Support granular control of specifying runtime crate versions

CHANGELOG.next.toml

@@ -16,3 +16,47 @@ message = "Add codegen version to generated package metadata"
 references = ["smithy-rs#1612"]
 meta = { "breaking" = false, "tada" = false, "bug" = false }
 author = "unexge"
+
+[[smithy-rs]]
+message = """
+Support granular control of specifying runtime crate versions.
+
+For code generation, the field `runtimeConfig.version` in smithy-build.json has been removed.
+The new field `runtimeConfig.verisions` is an object that keys are runtime crate names (e.g. aws-smithy-http),
+and values are their versions user specifying.
+
+If you previous set `version = "DEFAULT"`, then you're lucky.
+The new behaviour automatically detects and injects the version for you by checking the version of the code generator.
+You don't need to add any new configuration.
+
+If you specified a certain version such as `version = "0.47.0", you can migrate to a special reserved key `DEFAULT`.
+The equivalent JSON config would look like:
+
+```json
+{
+  "runtimeConfig": {
+      "versions": {
+          "DEFAULT": "0.47.0"
+      }
+  }
+}
+```
+
+Then all runtime crate are set with version 0.47.0 by default unless specified versions by crate name. For example,
+
+```json
+{
+  "runtimeConfig": {
+      "versions": {
+          "DEFAULT": "0.47.0",
+          "aws-smithy-http": "0.47.1"
+      }
+  }
+}
+```
+
+It implies that we're using aws-smithy-http 0.47.1 specifically. For other crates default to 0.47.0.
+"""
+references = ["smithy-rs#1635", "smithy-rs#1416"]
+meta = { "breaking" = true, "tada" = true, "bug" = false }
+author = "weihanglo"

aws/sdk-codegen/src/main/kotlin/software/amazon/smithy/rustsdk/AwsRuntimeDependency.kt

@@ -37,7 +37,7 @@ fun RuntimeConfig.awsRoot(): RuntimeCrateLocation {
         path
     }
     return runtimeCrateLocation.copy(
-        path = updatedPath, version = runtimeCrateLocation.version?.let { defaultSdkVersion() },
+        path = updatedPath, versions = runtimeCrateLocation.versions,
     )
 }
 
@@ -61,7 +61,7 @@ object AwsRuntimeType {
 }
 
 fun RuntimeConfig.awsRuntimeDependency(name: String, features: Set<String> = setOf()): CargoDependency =
-    CargoDependency(name, awsRoot().crateLocation(), features = features)
+    CargoDependency(name, awsRoot().crateLocation(null), features = features)
 
 fun RuntimeConfig.awsHttp(): CargoDependency = awsRuntimeDependency("aws-http")
 fun RuntimeConfig.awsTypes(): CargoDependency = awsRuntimeDependency("aws-types")

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/RuntimeTypes.kt

@@ -7,6 +7,7 @@ package software.amazon.smithy.rust.codegen.smithy
 
 import software.amazon.smithy.codegen.core.CodegenException
 import software.amazon.smithy.codegen.core.Symbol
+import software.amazon.smithy.model.node.Node
 import software.amazon.smithy.model.node.ObjectNode
 import software.amazon.smithy.model.traits.TimestampFormatTrait
 import software.amazon.smithy.rust.codegen.rustlang.CargoDependency
@@ -23,26 +24,33 @@ import software.amazon.smithy.rust.codegen.rustlang.asType
 import software.amazon.smithy.rust.codegen.util.orNull
 import java.util.Optional
 
+private const val DEFAULT_KEY = "DEFAULT"
+
 /**
  * Location of the runtime crates (aws-smithy-http, aws-smithy-types etc.)
  *
- * This can be configured via the `runtimeConfig.version` field in smithy-build.json
+ * This can be configured via the `runtimeConfig.versions` field in smithy-build.json
  */
-data class RuntimeCrateLocation(val path: String?, val version: String?) {
+data class RuntimeCrateLocation(val path: String?, val versions: CrateVersionMap) {
     init {
-        check(path != null || version != null) {
-            "path ($path) or version ($version) must not be null"
+        check(path != null || versions.map.isNotEmpty()) {
+            "path ($path) or versions ($versions) must not be null or empty"
         }
     }
 
     companion object {
-        fun Path(path: String) = RuntimeCrateLocation(path, null)
+        fun Path(path: String) = RuntimeCrateLocation(path, CrateVersionMap(emptyMap()))
     }
 }
 
-fun RuntimeCrateLocation.crateLocation(): DependencyLocation = when (this.path) {
-    null -> CratesIo(this.version!!)
-    else -> Local(this.path, this.version)
+fun RuntimeCrateLocation.crateLocation(crateName: String?): DependencyLocation {
+    val version = crateName.let { versions.map[crateName] } ?: versions.map[DEFAULT_KEY]
+    return when (this.path) {
+        // CratesIo needs an exact version. However, for local crate we do not
+        // provide a detected version unless user explicitly sets via `DEFAULT` key.
+        null -> CratesIo(version ?: defaultRuntimeCrateVersion())
+        else -> Local(this.path, version)
+    }
 }
 
 fun defaultRuntimeCrateVersion(): String {
@@ -53,6 +61,14 @@ fun defaultRuntimeCrateVersion(): String {
     }
 }
 
+/**
+ * A mapping for crate name to user specified version.
+ */
+@JvmInline
+value class CrateVersionMap(
+    val map: Map<String, String>,
+)
+
 /**
  * Prefix & crate location for the runtime crates.
  */
@@ -67,13 +83,12 @@ data class RuntimeConfig(
          */
         fun fromNode(node: Optional<ObjectNode>): RuntimeConfig {
             return if (node.isPresent) {
-                val resolvedVersion = when (val configuredVersion = node.get().getStringMember("version").orNull()?.value) {
-                    "DEFAULT" -> defaultRuntimeCrateVersion()
-                    null -> null
-                    else -> configuredVersion
+                val crateVersionMap = node.get().getObjectMember("versions").orElse(Node.objectNode()).members.entries.let { members ->
+                    val map = members.associate { it.key.toString() to it.value.expectStringNode().value }
+                    CrateVersionMap(map)
                 }
                 val path = node.get().getStringMember("relativePath").orNull()?.value
-                val runtimeCrateLocation = RuntimeCrateLocation(path = path, version = resolvedVersion)
+                val runtimeCrateLocation = RuntimeCrateLocation(path = path, versions = crateVersionMap)
                 RuntimeConfig(
                     node.get().getStringMemberOrDefault("cratePrefix", "aws-smithy"),
                     runtimeCrateLocation = runtimeCrateLocation,
@@ -86,8 +101,15 @@ data class RuntimeConfig(
 
     val crateSrcPrefix: String = cratePrefix.replace("-", "_")
 
-    fun runtimeCrate(runtimeCrateName: String, optional: Boolean = false, scope: DependencyScope = DependencyScope.Compile): CargoDependency =
-        CargoDependency("$cratePrefix-$runtimeCrateName", runtimeCrateLocation.crateLocation(), optional = optional, scope = scope)
+    fun runtimeCrate(runtimeCrateName: String, optional: Boolean = false, scope: DependencyScope = DependencyScope.Compile): CargoDependency {
+        val crateName = "$cratePrefix-$runtimeCrateName"
+        return CargoDependency(
+            crateName,
+            runtimeCrateLocation.crateLocation(crateName),
+            optional = optional,
+            scope = scope,
+        )
+    }
 }
 
 /**