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Inprocess Litestream primary.
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‎litestream/README.md‎

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# Litestream lightweight read-replicas
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# Litestream in-process replication and lightweight read-replicas
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This package implements the **EXPERIMENTAL** `"litestream"` SQLite VFS
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that offers Litestream [lightweight read-replicas](https://fly.io/blog/litestream-revamped/#lightweight-read-replicas).
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This package adds **EXPERIMENTAL** support for in-process [Litestream](https://litestream.io/).
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See the [example](vfs_test.go) for how to use.
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## Lightweight read-replicas
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The `"litestream"` SQLite VFS implements Litestream
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[lightweight read-replicas](https://fly.io/blog/litestream-revamped/#lightweight-read-replicas).
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See the [example](example_test.go) for how to use.
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To improve performance,
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increase `PollInterval` (and `MinLevel`) as much as you can,
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and set [`PRAGMA cache_size=N`](https://www.sqlite.org/pragma.html#pragma_cache_size)
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(or use `_pragma=cache_size(N)`).
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(or use `_pragma=cache_size(N)`).
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## In-process replication
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For disaster recovery, it is probably best if you run Litestream as a separate background process,
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as recommended by the [tutorial](https://litestream.io/getting-started/).
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However, running Litestream as a background process requires
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compatible locking and cross-process shared memory WAL
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(see our [support matrix](https://github.com/ncruces/go-sqlite3/wiki/Support-matrix)).
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If your OS lacks locking or shared memory support,
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you can use `NewPrimary` with the `sqlite3_dotlk` build tag to setup in-process replication.

‎litestream/api.go‎

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package litestream
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import (
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"context"
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"log/slog"
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"sync"
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"time"
@@ -76,3 +77,23 @@ func RemoveReplica(name string) {
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defer liteMtx.Unlock()
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delete(liteDBs, name)
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}
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// NewPrimary creates a new primary that replicates through a client.
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// If restore is not nil, the database is first restored.
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func NewPrimary(ctx context.Context, path string, client litestream.ReplicaClient, restore *litestream.RestoreOptions) (*litestream.DB, error) {
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lsdb := litestream.NewDB(path)
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lsdb.Replica = litestream.NewReplicaWithClient(lsdb, client)
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if restore != nil {
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err := lsdb.Replica.Restore(ctx, *restore)
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if err != nil {
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return nil, err
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}
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}
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err := lsdb.Open()
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if err != nil {
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return nil, err
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}
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return lsdb, nil
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}

‎litestream/go.mod‎

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@@ -7,6 +7,7 @@ require (
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github.com/ncruces/go-sqlite3 v0.30.1
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github.com/ncruces/wbt v0.2.0
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github.com/superfly/ltx v0.5.0
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golang.org/x/sync v0.18.0
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)
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// github.com/ncruces/go-sqlite3
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github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
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github.com/prometheus/client_golang v1.23.2 // indirect
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github.com/prometheus/client_model v0.6.2 // indirect
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github.com/prometheus/common v0.67.3 // indirect
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github.com/prometheus/common v0.67.4 // indirect
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github.com/prometheus/procfs v0.19.2 // indirect
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github.com/psanford/sqlite3vfs v0.0.0-20240315230605-24e1d98cf361 // indirect
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go.yaml.in/yaml/v2 v2.4.3 // indirect
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github.com/aws/smithy-go v1.22.5 // indirect
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)
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replace modernc.org/sqlite => github.com/ncruces/go-sqlite3/litestream/modernc v0.0.0-20251109124432-99b097de3b79
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replace modernc.org/sqlite => github.com/ncruces/go-sqlite3/litestream/modernc v0.30.1

