Initial commit of common

common/.gitignore

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+/build

common/build.gradle.kts

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+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+plugins {
+    id("com.android.library")
+    id("maven-publish")
+    id("com.ncorti.ktfmt.gradle")
+    id("changelog-plugin")
+    id("release-plugin")
+    kotlin("android")
+    kotlin("plugin.serialization")
+}
+
+ktfmt {
+    googleStyle()
+}
+
+android {
+    namespace = "com.google.ai.client.generativeai.common"
+    compileSdk = 34
+
+    buildFeatures.buildConfig = true
+
+    defaultConfig {
+        minSdk = 21
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+        consumerProguardFiles("consumer-rules.pro")
+
+        buildConfigField("String", "VERSION_NAME", "\"${project.version.toString()}\"")
+    }
+
+    publishing {
+        singleVariant("release") {
+            withSourcesJar()
+        }
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+    kotlinOptions {
+        jvmTarget = "17"
+    }
+
+    testOptions {
+        unitTests.isReturnDefaultValues = true
+    }
+}
+
+dependencies {
+    val ktorVersion = "2.3.2"
+
+    implementation("io.ktor:ktor-client-okhttp:$ktorVersion")
+    implementation("io.ktor:ktor-client-core:$ktorVersion")
+    implementation("io.ktor:ktor-client-content-negotiation:$ktorVersion")
+    implementation("io.ktor:ktor-serialization-kotlinx-json:$ktorVersion")
+    implementation("io.ktor:ktor-client-logging:$ktorVersion")
+
+    implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.5.1")
+    implementation("androidx.core:core-ktx:1.12.0")
+    implementation("org.slf4j:slf4j-nop:2.0.9")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.7.3")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-reactive:1.7.3")
+    implementation("org.reactivestreams:reactive-streams:1.0.3")
+
+    implementation("com.google.guava:listenablefuture:1.0")
+    implementation("androidx.concurrent:concurrent-futures:1.2.0-alpha02")
+    implementation("androidx.concurrent:concurrent-futures-ktx:1.2.0-alpha02")
+    testImplementation("junit:junit:4.13.2")
+    testImplementation("io.kotest:kotest-assertions-core:4.0.7")
+    testImplementation("io.kotest:kotest-assertions-jvm:4.0.7")
+    testImplementation("io.kotest:kotest-assertions-json:4.0.7")
+    testImplementation("io.ktor:ktor-client-mock:$ktorVersion")
+    androidTestImplementation("androidx.test.ext:junit:1.1.5")
+    androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")
+}
+
+publishing {
+    publications {
+        register<MavenPublication>("release") {
+            groupId = "com.google.ai.client.generativeai"
+            artifactId = "common"
+            version = project.version.toString()
+            pom {
+                licenses {
+                    license {
+                        name = "The Apache License, Version 2.0"
+                        url = "http://www.apache.org/licenses/LICENSE-2.0.txt"
+                    }
+                }
+            }
+            afterEvaluate {
+                from(components["release"])
+            }
+        }
+    }
+    repositories {
+        maven {
+            url = uri("${projectDir}/m2")
+        }
+    }
+}

common/consumer-rules.pro

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+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

common/gradle.properties

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+version=0.2.0

common/proguard-rules.pro

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+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

common/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2024 Google LLC
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.INTERNET"/>
+</manifest>

