mirror of https://github.com/k3s-io/k3s
49 lines
1.6 KiB
Go
49 lines
1.6 KiB
Go
package dqlite
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import (
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"fmt"
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"os"
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"github.com/canonical/go-dqlite/internal/bindings"
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"github.com/canonical/go-dqlite/internal/protocol"
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"github.com/pkg/errors"
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)
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// ConfigMultiThread sets the threading mode of SQLite to Multi-thread.
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//
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// By default go-dqlite configures SQLite to Single-thread mode, because the
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// dqlite engine itself is single-threaded, and enabling Multi-thread or
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// Serialized modes would incur in a performance penality.
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//
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// If your Go process also uses SQLite directly (e.g. using the
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// github.com/mattn/go-sqlite3 bindings) you might need to switch to
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// Multi-thread mode in order to be thread-safe.
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//
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// IMPORTANT: It's possible to successfully change SQLite's threading mode only
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// if no SQLite APIs have been invoked yet (e.g. no database has been opened
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// yet). Therefore you'll typically want to call ConfigMultiThread() very early
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// in your process setup. Alternatively you can set the GO_DQLITE_MULTITHREAD
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// environment variable to 1 at process startup, in order to prevent go-dqlite
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// from setting Single-thread mode at all.
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func ConfigMultiThread() error {
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if err := bindings.ConfigMultiThread(); err != nil {
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if err, ok := err.(protocol.Error); ok && err.Code == 21 /* SQLITE_MISUSE */ {
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return fmt.Errorf("SQLite is already initialized")
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}
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return errors.Wrap(err, "unknown error")
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}
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return nil
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}
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func init() {
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// Don't enable single thread mode by default if GO_DQLITE_MULTITHREAD
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// is set.
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if os.Getenv("GO_DQLITE_MULTITHREAD") == "1" {
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return
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}
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err := bindings.ConfigSingleThread()
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if err != nil {
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panic(errors.Wrap(err, "set single thread mode"))
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}
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}
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