Fix 'database is locked' error

[cerblue]

Fixes #652

Caused by concurrent access from deal goroutines to a single sqlite3 DB connection. By default, this will cause the 'database is locked' error, and it is the reason for failures in deal status updates and deal log appends. The fix comes from suggestions in https://github.com/mattn/go-sqlite3#:~:text=Error%3A%20database%20is%20locked and mattn/go-sqlite3#209.

I wrote a toy program to reproduce the error and confirmed that this change fixes the error, and does the same to my boost daemon instance.

[nonsense]

Thank you for this fix @cerblue .

I think we should also add the ?cache=shared as per docs at https://github.com/mattn/go-sqlite3#faq , what do you think?

---

I think we need to add the ?cache=shared at two places:

diff --git a/node/modules/storageminer.go b/node/modules/storageminer.go
index 0747c80..de7256c 100644
--- a/node/modules/storageminer.go
+++ b/node/modules/storageminer.go
@@ -285,7 +285,7 @@ func StorageNetworkName(ctx helpers.MetricsCtx, a v1api.FullNode) (dtypes.Networ
 }

 func NewBoostDB(r lotus_repo.LockedRepo) (*sql.DB, error) {
-       dbPath := path.Join(r.Path(), "boost.db")
+       dbPath := path.Join(r.Path(), "boost.db?cache=shared")
        return db.SqlDB(dbPath)
 }

@@ -294,7 +294,7 @@ type LogSqlDB struct {
 }

 func NewLogsSqlDB(r repo.LockedRepo) (*LogSqlDB, error) {
-       dbPath := path.Join(r.Path(), "boost.logs.db")
+       dbPath := path.Join(r.Path(), "boost.logs.db?cache=shared")
        d, err := db.SqlDB(dbPath)
        if err != nil {
                return nil, err

[jacobheun]

Closing this in favor of #679, which includes this.