decompressed.len() {
+                            let _msg_type = decompressed[pos];
+                            let len = u32::from_be_bytes([
+                                decompressed[pos + 1],
+                                decompressed[pos + 2],
+                                decompressed[pos + 3],
+                                decompressed[pos + 4],
+                            ]) as usize;
+                            pos += 5;
+                            if pos + len > decompressed.len() {
+                                break;
+                            }
+                            let json = &decompressed[pos..pos + len];
+                            if let Ok(msg) = serde_json::from_slice::<DecodedMessage>(json) {
+                                let _ = decode_tx.send(msg);
+                            }
+                            pos += len;
+                        }
+                    }
+                }
                 Ok((
                     AUDIO_MSG_VDES_DECODE
                     | AUDIO_MSG_AIS_DECODE