feat(mito): Write wal and memtable (GreptimeTeam#2135)

* feat: hold wal entry in RegionWriteCtx

* feat: entry id and commited sequence

* feat: write to wal

* feat: write memtable

* feat: fill missing columns

* feat: validate write request

* feat: more validation to write request

* chore: fix typos

* feat: remove init and validate rows in new()

* style: fix clippy

src/mito2/src/engine.rs

@@ -20,12 +20,12 @@ mod tests;
 use std::sync::Arc;
 
 use object_store::ObjectStore;
-use snafu::ResultExt;
+use snafu::{OptionExt, ResultExt};
 use store_api::logstore::LogStore;
 use store_api::storage::RegionId;
 
 use crate::config::MitoConfig;
-use crate::error::{RecvSnafu, Result};
+use crate::error::{RecvSnafu, RegionNotFoundSnafu, Result};
 use crate::request::{
     CloseRequest, CreateRequest, OpenRequest, RegionRequest, RequestBody, WriteRequest,
 };
@@ -90,12 +90,17 @@ impl MitoEngine {
     }
 
     /// Write to a region.
-    pub async fn write_region(&self, write_request: WriteRequest) -> Result<()> {
-        write_request.validate()?;
-
-        // TODO(yingwen): Fill default values.
-        // We need to fill default values before writing it to WAL so we can get
-        // the same default value after reopening the region.
+    pub async fn write_region(&self, mut write_request: WriteRequest) -> Result<()> {
+        let region = self
+            .inner
+            .workers
+            .get_region(write_request.region_id)
+            .context(RegionNotFoundSnafu {
+                region_id: write_request.region_id,
+            })?;
+        let metadata = region.metadata();
+
+        write_request.fill_missing_columns(&metadata)?;
 
         self.inner
             .handle_request_body(RequestBody::Write(write_request))

src/mito2/src/error.rs

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 use std::any::Any;
+use std::sync::Arc;
 
 use common_datasource::compression::CompressionType;
 use common_error::ext::{BoxedError, ErrorExt};
@@ -185,15 +186,10 @@ pub enum Error {
 
     /// An error type to indicate that schema is changed and we need
     /// to fill default values again.
-    #[snafu(display(
-        "Need to fill default value to column {} of region {}",
-        column,
-        region_id
-    ))]
+    #[snafu(display("Need to fill default value for region {}", region_id))]
     FillDefault {
         region_id: RegionId,
-        column: String,
-        // The error is for retry purpose so we don't need a location.
+        // The error is for internal use so we don't need a location.
     },
 
     #[snafu(display(
@@ -260,10 +256,21 @@ pub enum Error {
         location: Location,
         source: BoxedError,
     },
+
+    // Shared error for each writer in the write group.
+    #[snafu(display("Failed to write region, source: {}", source))]
+    WriteGroup { source: Arc<Error> },
 }
 
 pub type Result<T> = std::result::Result<T, Error>;
 
+impl Error {
+    /// Returns true if we need to fill default value for a region.
+    pub(crate) fn is_fill_default(&self) -> bool {
+        matches!(self, Error::FillDefault { .. })
+    }
+}
+
 impl ErrorExt for Error {
     fn status_code(&self) -> StatusCode {
         use Error::*;
@@ -296,6 +303,7 @@ impl ErrorExt for Error {
             | EncodeWal { .. }
             | DecodeWal { .. } => StatusCode::Internal,
             WriteBuffer { source, .. } => source.status_code(),
+            WriteGroup { source, .. } => source.status_code(),
         }
     }
 

src/mito2/src/memtable.rs

@@ -22,7 +22,7 @@ use std::sync::atomic::{AtomicU32, Ordering};
 use std::sync::Arc;
 
 use crate::error::Result;
-use crate::memtable::key_values::KeyValues;
+pub use crate::memtable::key_values::KeyValues;
 use crate::metadata::RegionMetadataRef;
 
 /// Id for memtables.

