1 files changed, 526 insertions, 0 deletions
diff --git a/vendor/google.golang.org/appengine/memcache/memcache.go b/vendor/google.golang.org/appengine/memcache/memcache.go
new file mode 100644
index 0000000..d8eed4b
--- /dev/null
+++ b/vendor/google.golang.org/appengine/memcache/memcache.go
@@ -0,0 +1,526 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+// Package memcache provides a client for App Engine's distributed in-memory
+// key-value store for small chunks of arbitrary data.
+//
+// The fundamental operations get and set items, keyed by a string.
+//
+//	item0, err := memcache.Get(c, "key")
+//	if err != nil && err != memcache.ErrCacheMiss {
+//		return err
+//	}
+//	if err == nil {
+//		fmt.Fprintf(w, "memcache hit: Key=%q Val=[% x]\n", item0.Key, item0.Value)
+//	} else {
+//		fmt.Fprintf(w, "memcache miss\n")
+//	}
+//
+// and
+//
+//	item1 := &memcache.Item{
+//		Key:   "foo",
+//		Value: []byte("bar"),
+//	}
+//	if err := memcache.Set(c, item1); err != nil {
+//		return err
+//	}
+package memcache // import "google.golang.org/appengine/memcache"
+
+import (
+	"bytes"
+	"encoding/gob"
+	"encoding/json"
+	"errors"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	"golang.org/x/net/context"
+
+	"google.golang.org/appengine"
+	"google.golang.org/appengine/internal"
+	pb "google.golang.org/appengine/internal/memcache"
+)
+
+var (
+	// ErrCacheMiss means that an operation 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")
+	// ErrNoStats means that no statistics were available.
+	ErrNoStats = errors.New("memcache: no statistics available")
+	// 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")
+	// ErrServerError means that a server error occurred.
+	ErrServerError = errors.New("memcache: server error")
+)
+
+// Item is the unit of memcache gets and sets.
+type Item struct {
+	// Key is the Item's key (250 bytes maximum).
+	Key string
+	// Value is the Item's value.
+	Value []byte
+	// Object is the Item's value for use with a Codec.
+	Object interface{}
+	// Flags are server-opaque flags whose semantics are entirely up to the
+	// App Engine app.
+	Flags uint32
+	// Expiration is the maximum duration that the item will stay
+	// in the cache.
+	// The zero value means the Item has no expiration time.
+	// Subsecond precision is ignored.
+	// This is not set when getting items.
+	Expiration time.Duration
+	// casID is a client-opaque value used for compare-and-swap operations.
+	// Zero means that compare-and-swap is not used.
+	casID uint64
+}
+
+const (
+	secondsIn30Years = 60 * 60 * 24 * 365 * 30 // from memcache server code
+	thirtyYears      = time.Duration(secondsIn30Years) * time.Second
+)
+
+// protoToItem converts a protocol buffer item to a Go struct.
+func protoToItem(p *pb.MemcacheGetResponse_Item) *Item {
+	return &Item{
+		Key:   string(p.Key),
+		Value: p.Value,
+		Flags: p.GetFlags(),
+		casID: p.GetCasId(),
+	}
+}
+
+// If err is an appengine.MultiError, return its first element. Otherwise, return err.
+func singleError(err error) error {
+	if me, ok := err.(appengine.MultiError); ok {
+		return me[0]
+	}
+	return err
+}
+
+// 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 Get(c context.Context, key string) (*Item, error) {
+	m, err := GetMulti(c, []string{key})
+	if err != nil {
+		return nil, err
+	}
+	if _, ok := m[key]; !ok {
+		return nil, ErrCacheMiss
+	}
+	return m[key], 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.
+func GetMulti(c context.Context, key []string) (map[string]*Item, error) {
+	if len(key) == 0 {
+		return nil, nil
+	}
+	keyAsBytes := make([][]byte, len(key))
+	for i, k := range key {
+		keyAsBytes[i] = []byte(k)
+	}
+	req := &pb.MemcacheGetRequest{
+		Key:    keyAsBytes,
+		ForCas: proto.Bool(true),
+	}
+	res := &pb.MemcacheGetResponse{}
+	if err := internal.Call(c, "memcache", "Get", req, res); err != nil {
+		return nil, err
+	}
+	m := make(map[string]*Item, len(res.Item))
+	for _, p := range res.Item {
+		t := protoToItem(p)
+		m[t.Key] = t
+	}
+	return m, nil
+}
+
+// Delete deletes the item for the given key.
+// ErrCacheMiss is returned if the specified item can not be found.
