Wasm/WASI target implementation

README.md

@@ -478,6 +478,24 @@ external object JsJodaTimeZoneModule
 private val jsJodaTz = JsJodaTimeZoneModule
 ```
 
+#### Note about time zones in Wasm/WASI
+
+By default, there's only one time zone available in Kotlin/Wasm WASI: the `UTC` time zone with a fixed offset.
+
+If you want to use all time zones in Kotlin/Wasm WASI platform, you need to add the following dependency:
+
+```kotlin
+kotlin {
+    sourceSets {
+        val wasmWasiMain by getting {
+            dependencies {
+                implementation("kotlinx-datetime-zoneinfo", "2024a-spi.0.6.0-RC.2")
+            }
+        }
+    }
+}
+```
+
 ### Maven
 
 Add a dependency to the `<dependencies>` element. Note that you need to use the platform-specific `-jvm` artifact in Maven.

buildSrc/src/main/kotlin/zoneInfosResourcesGenerator.kt

@@ -0,0 +1,101 @@
+import java.io.File
+
+/*
+ * Copyright 2019-2024 JetBrains s.r.o. and contributors.
+ * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
+ */
+
+private val pkg = "package kotlinx.datetime.timezones.tzData"
+
+private fun generateByteArrayProperty(tzData: TzData, header: String, propertyName: String): String = buildString {
+    append(header)
+    appendLine()
+    appendLine()
+    appendLine("/* ${tzData.fullTzNames.joinToString(", ")} */")
+    append("internal val $propertyName get() = byteArrayOf(")
+    for (chunk in tzData.data.toList().chunked(16)) {
+        appendLine()
+        append("    ")
+        val chunkText = chunk.joinToString {
+            it.toString().padStart(4, ' ')
+        } + ","
+        append(chunkText)
+    }
+    appendLine()
+    append(")")
+}
+
+private class TzData(val data: ByteArray, val fullTzNames: MutableList<String>)
+private fun loadTzBinaries(
+    zoneInfo: File,
+    currentName: String,
+    result: MutableList<TzData>
+) {
+    val zoneName = if (currentName.isEmpty()) zoneInfo.name else "$currentName/${zoneInfo.name}"
+    if (zoneInfo.isDirectory) {
+        zoneInfo.listFiles()?.forEach {
+            loadTzBinaries(it, zoneName, result)
+        }
+    } else {
+        val bytes = zoneInfo.readBytes()
+        val foundTzData = result.firstOrNull { it.data.contentEquals(bytes) }
+        val tzData: TzData
+        if (foundTzData != null) {
+            tzData = foundTzData
+        } else {
+            tzData = TzData(bytes, mutableListOf())
+            result.add(tzData)
+        }
+
+        tzData.fullTzNames.add(zoneName)
+    }
+}
+
+fun generateZoneInfosResources(zoneInfoDir: File, outputDir: File, version: String) {
+    val header = buildString {
+        appendLine()
+        append("/* AUTOGENERATED FROM ZONE INFO DATABASE v.$version */")
+        appendLine()
+        appendLine()
+        append(pkg)
+    }
+
+    val loadedZones = mutableListOf<TzData>()
+    zoneInfoDir.listFiles()?.forEach { file ->
+        loadTzBinaries(file, "", loadedZones)
+    }
+
+    val zoneDataByNameBody = StringBuilder()
+    val getTimeZonesBody = StringBuilder()
+    loadedZones.forEachIndexed { id, tzData ->
+        val tzDataName = "tzData$id"
+        val data = generateByteArrayProperty(tzData, header, tzDataName)
+        File(outputDir, "$tzDataName.kt").writeText(data)
+        tzData.fullTzNames.forEach { name ->
+            zoneDataByNameBody.appendLine("    \"$name\" -> $tzDataName")
+            getTimeZonesBody.appendLine("    \"$name\",")
+        }
+    }
+
+    val content = buildString {
+        append(header)
+        appendLine()
+        appendLine()
+        appendLine("internal fun zoneDataByName(name: String): ByteArray = when(name) {")
+        append(zoneDataByNameBody)
+        appendLine()
+        append("    else -> throw kotlinx.datetime.IllegalTimeZoneException(\"Invalid timezone name\")")
+        appendLine()
+        append("}")
+        appendLine()
+        appendLine()
+        append("internal val timeZones: Set<String> by lazy { setOf(")
+        appendLine()
+        append(getTimeZonesBody)
+        appendLine()
+        append(")")
+        append("}")
+    }
+
+    File(outputDir, "tzData.kt").writeText(content)
+}

core/build.gradle.kts

@@ -127,6 +127,10 @@ kotlin {
         }
     }
 
+    wasmWasi {
+        nodejs()
+    }
+
     @OptIn(ExperimentalKotlinGradlePluginApi::class)
     compilerOptions {
         freeCompilerArgs.add("-Xexpect-actual-classes")
@@ -207,14 +211,34 @@ kotlin {
             dependsOn(commonJsTest)
         }
 
-        val nativeMain by getting {
+        val commonKotlinMain by creating {
             dependsOn(commonMain.get())
             dependencies {
                 api("org.jetbrains.kotlinx:kotlinx-serialization-core:$serializationVersion")
             }
         }
 
+        val commonKotlinTest by creating {
+            dependsOn(commonTest.get())
+        }
+
+        val nativeMain by getting {
+            dependsOn(commonKotlinMain)
+        }
+
         val nativeTest by getting {
+            dependsOn(commonKotlinTest)
+        }
+
+        val wasmWasiMain by getting {
+            dependsOn(commonKotlinMain)
+        }
+
+        val wasmWasiTest by getting {
+            dependsOn(commonKotlinTest)
+            dependencies {
+                runtimeOnly(project(":kotlinx-datetime-zoneinfo"))
+            }
         }
 
         val darwinMain by getting {

core/common/src/TimeZone.kt

@@ -66,6 +66,8 @@ public expect open class TimeZone {
          * On Linux, this function queries the `/etc/localtime` symbolic link. If the link is missing, [UTC] is used.
