Monorepo for Tangled
tangled.org
knotserver/db: add owner UID assignment and repo isolation
author
Anirudh Oppiliappan
date
(Jun 12, 2026, 12:00 PM +0300)
commit
afcaab94
afcaab9447e715b151c696c5c483ac89068b1189
parent
f291e61e
f291e61e3238c644456ebca8e38b6f9c804cb6c8
change-id
omlykowv
omlykowvspvmlnzzoxrutpnqrzuqqnyv
+237
-7
+44
-7
knotserver/db/db.go
+44
-7
knotserver/db/db.go
···
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"log/slog"
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"os"
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"strings"
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"sync"
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securejoin "github.com/cyphar/filepath-securejoin"
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_ "github.com/mattn/go-sqlite3"
···
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type DB struct {
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db *sql.DB
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logger *slog.Logger
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+
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// uidAssignMu serialises GetOrAssignOwnerUID across goroutines so that
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// concurrent callers don't race on the uid_counter read-modify-write.
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uidAssignMu sync.Mutex
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}
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type DBTX interface {
···
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if err := orm.RunMigration(conn, logger, "create-knot-members", func(tx *sql.Tx) error {
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_, mErr := tx.ExecContext(ctx, `
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create table if not exists knot_members (
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id integer primary key autoincrement,
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did text not null,
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rkey text not null,
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subject text not null,
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created text not null default (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
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unique (did, rkey)
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create table if not exists knot_members (
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id integer primary key autoincrement,
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did text not null,
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rkey text not null,
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subject text not null,
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created text not null default (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
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unique (did, rkey)
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);
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`)
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return mErr
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}); err != nil {
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return nil, err
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}
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+
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if err := orm.RunMigration(conn, logger, "add-isolated-at-to-repo-keys", func(tx *sql.Tx) error {
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_, mErr := tx.ExecContext(ctx, `ALTER TABLE repo_keys ADD COLUMN isolated_at DATETIME`)
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return mErr
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}); err != nil {
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return nil, err
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}
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+
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if err := orm.RunMigration(conn, logger, "add-owner-uid-tables", func(tx *sql.Tx) error {
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_, mErr := tx.ExecContext(ctx, `
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CREATE TABLE IF NOT EXISTS owner_uid_assignments (
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owner_did TEXT PRIMARY KEY,
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uid INTEGER NOT NULL UNIQUE,
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created_at DATETIME DEFAULT CURRENT_TIMESTAMP
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);
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CREATE TABLE IF NOT EXISTS uid_counter (
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next_uid INTEGER NOT NULL DEFAULT 100000
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);
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`)
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if mErr != nil {
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return mErr
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}
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// Seed the counter only if the table is empty.
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_, mErr = tx.ExecContext(ctx, `
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INSERT INTO uid_counter (next_uid)
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SELECT 100000 WHERE NOT EXISTS (SELECT 1 FROM uid_counter)
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`)
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return mErr
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}); err != nil {
+102
knotserver/db/owner_uid.go
+102
knotserver/db/owner_uid.go
···
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+
package db
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import (
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"database/sql"
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)
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+
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// GetOrAssignOwnerUID returns the virtual UID for ownerDID, minting a new one
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// from the uid_counter table if this owner has not been seen before.
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// UIDs start at 100000 and increment by one per unique owner.
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//
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// A process-wide mutex serialises concurrent callers so two simultaneous
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// requests for distinct DIDs do not race to claim the same counter value.
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// The mutex is local to this DB instance and SQLite itself only permits one
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// writer at a time, so this does not impede throughput in practice.
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func (d *DB) GetOrAssignOwnerUID(ownerDID string) (uint32, error) {
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d.uidAssignMu.Lock()
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defer d.uidAssignMu.Unlock()
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tx, err := d.db.Begin()
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if err != nil {
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return 0, err
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}
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defer tx.Rollback()
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+
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var uid uint32
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err = tx.QueryRow(
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`SELECT uid FROM owner_uid_assignments WHERE owner_did = ?`,
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ownerDID,
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).Scan(&uid)
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if err == nil {
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return uid, tx.Commit()
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}
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if err != sql.ErrNoRows {
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return 0, err
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}
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if err := tx.QueryRow(`SELECT next_uid FROM uid_counter`).Scan(&uid); err != nil {
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return 0, err
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}
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if _, err := tx.Exec(`UPDATE uid_counter SET next_uid = next_uid + 1`); err != nil {
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return 0, err
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}
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if _, err := tx.Exec(
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`INSERT INTO owner_uid_assignments (owner_did, uid) VALUES (?, ?)`,
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ownerDID, uid,
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); err != nil {
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return 0, err
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}
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return uid, tx.Commit()
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}
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// AllReposForMigration returns all (repo_did, owner_did) pairs with a
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// non-null owner. Pass force=true to include already-migrated repos.
