Merge pull request #959 from go-kivik/reduceCombine

Extract reduce logic to separate function
go-kivik · May 2, 2024 · 5c375e0 · 5c375e0
2 parents 3541516 + 50eabc2
commit 5c375e0
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Showing 2 changed files with 73 additions and 85 deletions.
diff --git a/x/sqlite/query.go b/x/sqlite/query.go
@@ -13,7 +13,6 @@
 package sqlite
 
 import (
- "bytes"
  "context"
  "database/sql"
  "encoding/json"
@@ -22,7 +21,6 @@ import (
  "io"
  "log"
  "net/http"
- "slices"
  "strings"
 
  "github.com/dop251/goja"
@@ -193,42 +191,7 @@ func (d *db) performQuery(ctx context.Context, ddoc, view, update string, reduce
  }
 
  if reducible && (reduce == nil || *reduce) {
- reduceFn, err := d.reduceFunc(reduceFuncJS, d.logger)
- if err != nil {
- return nil, err
- }
- var (
- keys [][2]interface{}
- values []interface{}
-
- id, key, value *string
- )
-
- for results.Next() {
- if err := results.Scan(&id, &key, &value, discard{}, discard{}, discard{}); err != nil {
- return nil, err
- }
- keys = append(keys, [2]interface{}{id, key})
- if value == nil {
- values = append(values, nil)
- } else {
- values = append(values, *value)
- }
- }
-
- if err := results.Err(); err != nil {
- return nil, err
- }
-
- rv := reduceFn(keys, values, false)
- tmp, _ := json.Marshal(rv)
- return &reducedRows{
- {
- Key: json.RawMessage(`null`),
- Value: bytes.NewReader(tmp),
- },
- }, nil
-
+ return d.reduceRows(results, reduceFuncJS, false)
  }
 
  return &rows{
@@ -332,53 +295,7 @@ func (d *db) performGroupQuery(ctx context.Context, ddoc, view, update string, g
  }
  }
 
- reduceFn, err := d.reduceFunc(reduceFuncJS, d.logger)
- if err != nil {
- return nil, err
- }
- var (
- intermediate = map[string][]interface{}{}
-
- id, key string
- rowValue *string
- )
-
- for results.Next() {
- if err := results.Scan(&id, &key, &rowValue, discard{}, discard{}, discard{}); err != nil {
- return nil, err
- }
- var value interface{}
- if rowValue != nil {
- value = *rowValue
- }
- rv := reduceFn([][2]interface{}{{id, key}}, []interface{}{value}, false)
- intermediate[key] = append(intermediate[key], rv)
- }
-
- if err := results.Err(); err != nil {
- return nil, err
- }
-
- final := make(reducedRows, 0, len(intermediate))
- for key, values := range intermediate {
- var value json.RawMessage
- if len(values) > 1 {
- rv := reduceFn(nil, values, true)
- value, _ = json.Marshal(rv)
- } else {
- value, _ = json.Marshal(values[0])
- }
- final = append(final, driver.Row{
- Key: json.RawMessage(key),
- Value: bytes.NewReader(value),
- })
- }
-
- slices.SortFunc(final, func(a, b driver.Row) int {
- return couchdbCmpJSON(a.Key, b.Key)
- })
-
- return &final, nil
+ return d.reduceRows(results, reduceFuncJS, true)
 }
 
 const batchSize = 100

diff --git a/x/sqlite/reduce.go b/x/sqlite/reduce.go
@@ -13,11 +13,82 @@
 package sqlite
 
 import (
+ "bytes"
+ "database/sql"
+ "encoding/json"
  "io"
+ "slices"
 
  "github.com/go-kivik/kivik/v4/driver"
 )
 
+func (d *db) reduceRows(results *sql.Rows, reduceFuncJS *string, group bool) (driver.Rows, error) {
+ reduceFn, err := d.reduceFunc(reduceFuncJS, d.logger)
+ if err != nil {
+ return nil, err
+ }
+ var (
+ intermediate = map[string][]interface{}{}
+
+ id, key string
+ rowValue *string
+ )
+
+ for results.Next() {
+ if err := results.Scan(&id, &key, &rowValue, discard{}, discard{}, discard{}); err != nil {
+ return nil, err
+ }
+ var value interface{}
+ if rowValue != nil {
+ value = *rowValue
+ }
+ rv := reduceFn([][2]interface{}{{id, key}}, []interface{}{value}, false)
+ intermediate[key] = append(intermediate[key], rv)
+ }
+
+ if err := results.Err(); err != nil {
+ return nil, err
+ }
+
+ // Note that group_level is handled at the query level, so we don't need to
+ // worry about it here.
+ if !group {
+ var values []interface{}
+ for _, v := range intermediate {
+ values = append(values, v...)
+ }
+ rv := reduceFn(nil, values, true)
+ tmp, _ := json.Marshal(rv)
+ return &reducedRows{
+ {
+ Key: json.RawMessage(`null`),
+ Value: bytes.NewReader(tmp),
+ },
+ }, nil
+ }
+
+ final := make(reducedRows, 0, len(intermediate))
+ for key, values := range intermediate {
+ var value json.RawMessage
+ if len(values) > 1 {
+ rv := reduceFn(nil, values, true)
+ value, _ = json.Marshal(rv)
+ } else {
+ value, _ = json.Marshal(values[0])
+ }
+ final = append(final, driver.Row{
+ Key: json.RawMessage(key),
+ Value: bytes.NewReader(value),
+ })
+ }
+
+ slices.SortFunc(final, func(a, b driver.Row) int {
+ return couchdbCmpJSON(a.Key, b.Key)
+ })
+
+ return &final, nil
+}
+
 type reducedRows []driver.Row
 
 var _ driver.Rows = (*reducedRows)(nil)