+// The key must be at most 250 bytes in length.
+func Delete(c context.Context, key string) error {
+	return singleError(DeleteMulti(c, []string{key}))
+}
+
+// DeleteMulti is a batch version of Delete.
+// If any keys cannot be found, an appengine.MultiError is returned.
+// Each key must be at most 250 bytes in length.
+func DeleteMulti(c context.Context, key []string) error {
+	if len(key) == 0 {
+		return nil
+	}
+	req := &pb.MemcacheDeleteRequest{
+		Item: make([]*pb.MemcacheDeleteRequest_Item, len(key)),
+	}
+	for i, k := range key {
+		req.Item[i] = &pb.MemcacheDeleteRequest_Item{Key: []byte(k)}
+	}
+	res := &pb.MemcacheDeleteResponse{}
+	if err := internal.Call(c, "memcache", "Delete", req, res); err != nil {
+		return err
+	}
+	if len(res.DeleteStatus) != len(key) {
+		return ErrServerError
+	}
+	me, any := make(appengine.MultiError, len(key)), false
+	for i, s := range res.DeleteStatus {
+		switch s {
+		case pb.MemcacheDeleteResponse_DELETED:
+			// OK
+		case pb.MemcacheDeleteResponse_NOT_FOUND:
+			me[i] = ErrCacheMiss
+			any = true
+		default:
+			me[i] = ErrServerError
+			any = true
+		}
+	}
+	if any {
+		return me
+	}
+	return nil
+}
+
+// Increment atomically increments the decimal value in the given key
+// by delta and returns the new value. The value must fit in a uint64.
+// Overflow wraps around, and underflow is capped to zero. The
+// provided delta may be negative. If the key doesn't exist in
+// memcache, the provided initial value is used to atomically
+// populate it before the delta is applied.
+// The key must be at most 250 bytes in length.
+func Increment(c context.Context, key string, delta int64, initialValue uint64) (newValue uint64, err error) {
+	return incr(c, key, delta, &initialValue)
+}
+
+// IncrementExisting works like Increment but assumes that the key
+// already exists in memcache and doesn't take an initial value.
+// IncrementExisting can save work if calculating the initial value is
+// expensive.
+// An error is returned if the specified item can not be found.
+func IncrementExisting(c context.Context, key string, delta int64) (newValue uint64, err error) {
+	return incr(c, key, delta, nil)
+}
+
+func incr(c context.Context, key string, delta int64, initialValue *uint64) (newValue uint64, err error) {
+	req := &pb.MemcacheIncrementRequest{
+		Key:          []byte(key),
+		InitialValue: initialValue,
+	}
+	if delta >= 0 {
+		req.Delta = proto.Uint64(uint64(delta))
+	} else {
+		req.Delta = proto.Uint64(uint64(-delta))
+		req.Direction = pb.MemcacheIncrementRequest_DECREMENT.Enum()
+	}
+	res := &pb.MemcacheIncrementResponse{}
+	err = internal.Call(c, "memcache", "Increment", req, res)
+	if err != nil {
+		return
+	}
+	if res.NewValue == nil {
+		return 0, ErrCacheMiss
+	}
+	return *res.NewValue, nil
+}
+
+// set sets the given items using the given conflict resolution policy.
+// appengine.MultiError may be returned.
+func set(c context.Context, item []*Item, value [][]byte, policy pb.MemcacheSetRequest_SetPolicy) error {
+	if len(item) == 0 {
+		return nil
+	}
+	req := &pb.MemcacheSetRequest{
+		Item: make([]*pb.MemcacheSetRequest_Item, len(item)),
+	}
+	for i, t := range item {
+		p := &pb.MemcacheSetRequest_Item{
+			Key: []byte(t.Key),
+		}
+		if value == nil {
+			p.Value = t.Value
+		} else {
+			p.Value = value[i]
+		}
+		if t.Flags != 0 {
+			p.Flags = proto.Uint32(t.Flags)
+		}
+		if t.Expiration != 0 {
+			// In the .proto file, MemcacheSetRequest_Item uses a fixed32 (i.e. unsigned)
+			// for expiration time, while MemcacheGetRequest_Item uses int32 (i.e. signed).
+			// Throughout this .go file, we use int32.
+			// Also, in the proto, the expiration value is either a duration (in seconds)
+			// or an absolute Unix timestamp (in seconds), depending on whether the
+			// value is less than or greater than or equal to 30 years, respectively.
