feat: add connection pooling and DNS caching for performance

- Persistent HTTP sessions avoid Connection: close overhead
- DNS pre-resolution with timeout prevents indefinite hangs
- Thread-safe connection pool with LRU eviction
- TLS certificates parsed once at init, not per-request
- Extract TlsParser, DnsCache, ConnectionPool for SRP

Bump to v1.5.0

1 files changed, 59 insertions, 0 deletions

diff --git a/lib/net/hippie/connection_pool.rb b/lib/net/hippie/connection_pool.rb
new file mode 100644
index 0000000..2e220b7
--- /dev/null
+++ b/lib/net/hippie/connection_pool.rb
@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+module Net
+  module Hippie
+    # Thread-safe connection pool with LRU eviction.
+    class ConnectionPool
+      def initialize(max_size: 100, dns_ttl: 300)
+        @max_size = max_size
+        @dns_ttl = dns_ttl
+        @connections = {}
+        @monitor = Monitor.new
+      end
+
+      def checkout(key, &block)
+        reuse(key) || create(key, &block)
+      end
+
+      def close_all
+        @monitor.synchronize do
+          @connections.each_value(&:close)
+          @connections.clear
+        end
+      end
+
+      private
+
+      def reuse(key)
+        @monitor.synchronize do
+          return nil unless @connections.key?(key)
+
+          conn = @connections.delete(key)
+          return @connections[key] = conn unless conn.stale?(@dns_ttl)
+
+          conn.close
+          nil
+        end
+      end
+
+      def create(key)
+        conn = yield
+        @monitor.synchronize do
+          existing = reuse(key)
+          if existing
+            conn.close
+            return existing
+          end
+          evict_lru if @connections.size >= @max_size
+          @connections[key] = conn
+        end
+      end
+
+      def evict_lru
+        key, conn = @connections.first
+        conn.close
+        @connections.delete(key)
+      end
+    end
+  end
+end