Expose metrics on Connection interface

okhttp/api/android/okhttp.api

@@ -343,10 +343,15 @@ public abstract interface class okhttp3/CompressionInterceptor$DecompressionAlgo
 }
 
 public abstract interface class okhttp3/Connection {
+	public abstract fun callCount ()I
+	public abstract fun connectAtMillis ()J
 	public abstract fun handshake ()Lokhttp3/Handshake;
+	public abstract fun idleAtMillis ()Ljava/lang/Long;
+	public abstract fun noNewExchanges ()Z
 	public abstract fun protocol ()Lokhttp3/Protocol;
 	public abstract fun route ()Lokhttp3/Route;
 	public abstract fun socket ()Ljava/net/Socket;
+	public abstract fun successCount ()I
 }
 
 public final class okhttp3/ConnectionPool {

okhttp/api/jvm/okhttp.api

@@ -343,10 +343,15 @@ public abstract interface class okhttp3/CompressionInterceptor$DecompressionAlgo
 }
 
 public abstract interface class okhttp3/Connection {
+	public abstract fun callCount ()I
+	public abstract fun connectAtMillis ()J
 	public abstract fun handshake ()Lokhttp3/Handshake;
+	public abstract fun idleAtMillis ()Ljava/lang/Long;
+	public abstract fun noNewExchanges ()Z
 	public abstract fun protocol ()Lokhttp3/Protocol;
 	public abstract fun route ()Lokhttp3/Route;
 	public abstract fun socket ()Ljava/net/Socket;
+	public abstract fun successCount ()I
 }
 
 public final class okhttp3/ConnectionPool {

okhttp/src/commonJvmAndroid/kotlin/okhttp3/Connection.kt

@@ -89,4 +89,34 @@ interface Connection {
    * [Protocol.HTTP_1_0].
    */
   fun protocol(): Protocol
+
+  /**
+   * Returns the wall-clock time (epoch millis) when this connection was created. This is the time
+   * the TCP and TLS handshakes completed.
+   */
+  fun connectAtMillis(): Long
+
+  /**
+   * Returns the wall-clock time (epoch millis) when this connection became idle, or null if it is
+   * currently active (carrying one or more calls).
+   */
+  fun idleAtMillis(): Long?
+
+  /**
+   * Returns the number of exchanges successfully completed on this connection. Each completed
+   * request/response pair increments this count.
+   */
+  fun successCount(): Int
+
+  /**
+   * Returns the number of calls currently carried by this connection. This is 0 when the
+   * connection is idle, and may be greater than 1 for HTTP/2 connections.
+   */
+  fun callCount(): Int
+
+  /**
+   * Returns true if this connection will not accept new exchanges. This may be because the
+   * connection has been marked for closure, or because an error has occurred on this connection.
+   */
+  fun noNewExchanges(): Boolean
 }

okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/connection/ConnectPlan.kt

@@ -527,7 +527,7 @@ class ConnectPlan internal constructor(
     // Do nothing.
   }
 
-  override fun noNewExchanges() {
+  override fun prohibitNewExchanges() {
     // Do nothing.
   }
 

okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/connection/Exchange.kt

@@ -175,7 +175,7 @@ class Exchange(
   }
 
   fun noNewExchangesOnConnection() {
-    codec.carrier.noNewExchanges()
+    codec.carrier.prohibitNewExchanges()
   }
 
   fun cancel() {

okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/connection/RealCall.kt

@@ -321,6 +321,7 @@ class RealCall(
     check(this.connection == null)
     this.connection = connection
     connection.calls.add(CallReference(this, callStackTrace))
+    connection.idleAtEpochMillis = null
   }
 
   /**
@@ -452,6 +453,7 @@ class RealCall(
 
     if (calls.isEmpty()) {
       connection.idleAtNs = System.nanoTime()
+      connection.idleAtEpochMillis = System.currentTimeMillis()
       if (connectionPool.connectionBecameIdle(connection)) {
         return connection.socket()
       }

okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/connection/RealConnection.kt

