support avro map

src/common/src/types/map_type.rs

@@ -73,13 +73,13 @@ impl MapType {
         &self.0 .1
     }
 
-    pub fn into_struct(self) -> StructType {
+    pub fn into_struct(self) -> DataType {
         let (key, value) = *self.0;
-        Self::struct_type_for_map(key, value)
+        DataType::Struct(Self::struct_type_for_map(key, value))
     }
 
     pub fn into_list(self) -> DataType {
-        DataType::List(Box::new(DataType::Struct(self.into_struct())))
+        DataType::List(Box::new(self.into_struct()))
     }
 
     /// String and integral types are allowed.

src/common/src/types/mod.rs

@@ -345,8 +345,7 @@ impl DataType {
             }
             DataType::Map(datatype) => {
                 // Same as List<Struct<K,V>>
-                pb.field_type =
-                    vec![DataType::Struct(datatype.clone().into_struct()).to_protobuf()];
+                pb.field_type = vec![datatype.clone().into_struct().to_protobuf()];
             }
             DataType::Boolean
             | DataType::Int16

src/common/src/util/value_encoding/mod.rs

@@ -359,8 +359,7 @@ fn deserialize_value(ty: &DataType, data: &mut impl Buf) -> Result<ScalarImpl> {
         DataType::List(item_type) => deserialize_list(item_type, data)?,
         DataType::Map(map_type) => {
             // FIXME: clone type everytime here is inefficient
-            let list = deserialize_list(&DataType::Struct(map_type.clone().into_struct()), data)?
-                .into_list();
+            let list = deserialize_list(&map_type.clone().into_struct(), data)?.into_list();
             ScalarImpl::Map(MapValue::from_list_entries(list))
         }
     })

src/connector/codec/src/decoder/avro/mod.rs

@@ -25,8 +25,8 @@ use risingwave_common::array::{ListValue, StructValue};
 use risingwave_common::bail;
 use risingwave_common::log::LogSuppresser;
 use risingwave_common::types::{
-    DataType, Date, DatumCow, Interval, JsonbVal, ScalarImpl, Time, Timestamp, Timestamptz,
-    ToOwnedDatum,
+    DataType, Date, DatumCow, Interval, JsonbVal, MapValue, ScalarImpl, Time, Timestamp,
+    Timestamptz, ToOwnedDatum,
 };
 use risingwave_common::util::iter_util::ZipEqFast;
 
@@ -318,6 +318,29 @@ impl<'a> AvroParseOptions<'a> {
             (DataType::Varchar, Value::Uuid(uuid)) => {
                 uuid.as_hyphenated().to_string().into_boxed_str().into()
             }
+            (DataType::Map(map_type), Value::Map(map)) => {
+                let schema = self.extract_inner_schema(None);
+                let mut builder = map_type
+                    .clone()
+                    .into_struct()
+                    .create_array_builder(map.len());
+                // Since the map is HashMap, we can ensure
+                // key is non-null and unique, keys and values have the same length.
+                for (k, v) in map {
+                    let value_datum = Self {
+                        schema,
+                        relax_numeric: self.relax_numeric,
+                    }
+                    .convert_to_datum(v, map_type.value())?
+                    .to_owned_datum();
+                    builder.append(
+                        StructValue::new(vec![Some(k.as_str().into()), value_datum])
+                            .to_owned_datum(),
+                    );
+                }
+                let list = ListValue::new(builder.finish());
+                MapValue::from_list_entries(list).into()
+            }
 
             (_expected, _got) => Err(create_error())?,
         };

src/connector/codec/src/decoder/avro/schema.rs

@@ -20,7 +20,7 @@ use apache_avro::AvroResult;
 use itertools::Itertools;
 use risingwave_common::error::NotImplemented;
 use risingwave_common::log::LogSuppresser;
-use risingwave_common::types::{DataType, Decimal};
+use risingwave_common::types::{DataType, Decimal, MapType};
 use risingwave_common::{bail, bail_not_implemented};
 use risingwave_pb::plan_common::{AdditionalColumn, ColumnDesc, ColumnDescVersion};
 