          * If the link points to an invalid location, [IllegalTimeZoneException] is thrown.
          *
+         * Always returns the `UTC` timezone on the Wasm WASI platform due to the lack of support for retrieving system timezone information.
+         *
          * @sample kotlinx.datetime.test.samples.TimeZoneSamples.currentSystemDefault
          */
         public fun currentSystemDefault(): TimeZone
@@ -95,6 +97,10 @@ public expect open class TimeZone {
          *
          * @throws IllegalTimeZoneException if [zoneId] has an invalid format or a time-zone with the name [zoneId]
          * is not found.
+         *
+         * @throws IllegalTimeZoneException on the Wasm WASI platform for non-fixed-offset time zones,
+         * unless a dependency on the `kotlinx-datetime-zoneinfo` artifact is added.
+         *
          * @sample kotlinx.datetime.test.samples.TimeZoneSamples.constructorFunction
          */
         public fun of(zoneId: String): TimeZone

core/native/src/UtcOffset.kt → core/commonKotlin/src/UtcOffset.kt

@@ -10,6 +10,7 @@ import kotlinx.datetime.format.*
 import kotlinx.datetime.serializers.UtcOffsetSerializer
 import kotlinx.serialization.Serializable
 import kotlin.math.abs
+import kotlin.native.concurrent.ThreadLocal
 
 @Serializable(with = UtcOffsetSerializer::class)
 public actual class UtcOffset private constructor(public actual val totalSeconds: Int) {

core/commonKotlin/src/internal/Platform.kt

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2019-2024 JetBrains s.r.o. and contributors.
+ * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.datetime.internal
+
+import kotlinx.datetime.Instant
+
+internal expect val systemTzdb: TimeZoneDatabase
+
+internal expect fun currentSystemDefaultZone(): Pair<String, TimeZoneRules?>
+
+internal expect fun currentTime(): Instant

core/native/src/internal/Platform.kt

@@ -6,15 +6,11 @@
 package kotlinx.datetime.internal
 
 import kotlinx.cinterop.*
-import kotlinx.datetime.*
+import kotlinx.datetime.Instant
 import platform.posix.*
 
-internal expect val systemTzdb: TimeZoneDatabase
-
-internal expect fun currentSystemDefaultZone(): Pair<String, TimeZoneRules?>
-
 @OptIn(ExperimentalForeignApi::class, UnsafeNumber::class)
-internal fun currentTime(): Instant = memScoped {
+internal actual fun currentTime(): Instant = memScoped {
     val tm = alloc<timespec>()
     val error = clock_gettime(CLOCK_REALTIME.convert(), tm.ptr)
     check(error == 0) { "Error when reading the system clock: ${strerror(errno)?.toKString() ?: "Unknown error"}" }
@@ -24,4 +20,4 @@ internal fun currentTime(): Instant = memScoped {
     } catch (e: IllegalArgumentException) {
         throw IllegalStateException("The readings from the system clock (${tm.tv_sec} seconds, ${tm.tv_nsec} nanoseconds) are not representable as an Instant")
     }
-}
+}

core/wasmWasi/src/internal/Platform.kt

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2019-2024 JetBrains s.r.o. and contributors.
+ * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.datetime.internal
+
+import kotlinx.datetime.Instant
+import kotlin.wasm.WasmImport
+import kotlin.wasm.unsafe.UnsafeWasmMemoryApi
+import kotlin.wasm.unsafe.withScopedMemoryAllocator
+
+/**
+ * Return the time value of a clock. Note: This is similar to `clock_gettime` in POSIX.
