ProfileFileSupplier API changes, aggregating (#3558)

* Added methods for aggregating ProfileFile objects

* Removed redundant logic, changelog entry

* Removed redundant methods

* Use compare and set to make thread safe

Author: dave-fn

core/auth/src/main/java/software/amazon/awssdk/auth/credentials/ProfileCredentialsProvider.java

@@ -225,7 +225,9 @@ static final class BuilderImpl implements Builder {
 
         @Override
         public Builder profileFile(ProfileFile profileFile) {
-            return profileFile(ProfileFileSupplier.wrapIntoNullableSupplier(profileFile));
+            return profileFile(Optional.ofNullable(profileFile)
+                                       .map(ProfileFileSupplier::fixedProfileFile)
+                                       .orElse(null));
         }
 
         public void setProfileFile(ProfileFile profileFile) {

core/auth/src/test/java/software/amazon/awssdk/auth/credentials/ProfileCredentialsProviderTest.java

@@ -193,7 +193,7 @@ void resolveCredentials_presentProfileFileSupplier_returnsCredentials() {
 
         ProfileCredentialsProvider provider =
             ProfileCredentialsProvider.builder()
-                                      .profileFile(ProfileFileSupplier.reloadWhenModified(path))
+                                      .profileFile(ProfileFileSupplier.reloadWhenModified(path, ProfileFile.Type.CREDENTIALS))
                                       .profileName("default")
                                       .build();
 

core/profiles/src/main/java/software/amazon/awssdk/profiles/ProfileFileSupplier.java

@@ -16,7 +16,10 @@
 package software.amazon.awssdk.profiles;
 
 import java.nio.file.Path;
+import java.util.Arrays;
 import java.util.Objects;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Supplier;
 import software.amazon.awssdk.annotations.SdkPublicApi;
 import software.amazon.awssdk.profiles.internal.ProfileFileRefresher;
@@ -36,21 +39,53 @@ public interface ProfileFileSupplier extends Supplier<ProfileFile>, SdkAutoClose
     default void close() {
     }
 
+    /**
+     * Creates a {@link ProfileFileSupplier} capable of producing multiple profile objects by aggregating the default
+     * credentials and configuration files as determined by {@link ProfileFileLocation#credentialsFileLocation()} abd
+     * {@link ProfileFileLocation#configurationFileLocation()}. This supplier will return a new ProfileFile instance only once
+     * either disk file has been modified. Multiple calls to the supplier while both disk files are unchanged will return the
+     * same object.
+     *
+     * @return Implementation of {@link ProfileFileSupplier} that is capable of supplying a new aggregate profile when either file
+     *         has been modified.
+     */
+    static ProfileFileSupplier defaultSupplier() {
+        Optional<ProfileFileSupplier> credentialsSupplierOptional
+            = ProfileFileLocation.credentialsFileLocation()
+                                 .map(path -> reloadWhenModified(path, ProfileFile.Type.CREDENTIALS));
+
+        Optional<ProfileFileSupplier> configurationSupplierOptional
+            = ProfileFileLocation.configurationFileLocation()
+                                 .map(path -> reloadWhenModified(path, ProfileFile.Type.CONFIGURATION));
+
+        ProfileFileSupplier supplier = () -> null;
+        if (credentialsSupplierOptional.isPresent() && configurationSupplierOptional.isPresent()) {
+            supplier = aggregate(credentialsSupplierOptional.get(), configurationSupplierOptional.get());
+        } else if (credentialsSupplierOptional.isPresent()) {
+            supplier = credentialsSupplierOptional.get();
+        } else if (configurationSupplierOptional.isPresent()) {
+            supplier = configurationSupplierOptional.get();
+        }
+
+        return supplier;
+    }
+
     /**
      * Creates a {@link ProfileFileSupplier} capable of producing multiple profile objects from a file. This supplier will
      * return a new ProfileFile instance only once the disk file has been modified. Multiple calls to the supplier while the
      * disk file is unchanged will return the same object.
      *
      * @param path Path to the file to read from.
+     * @param type The type of file. See {@link ProfileFile.Type} for possible values.
      * @return Implementation of {@link ProfileFileSupplier} that is capable of supplying a new profile when the file
      *         has been modified.
      */
-    static ProfileFileSupplier reloadWhenModified(Path path) {
+    static ProfileFileSupplier reloadWhenModified(Path path, ProfileFile.Type type) {
         return new ProfileFileSupplier() {
 
             final ProfileFile.Builder builder = ProfileFile.builder()
                                                            .content(path)
-                                                           .type(ProfileFile.Type.CREDENTIALS);
+                                                           .type(type);
 
             final ProfileFileRefresher refresher = ProfileFileRefresher.builder()
                                                                        .profileFile(builder::build)
@@ -69,21 +104,6 @@ public void close() {
         };
     }
 
