Monorepo for Tangled
knotclient: introduce sqlite3 based cursor store
Signed-off-by: oppiliappan <me@oppi.li>
oppiliappan
(Jun 13, 2025, 12:49 PM +0100)
fe8c96f0
60444e90
+83
+83
knotclient/cursor/sqlite.go
+83
knotclient/cursor/sqlite.go
···
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package cursor
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import (
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"database/sql"
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"fmt"
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_ "github.com/mattn/go-sqlite3"
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)
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type SqliteStore struct {
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db *sql.DB
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tableName string
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}
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type SqliteStoreOpt func(*SqliteStore)
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func WithTableName(name string) SqliteStoreOpt {
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return func(s *SqliteStore) {
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s.tableName = name
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}
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}
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func NewSQLiteStore(dbPath string, opts ...SqliteStoreOpt) (*SqliteStore, error) {
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db, err := sql.Open("sqlite3", dbPath)
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if err != nil {
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return nil, fmt.Errorf("failed to open sqlite database: %w", err)
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}
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store := &SqliteStore{
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db: db,
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tableName: "cursors",
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}
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for _, o := range opts {
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o(store)
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}
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if err := store.init(); err != nil {
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return nil, err
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}
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return store, nil
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}
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func (s *SqliteStore) init() error {
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createTable := fmt.Sprintf(`
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create table if not exists %s (
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knot text primary key,
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cursor text
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);`, s.tableName)
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_, err := s.db.Exec(createTable)
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return err
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}
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func (s *SqliteStore) Set(knot string, cursor int64) {
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query := fmt.Sprintf(`
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insert into %s (knot, cursor)
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values (?, ?)
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on conflict(knot) do update set cursor=excluded.cursor;
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`, s.tableName)
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_, err := s.db.Exec(query, knot, cursor)
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if err != nil {
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// TODO: log here
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}
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}
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func (s *SqliteStore) Get(knot string) (cursor int64) {
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query := fmt.Sprintf(`
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select cursor from %s where knot = ?;
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`, s.tableName)
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err := s.db.QueryRow(query, knot).Scan(&cursor)
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if err != nil {
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if err != sql.ErrNoRows {
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// TODO: log here
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}
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return 0
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}
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return cursor
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}