@@ -121,6 +121,12 @@ class RealConnection internal constructor(
   /** Timestamp when `allocations.size()` reached zero. Also assigned upon initial connection. */
   var idleAtNs = Long.MAX_VALUE
 
+  /** Wall-clock time (epoch millis) when the connection was created. */
+  internal var connectAtEpochMillis: Long = 0L
+
+  /** Wall-clock time (epoch millis) when the connection became idle, or null if active. */
+  internal var idleAtEpochMillis: Long? = null
+
   /**
    * Returns true if this is an HTTP/2 connection. Such connections can be used in multiple HTTP
    * requests simultaneously.
@@ -129,7 +135,7 @@ class RealConnection internal constructor(
     get() = http2Connection != null
 
   /** Prevent further exchanges from being created on this connection. */
-  override fun noNewExchanges() {
+  override fun prohibitNewExchanges() {
     withLock {
       noNewExchanges = true
     }
@@ -152,6 +158,8 @@ class RealConnection internal constructor(
   @Throws(IOException::class)
   fun start() {
     idleAtNs = System.nanoTime()
+    connectAtEpochMillis = System.currentTimeMillis()
+    idleAtEpochMillis = connectAtEpochMillis
     if (protocol == Protocol.HTTP_2 || protocol == Protocol.H2_PRIOR_KNOWLEDGE) {
       startHttp2()
     }
@@ -284,7 +292,7 @@ class RealConnection internal constructor(
 
   internal fun useAsSocket() {
     javaNetSocket.soTimeout = 0
-    noNewExchanges()
+    prohibitNewExchanges()
   }
 
   override fun route(): Route = route
@@ -416,6 +424,16 @@ class RealConnection internal constructor(
 
   override fun protocol(): Protocol = protocol
 
+  override fun connectAtMillis(): Long = connectAtEpochMillis
+
+  override fun idleAtMillis(): Long? = withLock { idleAtEpochMillis }
+
+  override fun successCount(): Int = withLock { successCount }
+
+  override fun callCount(): Int = withLock { calls.size }
+
+  override fun noNewExchanges(): Boolean = withLock { noNewExchanges }
+
   override fun toString(): String =
     "Connection{${route.address.url.host}:${route.address.url.port}," +
       " proxy=${route.proxy}" +
@@ -456,6 +474,8 @@ class RealConnection internal constructor(
           connectionListener = ConnectionListener.NONE,
         )
       result.idleAtNs = idleAtNs
+      result.connectAtEpochMillis = System.currentTimeMillis()
+      result.idleAtEpochMillis = result.connectAtEpochMillis
       return result
     }
   }

okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/connection/RealConnectionPool.kt

@@ -314,6 +314,7 @@ class RealConnectionPool internal constructor(
       // If this was the last allocation, the connection is eligible for immediate eviction.
       if (references.isEmpty()) {
         connection.idleAtNs = now - keepAliveDurationNs
+        connection.idleAtEpochMillis = System.currentTimeMillis()
         return 0
       }
     }

okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/http/ExchangeCodec.kt

@@ -92,7 +92,7 @@ interface ExchangeCodec {
       e: IOException?,
     )
 
-    fun noNewExchanges()
+    fun prohibitNewExchanges()
 
     fun cancel()
   }

okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/http1/Http1ExchangeCodec.kt

@@ -283,7 +283,7 @@ class Http1ExchangeCodec(
   private fun newUnknownLengthSource(url: HttpUrl): Source {
     check(state == STATE_OPEN_RESPONSE_BODY) { "state: $state" }
     state = STATE_READING_RESPONSE_BODY
-    carrier.noNewExchanges()
+    carrier.prohibitNewExchanges()
     return UnknownLengthSource(url)
   }
 
