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authorUnknwon <u@gogs.io>2017-02-09 19:48:13 -0500
committerUnknwon <u@gogs.io>2017-02-09 19:48:13 -0500
commit2fd69f13d9599a6c58b47225565163fd7d87889f (patch)
treefd19e868e1c2e95a5fb83a268f6e393669d6ee79 /vendor/github.com/bradfitz/gomemcache/memcache/memcache.go
parenteb66060cd7b9bce996b1d75ae80ce1ef31d5ce62 (diff)
vendor: check in vendors
Bye bye glide...
Diffstat (limited to 'vendor/github.com/bradfitz/gomemcache/memcache/memcache.go')
-rw-r--r--vendor/github.com/bradfitz/gomemcache/memcache/memcache.go666
1 files changed, 666 insertions, 0 deletions
diff --git a/vendor/github.com/bradfitz/gomemcache/memcache/memcache.go b/vendor/github.com/bradfitz/gomemcache/memcache/memcache.go
new file mode 100644
index 00000000..7b5442d7
--- /dev/null
+++ b/vendor/github.com/bradfitz/gomemcache/memcache/memcache.go
@@ -0,0 +1,666 @@
+/*
+Copyright 2011 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package memcache provides a client for the memcached cache server.
+package memcache
+
+import (
+ "bufio"
+ "bytes"
+ "errors"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "net"
+
+ "strconv"
+ "strings"
+ "sync"
+ "time"
+)
+
+// Similar to:
+// http://code.google.com/appengine/docs/go/memcache/reference.html
+
+var (
+ // ErrCacheMiss means that a Get failed because the item wasn't present.
+ ErrCacheMiss = errors.New("memcache: cache miss")
+
+ // ErrCASConflict means that a CompareAndSwap call failed due to the
+ // cached value being modified between the Get and the CompareAndSwap.
+ // If the cached value was simply evicted rather than replaced,
+ // ErrNotStored will be returned instead.
+ ErrCASConflict = errors.New("memcache: compare-and-swap conflict")
+
+ // ErrNotStored means that a conditional write operation (i.e. Add or
+ // CompareAndSwap) failed because the condition was not satisfied.
+ ErrNotStored = errors.New("memcache: item not stored")
+
+ // ErrServer means that a server error occurred.
+ ErrServerError = errors.New("memcache: server error")
+
+ // ErrNoStats means that no statistics were available.
+ ErrNoStats = errors.New("memcache: no statistics available")
+
+ // ErrMalformedKey is returned when an invalid key is used.
+ // Keys must be at maximum 250 bytes long, ASCII, and not
+ // contain whitespace or control characters.
+ ErrMalformedKey = errors.New("malformed: key is too long or contains invalid characters")
+
+ // ErrNoServers is returned when no servers are configured or available.
+ ErrNoServers = errors.New("memcache: no servers configured or available")
+)
+
+// DefaultTimeout is the default socket read/write timeout.
+const DefaultTimeout = 100 * time.Millisecond
+
+const (
+ buffered = 8 // arbitrary buffered channel size, for readability
+ maxIdleConnsPerAddr = 2 // TODO(bradfitz): make this configurable?
+)
+
+// resumableError returns true if err is only a protocol-level cache error.
+// This is used to determine whether or not a server connection should
+// be re-used or not. If an error occurs, by default we don't reuse the
+// connection, unless it was just a cache error.
+func resumableError(err error) bool {
+ switch err {
+ case ErrCacheMiss, ErrCASConflict, ErrNotStored, ErrMalformedKey:
+ return true
+ }
+ return false
+}
+
+func legalKey(key string) bool {
+ if len(key) > 250 {
+ return false
+ }
+ for i := 0; i < len(key); i++ {
+ if key[i] <= ' ' || key[i] > 0x7e {
+ return false
+ }
+ }
+ return true
+}
+
+var (
+ crlf = []byte("\r\n")
+ space = []byte(" ")
+ resultOK = []byte("OK\r\n")
+ resultStored = []byte("STORED\r\n")
+ resultNotStored = []byte("NOT_STORED\r\n")
+ resultExists = []byte("EXISTS\r\n")
+ resultNotFound = []byte("NOT_FOUND\r\n")
+ resultDeleted = []byte("DELETED\r\n")
+ resultEnd = []byte("END\r\n")
+ resultOk = []byte("OK\r\n")
+ resultTouched = []byte("TOUCHED\r\n")
+
+ resultClientErrorPrefix = []byte("CLIENT_ERROR ")
+)
+
+// New returns a memcache client using the provided server(s)
+// with equal weight. If a server is listed multiple times,
+// it gets a proportional amount of weight.
