Atomic get-and-set: sets new value, returns old value. If key didn't exist, returns `None`. Preserves existing TTL.
(
&mut self,
tenant_id: u64,
collection: &str,
key: &[u8],
new_value: &[u8],
now_ms: u64,
)
| 239 | /// If key didn't exist, returns `None`. |
| 240 | /// Preserves existing TTL. |
| 241 | pub fn getset( |
| 242 | &mut self, |
| 243 | tenant_id: u64, |
| 244 | collection: &str, |
| 245 | key: &[u8], |
| 246 | new_value: &[u8], |
| 247 | now_ms: u64, |
| 248 | ) -> Option<Vec<u8>> { |
| 249 | let tkey = table_key(tenant_id, collection); |
| 250 | let table = self.ensure_table(tkey, tenant_id, collection); |
| 251 | let old = table.get(key, now_ms).map(|v| v.to_vec()); |
| 252 | |
| 253 | // For typed KV: update the first non-key string field in the map. |
| 254 | let write_bytes = if let Some(ref cur) = old |
| 255 | && let Ok(nodedb_types::Value::Object(mut map)) = nodedb_types::value_from_msgpack(cur) |
| 256 | && map.len() > 1 |
| 257 | { |
| 258 | let new_str = String::from_utf8_lossy(new_value).to_string(); |
| 259 | let mut updated = false; |
| 260 | for (k, v) in map.iter_mut() { |
| 261 | if k == "key" { |
| 262 | continue; |
| 263 | } |
| 264 | if matches!(v, nodedb_types::Value::String(_)) { |
| 265 | *v = nodedb_types::Value::String(new_str.clone()); |
| 266 | updated = true; |
| 267 | break; |
| 268 | } |
| 269 | } |
| 270 | if updated { |
| 271 | nodedb_types::value_to_msgpack(&nodedb_types::Value::Object(map)) |
| 272 | .unwrap_or_else(|_| new_value.to_vec()) |
| 273 | } else { |
| 274 | new_value.to_vec() |
| 275 | } |
| 276 | } else { |
| 277 | new_value.to_vec() |
| 278 | }; |
| 279 | |
| 280 | // GetSet preserves existing TTL (ttl_ms = 0). |
| 281 | self.atomic_put( |
| 282 | tenant_id, |
| 283 | collection, |
| 284 | tkey, |
| 285 | key, |
| 286 | &write_bytes, |
| 287 | 0, |
| 288 | now_ms, |
| 289 | old.is_none(), |
| 290 | ); |
| 291 | old |
| 292 | } |
| 293 | |
| 294 | /// Ensure a hash table exists for (tenant, collection), creating if needed. |
| 295 | /// Returns a mutable reference to the table. |