@@ -396,7 +396,7 @@ class Http1ExchangeCodec(
       try {
         socket.source.read(sink, byteCount)
       } catch (e: IOException) {
-        carrier.noNewExchanges()
+        carrier.prohibitNewExchanges()
         responseBodyComplete(TRAILERS_RESPONSE_BODY_TRUNCATED)
         throw e
       }
@@ -440,7 +440,7 @@ class Http1ExchangeCodec(
 
       val read = super.read(sink, minOf(bytesRemaining, byteCount))
       if (read == -1L) {
-        carrier.noNewExchanges() // The server didn't supply the promised content length.
+        carrier.prohibitNewExchanges() // The server didn't supply the promised content length.
         val e = ProtocolException("unexpected end of stream")
         responseBodyComplete(TRAILERS_RESPONSE_BODY_TRUNCATED)
         throw e
@@ -459,7 +459,7 @@ class Http1ExchangeCodec(
       if (bytesRemaining != 0L &&
         !discard(ExchangeCodec.DISCARD_STREAM_TIMEOUT_MILLIS, MILLISECONDS)
       ) {
-        carrier.noNewExchanges() // Unread bytes remain on the stream.
+        carrier.prohibitNewExchanges() // Unread bytes remain on the stream.
         responseBodyComplete(TRAILERS_RESPONSE_BODY_TRUNCATED)
       }
 
@@ -489,7 +489,7 @@ class Http1ExchangeCodec(
 
       val read = super.read(sink, minOf(byteCount, bytesRemainingInChunk))
       if (read == -1L) {
-        carrier.noNewExchanges() // The server didn't supply the promised chunk length.
+        carrier.prohibitNewExchanges() // The server didn't supply the promised chunk length.
         val e = ProtocolException("unexpected end of stream")
         responseBodyComplete(TRAILERS_RESPONSE_BODY_TRUNCATED)
         throw e
@@ -528,7 +528,7 @@ class Http1ExchangeCodec(
       if (hasMoreChunks &&
         !discard(ExchangeCodec.DISCARD_STREAM_TIMEOUT_MILLIS, MILLISECONDS)
       ) {
-        carrier.noNewExchanges() // Unread bytes remain on the stream.
+        carrier.prohibitNewExchanges() // Unread bytes remain on the stream.
         responseBodyComplete(TRAILERS_RESPONSE_BODY_TRUNCATED)
       }
       closed = true

okhttp/src/jvmTest/kotlin/okhttp3/ConnectionListenerTest.kt

@@ -25,7 +25,10 @@ import assertk.assertThat
 import assertk.assertions.containsExactly
 import assertk.assertions.hasMessage
 import assertk.assertions.isEqualTo
+import assertk.assertions.isFalse
+import assertk.assertions.isGreaterThan
 import assertk.assertions.isIn
+import assertk.assertions.isNotNull
 import java.io.IOException
 import java.net.InetSocketAddress
 import java.net.UnknownHostException
@@ -340,6 +343,29 @@ open class ConnectionListenerTest {
     assertThat(event.connection.route().proxy).isEqualTo(proxy)
   }
 
+  @Test
+  @Throws(IOException::class)
+  fun connectionMetrics() {
+    server.enqueue(MockResponse())
+    val call =
+      client.newCall(
+        Request
+          .Builder()
+          .url(server.url("/"))
+          .build(),
+      )
+    val response = call.execute()
+    assertThat(response.code).isEqualTo(200)
+    response.body.close()
+    val event = listener.removeUpToEvent(ConnectionEvent.ConnectEnd::class.java)
+    val connection = event.connection
+    assertThat(connection.connectAtMillis()).isGreaterThan(0L)
+    assertThat(connection.successCount()).isEqualTo(1)
+    assertThat(connection.callCount()).isEqualTo(0)
+    assertThat(connection.idleAtMillis()).isNotNull()
+    assertThat(connection.noNewExchanges()).isFalse()
+  }
+
   private fun enableTls() {
     client =
       client

okhttp/src/jvmTest/kotlin/okhttp3/KotlinSourceModernTest.kt

@@ -292,6 +292,16 @@ class KotlinSourceModernTest {
         override fun handshake(): Handshake? = TODO()
 
         override fun protocol(): Protocol = TODO()
+
+        override fun connectAtMillis(): Long = TODO()
+
+        override fun idleAtMillis(): Long? = TODO()
+
+        override fun successCount(): Int = TODO()
+
+        override fun callCount(): Int = TODO()
+
+        override fun noNewExchanges(): Boolean = TODO()
       }
   }