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@@ -0,0 +1,669 @@
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+/*
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+Copyright 2011 Google Inc.
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+
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+Licensed under the Apache License, Version 2.0 (the "License");
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+you may not use this file except in compliance with the License.
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+You may obtain a copy of the License at
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+
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+ http://www.apache.org/licenses/LICENSE-2.0
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+
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+Unless required by applicable law or agreed to in writing, software
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+distributed under the License is distributed on an "AS IS" BASIS,
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+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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+See the License for the specific language governing permissions and
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+limitations under the License.
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+*/
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+
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+// Package memcache provides a client for the memcached cache server.
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+package memcache
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+
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+import (
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+ "bufio"
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+ "bytes"
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+ "errors"
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+ "fmt"
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+ "io"
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+ "io/ioutil"
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+ "net"
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+
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+ "strconv"
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+ "strings"
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+ "sync"
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+ "time"
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+)
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+
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+// Similar to:
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+// http://code.google.com/appengine/docs/go/memcache/reference.html
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+
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+var (
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+ // ErrCacheMiss means that a Get failed because the item wasn't present.
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+ ErrCacheMiss = errors.New("memcache: cache miss")
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+
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+ // ErrCASConflict means that a CompareAndSwap call failed due to the
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+ // cached value being modified between the Get and the CompareAndSwap.
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+ // If the cached value was simply evicted rather than replaced,
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+ // ErrNotStored will be returned instead.
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+ ErrCASConflict = errors.New("memcache: compare-and-swap conflict")
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+
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+ // ErrNotStored means that a conditional write operation (i.e. Add or
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+ // CompareAndSwap) failed because the condition was not satisfied.
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+ ErrNotStored = errors.New("memcache: item not stored")
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+
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+ // ErrServer means that a server error occurred.
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+ ErrServerError = errors.New("memcache: server error")
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+
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+ // ErrNoStats means that no statistics were available.
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+ ErrNoStats = errors.New("memcache: no statistics available")
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+
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+ // ErrMalformedKey is returned when an invalid key is used.
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+ // Keys must be at maximum 250 bytes long, ASCII, and not
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+ // contain whitespace or control characters.
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+ ErrMalformedKey = errors.New("malformed: key is too long or contains invalid characters")
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+
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+ // ErrNoServers is returned when no servers are configured or available.
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+ ErrNoServers = errors.New("memcache: no servers configured or available")
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+)
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+
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+// DefaultTimeout is the default socket read/write timeout.
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+const DefaultTimeout = 100 * time.Millisecond
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+
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+const (
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+ buffered = 8 // arbitrary buffered channel size, for readability
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+ maxIdleConnsPerAddr = 2 // TODO(bradfitz): make this configurable?
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+)
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+
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+// resumableError returns true if err is only a protocol-level cache error.
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+// This is used to determine whether or not a server connection should
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+// be re-used or not. If an error occurs, by default we don't reuse the
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+// connection, unless it was just a cache error.
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+func resumableError(err error) bool {
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+ switch err {
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+ case ErrCacheMiss, ErrCASConflict, ErrNotStored, ErrMalformedKey:
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+ return true
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+ }
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+ return false
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+}
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+
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+func legalKey(key string) bool {
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+ if len(key) > 250 {
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+ return false
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+ }
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+ for i := 0; i < len(key); i++ {
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+ if key[i] <= ' ' || key[i] > 0x7e {
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+ return false
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+ }
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+ }
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+ return true
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+}
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+
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+var (
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+ crlf = []byte("\r\n")
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+ space = []byte(" ")
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+ resultOK = []byte("OK\r\n")
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+ resultStored = []byte("STORED\r\n")
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+ resultNotStored = []byte("NOT_STORED\r\n")
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+ resultExists = []byte("EXISTS\r\n")
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+ resultNotFound = []byte("NOT_FOUND\r\n")
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+ resultDeleted = []byte("DELETED\r\n")
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+ resultEnd = []byte("END\r\n")
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+ resultOk = []byte("OK\r\n")
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+ resultTouched = []byte("TOUCHED\r\n")
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+
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+ resultClientErrorPrefix = []byte("CLIENT_ERROR ")
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+)
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+
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+// New returns a memcache client using the provided server(s)
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+// with equal weight. If a server is listed multiple times,
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+// it gets a proportional amount of weight.