+			if t.Expiration < time.Second {
+				// Because an Expiration of 0 means no expiration, we take
+				// care here to translate an item with an expiration
+				// Duration between 0-1 seconds as immediately expiring
+				// (saying it expired a few seconds ago), rather than
+				// rounding it down to 0 and making it live forever.
+				p.ExpirationTime = proto.Uint32(uint32(time.Now().Unix()) - 5)
+			} else if t.Expiration >= thirtyYears {
+				p.ExpirationTime = proto.Uint32(uint32(time.Now().Unix()) + uint32(t.Expiration/time.Second))
+			} else {
+				p.ExpirationTime = proto.Uint32(uint32(t.Expiration / time.Second))
+			}
+		}
+		if t.casID != 0 {
+			p.CasId = proto.Uint64(t.casID)
+			p.ForCas = proto.Bool(true)
+		}
+		p.SetPolicy = policy.Enum()
+		req.Item[i] = p
+	}
+	res := &pb.MemcacheSetResponse{}
+	if err := internal.Call(c, "memcache", "Set", req, res); err != nil {
+		return err
+	}
+	if len(res.SetStatus) != len(item) {
+		return ErrServerError
+	}
+	me, any := make(appengine.MultiError, len(item)), false
+	for i, st := range res.SetStatus {
+		var err error
+		switch st {
+		case pb.MemcacheSetResponse_STORED:
+			// OK
+		case pb.MemcacheSetResponse_NOT_STORED:
+			err = ErrNotStored
+		case pb.MemcacheSetResponse_EXISTS:
+			err = ErrCASConflict
+		default:
+			err = ErrServerError
+		}
+		if err != nil {
+			me[i] = err
+			any = true
+		}
+	}
+	if any {
+		return me
+	}
+	return nil
+}
+
+// Set writes the given item, unconditionally.
+func Set(c context.Context, item *Item) error {
+	return singleError(set(c, []*Item{item}, nil, pb.MemcacheSetRequest_SET))
+}
+
+// SetMulti is a batch version of Set.
+// appengine.MultiError may be returned.
+func SetMulti(c context.Context, item []*Item) error {
+	return set(c, item, nil, pb.MemcacheSetRequest_SET)
+}
+
+// Add writes the given item, if no value already exists for its key.
+// ErrNotStored is returned if that condition is not met.
+func Add(c context.Context, item *Item) error {
+	return singleError(set(c, []*Item{item}, nil, pb.MemcacheSetRequest_ADD))
+}
+
+// AddMulti is a batch version of Add.
+// appengine.MultiError may be returned.
+func AddMulti(c context.Context, item []*Item) error {
+	return set(c, item, nil, pb.MemcacheSetRequest_ADD)
+}
+
+// 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 CompareAndSwap(c context.Context, item *Item) error {
+	return singleError(set(c, []*Item{item}, nil, pb.MemcacheSetRequest_CAS))
+}
+
+// CompareAndSwapMulti is a batch version of CompareAndSwap.
+// appengine.MultiError may be returned.
+func CompareAndSwapMulti(c context.Context, item []*Item) error {
+	return set(c, item, nil, pb.MemcacheSetRequest_CAS)
+}
+
+// Codec represents a symmetric pair of functions that implement a codec.
+// Items stored into or retrieved from memcache using a Codec have their
+// values marshaled or unmarshaled.
+//
+// All the methods provided for Codec behave analogously to the package level
+// function with same name.
+type Codec struct {
+	Marshal   func(interface{}) ([]byte, error)
+	Unmarshal func([]byte, interface{}) error
+}
+
+// Get gets the item for the given key and decodes the obtained value into v.
+// ErrCacheMiss is returned for a memcache cache miss.
+// The key must be at most 250 bytes in length.
+func (cd Codec) Get(c context.Context, key string, v interface{}) (*Item, error) {
+	i, err := Get(c, key)
+	if err != nil {
+		return nil, err
+	}
+	if err := cd.Unmarshal(i.Value, v); err != nil {
+		return nil, err
+	}
+	return i, nil
+}
+
+func (cd Codec) set(c context.Context, items []*Item, policy pb.MemcacheSetRequest_SetPolicy) error {
+	var vs [][]byte
+	var me appengine.MultiError
+	for i, item := range items {
+		v, err := cd.Marshal(item.Object)
+		if err != nil {
+			if me == nil {
+				me = make(appengine.MultiError, len(items))
+			}
+			me[i] = err
+			continue
+		}
+		if me == nil {
+			vs = append(vs, v)
+		}
+	}
+	if me != nil {
+		return me
+	}
+
+	return set(c, items, vs, policy)
+}
+
+// Set writes the given item, unconditionally.
