[ASTERIXDB-3603] Metadata and language changes for transform functions

- user model changes: yes
- storage format changes: no
- interface changes: yes

Ext-ref: MB-63039
Change-Id: Ifa0f1d4f83cb9f94f1a29c8b0b0943a1f133e7d1
Reviewed-on: https://asterix-gerrit.ics.uci.edu/c/asterixdb/+/19728
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Ali Alsuliman <ali.al.solaiman@gmail.com>
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/translator/QueryTranslator.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/translator/QueryTranslator.java
index 326191c..dcfd810 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/translator/QueryTranslator.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/translator/QueryTranslator.java
@@ -3340,7 +3340,7 @@
                 function = new Function(functionSignature, paramNames, paramTypes, returnTypeSignature, null,
                         FunctionKind.SCALAR.toString(), library.getLanguage(), libraryDatabaseName,
                         libraryDataverseName, libraryName, externalIdentifier, cfs.getNullCall(),
-                        cfs.getDeterministic(), cfs.getResources(), dependencies, creator);
+                        cfs.getDeterministic(), cfs.getResources(), dependencies, creator, false);
             } else {
                 List<Pair<VarIdentifier, TypeExpression>> paramList = cfs.getParameters();
                 int paramCount = paramList.size();
@@ -3359,7 +3359,8 @@
                 // Check whether the function is usable:
                 // create a function declaration for this function,
                 // and a query body calls this function with each argument set to 'missing'
-                FunctionDecl fd = new FunctionDecl(functionSignature, paramVars, cfs.getFunctionBodyExpression(), true);
+                FunctionDecl fd = new FunctionDecl(functionSignature, paramVars, cfs.getFunctionBodyExpression(), true,
+                        cfs.isTransform());
                 fd.setSourceLocation(sourceLoc);
 
                 Query wrappedQuery = queryRewriter.createFunctionAccessorQuery(fd);
@@ -3379,7 +3380,7 @@
                 newInlineTypes = Collections.emptyMap();
                 function = new Function(functionSignature, paramNames, null, null, cfs.getFunctionBody(),
                         FunctionKind.SCALAR.toString(), compilationProvider.getParserFactory().getLanguage(), null,
-                        null, null, null, null, null, null, dependencies, creator);
+                        null, null, null, null, null, null, dependencies, creator, cfs.isTransform());
             }
 
             if (existingFunction == null) {
diff --git a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/statement/CreateFunctionStatement.java b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/statement/CreateFunctionStatement.java
index e0623a1..74b7bbd 100644
--- a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/statement/CreateFunctionStatement.java
+++ b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/statement/CreateFunctionStatement.java
@@ -63,9 +63,11 @@
 
     private final boolean replaceIfExists;
     private final boolean ifNotExists;
+    private final boolean transform;
 
     public CreateFunctionStatement(FunctionSignature signature, List<Pair<VarIdentifier, TypeExpression>> paramList,
-            String functionBody, Expression functionBodyExpression, boolean replaceIfExists, boolean ifNotExists) {
+            String functionBody, Expression functionBodyExpression, boolean replaceIfExists, boolean ifNotExists,
+            boolean transform) {
         this.signature = signature;
         this.functionBody = functionBody;
         this.functionBodyExpression = functionBodyExpression;
@@ -77,6 +79,7 @@
         this.options = null;
         this.replaceIfExists = replaceIfExists;
         this.ifNotExists = ifNotExists;
+        this.transform = transform;
     }
 
     public CreateFunctionStatement(FunctionSignature signature, List<Pair<VarIdentifier, TypeExpression>> paramList,
@@ -93,6 +96,7 @@
         this.functionBodyExpression = null;
         this.replaceIfExists = replaceIfExists;
         this.ifNotExists = ifNotExists;
+        this.transform = false;
     }
 
     public boolean getReplaceIfExists() {
@@ -196,6 +200,10 @@
         return Category.DDL;
     }
 
+    public boolean isTransform() {
+        return transform;
+    }
+
     private IAdmNode getOption(String optionName) {
         return options != null ? options.get(optionName) : null;
     }
diff --git a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/statement/FunctionDecl.java b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/statement/FunctionDecl.java
index 2ef11ad..1a924ee 100644
--- a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/statement/FunctionDecl.java
+++ b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/statement/FunctionDecl.java
@@ -34,13 +34,20 @@
     private Expression funcBody;
     private Expression funcBodyNormalized;
     private final boolean isStored;
+    private final boolean transform;
 
     public FunctionDecl(FunctionSignature signature, List<VarIdentifier> paramList, Expression funcBody,
-            boolean isStored) {
+            boolean isStored, boolean transform) {
         this.signature = signature;
         this.paramList = paramList;
         this.funcBody = funcBody;
         this.isStored = isStored;
+        this.transform = transform;
+    }
+
+    public FunctionDecl(FunctionSignature signature, List<VarIdentifier> paramList, Expression funcBody,
+            boolean isStored) {
+        this(signature, paramList, funcBody, isStored, false);
     }
 
     public FunctionSignature getSignature() {
@@ -72,6 +79,10 @@
         return isStored;
     }
 