+ */
+@WasmImport("wasi_snapshot_preview1", "clock_time_get")
+private external fun wasiRawClockTimeGet(clockId: Int, precision: Long, resultPtr: Int): Int
+
+private const val CLOCKID_REALTIME = 0
+
+@OptIn(UnsafeWasmMemoryApi::class)
+private fun clockTimeGet(): Long = withScopedMemoryAllocator { allocator ->
+    val rp0 = allocator.allocate(8)
+    val ret = wasiRawClockTimeGet(
+        clockId = CLOCKID_REALTIME,
+        precision = 1,
+        resultPtr = rp0.address.toInt()
+    )
+    if (ret == 0) {
+        rp0.loadLong()
+    } else {
+        error("WASI call failed with $ret")
+    }
+}
+
+internal actual fun currentTime(): Instant = clockTimeGet().let { time ->
+    // Instant.MAX and Instant.MIN are never going to be exceeded using just the Long number of nanoseconds
+    Instant(time.floorDiv(NANOS_PER_ONE.toLong()), time.mod(NANOS_PER_ONE.toLong()).toInt())
+}
+
+internal actual fun currentSystemDefaultZone(): Pair<String, TimeZoneRules?> =
+    "UTC" to null
+
+internal actual val systemTzdb: TimeZoneDatabase = TzdbOnData()

core/wasmWasi/src/internal/TimeZonesInitializer.kt

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2019-2023 JetBrains s.r.o. and contributors.
+ * Use of this source code is governed by the Apache 2.0 License that can be found in the LICENSE.txt file.
+ */
+
+package kotlinx.datetime.internal
+
+import kotlinx.datetime.IllegalTimeZoneException
+
+@RequiresOptIn
+internal annotation class InternalDateTimeApi
+
+/*
+This is internal API which is not intended to use on user-side.
+ */
+@InternalDateTimeApi
+public interface TimeZonesProvider {
+    public fun  zoneDataByName(name: String): ByteArray
+    public fun getTimeZones(): Set<String>
+}
+
+/*
+This is internal API which is not intended to use on user-side.
+ */
+@InternalDateTimeApi
+public fun initializeTimeZonesProvider(provider: TimeZonesProvider) {
+    check(timeZonesProvider != provider) { "TimeZone database redeclaration" }
+    timeZonesProvider = provider
+}
+
+@InternalDateTimeApi
+private var timeZonesProvider: TimeZonesProvider? = null
+
+@OptIn(InternalDateTimeApi::class)
+internal class TzdbOnData: TimeZoneDatabase {
+    override fun rulesForId(id: String): TimeZoneRules {
+        val data = timeZonesProvider?.zoneDataByName(id)
+            ?: throw IllegalTimeZoneException("TimeZones are not supported")
+        return readTzFile(data).toTimeZoneRules()
+    }
+
+    override fun availableTimeZoneIds(): Set<String> =
+        timeZonesProvider?.getTimeZones() ?: setOf("UTC")
+}

gradle.properties

@@ -1,10 +1,12 @@
-org.gradle.jvmargs=-Xmx1G -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
+org.gradle.jvmargs=-Xmx2G -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
 org.gradle.java.installations.fromEnv=JDK_8
 
 group=org.jetbrains.kotlinx
 version=0.6.1
 versionSuffix=SNAPSHOT
 
+tzdbVersion=2024a
+
 defaultKotlinVersion=1.9.21
 dokkaVersion=1.9.20
 serializationVersion=1.6.2

serialization/build.gradle.kts

@@ -58,6 +58,11 @@ kotlin {
         }
     }
 
+    wasmWasi {
+        nodejs {
+        }
+    }
+
     sourceSets.all {
         val suffixIndex = name.indexOfLast { it.isUpperCase() }
         val targetName = name.substring(0, suffixIndex)
@@ -103,6 +108,13 @@ kotlin {
             }
         }
 
+        val wasmWasiMain by getting
+        val wasmWasiTest by getting {
+            dependencies {
+                runtimeOnly(project(":kotlinx-datetime-zoneinfo"))
+            }
+        }
+
         val nativeMain by getting
         val nativeTest by getting
     }

settings.gradle.kts

@@ -16,6 +16,8 @@ rootProject.name = "Kotlin-DateTime-library"
 
 include(":core")
 project(":core").name = "kotlinx-datetime"
+include(":timezones/full")
+project(":timezones/full").name = "kotlinx-datetime-zoneinfo"
 include(":serialization")
 project(":serialization").name = "kotlinx-datetime-serialization"
 include(":benchmarks")