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use mz_avro::schema::{FullName, SchemaNode};
use repr::{Diff, Row, Timestamp};
use serde_json::json;
use anyhow::anyhow;
use avro_derive::AvroDecodable;
use differential_dataflow::capture::{Message, Progress};
use mz_avro::error::{DecodeError, Error as AvroError};
use mz_avro::schema::Schema;
use mz_avro::{
define_unexpected, ArrayAsVecDecoder, AvroDecodable, AvroDecode, AvroDeserializer, AvroRead,
StatefulAvroDecodable,
};
use std::{cell::RefCell, rc::Rc};
use super::decode::RowWrapper;
pub fn extract_data_columns<'a>(schema: &'a Schema) -> anyhow::Result<SchemaNode<'a>> {
let data_name = FullName::from_parts("data", Some("com.materialize.cdc"), "");
let data_schema = &schema
.try_lookup_name(&data_name)
.ok_or_else(|| anyhow!("record not found: {}", data_name))?
.piece;
Ok(SchemaNode {
root: &schema,
inner: data_schema,
name: None,
})
}
#[derive(AvroDecodable)]
#[state_type(Rc<RefCell<Row>>, Rc<RefCell<Vec<u8>>>)]
struct MyUpdate {
#[state_expr(Rc::clone(&self._STATE.0), Rc::clone(&self._STATE.1))]
data: RowWrapper,
time: Timestamp,
diff: Diff,
}
#[derive(AvroDecodable)]
struct Count {
time: Timestamp,
count: usize,
}
fn make_counts_decoder() -> impl AvroDecode<Out = Vec<(Timestamp, usize)>> {
ArrayAsVecDecoder::new(|| {
<Count as AvroDecodable>::new_decoder().map_decoder(|ct| Ok((ct.time, ct.count)))
})
}
#[derive(AvroDecodable)]
struct MyProgress {
lower: Vec<Timestamp>,
upper: Vec<Timestamp>,
#[decoder_factory(make_counts_decoder)]
counts: Vec<(Timestamp, usize)>,
}
impl AvroDecode for Decoder {
type Out = Message<Row, Timestamp, Diff>;
fn union_branch<'a, R: AvroRead, D: AvroDeserializer>(
self,
idx: usize,
_n_variants: usize,
_null_variant: Option<usize>,
deserializer: D,
r: &'a mut R,
) -> Result<Self::Out, AvroError> {
match idx {
0 => {
let packer = Rc::new(RefCell::new(Row::default()));
let buf = Rc::new(RefCell::new(vec![]));
let d = ArrayAsVecDecoder::new(|| {
<MyUpdate as StatefulAvroDecodable>::new_decoder((
Rc::clone(&packer),
Rc::clone(&buf),
))
.map_decoder(|update| Ok((update.data.0, update.time, update.diff)))
});
let updates = deserializer.deserialize(r, d)?;
Ok(Message::Updates(updates))
}
1 => {
let progress =
deserializer.deserialize(r, <MyProgress as AvroDecodable>::new_decoder())?;
let progress = Progress {
lower: progress.lower,
upper: progress.upper,
counts: progress.counts,
};
Ok(Message::Progress(progress))
}
other => Err(DecodeError::Custom(format!(
"Unrecognized union variant in CDCv2 decoder: {}",
other
))
.into()),
}
}
define_unexpected! {
record, array, map, enum_variant, scalar, decimal, bytes, string, json, uuid, fixed
}
}
#[derive(Debug)]
pub struct Decoder;
pub fn build_schema(row_schema: serde_json::Value) -> Schema {
let updates_schema = json!({
"type": "array",
"items": {
"name" : "update",
"type" : "record",
"fields" : [
{
"name": "data",
"type": row_schema,
},
{
"name" : "time",
"type" : "long",
},
{
"name" : "diff",
"type" : "long",
},
],
},
});
let progress_schema = json!({
"name" : "progress",
"type" : "record",
"fields" : [
{
"name": "lower",
"type": {
"type": "array",
"items": "long"
}
},
{
