mirror of https://github.com/tidwall/tile38.git
95 lines
2.0 KiB
Go
95 lines
2.0 KiB
Go
package client
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import (
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"errors"
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"fmt"
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"math/rand"
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"sync"
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"time"
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)
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const dialTimeout = time.Second * 3
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const pingTimeout = time.Second
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// Pool represents a pool of tile38 connections.
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type Pool struct {
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mu sync.Mutex
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conns []*Conn
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addr string
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closed bool
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}
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// DialPool creates a new pool with 5 initial connections to the specified tile38 server.
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func DialPool(addr string) (*Pool, error) {
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pool := &Pool{
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addr: addr,
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}
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// create some connections. 5 is a good start
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var tconns []*Conn
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for i := 0; i < 5; i++ {
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conn, err := pool.Get()
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if err != nil {
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pool.Close()
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return nil, fmt.Errorf("unable to fill pool: %s", err)
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}
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tconns = append(tconns, conn)
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}
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pool.conns = tconns
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return pool, nil
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}
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// Close releases the resources used by the pool.
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func (pool *Pool) Close() error {
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pool.mu.Lock()
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defer pool.mu.Unlock()
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if pool.closed {
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return errors.New("pool closed")
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}
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pool.closed = true
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for _, conn := range pool.conns {
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conn.pool = nil
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conn.Close()
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}
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pool.conns = nil
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return nil
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}
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// Get borrows a connection. When the connection closes, the application returns it to the pool.
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func (pool *Pool) Get() (*Conn, error) {
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pool.mu.Lock()
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defer pool.mu.Unlock()
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for len(pool.conns) != 0 {
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i := rand.Int() % len(pool.conns)
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conn := pool.conns[i]
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pool.conns = append(pool.conns[:i], pool.conns[i+1:]...)
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// Ping to test on borrow.
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conn.SetDeadline(time.Now().Add(pingTimeout))
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if _, err := conn.Do("PING"); err != nil {
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conn.pool = nil
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conn.Close()
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continue
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}
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conn.SetDeadline(time.Time{})
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return conn, nil
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}
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conn, err := DialTimeout(pool.addr, dialTimeout)
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if err != nil {
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return nil, err
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}
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conn.pool = pool
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return conn, nil
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}
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func (pool *Pool) put(conn *Conn) error {
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pool.mu.Lock()
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defer pool.mu.Unlock()
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if pool.closed {
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return errors.New("pool closed")
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}
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conn.SetDeadline(time.Time{})
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conn.SetReadDeadline(time.Time{})
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conn.SetWriteDeadline(time.Time{})
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pool.conns = append(pool.conns, conn)
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return nil
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}
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