src/mito2/src/memtable/key_values.rs

@@ -190,11 +190,12 @@ mod tests {
     use datatypes::prelude::ConcreteDataType;
     use datatypes::schema::ColumnSchema;
     use greptime_proto::v1;
-    use greptime_proto::v1::{value, ColumnDataType, Value};
+    use greptime_proto::v1::ColumnDataType;
     use store_api::storage::RegionId;
 
     use super::*;
     use crate::metadata::{ColumnMetadata, RegionMetadataBuilder};
+    use crate::proto_util::i64_value;
 
     const TS_NAME: &str = "ts";
     const START_SEQ: SequenceNumber = 100;
@@ -290,12 +291,6 @@ mod tests {
         }
     }
 
-    fn i64_value(data: i64) -> Value {
-        Value {
-            value: Some(value::Value::I64Value(data)),
-        }
-    }
-
     fn check_key_values(kvs: &KeyValues, num_rows: usize, keys: &[i64], ts: i64, values: &[i64]) {
         assert_eq!(num_rows, kvs.num_rows());
         let mut expect_seq = START_SEQ;

src/mito2/src/memtable/version.rs

@@ -37,4 +37,9 @@ impl MemtableVersion {
             immutables: vec![],
         }
     }
+
+    /// Returns the mutable memtable.
+    pub(crate) fn mutable(&self) -> &MemtableRef {
+        &self.mutable
+    }
 }

src/mito2/src/proto_util.rs

@@ -120,6 +120,56 @@ pub(crate) fn to_proto_value(value: Value) -> Option<v1::Value> {
     Some(proto_value)
 }
 
+/// Returns the [ColumnDataType] of the value.
+///
+/// If value is null, returns `None`.
+pub(crate) fn proto_value_type(value: &v1::Value) -> Option<ColumnDataType> {
+    let value_data = value.value.as_ref()?;
+    let value_type = match value_data {
+        v1::value::Value::I8Value(_) => ColumnDataType::Int8,
+        v1::value::Value::I16Value(_) => ColumnDataType::Int16,
+        v1::value::Value::I32Value(_) => ColumnDataType::Int32,
+        v1::value::Value::I64Value(_) => ColumnDataType::Int64,
+        v1::value::Value::U8Value(_) => ColumnDataType::Uint8,
+        v1::value::Value::U16Value(_) => ColumnDataType::Uint16,
+        v1::value::Value::U32Value(_) => ColumnDataType::Uint32,
+        v1::value::Value::U64Value(_) => ColumnDataType::Uint64,
+        v1::value::Value::F32Value(_) => ColumnDataType::Float32,
+        v1::value::Value::F64Value(_) => ColumnDataType::Float64,
+        v1::value::Value::BoolValue(_) => ColumnDataType::Boolean,
+        v1::value::Value::BinaryValue(_) => ColumnDataType::Binary,
+        v1::value::Value::StringValue(_) => ColumnDataType::String,
+        v1::value::Value::DateValue(_) => ColumnDataType::Date,
+        v1::value::Value::DatetimeValue(_) => ColumnDataType::Datetime,
+        v1::value::Value::TsSecondValue(_) => ColumnDataType::TimestampSecond,
+        v1::value::Value::TsMillisecondValue(_) => ColumnDataType::TimestampMillisecond,
+        v1::value::Value::TsMicrosecondValue(_) => ColumnDataType::TimestampMicrosecond,
+        v1::value::Value::TsNanosecondValue(_) => ColumnDataType::TimestampNanosecond,
+        v1::value::Value::TimeSecondValue(_) => ColumnDataType::TimeSecond,
+        v1::value::Value::TimeMillisecondValue(_) => ColumnDataType::TimeMillisecond,
+        v1::value::Value::TimeMicrosecondValue(_) => ColumnDataType::TimeMicrosecond,
+        v1::value::Value::TimeNanosecondValue(_) => ColumnDataType::TimeNanosecond,
+    };
+    Some(value_type)
+}
+
+// TODO(yingwen): Support conversion in greptime-proto.
+/// Creates value for i64.
+#[cfg(test)]
+pub(crate) fn i64_value(data: i64) -> v1::Value {
+    v1::Value {
+        value: Some(v1::value::Value::I64Value(data)),
+    }
+}
+
+/// Creates value for timestamp millis.
+#[cfg(test)]
+pub(crate) fn ts_ms_value(data: i64) -> v1::Value {
+    v1::Value {
+        value: Some(v1::value::Value::TsMillisecondValue(data)),
+    }
+}
+
 /// Convert [ConcreteDataType] to [ColumnDataType].
 pub(crate) fn to_column_data_type(data_type: &ConcreteDataType) -> Option<ColumnDataType> {
     let column_data_type = match data_type {
@@ -186,3 +236,5 @@ fn is_column_type_eq(column_type: ColumnDataType, expect_type: &ConcreteDataType
         false
     }
 }
+
+// TODO(yingwen): Tests.

