diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/resolver/map.go')
| -rw-r--r-- | vendor/google.golang.org/grpc/resolver/map.go | 138 | 
1 files changed, 138 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/resolver/map.go b/vendor/google.golang.org/grpc/resolver/map.go new file mode 100644 index 0000000..efcb7f3 --- /dev/null +++ b/vendor/google.golang.org/grpc/resolver/map.go @@ -0,0 +1,138 @@ +/* + * + * 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 interface{} +} + +// 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 interface{}, 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 interface{}) { +	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() []interface{} { +	ret := make([]interface{}, 0, a.Len()) +	for _, entryList := range a.m { +		for _, entry := range entryList { +			ret = append(ret, entry.value) +		} +	} +	return ret +}  | 