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func (d *DB) AllReposForMigration(force bool) ([]RepoMigrationRow, error) {
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query := `SELECT repo_did, owner_did FROM repo_keys WHERE owner_did IS NOT NULL`
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if !force {
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query += ` AND isolated_at IS NULL`
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}
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rows, err := d.db.Query(query)
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if err != nil {
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return nil, err
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}
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defer rows.Close()
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var result []RepoMigrationRow
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for rows.Next() {
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var r RepoMigrationRow
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if err := rows.Scan(&r.RepoDID, &r.OwnerDID); err != nil {
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return nil, err
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}
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result = append(result, r)
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}
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return result, rows.Err()
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}
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// CountUnmigratedRepos returns the number of repos that have not yet been
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// isolation-migrated.
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func (d *DB) CountUnmigratedRepos() (int, error) {
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var n int
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err := d.db.QueryRow(`
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SELECT count(1) FROM repo_keys
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WHERE owner_did IS NOT NULL
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AND isolated_at IS NULL
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`).Scan(&n)
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return n, err
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}
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// MarkRepoIsolated sets isolated_at to the current time for repoDID.
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func (d *DB) MarkRepoIsolated(repoDID string) error {
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_, err := d.db.Exec(
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`UPDATE repo_keys SET isolated_at = strftime('%Y-%m-%dT%H:%M:%SZ','now') WHERE repo_did = ?`,
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repoDID,
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)
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return err
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}
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// RepoMigrationRow is a row returned by AllReposForMigration.
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type RepoMigrationRow struct {
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RepoDID string
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OwnerDID string
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}
+91
knotserver/db/owner_uid_test.go
+91
knotserver/db/owner_uid_test.go
···
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package db
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import (
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"context"
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"fmt"
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"path/filepath"
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"sync"
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"testing"
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)
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// TestGetOrAssignOwnerUID_Concurrent verifies that concurrent calls for
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// distinct DIDs each get a unique UID, with no duplicates from a race on
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// the uid_counter table.
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func TestGetOrAssignOwnerUID_Concurrent(t *testing.T) {
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d := newTestDB(t)
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const n = 50
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results := make([]uint32, n)
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var wg sync.WaitGroup
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wg.Add(n)
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for i := 0; i < n; i++ {
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go func(i int) {
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defer wg.Done()
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uid, err := d.GetOrAssignOwnerUID(fmt.Sprintf("did:plc:test-%03d", i))
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if err != nil {
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t.Errorf("GetOrAssignOwnerUID(%d): %v", i, err)
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return
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}
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results[i] = uid
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}(i)
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}
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wg.Wait()
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seen := map[uint32]int{}
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for i, uid := range results {
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if uid == 0 {
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t.Errorf("result[%d] is zero (probably an error above)", i)
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continue
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}
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if prev, ok := seen[uid]; ok {
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t.Errorf("uid %d was returned for both index %d and %d", uid, prev, i)
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}
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seen[uid] = i
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}
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if len(seen) != n {
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t.Errorf("got %d unique UIDs, want %d", len(seen), n)
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}
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}
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// TestGetOrAssignOwnerUID_Idempotent verifies that repeated calls for the
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// same DID return the same UID.
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func TestGetOrAssignOwnerUID_Idempotent(t *testing.T) {
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d := newTestDB(t)
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const did = "did:plc:stable"
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first, err := d.GetOrAssignOwnerUID(did)
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if err != nil {
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t.Fatalf("first call: %v", err)
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}
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for i := 0; i < 5; i++ {
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uid, err := d.GetOrAssignOwnerUID(did)
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if err != nil {
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t.Fatalf("repeat call %d: %v", i, err)
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}
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if uid != first {
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t.Errorf("repeat call %d returned %d, want %d", i, uid, first)
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}
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}
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}
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// TestGetOrAssignOwnerUID_StartsAt100000 verifies the counter seeds correctly.
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func TestGetOrAssignOwnerUID_StartsAt100000(t *testing.T) {
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d := newTestDB(t)
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uid, err := d.GetOrAssignOwnerUID("did:plc:first")
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if err != nil {
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t.Fatalf("first call: %v", err)
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}
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if uid != 100000 {
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t.Errorf("first UID = %d, want 100000", uid)
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}
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}
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func newTestDB(t *testing.T) *DB {
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t.Helper()
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d, err := Setup(context.Background(), filepath.Join(t.TempDir(), "test.db"))
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if err != nil {
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t.Fatalf("db.Setup: %v", err)
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}
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return d
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}