+func New(server ...string) *Client {
+ ss := new(ServerList)
+ ss.SetServers(server...)
+ return NewFromSelector(ss)
+}
+
+// NewFromSelector returns a new Client using the provided ServerSelector.
+func NewFromSelector(ss ServerSelector) *Client {
+ return &Client{selector: ss}
+}
+
+// Client is a memcache client.
+// It is safe for unlocked use by multiple concurrent goroutines.
+type Client struct {
+ // Timeout specifies the socket read/write timeout.
+ // If zero, DefaultTimeout is used.
+ Timeout time.Duration
+
+ selector ServerSelector
+
+ lk sync.Mutex
+ freeconn map[string][]*conn
+}
+
+// Item is an item to be got or stored in a memcached server.
+type Item struct {
+ // Key is the Item's key (250 bytes maximum).
+ Key string
+
+ // Value is the Item's value.
+ Value []byte
+
+ // Flags are server-opaque flags whose semantics are entirely
+ // up to the app.
+ Flags uint32
+
+ // Expiration is the cache expiration time, in seconds: either a relative
+ // time from now (up to 1 month), or an absolute Unix epoch time.
+ // Zero means the Item has no expiration time.
+ Expiration int32
+
+ // Compare and swap ID.
+ casid uint64
+}
+
+// conn is a connection to a server.
+type conn struct {
+ nc net.Conn
+ rw *bufio.ReadWriter
+ addr net.Addr
+ c *Client
+}
+
+// release returns this connection back to the client's free pool
+func (cn *conn) release() {
+ cn.c.putFreeConn(cn.addr, cn)
+}
+
+func (cn *conn) extendDeadline() {
+ cn.nc.SetDeadline(time.Now().Add(cn.c.netTimeout()))
+}
+
+// condRelease releases this connection if the error pointed to by err
+// is nil (not an error) or is only a protocol level error (e.g. a
+// cache miss). The purpose is to not recycle TCP connections that
+// are bad.
+func (cn *conn) condRelease(err *error) {
+ if *err == nil || resumableError(*err) {
+ cn.release()
+ } else {
+ cn.nc.Close()
+ }
+}
+
+func (c *Client) putFreeConn(addr net.Addr, cn *conn) {
+ c.lk.Lock()
+ defer c.lk.Unlock()
+ if c.freeconn == nil {
+ c.freeconn = make(map[string][]*conn)
+ }
+ freelist := c.freeconn[addr.String()]
+ if len(freelist) >= maxIdleConnsPerAddr {
+ cn.nc.Close()
+ return
+ }
+ c.freeconn[addr.String()] = append(freelist, cn)
+}
+
+func (c *Client) getFreeConn(addr net.Addr) (cn *conn, ok bool) {
+ c.lk.Lock()
+ defer c.lk.Unlock()
+ if c.freeconn == nil {
+ return nil, false
+ }
+ freelist, ok := c.freeconn[addr.String()]
+ if !ok || len(freelist) == 0 {
+ return nil, false
+ }
+ cn = freelist[len(freelist)-1]
+ c.freeconn[addr.String()] = freelist[:len(freelist)-1]
+ return cn, true
+}
+
+func (c *Client) netTimeout() time.Duration {
+ if c.Timeout != 0 {
+ return c.Timeout
+ }
+ return DefaultTimeout
+}
+
+// ConnectTimeoutError is the error type used when it takes
+// too long to connect to the desired host. This level of
+// detail can generally be ignored.
+type ConnectTimeoutError struct {
+ Addr net.Addr
+}
+
+func (cte *ConnectTimeoutError) Error() string {
+ return "memcache: connect timeout to " + cte.Addr.String()
+}
+
+func (c *Client) dial(addr net.Addr) (net.Conn, error) {
+ type connError struct {
+ cn net.Conn
+ err error
+ }
+
+ nc, err := net.DialTimeout(addr.Network(), addr.String(), c.netTimeout())
+ if err == nil {
+ return nc, nil
+ }
+
+ if ne, ok := err.(net.Error); ok && ne.Timeout() {
+ return nil, &ConnectTimeoutError{addr}
+ }
+
+ return nil, err
+}
+
+func (c *Client) getConn(addr net.Addr) (*conn, error) {
+ cn, ok := c.getFreeConn(addr)
+ if ok {
+ cn.extendDeadline()
+ return cn, nil
+ }
+ nc, err := c.dial(addr)
+ if err != nil {
+ return nil, err
+ }
+ cn = &conn{
+ nc: nc,
+ addr: addr,
+ rw: bufio.NewReadWriter(bufio.NewReader(nc), bufio.NewWriter(nc)),
+ c: c,
+ }
+ cn.extendDeadline()
+ return cn, nil
+}
+
+func (c *Client) onItem(item *Item, fn func(*Client, *bufio.ReadWriter, *Item) error) error {
+ addr, err := c.selector.PickServer(item.Key)
+ if err != nil {
+ return err
+ }
+ cn, err := c.getConn(addr)
+ if err != nil {
+ return err
+ }
+ defer cn.condRelease(&err)
+ if err = fn(c, cn.rw, item); err != nil {
+ return err
+ }
+ return nil
+}
+
+func (c *Client) FlushAll() error {
+ return c.selector.Each(c.flushAllFromAddr)
+}
+
+// Get gets the item for the given key. ErrCacheMiss is returned for a
+// memcache cache miss. The key must be at most 250 bytes in length.