+    public boolean isTransform() {
+        return transform;
+    }
+
     @Override
     public int hashCode() {
         return signature.hashCode();
diff --git a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/visitor/CloneAndSubstituteVariablesVisitor.java b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/visitor/CloneAndSubstituteVariablesVisitor.java
index 06f22b7..4f09722 100644
--- a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/visitor/CloneAndSubstituteVariablesVisitor.java
+++ b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/visitor/CloneAndSubstituteVariablesVisitor.java
@@ -179,7 +179,8 @@
         }
 
         Pair<ILangExpression, VariableSubstitutionEnvironment> p1 = fd.getFuncBody().accept(this, env);
-        FunctionDecl newF = new FunctionDecl(fd.getSignature(), newList, (Expression) p1.first, fd.isStored());
+        FunctionDecl newF =
+                new FunctionDecl(fd.getSignature(), newList, (Expression) p1.first, fd.isStored(), fd.isTransform());
         newF.setSourceLocation(fd.getSourceLocation());
         return new Pair<>(newF, env);
     }
diff --git a/asterixdb/asterix-lang-sqlpp/src/main/java/org/apache/asterix/lang/sqlpp/visitor/DeepCopyVisitor.java b/asterixdb/asterix-lang-sqlpp/src/main/java/org/apache/asterix/lang/sqlpp/visitor/DeepCopyVisitor.java
index 1d43d0b..9941dde 100644
--- a/asterixdb/asterix-lang-sqlpp/src/main/java/org/apache/asterix/lang/sqlpp/visitor/DeepCopyVisitor.java
+++ b/asterixdb/asterix-lang-sqlpp/src/main/java/org/apache/asterix/lang/sqlpp/visitor/DeepCopyVisitor.java
@@ -267,7 +267,7 @@
     @Override
     public FunctionDecl visit(FunctionDecl fd, Void arg) throws CompilationException {
         FunctionDecl copy = new FunctionDecl(fd.getSignature(), fd.getParamList(),
-                (Expression) fd.getFuncBody().accept(this, arg), fd.isStored());
+                (Expression) fd.getFuncBody().accept(this, arg), fd.isStored(), fd.isTransform());
         copy.setSourceLocation(fd.getSourceLocation());
         return copy;
     }
diff --git a/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj b/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
index a91b3d5..8afe035 100644
--- a/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
+++ b/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
@@ -1868,13 +1868,18 @@
   CreateFunctionStatement stmt = null;
 }
 {
-  <FUNCTION> stmt = FunctionSpecification(startStmtToken, orReplace)
+  <TRANSFORM> <FUNCTION> stmt = FunctionSpecification(startStmtToken, orReplace, true)
+  {
+    return stmt;
+  }
+  |
+  <FUNCTION> stmt = FunctionSpecification(startStmtToken, orReplace, false)
   {
     return stmt;
   }
 }
 
-CreateFunctionStatement FunctionSpecification(Token startStmtToken, boolean orReplace) throws ParseException:
+CreateFunctionStatement FunctionSpecification(Token startStmtToken, boolean orReplace, boolean transform) throws ParseException:
 {
   FunctionSignature signature = null;
   FunctionName fctName = null;
@@ -1929,7 +1934,7 @@
         getCurrentScope().addFunctionDescriptor(signature, false);
         removeCurrentScope();
         ensureNoTypeDeclsInFunction(fctName.function, params, returnType, startStmtToken);
-        stmt = new CreateFunctionStatement(signature, params, functionBody, functionBodyExpr, orReplace, ifNotExists);
+        stmt = new CreateFunctionStatement(signature, params, functionBody, functionBodyExpr, orReplace, ifNotExists, transform);
       }
     )
   |
@@ -6106,6 +6111,7 @@
   | <WITH : "with">
   | <WRITE : "write">
   | <COPY : "copy">
+  | <TRANSFORM : "transform">
 }
 
