chore: expose session id

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## Next
 
+- recording: expose session id ([#166](https://github.com/PostHog/posthog-android/pull/166))
+
 ## 3.5.1 - 2024-08-26
 
 - recording: capture touch interaction off of main thread to avoid ANRs ([#165](https://github.com/PostHog/posthog-android/pull/165))

posthog-android/src/test/java/com/posthog/android/PostHogFake.kt

@@ -3,6 +3,7 @@ package com.posthog.android
 import com.posthog.PostHogConfig
 import com.posthog.PostHogInterface
 import com.posthog.PostHogOnFeatureFlags
+import java.util.UUID
 
 public class PostHogFake : PostHogInterface {
     public var event: String? = null
@@ -119,6 +120,10 @@ public class PostHogFake : PostHogInterface {
         return false
     }
 
+    override fun getSessionId(): UUID? {
+        return null
+    }
+
     override fun <T : PostHogConfig> getConfig(): T? {
         return null
     }

posthog/api/posthog.api

@@ -11,6 +11,7 @@ public final class com/posthog/PostHog : com/posthog/PostHogInterface {
 	public fun getConfig ()Lcom/posthog/PostHogConfig;
 	public fun getFeatureFlag (Ljava/lang/String;Ljava/lang/Object;)Ljava/lang/Object;
 	public fun getFeatureFlagPayload (Ljava/lang/String;Ljava/lang/Object;)Ljava/lang/Object;
+	public fun getSessionId ()Ljava/util/UUID;
 	public fun group (Ljava/lang/String;Ljava/lang/String;Ljava/util/Map;)V
 	public fun identify (Ljava/lang/String;Ljava/util/Map;Ljava/util/Map;)V
 	public fun isFeatureEnabled (Ljava/lang/String;Z)Z
@@ -38,6 +39,7 @@ public final class com/posthog/PostHog$Companion : com/posthog/PostHogInterface
 	public fun getConfig ()Lcom/posthog/PostHogConfig;
 	public fun getFeatureFlag (Ljava/lang/String;Ljava/lang/Object;)Ljava/lang/Object;
 	public fun getFeatureFlagPayload (Ljava/lang/String;Ljava/lang/Object;)Ljava/lang/Object;
+	public fun getSessionId ()Ljava/util/UUID;
 	public fun group (Ljava/lang/String;Ljava/lang/String;Ljava/util/Map;)V
 	public fun identify (Ljava/lang/String;Ljava/util/Map;Ljava/util/Map;)V
 	public fun isFeatureEnabled (Ljava/lang/String;Z)Z
@@ -178,6 +180,7 @@ public abstract interface class com/posthog/PostHogInterface {
 	public abstract fun getConfig ()Lcom/posthog/PostHogConfig;
 	public abstract fun getFeatureFlag (Ljava/lang/String;Ljava/lang/Object;)Ljava/lang/Object;
 	public abstract fun getFeatureFlagPayload (Ljava/lang/String;Ljava/lang/Object;)Ljava/lang/Object;
+	public abstract fun getSessionId ()Ljava/util/UUID;
 	public abstract fun group (Ljava/lang/String;Ljava/lang/String;Ljava/util/Map;)V
 	public abstract fun identify (Ljava/lang/String;Ljava/util/Map;Ljava/util/Map;)V
 	public abstract fun isFeatureEnabled (Ljava/lang/String;Z)Z
@@ -302,6 +305,15 @@ public final class com/posthog/internal/PostHogSerializer {
 	public final fun serializeObject (Ljava/lang/Object;)Ljava/lang/String;
 }
 
+public final class com/posthog/internal/PostHogSessionManager {
+	public static final field INSTANCE Lcom/posthog/internal/PostHogSessionManager;
+	public final fun endSession ()V
+	public final fun getActiveSessionId ()Ljava/util/UUID;
+	public final fun isSessionActive ()Z
+	public final fun setSessionId (Ljava/util/UUID;)V
+	public final fun startSession ()V
+}
+
 public final class com/posthog/internal/PostHogThreadFactory : java/util/concurrent/ThreadFactory {
 	public fun <init> (Ljava/lang/String;)V
 	public fun newThread (Ljava/lang/Runnable;)Ljava/lang/Thread;

posthog/src/main/java/com/posthog/PostHog.kt

@@ -17,6 +17,7 @@ import com.posthog.internal.PostHogPrintLogger
 import com.posthog.internal.PostHogQueue
 import com.posthog.internal.PostHogSendCachedEventsIntegration
 import com.posthog.internal.PostHogSerializer
+import com.posthog.internal.PostHogSessionManager
 import com.posthog.internal.PostHogThreadFactory
 import com.posthog.vendor.uuid.TimeBasedEpochGenerator
 import java.util.UUID
@@ -48,13 +49,8 @@ public class PostHog private constructor(
     private val setupLock = Any()
     private val optOutLock = Any()
     private val anonymousLock = Any()
-    private val sessionLock = Any()
     private val groupsLock = Any()
 
