/
query_options.go
79 lines (67 loc) · 2.59 KB
/
query_options.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"
"errors"
"fmt"
)
const (
defaultBatching = true
)
// QueryOptionFn is a function that can be passed to Read or Query to configure options for reading or querying spanner.
type QueryOptionFn func(*queryOptions) error
// queryOptions represents additional options for executing a query.
type queryOptions struct {
Batching bool `json:"batching"` // Batched reading, default is true.
MaxPartitions int64 `json:"maxPartitions"` // Maximum partitions
TimestampBound spanner.TimestampBound `json:"timestampBound"` // The TimestampBound to use for batched reading
}
func newQueryOptions(options ...QueryOptionFn) queryOptions {
opts := queryOptions{
Batching: defaultBatching,
}
for _, opt := range options {
if err := opt(&opts); err != nil {
panic(fmt.Sprintf("spannerio.Query: invalid option: %v", err))
}
}
return opts
}
// WithBatching sets whether we will use a batched reader. Batching is set to true by default, disable it when the
// underlying query is not root-partitionable.
func WithBatching(batching bool) QueryOptionFn {
return func(opts *queryOptions) error {
opts.Batching = batching
return nil
}
}
// WithMaxPartitions sets the maximum number of Partitions to split the query into when batched reading.
func WithMaxPartitions(maxPartitions int64) QueryOptionFn {
return func(opts *queryOptions) error {
if maxPartitions <= 0 {
return errors.New("max partitions must be greater than 0")
}
opts.MaxPartitions = maxPartitions
return nil
}
}
// WithTimestampBound sets the TimestampBound to use when doing batched reads.
func WithTimestampBound(timestampBound spanner.TimestampBound) QueryOptionFn {
return func(opts *queryOptions) error {
opts.TimestampBound = timestampBound
return nil
}
}