Add iOS SocketTransport implementation (#542)

This is rather crude, but it seems to work. Protocol and Transport are blocking APIs; in Android (and Java generally) that's okay, but Apple strongly pushes you towards async networking in iOS. So strongly in fact that all high-level APIs that are not yet deprecated are async-only, including Network.framework. This framework is also the only non-deprecated game in town when it comes to TLS.

In order to bridge the gap between Network.framework and our blocking APIs, this PR makes extensive use of dispatch semaphores - essentially, we block the calling thread until a completion handler signals the semaphore.

In the next major version of Thrifty, we should see about making the core APIs suspend, with blocking shims for migration. In that version, we can drop this charade and just use ktor or something. Until that glorious day, we get NwSocket.

.github/workflows/pre-merge.yml

@@ -14,7 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         jvm-version: [17]
-        os: [ubuntu-latest, windows-latest]
+        os: [ubuntu-latest, macos-13]
     env:
       JDK_VERSION: ${{ matrix.jvm-version }}
       GRADLE_OPTS: -Dorg.gradle.daemon=false
@@ -34,6 +34,7 @@ jobs:
           path: |
             ~/.gradle/caches/
             ~/.gradle/wrapper/
+            ~/.konan/
             .build-cache/
           key: cache-gradle-${{ matrix.os }}-${{ matrix.jvm-version }}-${{ hashFiles('settings.gradle') }}-${{ hashFiles('**/build.gradle') }}
           restore-keys: |
@@ -56,6 +57,16 @@ jobs:
         shell: bash
         run: ./gradlew check codeCoverageReport --parallel --no-daemon
 
+      - name: Boot simulator
+        if: matrix.os == 'macos-13'
+        shell: bash
+        run: xcrun simctl boot 'iPhone 14 Pro Max' || true
+
+      - name: Run simulator tests
+        if: matrix.os == 'macos-13'
+        shell: bash
+        run: ./gradlew -PiosDevice="iPhone 14 Pro Max" iosTest
+
       - name: Upload coverage stats
         if: success() && matrix.os == 'ubuntu-latest' && matrix.jvm-version == '8'
         uses: codecov/codecov-action@v3

gradle.properties

@@ -23,3 +23,5 @@ org.gradle.jvmargs=-XX:MaxMetaspaceSize=512m
 
 # Build cache is helpful
 org.gradle.caching=true
+
+kotlin.mpp.enableCInteropCommonization=true

thrifty-runtime/build.gradle

@@ -47,6 +47,10 @@ kotlin {
                 baseName = "Thrifty"
             }
         }
+
+        compilations.main.cinterops {
+            KT62102Workaround {}
+        }
     }
 
     iosX64 {
@@ -55,6 +59,10 @@ kotlin {
                 baseName = "Thrifty"
             }
         }
+
+        compilations.main.cinterops {
+            KT62102Workaround {}
+        }
     }
 
     sourceSets {
@@ -98,6 +106,12 @@ kotlin {
 
         iosTest {
             dependsOn commonTest
+
+            dependencies {
+                implementation libs.kotlin.test.common
+                implementation libs.kotest.assertions.common
+                implementation libs.kotest.assertions.core
+            }
         }
 
         iosArm64Main {
@@ -122,6 +136,21 @@ jvmTest {
     useJUnitPlatform()
 }
 
+tasks.register("iosTest") {
+    def device = project.findProperty("iosDevice")?.toString() ?: "iPhone 15 Pro Max"
+    dependsOn 'linkDebugTestIosX64'
+    group = JavaBasePlugin.VERIFICATION_GROUP
+    description = "Runs tests for target 'ios' on an iOS simulator"
+
+    doLast {
+        def binary = kotlin.targets.iosX64.binaries.getTest('DEBUG').outputFile
+        println("muh binary: ${binary.absolutePath}")
+        exec {
+            commandLine 'xcrun', 'simctl', 'spawn', device, binary.absolutePath
+        }
+    }
+}
+
 // What have I gotten myself in to
 configurations {
     jvmApiElements {

thrifty-runtime/src/commonMain/kotlin/com/microsoft/thrifty/transport/SocketTransport.kt

@@ -0,0 +1,47 @@
+/*
+ * Thrifty
+ *
+ * Copyright (c) Microsoft Corporation
+ *
+ * All rights reserved.
+ *
+ * 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
+ *
+ * THIS CODE IS PROVIDED ON AN  *AS IS* BASIS, WITHOUT WARRANTIES OR
+ * CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
+ * WITHOUT LIMITATION ANY IMPLIED WARRANTIES OR CONDITIONS OF TITLE,
+ * FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABLITY OR NON-INFRINGEMENT.
+ *
+ * See the Apache Version 2.0 License for specific language governing permissions and limitations under the License.
+ */
+package com.microsoft.thrifty.transport
+
+expect class SocketTransport internal constructor(
+    builder: Builder
+) : Transport {
+    class Builder(host: String, port: Int) {
+        /**
+         * The number of milliseconds to wait for a connection to be established.
+         */
+        fun connectTimeout(connectTimeout: Int): Builder
+
+        /**
+         * The number of milliseconds a read operation should wait for completion.
+         */
+        fun readTimeout(readTimeout: Int): Builder
+
+        /**
+         * Enable TLS for this connection.
+         */
+        fun enableTls(enableTls: Boolean): Builder
+
+        fun build(): SocketTransport
+    }
+
+    @Throws(okio.IOException::class)
+    fun connect()
+}