README
¶
go-pg-mutex
Mutex lock based on PostgreSQL advisory locks for Go. Can be used to acquire a lock on a resource exclusively across several running instances of the application.
Install
$ go get -u -v github.com/vgarvardt/go-pg-mutex
PostgreSQL drivers
The store accepts an adapter interface that interacts with the DB. Adapter and implementations are extracted to separate package github.com/vgarvardt/go-pg-adapter for easier maintenance.
Usage example
package main
import (
"fmt"
"os"
"time"
"github.com/jackc/pgx"
"github.com/vgarvardt/go-pg-adapter/pgxadapter"
"github.com/vgarvardt/go-pg-mutex"
)
func main() {
pgxConnConfig, _ := pgx.ParseURI(os.Getenv("DB_URI"))
pgxConn, _ := pgx.Connect(pgxConnConfig)
m, _ := pgmutex.New(pgxadapter.NewConn(pgxConn))
useExclusiveResource(m)
if !useExclusiveResourceOrNoOp(m) {
fmt.Println("Resource is busy, doing nothing")
}
}
func useExclusiveResource(m *pgmutex.PgMutex) {
lockName := "my-lock"
_ := m.Lock(lockName)
defer m.Unlock(lockName)
// do something with resource exclusively across several instances
}
func useExclusiveResourceOrNoOp(m *pgmutex.PgMutex) bool {
lockName := "my-try-lock"
if success, _ := m.TryLock(lockName); !success {
return false
}
defer m.Unlock(lockName)
// do something with resource exclusively across several instances
}
How to run tests
You will need running PostgreSQL instance. E.g. the one running in docker and exposing a port to a host system
docker run --rm -p 5432:5432 -it -e POSTGRES_PASSWORD=mutex -e POSTGRES_USER=mutex -e POSTGRES_DB=mutex postgres:10
Now you can run tests using the running PostgreSQL instance using PG_URI environment variable
PG_URI=postgres://mutex:mutex@localhost:5432/mutex?sslmode=disable go test -cover ./...
MIT License
Copyright (c) 2019 Vladimir Garvardt
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Option ¶
type Option func(mutex *PgMutex)
Option is the configuration options type for PgMutex
func WithInitTableDisabled ¶
func WithInitTableDisabled() Option
WithInitTableDisabled returns option that disables table creation on PgMutex instantiation
func WithTableName ¶
WithTableName returns option that sets PgMutex table name
type PgMutex ¶
type PgMutex struct {
// contains filtered or unexported fields
}
PgMutex is the mutex lock based on PostgreSQL advisory locks
Source Files