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+func New(server ...string) *Client {
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+ ss := new(ServerList)
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+ ss.SetServers(server...)
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+ return NewFromSelector(ss)
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+}
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+
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+// NewFromSelector returns a new Client using the provided ServerSelector.
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+func NewFromSelector(ss ServerSelector) *Client {
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+ return &Client{selector: ss}
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+}
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+
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+// Client is a memcache client.
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+// It is safe for unlocked use by multiple concurrent goroutines.
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+type Client struct {
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+ // Timeout specifies the socket read/write timeout.
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+ // If zero, DefaultTimeout is used.
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+ Timeout time.Duration
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+
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+ selector ServerSelector
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+
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+ lk sync.Mutex
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+ freeconn map[string][]*conn
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+}
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+
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+// Item is an item to be got or stored in a memcached server.
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+type Item struct {
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+ // Key is the Item's key (250 bytes maximum).
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+ Key string
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+
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+ // Value is the Item's value.
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+ Value []byte
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+
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+ // Object is the Item's value for use with a Codec.
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+ Object interface{}
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+
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+ // Flags are server-opaque flags whose semantics are entirely
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+ // up to the app.
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+ Flags uint32
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+
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+ // Expiration is the cache expiration time, in seconds: either a relative
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+ // time from now (up to 1 month), or an absolute Unix epoch time.
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+ // Zero means the Item has no expiration time.
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+ Expiration int32
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+
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+ // Compare and swap ID.
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+ casid uint64
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+}
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+
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+// conn is a connection to a server.
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+type conn struct {
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+ nc net.Conn
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+ rw *bufio.ReadWriter
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+ addr net.Addr
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+ c *Client
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+}
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+
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+// release returns this connection back to the client's free pool
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+func (cn *conn) release() {
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+ cn.c.putFreeConn(cn.addr, cn)
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+}
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+
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+func (cn *conn) extendDeadline() {
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+ cn.nc.SetDeadline(time.Now().Add(cn.c.netTimeout()))
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+}
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+
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+// condRelease releases this connection if the error pointed to by err
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+// is nil (not an error) or is only a protocol level error (e.g. a
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+// cache miss). The purpose is to not recycle TCP connections that
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+// are bad.
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+func (cn *conn) condRelease(err *error) {
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+ if *err == nil || resumableError(*err) {
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+ cn.release()
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+ } else {
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+ cn.nc.Close()
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+ }
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+}
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+
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+func (c *Client) putFreeConn(addr net.Addr, cn *conn) {
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+ c.lk.Lock()
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+ defer c.lk.Unlock()
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+ if c.freeconn == nil {
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+ c.freeconn = make(map[string][]*conn)
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+ }
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+ freelist := c.freeconn[addr.String()]
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+ if len(freelist) >= maxIdleConnsPerAddr {
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+ cn.nc.Close()
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+ return
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+ }
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+ c.freeconn[addr.String()] = append(freelist, cn)
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+}
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+
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+func (c *Client) getFreeConn(addr net.Addr) (cn *conn, ok bool) {
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+ c.lk.Lock()
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+ defer c.lk.Unlock()
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+ if c.freeconn == nil {
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+ return nil, false
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+ }
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+ freelist, ok := c.freeconn[addr.String()]
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+ if !ok || len(freelist) == 0 {
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+ return nil, false
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+ }
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+ cn = freelist[len(freelist)-1]
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+ c.freeconn[addr.String()] = freelist[:len(freelist)-1]
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+ return cn, true
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+}
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+
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+func (c *Client) netTimeout() time.Duration {
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+ if c.Timeout != 0 {
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+ return c.Timeout
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+ }
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+ return DefaultTimeout
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+}
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+
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+// ConnectTimeoutError is the error type used when it takes
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+// too long to connect to the desired host. This level of
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+// detail can generally be ignored.
