[router] grpc router bootstraps (#9759)

sgl-router/src/routers/http/mod.rs

@@ -0,0 +1,5 @@
+//! HTTP router implementations
+
+pub mod pd_router;
+pub mod pd_types;
+pub mod router;

sgl-router/src/routers/http/pd_types.rs

@@ -0,0 +1,81 @@
+// Custom error type for PD router operations
+#[derive(Debug, thiserror::Error)]
+pub enum PDRouterError {
+    #[error("Worker already exists: {url}")]
+    WorkerAlreadyExists { url: String },
+
+    #[error("Worker not found: {url}")]
+    WorkerNotFound { url: String },
+
+    #[error("Lock acquisition failed: {operation}")]
+    LockError { operation: String },
+
+    #[error("Health check failed for worker: {url}")]
+    HealthCheckFailed { url: String },
+
+    #[error("Invalid worker configuration: {reason}")]
+    InvalidConfiguration { reason: String },
+
+    #[error("Network error: {message}")]
+    NetworkError { message: String },
+
+    #[error("Timeout waiting for worker: {url}")]
+    Timeout { url: String },
+}
+
+// Helper functions for workers
+pub fn api_path(url: &str, api_path: &str) -> String {
+    if api_path.starts_with("/") {
+        format!("{}{}", url, api_path)
+    } else {
+        format!("{}/{}", url, api_path)
+    }
+}
+
+pub fn get_hostname(url: &str) -> String {
+    // Simple hostname extraction without external dependencies
+    let url = url
+        .trim_start_matches("http://")
+        .trim_start_matches("https://");
+    url.split(':').next().unwrap_or("localhost").to_string()
+}
+
+use serde::Serialize;
+
+// Optimized bootstrap wrapper for single requests
+#[derive(Serialize)]
+pub struct RequestWithBootstrap<'a, T: Serialize> {
+    #[serde(flatten)]
+    pub original: &'a T,
+    pub bootstrap_host: String,
+    pub bootstrap_port: Option<u16>,
+    pub bootstrap_room: u64,
+}
+
+// Optimized bootstrap wrapper for batch requests
+#[derive(Serialize)]
+pub struct BatchRequestWithBootstrap<'a, T: Serialize> {
+    #[serde(flatten)]
+    pub original: &'a T,
+    pub bootstrap_host: Vec<String>,
+    pub bootstrap_port: Vec<Option<u16>>,
+    pub bootstrap_room: Vec<u64>,
+}
+
+// Helper to generate bootstrap room ID
+pub fn generate_room_id() -> u64 {
+    // Generate a value in the range [0, 2^63 - 1] to match Python's random.randint(0, 2**63 - 1)
+    rand::random::<u64>() & (i64::MAX as u64)
+}
+
+// PD-specific routing policies
+#[derive(Debug, Clone, PartialEq)]
+pub enum PDSelectionPolicy {
+    Random,
+    PowerOfTwo,
+    CacheAware {
+        cache_threshold: f32,
+        balance_abs_threshold: usize,
+        balance_rel_threshold: f32,
+    },
+}