@@ -57,8 +57,7 @@ impl ResolvedAvroSchema {
 #[derive(Debug, Copy, Clone)]
 pub enum MapHandling {
     Jsonb,
-    // TODO: <https://github.com/risingwavelabs/risingwave/issues/13387>
-    // Map
+    Map,
 }
 
 impl MapHandling {
@@ -266,12 +265,10 @@ fn avro_type_mapping(
                         );
                     }
                 }
-                None => {
-                    // We require it to be specified, because we don't want to have a bad default behavior.
-                    // But perhaps changing the default behavior won't be a breaking change,
-                    // because it affects only on creation time, what the result ColumnDesc will be, and the ColumnDesc will be persisted.
-                    // This is unlike timestamp.handing.mode, which affects parser's behavior on the runtime.
-                    bail!("`map.handling.mode` not specified in ENCODE AVRO (...). Currently supported modes: `jsonb`")
+                Some(MapHandling::Map) | None => {
+                    let value = avro_type_mapping(value_schema.as_ref(), map_handling)
+                        .context("failed to convert Avro map type")?;
+                    DataType::Map(MapType::from_kv(DataType::Varchar, value))
                 }
             }
         }

src/connector/codec/tests/integration_tests/avro.rs

@@ -885,3 +885,108 @@ fn test_union() {
             ])"#]],
     );
 }
+
+#[test]
+fn test_map() {
+    let schema = r#"
+{
+    "type": "record",
+    "namespace": "com.redpanda.examples.avro",
+    "name": "ClickEvent",
+    "fields": [
+        {
+            "name": "map_str",
+            "type": {
+                "type": "map",
+                "values": "string"
+            },
+            "default": {}
+        },
+        {
+            "name": "map_map_int",
+            "type": {
+                "type": "map",
+                "values": {
+                    "type": "map",
+                    "values": "int"
+                }
+            }
+        }
+    ]
+}
+    "#;
+
+    let data = &[
+        // {"map": {"a":1,"b":2}, "map_map_int": {"m1": {"a":1,"b":2}, "m2": {"c":3,"d":4}}}
+        "0004046d310402610202620400046d32040263060264080000",
+        // {"map_map_int": {}}
+        "0000",
+    ];
+
+    check(
+        schema,
+        data,
+        Config {
+            map_handling: None,
+            data_encoding: TestDataEncoding::HexBinary,
+        },
+        expect![[r#"
+            [
+                map_str(#1): Map(Varchar,Varchar),
+                map_map_int(#2): Map(Varchar,Map(Varchar,Int32)),
+            ]"#]],
+        expect![[r#"
+            Owned([])
+            Owned([
+                StructValue(
+                    Utf8("m2"),
+                    [
+                        StructValue(
+                            Utf8("d"),
+                            Int32(4),
+                        ),
+                        StructValue(
+                            Utf8("c"),
+                            Int32(3),
+                        ),
+                    ],
+                ),
+                StructValue(
+                    Utf8("m1"),
+                    [
+                        StructValue(
+                            Utf8("a"),
+                            Int32(1),
+                        ),
+                        StructValue(
+                            Utf8("b"),
+                            Int32(2),
+                        ),
+                    ],
+                ),
+            ])
+            ----
+            Owned([])
+            Owned([])"#]],
+    );
+
+    check(
+        schema,
+        data,
+        Config {
+            map_handling: Some(MapHandling::Jsonb),
+            data_encoding: TestDataEncoding::HexBinary,
+        },
+        expect![[r#"
+            [
+                map_str(#1): Jsonb,
+                map_map_int(#2): Jsonb,
+            ]"#]],
+        expect![[r#"
+            Owned(Jsonb(JsonbRef({})))
+            Owned(Jsonb(JsonbRef({"m1": {"a": Number(1), "b": Number(2)}, "m2": {"c": Number(3), "d": Number(4)}})))
+            ----
+            Owned(Jsonb(JsonbRef({})))
+            Owned(Jsonb(JsonbRef({})))"#]],
+    );
+}

src/connector/codec/tests/integration_tests/utils.rs

@@ -44,6 +44,14 @@ impl<'a> std::fmt::Debug for DataTypeTestDisplay<'a> {
                 .debug_tuple("List")
                 .field(&DataTypeTestDisplay(t))
                 .finish(),
+            DataType::Map(m) => {
+                write!(
+                    f,
+                    "Map({:?},{:?})",
+                    &DataTypeTestDisplay(m.key()),
+                    &DataTypeTestDisplay(m.value())
+                )
+            }
             _ => {
                 // do not use alternative display for simple types
                 write!(f, "{:?}", self.0)
@@ -76,6 +84,10 @@ impl<'a> std::fmt::Debug for ScalarRefImplTestDisplay<'a> {
                 .debug_list()
                 .entries(l.iter().map(DatumRefTestDisplay))
                 .finish(),
+            ScalarRefImpl::Map(m) => f
+                .debug_list()
+                .entries(m.inner().iter().map(DatumRefTestDisplay))
+                .finish(),
             _ => {
                 // do not use alternative display for simple types
                 write!(f, "{:?}", self.0)