 <DEFAULT,IN_DBL_BRACE>
diff --git a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/MetadataTransactionContext.java b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/MetadataTransactionContext.java
index 70bf83a..8db32d6 100644
--- a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/MetadataTransactionContext.java
+++ b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/MetadataTransactionContext.java
@@ -203,7 +203,7 @@
 
     public void dropFunction(FunctionSignature signature) {
         Function function = new Function(signature, null, null, null, null, null, null, null, null, null, null, false,
-                false, null, null, null);
+                false, null, null, null, false);
         droppedCache.addFunctionIfNotExists(function);
         logAndApply(new MetadataLogicalOperation(function, false));
     }
diff --git a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/bootstrap/MetadataRecordTypes.java b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/bootstrap/MetadataRecordTypes.java
index 338e00d..31a7f9b 100644
--- a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/bootstrap/MetadataRecordTypes.java
+++ b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/bootstrap/MetadataRecordTypes.java
@@ -53,6 +53,7 @@
     public static final String FIELD_NAME_DEFAULT = "Default";
     public static final String FIELD_NAME_DEFINITION = "Definition";
     public static final String FIELD_NAME_DEPENDENCIES = "Dependencies";
+    public static final String FIELD_NAME_IS_TRANSFORM = "IsTransform";
     public static final String FIELD_NAME_DERIVED = "Derived";
     public static final String FIELD_NAME_DESCRIPTION = "Description";
     public static final String FIELD_NAME_EXTERNAL_DETAILS = "ExternalDetails";
diff --git a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entities/Function.java b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entities/Function.java
index 3c1515b..c19b542 100644
--- a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entities/Function.java
+++ b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entities/Function.java
@@ -51,12 +51,13 @@
     private final Map<String, String> resources;
     private final List<List<DependencyFullyQualifiedName>> dependencies;
     private final Creator creator;
+    private final boolean transform;
 
     public Function(FunctionSignature signature, List<String> paramNames, List<TypeSignature> paramTypes,
             TypeSignature returnType, String functionBody, String functionKind, String language,
             String libraryDatabaseName, DataverseName libraryDataverseName, String libraryName,
             List<String> externalIdentifier, Boolean nullCall, Boolean deterministic, Map<String, String> resources,
-            List<List<DependencyFullyQualifiedName>> dependencies, Creator creator) {
+            List<List<DependencyFullyQualifiedName>> dependencies, Creator creator, boolean transform) {
         this.signature = signature;
         this.paramNames = paramNames;
         this.paramTypes = paramTypes;
@@ -75,6 +76,7 @@
                 ? Arrays.asList(Collections.emptyList(), Collections.emptyList(), Collections.emptyList())
                 : dependencies;
         this.creator = creator;
+        this.transform = transform;
     }
 
     public FunctionSignature getSignature() {
@@ -168,6 +170,10 @@
         return creator;
     }
 
+    public boolean isTransform() {
+        return transform;
+    }
+
     @Override
     public Function addToCache(MetadataCache cache) {
         return cache.addFunctionIfNotExists(this);
diff --git a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entitytupletranslators/FunctionTupleTranslator.java b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entitytupletranslators/FunctionTupleTranslator.java
index 2741d12..2319cb0 100644
--- a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entitytupletranslators/FunctionTupleTranslator.java
+++ b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entitytupletranslators/FunctionTupleTranslator.java
@@ -206,9 +206,14 @@
         FunctionSignature signature = new FunctionSignature(databaseName, dataverseName, functionName, arity);
         Creator creator = Creator.createOrDefault(functionRecord);
 
+        int isTransformIndex = functionRecord.getType().getFieldIndex(MetadataRecordTypes.FIELD_NAME_IS_TRANSFORM);
+        boolean transform = false;
+        if (isTransformIndex >= 0) {
+            transform = ((ABoolean) functionRecord.getValueByPos(isTransformIndex)).getBoolean();
+        }
         return new Function(signature, paramNames, paramTypes, returnType, definition, functionKind, language,
                 libraryDatabaseName, libraryDataverseName, libraryName, externalIdentifier, nullCall, deterministic,
-                resources, dependencies, creator);
+                resources, dependencies, creator, transform);
     }
 
     private List<TypeSignature> getParamTypes(ARecord functionRecord, String functionDatabaseName,
@@ -435,6 +440,7 @@
         writeNullCall(function);
         writeDeterministic(function);
         writeFunctionCreator(function);
+        writeIsTransform(function);
     }
 
     protected void writeResources(Function function) throws HyracksDataException {
@@ -722,4 +728,15 @@
             recordBuilder.addField(fieldName, fieldValue);
         }
     }
+
+    private void writeIsTransform(Function function) throws HyracksDataException {
+        if (function.isTransform()) {
+            fieldName.reset();
+            aString.setValue(MetadataRecordTypes.FIELD_NAME_IS_TRANSFORM);
+            stringSerde.serialize(aString, fieldName.getDataOutput());
+            fieldValue.reset();
+            booleanSerde.serialize(ABoolean.TRUE, fieldValue.getDataOutput());
+            recordBuilder.addField(fieldName, fieldValue);
+        }
+    }
 }