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+type ConnectTimeoutError struct {
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+ Addr net.Addr
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+}
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+
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+func (cte *ConnectTimeoutError) Error() string {
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+ return "memcache: connect timeout to " + cte.Addr.String()
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+}
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+
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+func (c *Client) dial(addr net.Addr) (net.Conn, error) {
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+ type connError struct {
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+ cn net.Conn
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+ err error
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+ }
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+
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+ nc, err := net.DialTimeout(addr.Network(), addr.String(), c.netTimeout())
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+ if err == nil {
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+ return nc, nil
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+ }
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+
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+ if ne, ok := err.(net.Error); ok && ne.Timeout() {
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+ return nil, &ConnectTimeoutError{addr}
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+ }
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+
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+ return nil, err
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+}
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+
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+func (c *Client) getConn(addr net.Addr) (*conn, error) {
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+ cn, ok := c.getFreeConn(addr)
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+ if ok {
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+ cn.extendDeadline()
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+ return cn, nil
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+ }
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+ nc, err := c.dial(addr)
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+ if err != nil {
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+ return nil, err
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+ }
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+ cn = &conn{
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+ nc: nc,
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+ addr: addr,
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+ rw: bufio.NewReadWriter(bufio.NewReader(nc), bufio.NewWriter(nc)),
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+ c: c,
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+ }
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+ cn.extendDeadline()
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+ return cn, nil
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+}
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+
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+func (c *Client) onItem(item *Item, fn func(*Client, *bufio.ReadWriter, *Item) error) error {
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+ addr, err := c.selector.PickServer(item.Key)
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+ if err != nil {
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+ return err
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+ }
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+ cn, err := c.getConn(addr)
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+ if err != nil {
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+ return err
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+ }
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+ defer cn.condRelease(&err)
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+ if err = fn(c, cn.rw, item); err != nil {
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+ return err
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+ }
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+ return nil
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+}
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+
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+func (c *Client) FlushAll() error {
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+ return c.selector.Each(c.flushAllFromAddr)
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+}
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+
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+// Get gets the item for the given key. ErrCacheMiss is returned for a
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+// memcache cache miss. The key must be at most 250 bytes in length.
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+func (c *Client) Get(key string) (item *Item, err error) {
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+ err = c.withKeyAddr(key, func(addr net.Addr) error {
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+ return c.getFromAddr(addr, []string{key}, func(it *Item) { item = it })
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+ })
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+ if err == nil && item == nil {
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+ err = ErrCacheMiss
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+ }
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+ return
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+}
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+
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+// Touch updates the expiry for the given key. The seconds parameter is either
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+// a Unix timestamp or, if seconds is less than 1 month, the number of seconds
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+// into the future at which time the item will expire. ErrCacheMiss is returned if the
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+// key is not in the cache. The key must be at most 250 bytes in length.
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+func (c *Client) Touch(key string, seconds int32) (err error) {
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+ return c.withKeyAddr(key, func(addr net.Addr) error {
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+ return c.touchFromAddr(addr, []string{key}, seconds)
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+ })
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+}
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+
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+func (c *Client) withKeyAddr(key string, fn func(net.Addr) error) (err error) {
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+ if !legalKey(key) {
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+ return ErrMalformedKey
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+ }
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+ addr, err := c.selector.PickServer(key)
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+ if err != nil {
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+ return err
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+ }
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+ return fn(addr)
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+}
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+
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+func (c *Client) withAddrRw(addr net.Addr, fn func(*bufio.ReadWriter) error) (err error) {
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+ cn, err := c.getConn(addr)
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+ if err != nil {
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+ return err
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+ }
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+ defer cn.condRelease(&err)
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+ return fn(cn.rw)
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+}
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+
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+func (c *Client) withKeyRw(key string, fn func(*bufio.ReadWriter) error) error {
