/
generate_partitions.go
100 lines (81 loc) · 2.96 KB
/
generate_partitions.go
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// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package spannerio
import (
"cloud.google.com/go/spanner/apiv1/spannerpb"
"context"
"fmt"
"github.com/apache/beam/sdks/v2/go/pkg/beam"
"reflect"
"cloud.google.com/go/spanner"
"github.com/apache/beam/sdks/v2/go/pkg/beam/register"
)
func init() {
register.DoFn3x1[context.Context, []byte, func(read partitionedRead), error]((*generatePartitionsFn)(nil))
register.Emitter1[*partitionedRead]()
}
type generatePartitionsFn struct {
spannerFn
Query string `json:"query"` // Table is the table identifier.
Options queryOptions `json:"options"` // Options specifies additional query execution options.
}
func generatePartitions(s beam.Scope, db string, query string, t reflect.Type, options queryOptions) beam.PCollection {
s = s.Scope("spannerio.GeneratePartitions")
imp := beam.Impulse(s)
return beam.ParDo(s, newGeneratePartitionsFn(db, query, options), imp)
}
func (f *generatePartitionsFn) Setup(ctx context.Context) error {
return f.spannerFn.Setup(ctx)
}
func (f *generatePartitionsFn) Teardown() {
f.spannerFn.Teardown()
}
func partitionOptions(options queryOptions) spanner.PartitionOptions {
partitionOptions := spanner.PartitionOptions{}
if options.MaxPartitions != 0 {
partitionOptions.MaxPartitions = options.MaxPartitions
}
return partitionOptions
}
func newGeneratePartitionsFn(
db string,
query string,
options queryOptions,
) *generatePartitionsFn {
if db == "" {
panic("no database provided")
}
return &generatePartitionsFn{
spannerFn: newSpannerFn(db),
Query: query,
Options: options,
}
}
func (f *generatePartitionsFn) ProcessElement(ctx context.Context, _ []byte, emit func(partitionedRead)) error {
txn, err := f.client.BatchReadOnlyTransaction(ctx, f.Options.TimestampBound)
if err != nil {
panic("unable to create batch read only transaction: " + err.Error())
}
defer txn.Close()
mode := spannerpb.ExecuteSqlRequest_PROFILE
partitions, err := txn.PartitionQueryWithOptions(ctx, spanner.Statement{SQL: f.Query}, partitionOptions(f.Options), spanner.QueryOptions{Mode: &mode})
if err != nil {
panic(fmt.Sprintf("unable to partition query: %v", err))
}
for _, p := range partitions {
emit(newPartitionedRead(txn.ID, p))
}
return nil
}