‎litestream/go.sum‎

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@@ -115,8 +115,8 @@ github.com/nats-io/nuid v1.0.1 h1:5iA8DT8V7q8WK2EScv2padNa/rTESc1KdnPw4TC2paw=
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github.com/nats-io/nuid v1.0.1/go.mod h1:19wcPz3Ph3q0Jbyiqsd0kePYG7A95tJPxeL+1OSON2c=
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github.com/ncruces/go-sqlite3 v0.30.1 h1:pHC3YsyRdJv4pCMB4MO1Q2BXw/CAa+Hoj7GSaKtVk+g=
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github.com/ncruces/go-sqlite3 v0.30.1/go.mod h1:UVsWrQaq1qkcal5/vT5lOJnZCVlR5rsThKdwidjFsKc=
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github.com/ncruces/go-sqlite3/litestream/modernc v0.0.0-20251109124432-99b097de3b79 h1:evpQceUV2vRbOe84U/QhBBchfqFERRHTx1JOadFFMLE=
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github.com/ncruces/go-sqlite3/litestream/modernc v0.0.0-20251109124432-99b097de3b79/go.mod h1:GSM2gXEOb9HIFFtsl0IUtnpvpDmVi7Kbp8z5GzwA0Tw=
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github.com/ncruces/go-sqlite3/litestream/modernc v0.30.1 h1:3SNAOrm+qmLprkZybcvBrVNHyt0QYHljUGxmOXnL+K0=
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github.com/ncruces/go-sqlite3/litestream/modernc v0.30.1/go.mod h1:GSM2gXEOb9HIFFtsl0IUtnpvpDmVi7Kbp8z5GzwA0Tw=
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github.com/ncruces/julianday v1.0.0 h1:fH0OKwa7NWvniGQtxdJRxAgkBMolni2BjDHaWTxqt7M=
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github.com/ncruces/julianday v1.0.0/go.mod h1:Dusn2KvZrrovOMJuOt0TNXL6tB7U2E8kvza5fFc9G7g=
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github.com/ncruces/wbt v0.2.0 h1:Q9zlKOBSZc7Yy/R2cGa35g6RKUUE3BjNIW3tfGC4F04=
@@ -133,8 +133,8 @@ github.com/prometheus/client_golang v1.23.2 h1:Je96obch5RDVy3FDMndoUsjAhG5Edi49h
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github.com/prometheus/client_golang v1.23.2/go.mod h1:Tb1a6LWHB3/SPIzCoaDXI4I8UHKeFTEQ1YCr+0Gyqmg=
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github.com/prometheus/client_model v0.6.2 h1:oBsgwpGs7iVziMvrGhE53c/GrLUsZdHnqNwqPLxwZyk=
135135
github.com/prometheus/client_model v0.6.2/go.mod h1:y3m2F6Gdpfy6Ut/GBsUqTWZqCUvMVzSfMLjcu6wAwpE=
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github.com/prometheus/common v0.67.3 h1:shd26MlnwTw5jksTDhC7rTQIteBxy+ZZDr3t7F2xN2Q=
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github.com/prometheus/common v0.67.3/go.mod h1:gP0fq6YjjNCLssJCQp0yk4M8W6ikLURwkdd/YKtTbyI=
136+
github.com/prometheus/common v0.67.4 h1:yR3NqWO1/UyO1w2PhUvXlGQs/PtFmoveVO0KZ4+Lvsc=
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github.com/prometheus/common v0.67.4/go.mod h1:gP0fq6YjjNCLssJCQp0yk4M8W6ikLURwkdd/YKtTbyI=
138138
github.com/prometheus/procfs v0.19.2 h1:zUMhqEW66Ex7OXIiDkll3tl9a1ZdilUOd/F6ZXw4Vws=
139139
github.com/prometheus/procfs v0.19.2/go.mod h1:M0aotyiemPhBCM0z5w87kL22CxfcH05ZpYlu+b4J7mw=
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github.com/psanford/sqlite3vfs v0.0.0-20240315230605-24e1d98cf361 h1:vAKifIJuYY306ZJSrwDgKonWcJGELijdaenABqbV03E=
@@ -169,8 +169,8 @@ golang.org/x/net v0.47.0 h1:Mx+4dIFzqraBXUugkia1OOvlD6LemFo1ALMHjrXDOhY=
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golang.org/x/net v0.47.0/go.mod h1:/jNxtkgq5yWUGYkaZGqo27cfGZ1c5Nen03aYrrKpVRU=
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golang.org/x/oauth2 v0.32.0 h1:jsCblLleRMDrxMN29H3z/k1KliIvpLgCkE6R8FXXNgY=
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golang.org/x/oauth2 v0.32.0/go.mod h1:lzm5WQJQwKZ3nwavOZ3IS5Aulzxi68dUSgRHujetwEA=
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golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
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golang.org/x/sync v0.17.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
172+
golang.org/x/sync v0.18.0 h1:kr88TuHDroi+UVf+0hZnirlk8o8T+4MrK6mr60WkH/I=
173+
golang.org/x/sync v0.18.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
174174
golang.org/x/sys v0.38.0 h1:3yZWxaJjBmCWXqhN1qh02AkOnCQ1poK6oF+a7xWL6Gc=
175175
golang.org/x/sys v0.38.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
176176
golang.org/x/text v0.31.0 h1:aC8ghyu4JhP8VojJ2lEHBnochRno1sgL6nEi9WGFGMM=

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