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+ return c.withKeyAddr(key, func(addr net.Addr) error {
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+ return c.withAddrRw(addr, fn)
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+ })
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+}
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+
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+func (c *Client) getFromAddr(addr net.Addr, keys []string, cb func(*Item)) error {
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+ return c.withAddrRw(addr, func(rw *bufio.ReadWriter) error {
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+ if _, err := fmt.Fprintf(rw, "gets %s\r\n", strings.Join(keys, " ")); err != nil {
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+ return err
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+ }
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+ if err := rw.Flush(); err != nil {
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+ return err
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+ }
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+ if err := parseGetResponse(rw.Reader, cb); err != nil {
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+ return err
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+ }
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+ return nil
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+ })
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+}
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+
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+// flushAllFromAddr send the flush_all command to the given addr
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+func (c *Client) flushAllFromAddr(addr net.Addr) error {
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+ return c.withAddrRw(addr, func(rw *bufio.ReadWriter) error {
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+ if _, err := fmt.Fprintf(rw, "flush_all\r\n"); err != nil {
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+ return err
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+ }
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+ if err := rw.Flush(); err != nil {
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+ return err
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+ }
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+ line, err := rw.ReadSlice('\n')
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+ if err != nil {
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+ return err
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+ }
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+ switch {
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+ case bytes.Equal(line, resultOk):
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+ break
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+ default:
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+ return fmt.Errorf("memcache: unexpected response line from flush_all: %q", string(line))
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+ }
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+ return nil
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+ })
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+}
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+
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+func (c *Client) touchFromAddr(addr net.Addr, keys []string, expiration int32) error {
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+ return c.withAddrRw(addr, func(rw *bufio.ReadWriter) error {
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+ for _, key := range keys {
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+ if _, err := fmt.Fprintf(rw, "touch %s %d\r\n", key, expiration); err != nil {
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+ return err
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+ }
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+ if err := rw.Flush(); err != nil {
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+ return err
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+ }
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+ line, err := rw.ReadSlice('\n')
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+ if err != nil {
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+ return err
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+ }
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+ switch {
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+ case bytes.Equal(line, resultTouched):
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+ break
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+ case bytes.Equal(line, resultNotFound):
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+ return ErrCacheMiss
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+ default:
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+ return fmt.Errorf("memcache: unexpected response line from touch: %q", string(line))
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+ }
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+ }
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+ return nil
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+ })
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+}
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+
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+// GetMulti is a batch version of Get. The returned map from keys to
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+// items may have fewer elements than the input slice, due to memcache
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+// cache misses. Each key must be at most 250 bytes in length.
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+// If no error is returned, the returned map will also be non-nil.
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+func (c *Client) GetMulti(keys []string) (map[string]*Item, error) {
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+ var lk sync.Mutex
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+ m := make(map[string]*Item)
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+ addItemToMap := func(it *Item) {
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+ lk.Lock()
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+ defer lk.Unlock()
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|
|
+ m[it.Key] = it
|
|
|
+ }
|
|
|
+
|
|
|
+ keyMap := make(map[net.Addr][]string)
|
|
|
+ for _, key := range keys {
|
|
|
+ if !legalKey(key) {
|
|
|
+ return nil, ErrMalformedKey
|
|
|
+ }
|
|
|
+ addr, err := c.selector.PickServer(key)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ keyMap[addr] = append(keyMap[addr], key)
|
|
|
+ }
|
|
|
+
|
|
|
+ ch := make(chan error, buffered)
|
|
|
+ for addr, keys := range keyMap {
|
|
|
+ go func(addr net.Addr, keys []string) {
|
|
|
+ ch <- c.getFromAddr(addr, keys, addItemToMap)
|
|
|
+ }(addr, keys)
|
|
|
+ }
|
|
|
+
|
|
|
+ var err error
|
|
|
+ for _ = range keyMap {
|
|
|
+ if ge := <-ch; ge != nil {
|
|
|
+ err = ge
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return m, err
|
|
|
+}
|
|
|
+
|
|
|
+// parseGetResponse reads a GET response from r and calls cb for each
|
|
|
+// read and allocated Item
|
|
|
+func parseGetResponse(r *bufio.Reader, cb func(*Item)) error {
|
|
|
+ for {
|
|
|
+ line, err := r.ReadSlice('\n')
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ if bytes.Equal(line, resultEnd) {
|
|
|
+ return nil
|
|
|
+ }
|
|
|
+ it := new(Item)
|
|
|
+ size, err := scanGetResponseLine(line, it)
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ it.Value, err = ioutil.ReadAll(io.LimitReader(r, int64(size)+2))
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ if !bytes.HasSuffix(it.Value, crlf) {
|
|
|
+ return fmt.Errorf("memcache: corrupt get result read")
|
|
|
+ }
|
|
|
+ it.Value = it.Value[:size]
|
|
|
+ cb(it)
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// scanGetResponseLine populates it and returns the declared size of the item.
|
|
|
+// It does not read the bytes of the item.
|
|
|
+func scanGetResponseLine(line []byte, it *Item) (size int, err error) {
|
|
|
+ pattern := "VALUE %s %d %d %d\r\n"
|
|
|
+ dest := []interface{}{&it.Key, &it.Flags, &size, &it.casid}
|
|
|
+ if bytes.Count(line, space) == 3 {
|
|
|
+ pattern = "VALUE %s %d %d\r\n"
|
|
|
+ dest = dest[:3]
|
|
|
+ }
|
|
|
+ n, err := fmt.Sscanf(string(line), pattern, dest...)