+func (cd Codec) Set(c context.Context, item *Item) error {
+	return singleError(cd.set(c, []*Item{item}, pb.MemcacheSetRequest_SET))
+}
+
+// SetMulti is a batch version of Set.
+// appengine.MultiError may be returned.
+func (cd Codec) SetMulti(c context.Context, items []*Item) error {
+	return cd.set(c, items, pb.MemcacheSetRequest_SET)
+}
+
+// Add writes the given item, if no value already exists for its key.
+// ErrNotStored is returned if that condition is not met.
+func (cd Codec) Add(c context.Context, item *Item) error {
+	return singleError(cd.set(c, []*Item{item}, pb.MemcacheSetRequest_ADD))
+}
+
+// AddMulti is a batch version of Add.
+// appengine.MultiError may be returned.
+func (cd Codec) AddMulti(c context.Context, items []*Item) error {
+	return cd.set(c, items, pb.MemcacheSetRequest_ADD)
+}
+
+// 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 (cd Codec) CompareAndSwap(c context.Context, item *Item) error {
+	return singleError(cd.set(c, []*Item{item}, pb.MemcacheSetRequest_CAS))
+}
+
+// CompareAndSwapMulti is a batch version of CompareAndSwap.
+// appengine.MultiError may be returned.
+func (cd Codec) CompareAndSwapMulti(c context.Context, items []*Item) error {
+	return cd.set(c, items, pb.MemcacheSetRequest_CAS)
+}
+
+var (
+	// Gob is a Codec that uses the gob package.
+	Gob = Codec{gobMarshal, gobUnmarshal}
+	// JSON is a Codec that uses the json package.
+	JSON = Codec{json.Marshal, json.Unmarshal}
+)
+
+func gobMarshal(v interface{}) ([]byte, error) {
+	var buf bytes.Buffer
+	if err := gob.NewEncoder(&buf).Encode(v); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+func gobUnmarshal(data []byte, v interface{}) error {
+	return gob.NewDecoder(bytes.NewBuffer(data)).Decode(v)
+}
+
+// Statistics represents a set of statistics about the memcache cache.
+// This may include items that have expired but have not yet been removed from the cache.
+type Statistics struct {
+	Hits     uint64 // Counter of cache hits
+	Misses   uint64 // Counter of cache misses
+	ByteHits uint64 // Counter of bytes transferred for gets
+
+	Items uint64 // Items currently in the cache
+	Bytes uint64 // Size of all items currently in the cache
+
+	Oldest int64 // Age of access of the oldest item, in seconds
+}
+
+// Stats retrieves the current memcache statistics.
+func Stats(c context.Context) (*Statistics, error) {
+	req := &pb.MemcacheStatsRequest{}
+	res := &pb.MemcacheStatsResponse{}
+	if err := internal.Call(c, "memcache", "Stats", req, res); err != nil {
+		return nil, err
+	}
+	if res.Stats == nil {
+		return nil, ErrNoStats
+	}
+	return &Statistics{
+		Hits:     *res.Stats.Hits,
+		Misses:   *res.Stats.Misses,
+		ByteHits: *res.Stats.ByteHits,
+		Items:    *res.Stats.Items,
+		Bytes:    *res.Stats.Bytes,
+		Oldest:   int64(*res.Stats.OldestItemAge),
+	}, nil
+}
+
+// Flush flushes all items from memcache.
+func Flush(c context.Context) error {
+	req := &pb.MemcacheFlushRequest{}
+	res := &pb.MemcacheFlushResponse{}
+	return internal.Call(c, "memcache", "FlushAll", req, res)
+}
+
+func namespaceMod(m proto.Message, namespace string) {
+	switch m := m.(type) {
+	case *pb.MemcacheDeleteRequest:
+		if m.NameSpace == nil {
+			m.NameSpace = &namespace
+		}
+	case *pb.MemcacheGetRequest:
+		if m.NameSpace == nil {
+			m.NameSpace = &namespace
+		}
+	case *pb.MemcacheIncrementRequest:
+		if m.NameSpace == nil {
+			m.NameSpace = &namespace
+		}
+	case *pb.MemcacheSetRequest:
+		if m.NameSpace == nil {
+			m.NameSpace = &namespace
+		}
+		// MemcacheFlushRequest, MemcacheStatsRequest do not apply namespace.
+	}
+}
+
+func init() {
+	internal.RegisterErrorCodeMap("memcache", pb.MemcacheServiceError_ErrorCode_name)
+	internal.NamespaceMods["memcache"] = namespaceMod
+}