Merge pull request #998 from go-kivik/useCache2

More cache use, and flesh out some options for reduced views

x/sqlite/options.go

@@ -547,10 +547,28 @@ func (o optsMap) attEncodingInfo() (bool, error) {
  return v, nil
 }
 
+const defaultWhereCap = 3
+
+// buildGroupWhere returns WHERE conditions for use with grouping.
+func (v viewOptions) buildGroupWhere(args *[]any) []string {
+ where := make([]string, 0, defaultWhereCap)
+ if v.endkey != "" {
+ op := endKeyOp(v.descending, v.inclusiveEnd)
+ where = append(where, fmt.Sprintf("view.key %s $%d", op, len(*args)+1))
+ *args = append(*args, v.endkey)
+ }
+ if v.startkey != "" {
+ op := startKeyOp(v.descending)
+ where = append(where, fmt.Sprintf("view.key %s $%d", op, len(*args)+1))
+ *args = append(*args, v.startkey)
+ }
+ return where
+}
+
 // buildWhere returns WHERE conditions based on the provided configuration
 // arguments, and may append to args as needed.
 func (v viewOptions) buildWhere(args *[]any) []string {
- where := make([]string, 0, 3)
+ where := make([]string, 0, defaultWhereCap)
  switch v.view {
  case viewAllDocs:
  where = append(where, `view.key NOT LIKE '"_local/%'`)

x/sqlite/query.go

@@ -213,6 +213,7 @@ func (d *db) performQuery(
  JOIN reduce ON reduce.reducible AND ($3 IS NULL OR $3 == TRUE)
  LEFT JOIN cache ON view.key >= cache.first_key AND view.key <= cache.last_key
  WHERE cache.first_key IS NULL
+ %[2]s -- WHERE
  %[5]s -- ORDER BY
  )
 
@@ -302,7 +303,11 @@ func (d *db) performQuery(
  _ = results.Close() //nolint:sqlclosecheck // invalid option specified for reduce, so abort the query
  return nil, &internal.Error{Status: http.StatusBadRequest, Message: "conflicts is invalid for reduce"}
  }
- return d.reduce(ctx, meta.lastSeq, ddoc, view, rev.String(), results, meta.reduceFuncJS, vopts.reduceGroupLevel())
+ result, err := d.reduce(ctx, meta.lastSeq, ddoc, view, rev.String(), results, meta.reduceFuncJS, vopts.reduceGroupLevel())
+ if err != nil {
+ return nil, err
+ }
+ return metaReduced{Rows: result, meta: meta}, nil
  }
 
  // If the results are up to date, OR, we're in false/lazy update mode,
@@ -316,6 +321,16 @@ func (d *db) performQuery(
  }
 }
 
+// metaReduced wraps a driver.Rows and some metadata, to serve both.
+type metaReduced struct {
+ driver.Rows
+ meta *viewMetadata
+}
+
+func (m metaReduced) UpdateSeq() string {
+ return m.meta.updateSeq
+}
+
 func (d *db) performGroupQuery(ctx context.Context, ddoc, view string, vopts *viewOptions) (driver.Rows, error) {
  var (
  results *sql.Rows
@@ -331,6 +346,9 @@ func (d *db) performGroupQuery(ctx context.Context, ddoc, view string, vopts *vi
  return nil, err
  }
 
+ args := []any{"_design/" + ddoc, rev.rev, rev.id, view, kivik.EndKeySuffix, true}
+ where := append([]string{""}, vopts.buildGroupWhere(&args)...)
+
  query := fmt.Sprintf(d.ddocQuery(ddoc, view, rev.String(), `
  WITH reduce AS (
  SELECT
@@ -344,6 +362,7 @@ func (d *db) performGroupQuery(ctx context.Context, ddoc, view string, vopts *vi
  AND func_name = $4
  )
 
+ -- Metadata
  SELECT
  COALESCE(MAX(last_seq), 0) == (SELECT COALESCE(max(seq),0) FROM {{ .Docs }}) AS up_to_date,
  reduce.reducible,
@@ -368,17 +387,18 @@ func (d *db) performGroupQuery(ctx context.Context, ddoc, view string, vopts *vi
 
  UNION ALL
 
+ -- Actual results
  SELECT *
  FROM (
  SELECT
- id AS id,
- COALESCE(key, "null") AS key,
- value AS value,
- pk AS first,
- pk AS last,
+ view.id AS id,
+ COALESCE(view.key, "null") AS key,
+ view.value AS value,
+ view.pk AS first,
+ view.pk AS last,
  NULL AS conflicts,
  0 AS attachment_count,
- NULL AS filename,
+ NULL, --
  NULL AS content_type,
  NULL AS length,
  NULL AS digest,
@@ -387,14 +407,12 @@ func (d *db) performGroupQuery(ctx context.Context, ddoc, view string, vopts *vi
  FROM {{ .Map }} AS view
  JOIN reduce
  WHERE reduce.reducible AND ($6 IS NULL OR $6 == TRUE)
+ %[2]s
  %[1]s -- ORDER BY
  )
- `), vopts.buildOrderBy("pk"))
+ `), vopts.buildOrderBy("pk"), strings.Join(where, " AND "))
+ results, err = d.db.QueryContext(ctx, query, args...) //nolint:rowserrcheck // Err checked in iterator
 
- results, err = d.db.QueryContext( //nolint:rowserrcheck // Err checked in iterator
- ctx, query,
- "_design/"+ddoc, rev.rev, rev.id, view, kivik.EndKeySuffix, true,
- )
  switch {
  case errIsNoSuchTable(err):
  return nil, &internal.Error{Status: http.StatusNotFound, Message: "missing named view"}