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use std::collections::HashMap;
use std::sync::Arc;
use datalogic_rs::CompiledLogic;
use tokio::sync::{RwLock, Semaphore};
use super::KeyedLimiter;
use super::build_keyed_limiter;
use super::config::ChannelConfig;
use super::routing::{RouteMatch, RouteTable};
use crate::connector::ConnectorConfig;
use crate::connector::ConnectorRegistry;
use crate::connector::cache_backend::{CacheBackend, CachePool};
use crate::storage::models::Channel;
/// Runtime state for a single active channel.
pub struct ChannelRuntimeConfig {
/// The channel DB model.
pub channel: Channel,
/// Parsed per-channel configuration.
pub parsed_config: ChannelConfig,
/// Per-channel rate limiter, built from `parsed_config.rate_limit` if configured.
pub rate_limiter: Option<Arc<KeyedLimiter>>,
/// Pre-compiled JSONLogic expression for computing the rate limit key.
pub rate_limit_key_logic: Option<CompiledLogic>,
/// Pre-compiled JSONLogic expression for input validation.
/// Evaluated against request data — truthy = pass, falsy = 400 reject.
pub validation_logic: Option<CompiledLogic>,
/// Per-channel concurrency limiter for backpressure.
/// Limits max in-flight requests — returns 503 when exhausted.
pub backpressure_semaphore: Option<Arc<Semaphore>>,
/// Per-channel deduplication backend for idempotent request handling.
/// Can be backed by in-memory DashMap or Redis, depending on channel config.
pub dedup_store: Option<Arc<dyn CacheBackend>>,
/// Per-channel response cache backend.
/// When set, sync responses are cached with a configurable TTL.
pub response_cache: Option<Arc<dyn CacheBackend>>,
}
/// In-memory registry of active channels, rebuilt on engine reload.
/// Mirrors the ConnectorRegistry pattern.
pub struct ChannelRegistry {
by_name: RwLock<HashMap<String, Arc<ChannelRuntimeConfig>>>,
route_table: RwLock<RouteTable>,
}
impl Default for ChannelRegistry {
fn default() -> Self {
Self::new()
}
}
impl ChannelRegistry {
pub fn new() -> Self {
Self {
by_name: RwLock::new(HashMap::new()),
route_table: RwLock::new(RouteTable::new()),
}
}
/// Look up an active channel by name.
pub async fn get_by_name(&self, name: &str) -> Option<Arc<ChannelRuntimeConfig>> {
self.by_name.read().await.get(name).cloned()
}
/// Match a request (method, path) against REST channel route patterns.
/// Path should NOT include the `/api/v1/data/` prefix.
pub async fn match_route(&self, method: &str, path: &str) -> Option<RouteMatch> {
self.route_table.read().await.match_route(method, path)
}
/// Rebuild the registry from a list of active channels.
/// Builds per-channel rate limiters from `config_json.rate_limit` if configured.
pub async fn reload(
&self,
channels: &[Channel],
connector_registry: &ConnectorRegistry,
cache_pool: &CachePool,
) {
let mut new_map = HashMap::new();
for channel in channels {
let parsed_config: ChannelConfig =
serde_json::from_str(&channel.config_json).unwrap_or_default();
let rate_limiter = parsed_config.rate_limit.as_ref().map(|rl| {
let burst = rl.burst.unwrap_or(rl.requests_per_second / 2 + 1);
Arc::new(build_keyed_limiter(rl.requests_per_second, burst))
});
let rate_limit_key_logic = parsed_config
.rate_limit
.as_ref()
.and_then(|rl| rl.key_logic.as_ref())
.and_then(|logic| {
CompiledLogic::compile(logic)
.map_err(|e| {
tracing::warn!(
channel = %channel.name,
error = %e,
"Failed to compile rate limit key_logic, falling back to client_ip"
);
})
.ok()
});
let validation_logic = parsed_config.validation_logic.as_ref().and_then(|logic| {
CompiledLogic::compile(logic)
.map_err(|e| {
tracing::warn!(
channel = %channel.name,
error = %e,
"Failed to compile validation_logic, skipping input validation"
);
})
.ok()
});
let backpressure_semaphore = parsed_config
.backpressure
.as_ref()
.map(|bp| Arc::new(Semaphore::new(bp.max_concurrent)));
let dedup_store: Option<Arc<dyn CacheBackend>> =
if let Some(ref dedup) = parsed_config.deduplication {
if let Some(ref connector_name) = dedup.connector {
// Use the configured cache connector for dedup
match connector_registry.get(connector_name).await {
Some(cfg) => match cfg.as_ref() {
ConnectorConfig::Cache(cache_cfg) => {
match cache_pool.get_backend(connector_name, cache_cfg).await {
Ok(backend) => Some(backend),
Err(e) => {
tracing::warn!(
channel = %channel.name,
connector = %connector_name,
error = %e,
"Failed to create dedup backend from connector, \
falling back to in-memory"
);
Some(cache_pool.memory())
}
}
}
_ => {
tracing::warn!(
channel = %channel.name,
connector = %connector_name,
"Dedup connector is not a cache connector, \
falling back to in-memory"
);
Some(cache_pool.memory())
}
},
None => {
tracing::warn!(
channel = %channel.name,
connector = %connector_name,
"Dedup connector not found, falling back to in-memory"
);
Some(cache_pool.memory())
}
}
} else {
// No connector specified — use built-in in-memory
Some(cache_pool.memory())
}
} else {
None
};
// Resolve response cache backend (same pattern as dedup)
let response_cache: Option<Arc<dyn CacheBackend>> = if let Some(ref cache_cfg) =
parsed_config.cache
&& cache_cfg.enabled
{
if let Some(ref connector_name) = cache_cfg.connector {
match connector_registry.get(connector_name).await {
Some(cfg) => match cfg.as_ref() {
ConnectorConfig::Cache(cc) => {
match cache_pool.get_backend(connector_name, cc).await {
Ok(backend) => Some(backend),
Err(e) => {
tracing::warn!(
channel = %channel.name,
connector = %connector_name,
error = %e,
"Failed to create cache backend from connector, \
falling back to in-memory"
);
Some(cache_pool.memory())
}
}
}
_ => {
tracing::warn!(
channel = %channel.name,
connector = %connector_name,
"Cache connector is not a cache connector, \
falling back to in-memory"
);
Some(cache_pool.memory())
}
},
None => {
tracing::warn!(
channel = %channel.name,
connector = %connector_name,
"Cache connector not found, falling back to in-memory"
);
Some(cache_pool.memory())
}
}
} else {
Some(cache_pool.memory())
}
} else {
None
};
let runtime = Arc::new(ChannelRuntimeConfig {
channel: channel.clone(),
parsed_config,
rate_limiter,
rate_limit_key_logic,
validation_logic,
backpressure_semaphore,
dedup_store,
response_cache,
});
new_map.insert(channel.name.clone(), runtime);
}
*self.by_name.write().await = new_map;
// Rebuild the REST route table from active channels
*self.route_table.write().await = RouteTable::build(channels);
}
/// Get all active channel names.
pub async fn channel_names(&self) -> Vec<String> {
self.by_name.read().await.keys().cloned().collect()
}
}
#[cfg(test)]
mod tests {
use super::*;
#[tokio::test]
async fn test_channel_registry_empty() {
let registry = ChannelRegistry::new();
assert!(registry.get_by_name("nonexistent").await.is_none());
assert!(registry.channel_names().await.is_empty());
}
}