1 files changed, 172 insertions, 0 deletions
diff --git a/examples/llama.android/llama/src/main/java/android/llama/cpp/LLamaAndroid.kt b/examples/llama.android/llama/src/main/java/android/llama/cpp/LLamaAndroid.kt
new file mode 100644
index 00000000..6c63e54e
--- /dev/null
+++ b/examples/llama.android/llama/src/main/java/android/llama/cpp/LLamaAndroid.kt
@@ -0,0 +1,172 @@
+package android.llama.cpp
+
+import android.util.Log
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.asCoroutineDispatcher
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import kotlinx.coroutines.withContext
+import java.util.concurrent.Executors
+import kotlin.concurrent.thread
+
+class LLamaAndroid {
+    private val tag: String? = this::class.simpleName
+
+    private val threadLocalState: ThreadLocal<State> = ThreadLocal.withInitial { State.Idle }
+
+    private val runLoop: CoroutineDispatcher = Executors.newSingleThreadExecutor {
+        thread(start = false, name = "Llm-RunLoop") {
+            Log.d(tag, "Dedicated thread for native code: ${Thread.currentThread().name}")
+
+            // No-op if called more than once.
+            System.loadLibrary("llama-android")
+
+            // Set llama log handler to Android
+            log_to_android()
+            backend_init(false)
+
+            Log.d(tag, system_info())
+
+            it.run()
+        }.apply {
+            uncaughtExceptionHandler = Thread.UncaughtExceptionHandler { _, exception: Throwable ->
+                Log.e(tag, "Unhandled exception", exception)
+            }
+        }
+    }.asCoroutineDispatcher()
+
+    private val nlen: Int = 64
+
+    private external fun log_to_android()
+    private external fun load_model(filename: String): Long
+    private external fun free_model(model: Long)
+    private external fun new_context(model: Long): Long
+    private external fun free_context(context: Long)
+    private external fun backend_init(numa: Boolean)
+    private external fun backend_free()
+    private external fun free_batch(batch: Long)
+    private external fun new_batch(nTokens: Int, embd: Int, nSeqMax: Int): Long
+    private external fun bench_model(
+        context: Long,
+        model: Long,
+        batch: Long,
+        pp: Int,
+        tg: Int,
+        pl: Int,
+        nr: Int
+    ): String
+
+    private external fun system_info(): String
+
+    private external fun completion_init(
+        context: Long,
+        batch: Long,
+        text: String,
+        nLen: Int
+    ): Int
+
+    private external fun completion_loop(
+        context: Long,
+        batch: Long,
+        nLen: Int,
+        ncur: IntVar
+    ): String?
+
+    private external fun kv_cache_clear(context: Long)
+
+    suspend fun bench(pp: Int, tg: Int, pl: Int, nr: Int = 1): String {
+        return withContext(runLoop) {
+            when (val state = threadLocalState.get()) {
+                is State.Loaded -> {
+                    Log.d(tag, "bench(): $state")
+                    bench_model(state.context, state.model, state.batch, pp, tg, pl, nr)
+                }
+
+                else -> throw IllegalStateException("No model loaded")
+            }
+        }
+    }
+
+    suspend fun load(pathToModel: String) {
+        withContext(runLoop) {
+            when (threadLocalState.get()) {
+                is State.Idle -> {
+                    val model = load_model(pathToModel)
+                    if (model == 0L)  throw IllegalStateException("load_model() failed")
+
+                    val context = new_context(model)
+                    if (context == 0L) throw IllegalStateException("new_context() failed")
+
+                    val batch = new_batch(512, 0, 1)
+                    if (batch == 0L) throw IllegalStateException("new_batch() failed")
+
+                    Log.i(tag, "Loaded model $pathToModel")
+                    threadLocalState.set(State.Loaded(model, context, batch))
+                }
+                else -> throw IllegalStateException("Model already loaded")
+            }
+        }
+    }
+
+    fun send(message: String): Flow<String> = flow {
+        when (val state = threadLocalState.get()) {
+            is State.Loaded -> {
+                val ncur = IntVar(completion_init(state.context, state.batch, message, nlen))
+                while (ncur.value <= nlen) {
+                    val str = completion_loop(state.context, state.batch, nlen, ncur)
+                    if (str == null) {
+                        break
+                    }
+                    emit(str)
+                }
+                kv_cache_clear(state.context)
+            }
+            else -> {}
+        }
+    }.flowOn(runLoop)
+
+    /**
+     * Unloads the model and frees resources.
+     *
+     * This is a no-op if there's no model loaded.
+     */
+    suspend fun unload() {
+        withContext(runLoop) {
+            when (val state = threadLocalState.get()) {
+                is State.Loaded -> {
+                    free_context(state.context)
+                    free_model(state.model)
+                    free_batch(state.batch)
+
+                    threadLocalState.set(State.Idle)
+                }
+                else -> {}
+            }
+        }
+    }
+
+    companion object {
+        private class IntVar(value: Int) {
+            @Volatile
+            var value: Int = value
+                private set
+
+            fun inc() {
+                synchronized(this) {
+                    value += 1
+                }
+            }
+        }
+
+        private sealed interface State {
+            data object Idle: State
+            data class Loaded(val model: Long, val context: Long, val batch: Long): State
+        }
+
+        // Enforce only one instance of Llm.
+        private val _instance: LLamaAndroid = LLamaAndroid()
+
+        fun instance(): LLamaAndroid = _instance
+    }
+}