Awesome

wal

A simple and fast write ahead log for Go.

Features

• High durability
• Fast operations
• Monotonic indexes
• Batch writes
• Log truncation from front or back.

Getting Started

Installing

To start using wal, install Go and run go get:

$ go get -u github.com/tidwall/wal

This will retrieve the library.

Example

// open a new log file
log, err := wal.Open("mylog", nil)

// write some entries
err = log.Write(1, []byte("first entry"))
err = log.Write(2, []byte("second entry"))
err = log.Write(3, []byte("third entry"))

// read an entry
data, err := log.Read(1)
println(string(data))  // output: first entry

// close the log
err = log.Close()

Batch writes:

// write three entries as a batch
batch := new(wal.Batch)
batch.Write(1, []byte("first entry"))
batch.Write(2, []byte("second entry"))
batch.Write(3, []byte("third entry"))

err = log.WriteBatch(batch)

Truncating:

// write some entries
err = log.Write(1, []byte("first entry"))
...
err = log.Write(1000, []byte("thousandth entry"))

// truncate the log from index starting 350 and ending with 950.
err = log.TruncateFront(350)
err = log.TruncateBack(950)

Contact

Josh Baker @tidwall

License

wal source code is available under the MIT License.