src/mito2/src/region.rs

@@ -25,7 +25,8 @@ use store_api::storage::RegionId;
 
 use crate::error::Result;
 use crate::manifest::manager::RegionManifestManager;
-use crate::region::version::{VersionControlRef, VersionRef};
+use crate::metadata::RegionMetadataRef;
+use crate::region::version::VersionControlRef;
 
 /// Type to store region version.
 pub type VersionNumber = u32;
@@ -40,7 +41,7 @@ pub(crate) struct MitoRegion {
     pub(crate) region_id: RegionId,
 
     /// Version controller for this region.
-    version_control: VersionControlRef,
+    pub(crate) version_control: VersionControlRef,
     /// Manager to maintain manifest for this region.
     manifest_manager: RegionManifestManager,
 }
@@ -57,9 +58,10 @@ impl MitoRegion {
         Ok(())
     }
 
-    /// Returns current version of the region.
-    pub(crate) fn version(&self) -> VersionRef {
-        self.version_control.current()
+    /// Returns current metadata of the region.
+    pub(crate) fn metadata(&self) -> RegionMetadataRef {
+        let version_data = self.version_control.current();
+        version_data.version.metadata.clone()
     }
 }
 

src/mito2/src/region/version.rs

@@ -23,39 +23,56 @@
 //! Reason: data may be flushed/compacted and some data with old sequence may be removed
 //! and became invisible between step 1 and 2, so need to acquire version at first.
 
-use std::sync::Arc;
+use std::sync::{Arc, RwLock};
 
-use arc_swap::ArcSwap;
 use store_api::storage::SequenceNumber;
 
 use crate::memtable::version::{MemtableVersion, MemtableVersionRef};
 use crate::memtable::MemtableRef;
 use crate::metadata::RegionMetadataRef;
 use crate::sst::version::{SstVersion, SstVersionRef};
+use crate::wal::EntryId;
 
-/// Controls version of in memory metadata for a region.
+/// Controls metadata and sequence numbers for a region.
+///
+/// It manages metadata in a copy-on-write fashion. Any modification to a region's metadata
+/// will generate a new [Version].
 #[derive(Debug)]
 pub(crate) struct VersionControl {
-    /// Latest version.
-    version: ArcSwap<Version>,
+    data: RwLock<VersionControlData>,
 }
 
 impl VersionControl {
     /// Returns a new [VersionControl] with specific `version`.
     pub(crate) fn new(version: Version) -> VersionControl {
         VersionControl {
-            version: ArcSwap::new(Arc::new(version)),
+            data: RwLock::new(VersionControlData {
+                version: Arc::new(version),
+                committed_sequence: 0,
+                last_entry_id: 0,
+            }),
         }
     }
 
-    /// Returns current [Version].
-    pub(crate) fn current(&self) -> VersionRef {
-        self.version.load_full()
+    /// Returns current copy of data.
+    pub(crate) fn current(&self) -> VersionControlData {
+        self.data.read().unwrap().clone()
     }
 }
 
 pub(crate) type VersionControlRef = Arc<VersionControl>;
 
+/// Data of [VersionControl].
+#[derive(Debug, Clone)]
+pub(crate) struct VersionControlData {
+    /// Latest version.
+    pub(crate) version: VersionRef,
+    /// Sequence number of last committed data.
+    pub(crate) committed_sequence: SequenceNumber,
+    /// Last WAL entry Id.
+    pub(crate) last_entry_id: EntryId,
+}
+
 /// Static metadata of a region.
 #[derive(Clone, Debug)]
 pub(crate) struct Version {