github.com/hasnat/dolt/go@v0.0.0-20210628190320-9eb5d843fbb7/libraries/utils/pipeline/local_storage.go (about) 1 // Copyright 2020 Dolthub, Inc. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package pipeline 16 17 import "context" 18 19 const localStorageKey = "ls" 20 21 // TODO: get rid of this 22 // LocalStorage provides routine local storage on go routines spawned by a pipeline 23 type LocalStorage map[int]interface{} 24 25 // Get retrieves an item from localStorage 26 func (ls LocalStorage) Get(id int) (interface{}, bool) { 27 val, ok := ls[id] 28 return val, ok 29 } 30 31 // Put stores an item in local storage 32 func (ls LocalStorage) Put(id int, val interface{}) { 33 ls[id] = val 34 } 35 36 // GetLocalStorage retrieves the LocalStorage from the context. This only works if the context was generated 37 // by the pipeline package when starting the pipeline 38 func GetLocalStorage(ctx context.Context) LocalStorage { 39 val := ctx.Value(localStorageKey) 40 41 if val == nil { 42 panic("This isn't the context for a pipeline spawned go routine, or the LocalStorage was deleted") 43 } 44 45 if ls, ok := val.(LocalStorage); !ok { 46 panic("This isn't the context for a pipeline spawned go routine, or the LocalStorage was deleted") 47 } else { 48 return ls 49 } 50 }