seaweedfs/weed/wdclient/net2/connection_pool.go
Chris Lu 1444e9d275 migrated multi host connection pool from godropbox package
removing unneeded dependencies, which involved etcd versions.
2021-03-06 14:26:27 -08:00

98 lines
3.2 KiB
Go

package net2
import (
"net"
"time"
)
type ConnectionOptions struct {
// The maximum number of connections that can be active per host at any
// given time (A non-positive value indicates the number of connections
// is unbounded).
MaxActiveConnections int32
// The maximum number of idle connections per host that are kept alive by
// the connection pool.
MaxIdleConnections uint32
// The maximum amount of time an idle connection can alive (if specified).
MaxIdleTime *time.Duration
// This limits the number of concurrent Dial calls (there's no limit when
// DialMaxConcurrency is non-positive).
DialMaxConcurrency int
// Dial specifies the dial function for creating network connections.
// If Dial is nil, net.DialTimeout is used, with timeout set to 1 second.
Dial func(network string, address string) (net.Conn, error)
// This specifies the now time function. When the function is non-nil, the
// connection pool will use the specified function instead of time.Now to
// generate the current time.
NowFunc func() time.Time
// This specifies the timeout for any Read() operation.
// Note that setting this to 0 (i.e. not setting it) will make
// read operations block indefinitely.
ReadTimeout time.Duration
// This specifies the timeout for any Write() operation.
// Note that setting this to 0 (i.e. not setting it) will make
// write operations block indefinitely.
WriteTimeout time.Duration
}
func (o ConnectionOptions) getCurrentTime() time.Time {
if o.NowFunc == nil {
return time.Now()
} else {
return o.NowFunc()
}
}
// A generic interface for managed connection pool. All connection pool
// implementations must be threadsafe.
type ConnectionPool interface {
// This returns the number of active connections that are on loan.
NumActive() int32
// This returns the highest number of active connections for the entire
// lifetime of the pool.
ActiveHighWaterMark() int32
// This returns the number of idle connections that are in the pool.
NumIdle() int
// This associates (network, address) to the connection pool; afterwhich,
// the user can get connections to (network, address).
Register(network string, address string) error
// This dissociate (network, address) from the connection pool;
// afterwhich, the user can no longer get connections to
// (network, address).
Unregister(network string, address string) error
// This returns the list of registered (network, address) entries.
ListRegistered() []NetworkAddress
// This gets an active connection from the connection pool. The connection
// will remain active until one of the following is called:
// 1. conn.ReleaseConnection()
// 2. conn.DiscardConnection()
// 3. pool.Release(conn)
// 4. pool.Discard(conn)
Get(network string, address string) (ManagedConn, error)
// This releases an active connection back to the connection pool.
Release(conn ManagedConn) error
// This discards an active connection from the connection pool.
Discard(conn ManagedConn) error
// Enter the connection pool into lame duck mode. The connection pool
// will no longer return connections, and all idle connections are closed
// immediately (including active connections that are released back to the
// pool afterward).
EnterLameDuckMode()
}