|
|
|
+ if err != nil || n != len(dest) {
|
|
|
+ return -1, fmt.Errorf("memcache: unexpected line in get response: %q", line)
|
|
|
+ }
|
|
|
+ return size, nil
|
|
|
+}
|
|
|
+
|
|
|
+// Set writes the given item, unconditionally.
|
|
|
+func (c *Client) Set(item *Item) error {
|
|
|
+ return c.onItem(item, (*Client).set)
|
|
|
+}
|
|
|
+
|
|
|
+func (c *Client) set(rw *bufio.ReadWriter, item *Item) error {
|
|
|
+ return c.populateOne(rw, "set", item)
|
|
|
+}
|
|
|
+
|
|
|
+// Add writes the given item, if no value already exists for its
|
|
|
+// key. ErrNotStored is returned if that condition is not met.
|
|
|
+func (c *Client) Add(item *Item) error {
|
|
|
+ return c.onItem(item, (*Client).add)
|
|
|
+}
|
|
|
+
|
|
|
+func (c *Client) add(rw *bufio.ReadWriter, item *Item) error {
|
|
|
+ return c.populateOne(rw, "add", item)
|
|
|
+}
|
|
|
+
|
|
|
+// Replace writes the given item, but only if the server *does*
|
|
|
+// already hold data for this key
|
|
|
+func (c *Client) Replace(item *Item) error {
|
|
|
+ return c.onItem(item, (*Client).replace)
|
|
|
+}
|
|
|
+
|
|
|
+func (c *Client) replace(rw *bufio.ReadWriter, item *Item) error {
|
|
|
+ return c.populateOne(rw, "replace", item)
|
|
|
+}
|
|
|
+
|
|
|
+// CompareAndSwap writes the given item that was previously returned
|
|
|
+// by Get, if the value was neither modified or evicted between the
|
|
|
+// Get and the CompareAndSwap calls. The item's Key should not change
|
|
|
+// between calls but all other item fields may differ. ErrCASConflict
|
|
|
+// is returned if the value was modified in between the
|
|
|
+// calls. ErrNotStored is returned if the value was evicted in between
|
|
|
+// the calls.
|
|
|
+func (c *Client) CompareAndSwap(item *Item) error {
|
|
|
+ return c.onItem(item, (*Client).cas)
|
|
|
+}
|
|
|
+
|
|
|
+func (c *Client) cas(rw *bufio.ReadWriter, item *Item) error {
|
|
|
+ return c.populateOne(rw, "cas", item)
|
|
|
+}
|
|
|
+
|
|
|
+func (c *Client) populateOne(rw *bufio.ReadWriter, verb string, item *Item) error {
|
|
|
+ if !legalKey(item.Key) {
|
|
|
+ return ErrMalformedKey
|
|
|
+ }
|
|
|
+ var err error
|
|
|
+ if verb == "cas" {
|
|
|
+ _, err = fmt.Fprintf(rw, "%s %s %d %d %d %d\r\n",
|
|
|
+ verb, item.Key, item.Flags, item.Expiration, len(item.Value), item.casid)
|
|
|
+ } else {
|
|
|
+ _, err = fmt.Fprintf(rw, "%s %s %d %d %d\r\n",
|
|
|
+ verb, item.Key, item.Flags, item.Expiration, len(item.Value))
|
|
|
+ }
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ if _, err = rw.Write(item.Value); err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ if _, err := rw.Write(crlf); err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ if err := rw.Flush(); err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ line, err := rw.ReadSlice('\n')
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ switch {
|
|
|
+ case bytes.Equal(line, resultStored):
|
|
|
+ return nil
|
|
|
+ case bytes.Equal(line, resultNotStored):
|
|
|
+ return ErrNotStored
|
|
|
+ case bytes.Equal(line, resultExists):
|
|
|
+ return ErrCASConflict
|
|
|
+ case bytes.Equal(line, resultNotFound):
|
|
|
+ return ErrCacheMiss
|
|
|
+ }
|
|
|
+ return fmt.Errorf("memcache: unexpected response line from %q: %q", verb, string(line))
|
|
|
+}
|
|
|
+
|
|
|
+func writeReadLine(rw *bufio.ReadWriter, format string, args ...interface{}) ([]byte, error) {
|
|
|
+ _, err := fmt.Fprintf(rw, format, args...)
|
|
|
+ if err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ if err := rw.Flush(); err != nil {
|
|
|
+ return nil, err
|
|
|
+ }
|
|
|
+ line, err := rw.ReadSlice('\n')
|
|
|
+ return line, err
|
|
|
+}
|
|
|
+
|
|
|
+func writeExpectf(rw *bufio.ReadWriter, expect []byte, format string, args ...interface{}) error {
|
|
|
+ line, err := writeReadLine(rw, format, args...)