+func (c *Client) Get(key string) (item *Item, err error) {
+ err = c.withKeyAddr(key, func(addr net.Addr) error {
+ return c.getFromAddr(addr, []string{key}, func(it *Item) { item = it })
+ })
+ if err == nil && item == nil {
+ err = ErrCacheMiss
+ }
+ return
+}
+
+// Touch updates the expiry for the given key. The seconds parameter is either
+// a Unix timestamp or, if seconds is less than 1 month, the number of seconds
+// into the future at which time the item will expire. ErrCacheMiss is returned if the
+// key is not in the cache. The key must be at most 250 bytes in length.
+func (c *Client) Touch(key string, seconds int32) (err error) {
+ return c.withKeyAddr(key, func(addr net.Addr) error {
+ return c.touchFromAddr(addr, []string{key}, seconds)
+ })
+}
+
+func (c *Client) withKeyAddr(key string, fn func(net.Addr) error) (err error) {
+ if !legalKey(key) {
+ return ErrMalformedKey
+ }
+ addr, err := c.selector.PickServer(key)
+ if err != nil {
+ return err
+ }
+ return fn(addr)
+}
+
+func (c *Client) withAddrRw(addr net.Addr, fn func(*bufio.ReadWriter) error) (err error) {
+ cn, err := c.getConn(addr)
+ if err != nil {
+ return err
+ }
+ defer cn.condRelease(&err)
+ return fn(cn.rw)
+}
+
+func (c *Client) withKeyRw(key string, fn func(*bufio.ReadWriter) error) error {
+ return c.withKeyAddr(key, func(addr net.Addr) error {
+ return c.withAddrRw(addr, fn)
+ })
+}
+
+func (c *Client) getFromAddr(addr net.Addr, keys []string, cb func(*Item)) error {
+ return c.withAddrRw(addr, func(rw *bufio.ReadWriter) error {
+ if _, err := fmt.Fprintf(rw, "gets %s\r\n", strings.Join(keys, " ")); err != nil {
+ return err
+ }
+ if err := rw.Flush(); err != nil {
+ return err
+ }
+ if err := parseGetResponse(rw.Reader, cb); err != nil {
+ return err
+ }
+ return nil
+ })
+}
+
+// flushAllFromAddr send the flush_all command to the given addr
+func (c *Client) flushAllFromAddr(addr net.Addr) error {
+ return c.withAddrRw(addr, func(rw *bufio.ReadWriter) error {
+ if _, err := fmt.Fprintf(rw, "flush_all\r\n"); 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, resultOk):
+ break
+ default:
+ return fmt.Errorf("memcache: unexpected response line from flush_all: %q", string(line))
+ }
+ return nil
+ })
+}
+
+func (c *Client) touchFromAddr(addr net.Addr, keys []string, expiration int32) error {
+ return c.withAddrRw(addr, func(rw *bufio.ReadWriter) error {
+ for _, key := range keys {
+ if _, err := fmt.Fprintf(rw, "touch %s %d\r\n", key, expiration); 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, resultTouched):
+ break
+ case bytes.Equal(line, resultNotFound):
+ return ErrCacheMiss
+ default:
+ return fmt.Errorf("memcache: unexpected response line from touch: %q", string(line))
+ }
+ }
+ return nil
+ })
+}
+
+// GetMulti is a batch version of Get. The returned map from keys to
+// items may have fewer elements than the input slice, due to memcache
+// cache misses. Each key must be at most 250 bytes in length.
+// If no error is returned, the returned map will also be non-nil.
+func (c *Client) GetMulti(keys []string) (map[string]*Item, error) {
+ var lk sync.Mutex
+ m := make(map[string]*Item)
+ addItemToMap := func(it *Item) {
+ lk.Lock()
+ defer lk.Unlock()
+ 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
+}