-    // do not move to companion object, otherwise sessionId will be null
-    private val sessionIdNone = UUID(0, 0)
-
-    private var sessionId = sessionIdNone
     private val featureFlagsCalledLock = Any()
 
     private var config: PostHogConfig? = null
@@ -170,6 +166,10 @@ public class PostHog private constructor(
     public override fun close() {
         synchronized(setupLock) {
             try {
+                if (!isEnabled()) {
+                    return
+                }
+
                 enabled = false
 
                 config?.let { config ->
@@ -272,15 +272,13 @@ public class PostHog private constructor(
             }
         }
 
-        synchronized(sessionLock) {
-            if (sessionId != sessionIdNone) {
-                val sessionId = sessionId.toString()
-                props["\$session_id"] = sessionId
-                if (config?.sessionReplay == true) {
-                    // Session replay requires $window_id, so we set as the same as $session_id.
-                    // the backend might fallback to $session_id if $window_id is not present next.
-                    props["\$window_id"] = sessionId
-                }
+        PostHogSessionManager.getActiveSessionId()?.let { sessionId ->
+            val tempSessionId = sessionId.toString()
+            props["\$session_id"] = tempSessionId
+            if (config?.sessionReplay == true) {
+                // Session replay requires $window_id, so we set as the same as $session_id.
+                // the backend might fallback to $session_id if $window_id is not present next.
+                props["\$window_id"] = tempSessionId
             }
         }
 
@@ -697,25 +695,35 @@ public class PostHog private constructor(
     }
 
     override fun startSession() {
-        synchronized(sessionLock) {
-            if (sessionId == sessionIdNone) {
-                sessionId = TimeBasedEpochGenerator.generate()
-            }
+        if (!isEnabled()) {
+            return
         }
+
+        PostHogSessionManager.startSession()
     }
 
     override fun endSession() {
-        synchronized(sessionLock) {
-            sessionId = sessionIdNone
+        if (!isEnabled()) {
+            return
         }
+
+        PostHogSessionManager.endSession()
     }
 
     override fun isSessionActive(): Boolean {
-        var active: Boolean
-        synchronized(sessionLock) {
-            active = sessionId != sessionIdNone
+        if (!isEnabled()) {
+            return false
+        }
+
+        return PostHogSessionManager.isSessionActive()
+    }
+
+    override fun getSessionId(): UUID? {
+        if (!isEnabled()) {
+            return null
         }
-        return active
+
+        return PostHogSessionManager.getActiveSessionId()
     }
 
     override fun <T : PostHogConfig> getConfig(): T? {
@@ -896,6 +904,10 @@ public class PostHog private constructor(
             return shared.isSessionActive()
         }
 
+        override fun getSessionId(): UUID? {
+            return shared.getSessionId()
+        }
+
         override fun <T : PostHogConfig> getConfig(): T? {
             return shared.getConfig()
         }

posthog/src/main/java/com/posthog/PostHogInterface.kt

@@ -1,5 +1,7 @@
 package com.posthog
 
+import java.util.UUID
+
 /**
  * The PostHog SDK entry point
  */
@@ -189,6 +191,11 @@ public interface PostHogInterface {
      */
     public fun isSessionActive(): Boolean
 
+    /**
+     * Returns the session Id if a session is active
+     */
+    public fun getSessionId(): UUID?
+
     @PostHogInternal
     public fun <T : PostHogConfig> getConfig(): T?
 }

posthog/src/main/java/com/posthog/internal/PostHogSessionManager.kt

@@ -0,0 +1,54 @@
+package com.posthog.internal
+
+import com.posthog.PostHogInternal
+import com.posthog.vendor.uuid.TimeBasedEpochGenerator
+import java.util.UUID
+
+/**
+ * Class that manages the Session ID
+ */
+@PostHogInternal
+public object PostHogSessionManager {
+    private val sessionLock = Any()
+
+    // do not move to companion object, otherwise sessionId will be null
+    private val sessionIdNone = UUID(0, 0)
+
+    private var sessionId = sessionIdNone
+
+    public fun startSession() {
+        synchronized(sessionLock) {
+            if (sessionId == sessionIdNone) {
+                sessionId = TimeBasedEpochGenerator.generate()
+            }
+        }
+    }
+
+    public fun endSession() {
+        synchronized(sessionLock) {
+            sessionId = sessionIdNone
+        }
+    }
+
+    public fun getActiveSessionId(): UUID? {
+        var tempSessionId: UUID?
+        synchronized(sessionLock) {
+            tempSessionId = if (sessionId != sessionIdNone) sessionId else null
+        }
+        return tempSessionId
+    }
+
+    public fun setSessionId(sessionId: UUID) {
+        synchronized(sessionLock) {
+            this.sessionId = sessionId
+        }
+    }
+
+    public fun isSessionActive(): Boolean {
+        var active: Boolean
+        synchronized(sessionLock) {
+            active = sessionId != sessionIdNone
+        }
+        return active
+    }
+}