unique_ids.go

// Copyright (c) 2017 Uber Technologies, 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 dbmodel

// UniqueTraceIDs is a set of unique dbmodel TraceIDs, implemented via map.
type UniqueTraceIDs map[TraceID]struct{}

// UniqueTraceIDsFromList Takes a list of traceIDs and returns the unique set
func UniqueTraceIDsFromList(traceIDs []TraceID) UniqueTraceIDs {
	uniqueTraceIDs := UniqueTraceIDs{}
	for _, traceID := range traceIDs {
		uniqueTraceIDs[traceID] = struct{}{}
	}
	return uniqueTraceIDs
}

// Add adds a traceID to the existing map
func (u UniqueTraceIDs) Add(traceID TraceID) {
	u[traceID] = struct{}{}
}

// IntersectTraceIDs takes a list of UniqueTraceIDs and intersects them.
func IntersectTraceIDs(uniqueTraceIdsList []UniqueTraceIDs) UniqueTraceIDs {
	retMe := UniqueTraceIDs{}
	for key, value := range uniqueTraceIdsList[0] {
		keyExistsInAll := true
		for _, otherTraceIds := range uniqueTraceIdsList[1:] {
			if _, ok := otherTraceIds[key]; !ok {
				keyExistsInAll = false
				break
			}
		}
		if keyExistsInAll {
			retMe[key] = value
		}
	}
	return retMe
}