common/src/main/kotlin/com/google/ai/client/generativeai/common/APIController.kt

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+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.ai.client.generativeai.common
+
+import com.google.ai.client.generativeai.common.BuildConfig
+import com.google.ai.client.generativeai.common.util.decodeToFlow
+import io.ktor.client.HttpClient
+import io.ktor.client.call.body
+import io.ktor.client.engine.HttpClientEngine
+import io.ktor.client.engine.okhttp.OkHttp
+import io.ktor.client.plugins.HttpTimeout
+import io.ktor.client.plugins.contentnegotiation.ContentNegotiation
+import io.ktor.client.request.HttpRequestBuilder
+import io.ktor.client.request.header
+import io.ktor.client.request.post
+import io.ktor.client.request.preparePost
+import io.ktor.client.request.setBody
+import io.ktor.client.statement.HttpResponse
+import io.ktor.client.statement.bodyAsChannel
+import io.ktor.client.statement.bodyAsText
+import io.ktor.http.ContentType
+import io.ktor.http.HttpStatusCode
+import io.ktor.http.contentType
+import io.ktor.serialization.kotlinx.json.json
+import kotlinx.coroutines.CoroutineName
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.channelFlow
+import kotlinx.coroutines.flow.timeout
+import kotlinx.coroutines.launch
+import kotlinx.serialization.json.Json
+
+const val DOMAIN = "https://generativelanguage.googleapis.com"
+
+val JSON = Json {
+  ignoreUnknownKeys = true
+  prettyPrint = false
+}
+
+/**
+ * Backend class for interfacing with the Gemini API.
+ *
+ * This class handles making HTTP requests to the API and streaming the responses back.
+ *
+ * @param httpEngine The HTTP client engine to be used for making requests. Defaults to CIO engine.
+ *   Exposed primarily for DI in tests.
+ * @property key The API key used for authentication.
+ * @property model The model to use for generation.
+ * @property apiVersion the endpoint version to communicate with.
+ * @property timeout the maximum amount of time for a request to take in the initial exchange.
+ */
+class APIController(
+  private val key: String,
+  model: String,
+  private val requestOptions: RequestOptions,
+  httpEngine: HttpClientEngine = OkHttp.create(),
+) {
+  private val model = fullModelName(model)
+
+  private val client =
+    HttpClient(httpEngine) {
+      install(HttpTimeout) {
+        requestTimeoutMillis = requestOptions.timeout.inWholeMilliseconds
+        socketTimeoutMillis = 80_000
+      }
+      install(ContentNegotiation) { json(JSON) }
+    }
+
+  suspend fun generateContent(request: GenerateContentRequest): GenerateContentResponse =
+    client
+      .post("$DOMAIN/${requestOptions.apiVersion}/$model:generateContent") {
+        applyCommonConfiguration(request)
+      }
+      .also { validateResponse(it) }
+      .body()
+
+  fun generateContentStream(request: GenerateContentRequest): Flow<GenerateContentResponse> {
+    return client.postStream<GenerateContentResponse>(
+      "$DOMAIN/${requestOptions.apiVersion}/$model:streamGenerateContent?alt=sse"
+    ) {
+      applyCommonConfiguration(request)
+    }
+  }
+
+  suspend fun countTokens(request: CountTokensRequest): CountTokensResponse =
+    client
+      .post("$DOMAIN/${requestOptions.apiVersion}/$model:countTokens") {
+        applyCommonConfiguration(request)
+      }
+      .also { validateResponse(it) }
+      .body()
+
+  private fun HttpRequestBuilder.applyCommonConfiguration(request: Request) {
+    when (request) {
+      is GenerateContentRequest -> setBody<GenerateContentRequest>(request)
+      is CountTokensRequest -> setBody<CountTokensRequest>(request)
+    }
+    contentType(ContentType.Application.Json)
+    header("x-goog-api-key", key)
+    header("x-goog-api-client", "genai-android/${BuildConfig.VERSION_NAME}")
+  }
+}
+
+/**
+ * Ensures the model name provided has a `models/` prefix
+ *
+ * Models must be prepended with the `models/` prefix when communicating with the backend.
+ */
+private fun fullModelName(name: String): String = name.takeIf { it.contains("/") } ?: "models/$name"
+
+/**
+ * Makes a POST request to the specified [url] and returns a [Flow] of deserialized response objects
+ * of type [R]. The response is expected to be a stream of JSON objects that are parsed in real-time
+ * as they are received from the server.
+ *
+ * This function is intended for internal use within the client that handles streaming responses.
+ *
+ * Example usage:
+ * ```
+ * val client: HttpClient = HttpClient(CIO)
+ * val request: Request = GenerateContentRequest(...)
+ * val url: String = "http://example.com/stream"
+ *
+ * val responses: GenerateContentResponse = client.postStream(url) {
+ *   setBody(request)
+ *   contentType(ContentType.Application.Json)
+ * }
+ * responses.collect {
+ *   println("Got a response: $it")
+ * }
+ * ```
+ *
+ * @param R The type of the response object.
+ * @param url The URL to which the POST request will be made.
+ * @param config An optional [HttpRequestBuilder] callback for request configuration.
+ * @return A [Flow] of response objects of type [R].
+ */
+private inline fun <reified R : Response> HttpClient.postStream(
+  url: String,
+  crossinline config: HttpRequestBuilder.() -> Unit = {}
+): Flow<R> = channelFlow {
+  launch(CoroutineName("postStream")) {
+    preparePost(url) { config() }
+      .execute {
+        validateResponse(it)
+
+        val channel = it.bodyAsChannel()
+        val flow = JSON.decodeToFlow<R>(channel)
+
+        flow.collect { send(it) }
+      }
+  }
+}
+
+private suspend fun validateResponse(response: HttpResponse) {
+  if (response.status != HttpStatusCode.OK) {
+    val text = response.bodyAsText()
+    val message =
+      try {
+        JSON.decodeFromString<GRpcErrorResponse>(text).error.message
+      } catch (e: Throwable) {
+        "Unexpected Response:\n$text"
+      }
+    if (message.contains("API key not valid")) {
+      throw InvalidAPIKeyException(message)
+    }
+    // TODO (b/325117891): Use a better method than string matching.
+    if (message == "User location is not supported for the API use.") {
+      throw UnsupportedUserLocationException()
+    }
+    throw ServerException(message)
+  }
+}