-    /**
-     * Creates a {@link ProfileFileSupplier} capable of producing a single profile object from a file.
-     *
-     * @param path Path to the file to read from.
-     * @return Implementation of {@link ProfileFileSupplier} that is capable of supplying a single profile.
-     */
-    static ProfileFileSupplier fixedProfileFile(Path path) {
-        ProfileFile profileFile = ProfileFile.builder()
-                                             .content(path)
-                                             .type(ProfileFile.Type.CREDENTIALS)
-                                             .build();
-
-        return () -> profileFile;
-    }
-
     /**
      * Creates a {@link ProfileFileSupplier} that produces an existing profile.
      *
@@ -95,14 +115,46 @@ static ProfileFileSupplier fixedProfileFile(ProfileFile profileFile) {
     }
 
     /**
-     * creates a {@link ProfileFileSupplier} that produces an existing non-null profile. If the given profile
-     * is null, then the created supplier will also be null.
+     * Creates a {@link ProfileFileSupplier} by combining the {@link ProfileFile} objects from two {@code ProfileFileSupplier}s.
+     * Objects are passed into {@link ProfileFile.Aggregator}.
      *
-     * @param profileFile Profile object to supply.
-     * @return Implementation of {@link ProfileFileSupplier} that is capable of supplying a single profile.
+     * @param suppliers Array of {@code ProfileFileSupplier} objects. {@code ProfileFile} objects are passed to
+     *                  {@link ProfileFile.Aggregator#addFile(ProfileFile)} in the same argument order as the supplier that
+     *                  generated it.
+     * @return Implementation of {@link ProfileFileSupplier} aggregating results from the supplier objects.
      */
-    static ProfileFileSupplier wrapIntoNullableSupplier(ProfileFile profileFile) {
-        return Objects.nonNull(profileFile) ? () -> profileFile : null;
+    static ProfileFileSupplier aggregate(ProfileFileSupplier... suppliers) {
+
+        return new ProfileFileSupplier() {
+
+            final AtomicReference<ProfileFile> currentAggregateProfileFile = new AtomicReference<>();
+
+            @Override
+            public ProfileFile get() {
+                ProfileFile.Aggregator aggregator = ProfileFile.aggregator();
+                for (ProfileFileSupplier supplier : suppliers) {
+                    aggregator.addFile(supplier.get());
+                }
+
+                return refreshAndGetCurrentAggregate(aggregator);
+            }
+
+            @Override
+            public void close() {
+                Arrays.stream(suppliers).forEach(ProfileFileSupplier::close);
+            }
+
+            private ProfileFile refreshAndGetCurrentAggregate(ProfileFile.Aggregator aggregator) {
+                ProfileFile current = currentAggregateProfileFile.get();
+                ProfileFile next = aggregator.build();
+                if (!Objects.equals(current, next)) {
+                    currentAggregateProfileFile.compareAndSet(current, next);
+                }
+
+                return currentAggregateProfileFile.get();
+            }
+
+        };
     }
 
 }

core/profiles/src/main/java/software/amazon/awssdk/profiles/ProfileFileSupplierBuilder.java

@@ -32,20 +32,20 @@ final class ProfileFileSupplierBuilder {
     private Clock clock;
     private Consumer<ProfileFile> onProfileFileLoad;
 
-    public ProfileFileSupplierBuilder reloadWhenModified(Path path) {
+    public ProfileFileSupplierBuilder reloadWhenModified(Path path, ProfileFile.Type type) {
         ProfileFile.Builder builder = ProfileFile.builder()
                                                  .content(path)
-                                                 .type(ProfileFile.Type.CREDENTIALS);
+                                                 .type(type);
         this.profileFile = builder::build;
         this.profileFilePath = path;
         this.reloadingSupplier = true;
         return this;
     }
 
-    public ProfileFileSupplierBuilder fixedProfileFile(Path path) {
+    public ProfileFileSupplierBuilder fixedProfileFile(Path path, ProfileFile.Type type) {
         return fixedProfileFile(ProfileFile.builder()
                                            .content(path)
-                                           .type(ProfileFile.Type.CREDENTIALS)
+                                           .type(type)
                                            .build());
     }