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ switch {
|
|
|
+ case bytes.Equal(line, resultOK):
|
|
|
+ return nil
|
|
|
+ case bytes.Equal(line, expect):
|
|
|
+ return nil
|
|
|
+ case bytes.Equal(line, resultNotStored):
|
|
|
+ return ErrNotStored
|
|
|
+ case bytes.Equal(line, resultExists):
|
|
|
+ return ErrCASConflict
|
|
|
+ case bytes.Equal(line, resultNotFound):
|
|
|
+ return ErrCacheMiss
|
|
|
+ }
|
|
|
+ return fmt.Errorf("memcache: unexpected response line: %q", string(line))
|
|
|
+}
|
|
|
+
|
|
|
+// Delete deletes the item with the provided key. The error ErrCacheMiss is
|
|
|
+// returned if the item didn't already exist in the cache.
|
|
|
+func (c *Client) Delete(key string) error {
|
|
|
+ return c.withKeyRw(key, func(rw *bufio.ReadWriter) error {
|
|
|
+ return writeExpectf(rw, resultDeleted, "delete %s\r\n", key)
|
|
|
+ })
|
|
|
+}
|
|
|
+
|
|
|
+// DeleteAll deletes all items in the cache.
|
|
|
+func (c *Client) DeleteAll() error {
|
|
|
+ return c.withKeyRw("", func(rw *bufio.ReadWriter) error {
|
|
|
+ return writeExpectf(rw, resultDeleted, "flush_all\r\n")
|
|
|
+ })
|
|
|
+}
|
|
|
+
|
|
|
+// Increment atomically increments key by delta. The return value is
|
|
|
+// the new value after being incremented or an error. If the value
|
|
|
+// didn't exist in memcached the error is ErrCacheMiss. The value in
|
|
|
+// memcached must be an decimal number, or an error will be returned.
|
|
|
+// On 64-bit overflow, the new value wraps around.
|
|
|
+func (c *Client) Increment(key string, delta uint64) (newValue uint64, err error) {
|
|
|
+ return c.incrDecr("incr", key, delta)
|
|
|
+}
|
|
|
+
|
|
|
+// Decrement atomically decrements key by delta. The return value is
|
|
|
+// the new value after being decremented or an error. If the value
|
|
|
+// didn't exist in memcached the error is ErrCacheMiss. The value in
|
|
|
+// memcached must be an decimal number, or an error will be returned.
|
|
|
+// On underflow, the new value is capped at zero and does not wrap
|
|
|
+// around.
|
|
|
+func (c *Client) Decrement(key string, delta uint64) (newValue uint64, err error) {
|
|
|
+ return c.incrDecr("decr", key, delta)
|
|
|
+}
|
|
|
+
|
|
|
+func (c *Client) incrDecr(verb, key string, delta uint64) (uint64, error) {
|
|
|
+ var val uint64
|
|
|
+ err := c.withKeyRw(key, func(rw *bufio.ReadWriter) error {
|
|
|
+ line, err := writeReadLine(rw, "%s %s %d\r\n", verb, key, delta)
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ switch {
|
|
|
+ case bytes.Equal(line, resultNotFound):
|
|
|
+ return ErrCacheMiss
|
|
|
+ case bytes.HasPrefix(line, resultClientErrorPrefix):
|
|
|
+ errMsg := line[len(resultClientErrorPrefix) : len(line)-2]
|
|
|
+ return errors.New("memcache: client error: " + string(errMsg))
|
|
|
+ }
|
|
|
+ val, err = strconv.ParseUint(string(line[:len(line)-2]), 10, 64)
|
|
|
+ if err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ return nil
|
|
|
+ })
|
|
|
+ return val, err
|
|
|
+}
|