Model the config model view of model-integration

This is to make it clearer that these methods are part
of the config model API.

4 files changed, 181 insertions, 0 deletions

diff --git a/config-model-api/src/main/java/com/yahoo/config/model/api/ImportedMlFunction.java b/config-model-api/src/main/java/com/yahoo/config/model/api/ImportedMlFunction.java
new file mode 100644
index 00000000000..54cdf807878
--- /dev/null
+++ b/config-model-api/src/main/java/com/yahoo/config/model/api/ImportedMlFunction.java
@@ -0,0 +1,37 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.config.model.api;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * An imported function of an imported machine-learned model
+ *
+ * @author bratseth
+ */
+public class ImportedMlFunction {
+
+    private final String name;
+    private final List<String> arguments;
+    private final Map<String, String> argumentTypes;
+    private final String  expression;
+    private final Optional<String> returnType;
+
+    public ImportedMlFunction(String name, List<String> arguments, String expression,
+                              Map<String, String> argumentTypes, Optional<String> returnType) {
+        this.name = name;
+        this.arguments = Collections.unmodifiableList(arguments);
+        this.expression = expression;
+        this.argumentTypes = Collections.unmodifiableMap(argumentTypes);
+        this.returnType = returnType;
+    }
+
+    public String name() { return name; }
+    public List<String> arguments() { return arguments; }
+    public Map<String, String> argumentTypes() { return argumentTypes; }
+    public String expression() { return expression; }
+    public Optional<String> returnType() { return returnType; }
+
+}
diff --git a/config-model-api/src/main/java/com/yahoo/config/model/api/ImportedMlModel.java b/config-model-api/src/main/java/com/yahoo/config/model/api/ImportedMlModel.java
new file mode 100644
index 00000000000..078e4c239d6
--- /dev/null
+++ b/config-model-api/src/main/java/com/yahoo/config/model/api/ImportedMlModel.java
@@ -0,0 +1,23 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.config.model.api;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * Config model view of an imported machine-learned model.
+ *
+ * @author bratseth
+ */
+public interface ImportedMlModel {
+
+    String name();
+    String source();
+    Optional<String> inputTypeSpec(String input);
+    Map<String, String> smallConstants();
+    Map<String, String> largeConstants();
+    Map<String, String> functions();
+    List<ImportedMlFunction> outputExpressions();
+
+}
diff --git a/config-model-api/src/main/java/com/yahoo/config/model/api/ImportedMlModels.java b/config-model-api/src/main/java/com/yahoo/config/model/api/ImportedMlModels.java
new file mode 100644
index 00000000000..aeef81788b8
--- /dev/null
+++ b/config-model-api/src/main/java/com/yahoo/config/model/api/ImportedMlModels.java
@@ -0,0 +1,105 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.config.model.api;
+
+import com.yahoo.path.Path;
+
+import java.io.File;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * All models imported from the models/ directory in the application package.
+ * If this is empty it may be due to either not having any models in the application package,
+ * or this being created for a ZooKeeper application package, which does not have imported models.
+ *
+ * @author bratseth
+ */
+public class ImportedMlModels {
+
+    /** All imported models, indexed by their names */
+    private final Map<String, ImportedMlModel> importedModels;
+
+    /** Create a null imported models */
+    public ImportedMlModels() {
+        importedModels = Collections.emptyMap();
+    }
+
+    public ImportedMlModels(File modelsDirectory, Collection<MlModelImporter> importers) {
+        Map<String, ImportedMlModel> models = new HashMap<>();
+
+        // Find all subdirectories recursively which contains a model we can read
+        importRecursively(modelsDirectory, models, importers);
+        importedModels = Collections.unmodifiableMap(models);
+    }
+
+    /**
+     * Returns the model at the given location in the application package.
+     *
+     * @param modelPath the path to this model (file or directory, depending on model type)
+     *                  under the application package, both from the root or relative to the
+     *                  models directory works
+     * @return the model at this path or null if none
+     */
+    public ImportedMlModel get(File modelPath) {
+        return importedModels.get(toName(modelPath));
+    }
+
+    /** Returns an immutable collection of all the imported models */
+    public Collection<ImportedMlModel> all() {
+        return importedModels.values();
+    }
+
+    private static void importRecursively(File dir,
+                                          Map<String, ImportedMlModel> models,
+                                          Collection<MlModelImporter> importers) {
+        if ( ! dir.isDirectory()) return;
+
+        Arrays.stream(dir.listFiles()).sorted().forEach(child -> {
+            Optional<MlModelImporter> importer = findImporterOf(child, importers);
+            if (importer.isPresent()) {
+                String name = toName(child);
+                ImportedMlModel existing = models.get(name);
+                if (existing != null)
+                    throw new IllegalArgumentException("The models in " + child + " and " + existing.source() +
+                                                       " both resolve to the model name '" + name + "'");
+                models.put(name, importer.get().importModel(name, child));
+            }
+            else {
+                importRecursively(child, models, importers);
+            }
+        });
+    }
+
+    private static Optional<MlModelImporter> findImporterOf(File path, Collection<MlModelImporter> importers) {
+        return importers.stream().filter(item -> item.canImport(path.toString())).findFirst();
+    }
+
+    private static String toName(File modelFile) {
+        Path modelPath = Path.fromString(modelFile.toString());
+        if (modelFile.isFile())
+            modelPath = stripFileEnding(modelPath);
+        String localPath = concatenateAfterModelsDirectory(modelPath);
+        return localPath.replace('.', '_');
+    }
+
+    private static Path stripFileEnding(Path path) {
+        int dotIndex = path.last().lastIndexOf(".");
+        if (dotIndex <= 0) return path;
+        return path.withLast(path.last().substring(0, dotIndex));
+    }
+
+    private static String concatenateAfterModelsDirectory(Path path) {
+        boolean afterModels = false;
+        StringBuilder result = new StringBuilder();
+        for (String element : path.elements()) {
+            if (afterModels) result.append(element).append("_");
+            if (element.equals("models")) afterModels = true;
+        }
+        return result.substring(0, result.length()-1);
+    }
+
+}
diff --git a/config-model-api/src/main/java/com/yahoo/config/model/api/MlModelImporter.java b/config-model-api/src/main/java/com/yahoo/config/model/api/MlModelImporter.java
new file mode 100644
index 00000000000..d24eeb2d55a
--- /dev/null
+++ b/config-model-api/src/main/java/com/yahoo/config/model/api/MlModelImporter.java
@@ -0,0 +1,16 @@
+package com.yahoo.config.model.api;
+
+import java.io.File;
+
+/**
+ * Config model view of a machine-learned model importer
+ *
+ * @author bratseth
+ */
+public interface MlModelImporter {
+
+    boolean canImport(String modelPath);
+
+    ImportedMlModel importModel(String modelName, File modelPath);
+
+}