cloudflared-mirror/vendor/google.golang.org/grpc/resolver/map.go

252 lines
7.1 KiB
Go

/*
*
* Copyright 2021 gRPC authors.
*
* 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 resolver
type addressMapEntry struct {
addr Address
value any
}
// AddressMap is a map of addresses to arbitrary values taking into account
// Attributes. BalancerAttributes are ignored, as are Metadata and Type.
// Multiple accesses may not be performed concurrently. Must be created via
// NewAddressMap; do not construct directly.
type AddressMap struct {
// The underlying map is keyed by an Address with fields that we don't care
// about being set to their zero values. The only fields that we care about
// are `Addr`, `ServerName` and `Attributes`. Since we need to be able to
// distinguish between addresses with same `Addr` and `ServerName`, but
// different `Attributes`, we cannot store the `Attributes` in the map key.
//
// The comparison operation for structs work as follows:
// Struct values are comparable if all their fields are comparable. Two
// struct values are equal if their corresponding non-blank fields are equal.
//
// The value type of the map contains a slice of addresses which match the key
// in their `Addr` and `ServerName` fields and contain the corresponding value
// associated with them.
m map[Address]addressMapEntryList
}
func toMapKey(addr *Address) Address {
return Address{Addr: addr.Addr, ServerName: addr.ServerName}
}
type addressMapEntryList []*addressMapEntry
// NewAddressMap creates a new AddressMap.
func NewAddressMap() *AddressMap {
return &AddressMap{m: make(map[Address]addressMapEntryList)}
}
// find returns the index of addr in the addressMapEntry slice, or -1 if not
// present.
func (l addressMapEntryList) find(addr Address) int {
for i, entry := range l {
// Attributes are the only thing to match on here, since `Addr` and
// `ServerName` are already equal.
if entry.addr.Attributes.Equal(addr.Attributes) {
return i
}
}
return -1
}
// Get returns the value for the address in the map, if present.
func (a *AddressMap) Get(addr Address) (value any, ok bool) {
addrKey := toMapKey(&addr)
entryList := a.m[addrKey]
if entry := entryList.find(addr); entry != -1 {
return entryList[entry].value, true
}
return nil, false
}
// Set updates or adds the value to the address in the map.
func (a *AddressMap) Set(addr Address, value any) {
addrKey := toMapKey(&addr)
entryList := a.m[addrKey]
if entry := entryList.find(addr); entry != -1 {
entryList[entry].value = value
return
}
a.m[addrKey] = append(entryList, &addressMapEntry{addr: addr, value: value})
}
// Delete removes addr from the map.
func (a *AddressMap) Delete(addr Address) {
addrKey := toMapKey(&addr)
entryList := a.m[addrKey]
entry := entryList.find(addr)
if entry == -1 {
return
}
if len(entryList) == 1 {
entryList = nil
} else {
copy(entryList[entry:], entryList[entry+1:])
entryList = entryList[:len(entryList)-1]
}
a.m[addrKey] = entryList
}
// Len returns the number of entries in the map.
func (a *AddressMap) Len() int {
ret := 0
for _, entryList := range a.m {
ret += len(entryList)
}
return ret
}
// Keys returns a slice of all current map keys.
func (a *AddressMap) Keys() []Address {
ret := make([]Address, 0, a.Len())
for _, entryList := range a.m {
for _, entry := range entryList {
ret = append(ret, entry.addr)
}
}
return ret
}
// Values returns a slice of all current map values.
func (a *AddressMap) Values() []any {
ret := make([]any, 0, a.Len())
for _, entryList := range a.m {
for _, entry := range entryList {
ret = append(ret, entry.value)
}
}
return ret
}
type endpointNode struct {
addrs map[string]struct{}
}
// Equal returns whether the unordered set of addrs are the same between the
// endpoint nodes.
func (en *endpointNode) Equal(en2 *endpointNode) bool {
if len(en.addrs) != len(en2.addrs) {
return false
}
for addr := range en.addrs {
if _, ok := en2.addrs[addr]; !ok {
return false
}
}
return true
}
func toEndpointNode(endpoint Endpoint) endpointNode {
en := make(map[string]struct{})
for _, addr := range endpoint.Addresses {
en[addr.Addr] = struct{}{}
}
return endpointNode{
addrs: en,
}
}
// EndpointMap is a map of endpoints to arbitrary values keyed on only the
// unordered set of address strings within an endpoint. This map is not thread
// safe, thus it is unsafe to access concurrently. Must be created via
// NewEndpointMap; do not construct directly.
type EndpointMap struct {
endpoints map[*endpointNode]any
}
// NewEndpointMap creates a new EndpointMap.
func NewEndpointMap() *EndpointMap {
return &EndpointMap{
endpoints: make(map[*endpointNode]any),
}
}
// Get returns the value for the address in the map, if present.
func (em *EndpointMap) Get(e Endpoint) (value any, ok bool) {
en := toEndpointNode(e)
if endpoint := em.find(en); endpoint != nil {
return em.endpoints[endpoint], true
}
return nil, false
}
// Set updates or adds the value to the address in the map.
func (em *EndpointMap) Set(e Endpoint, value any) {
en := toEndpointNode(e)
if endpoint := em.find(en); endpoint != nil {
em.endpoints[endpoint] = value
return
}
em.endpoints[&en] = value
}
// Len returns the number of entries in the map.
func (em *EndpointMap) Len() int {
return len(em.endpoints)
}
// Keys returns a slice of all current map keys, as endpoints specifying the
// addresses present in the endpoint keys, in which uniqueness is determined by
// the unordered set of addresses. Thus, endpoint information returned is not
// the full endpoint data (drops duplicated addresses and attributes) but can be
// used for EndpointMap accesses.
func (em *EndpointMap) Keys() []Endpoint {
ret := make([]Endpoint, 0, len(em.endpoints))
for en := range em.endpoints {
var endpoint Endpoint
for addr := range en.addrs {
endpoint.Addresses = append(endpoint.Addresses, Address{Addr: addr})
}
ret = append(ret, endpoint)
}
return ret
}
// Values returns a slice of all current map values.
func (em *EndpointMap) Values() []any {
ret := make([]any, 0, len(em.endpoints))
for _, val := range em.endpoints {
ret = append(ret, val)
}
return ret
}
// find returns a pointer to the endpoint node in em if the endpoint node is
// already present. If not found, nil is returned. The comparisons are done on
// the unordered set of addresses within an endpoint.
func (em EndpointMap) find(e endpointNode) *endpointNode {
for endpoint := range em.endpoints {
if e.Equal(endpoint) {
return endpoint
}
}
return nil
}
// Delete removes the specified endpoint from the map.
func (em *EndpointMap) Delete(e Endpoint) {
en := toEndpointNode(e)
if entry := em.find(en); entry != nil {
delete(em.endpoints, entry)
}
}