"name": "upper",
"type": {
"type": "array",
"items": "long"
}
},
{
"name": "counts",
"type": {
"type": "array",
"items": {
"type": "record",
"name": "counts",
"fields": [
{
"name": "time",
"type": "long",
},
{
"name": "count",
"type": "long",
},
],
}
}
},
],
});
let message_schema = json!([updates_schema, progress_schema,]);
Schema::parse(&message_schema).expect("schema constrution failed")
}
#[cfg(test)]
mod tests {
use super::*;
use crate::avro::encode_datums_as_avro;
use crate::encode::column_names_and_types;
use mz_avro::types::Value;
use mz_avro::AvroDeserializer;
use mz_avro::GeneralDeserializer;
use repr::{ColumnName, ColumnType, RelationDesc, Row, ScalarType};
use crate::json::build_row_schema_json;
#[derive(Debug)]
struct Encoder {
columns: Vec<(ColumnName, ColumnType)>,
}
impl Encoder {
pub fn new(desc: RelationDesc) -> Self {
let columns = column_names_and_types(desc);
Self { columns }
}
pub fn encode_updates(&self, updates: &[(Row, i64, i64)]) -> Value {
let mut enc_updates = Vec::new();
for (data, time, diff) in updates {
let enc_data = encode_datums_as_avro(&**data, &self.columns);
let enc_time = Value::Long(time.clone());
let enc_diff = Value::Long(diff.clone());
enc_updates.push(Value::Record(vec![
("data".to_string(), enc_data),
("time".to_string(), enc_time),
("diff".to_string(), enc_diff),
]));
}
Value::Union {
index: 0,
inner: Box::new(Value::Array(enc_updates)),
n_variants: 2,
null_variant: None,
}
}
pub fn encode_progress(
&self,
lower: &[i64],
upper: &[i64],
counts: &[(i64, i64)],
) -> Value {
let enc_lower = Value::Array(lower.iter().cloned().map(Value::Long).collect());
let enc_upper = Value::Array(upper.iter().cloned().map(Value::Long).collect());
let enc_counts = Value::Array(
counts
.iter()
.map(|(time, count)| {
Value::Record(vec![
("time".to_string(), Value::Long(time.clone())),
("count".to_string(), Value::Long(count.clone())),
])
})
.collect(),
);
let enc_progress = Value::Record(vec![
("lower".to_string(), enc_lower),
("upper".to_string(), enc_upper),
("counts".to_string(), enc_counts),
]);
Value::Union {
index: 1,
inner: Box::new(enc_progress),
n_variants: 2,
null_variant: None,
}
}
}
#[test]
fn test_roundtrip() {
let desc = RelationDesc::empty()
.with_column("id", ScalarType::Int64.nullable(false))
.with_column("price", ScalarType::Float64.nullable(true));
let encoder = Encoder::new(desc.clone());
let row_schema =
build_row_schema_json(&crate::encode::column_names_and_types(desc), "data");
let schema = build_schema(row_schema);
let values = vec![
encoder.encode_updates(&[]),
encoder.encode_progress(&[0], &[3], &[]),
encoder.encode_progress(&[3], &[], &[]),
];
use mz_avro::encode::encode_to_vec;
let mut values: Vec<_> = values
.into_iter()
.map(|v| encode_to_vec(&v, &schema))
.collect();
let g = GeneralDeserializer {
schema: schema.top_node(),
};
assert!(matches!(
g.deserialize(&mut &values.remove(0)[..], Decoder).unwrap(),
Message::Updates(_)
),);
assert!(matches!(
g.deserialize(&mut &values.remove(0)[..], Decoder).unwrap(),
Message::Progress(_)
),);
assert!(matches!(
g.deserialize(&mut &values.remove(0)[..], Decoder).unwrap(),
Message::Progress(_)
),);
}
}