av/stream/mts/meta.go

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/*
NAME
meta.go
DESCRIPTION
See Readme.md
AUTHOR
Saxon Nelson-Milton <saxon@ausocean.org>
LICENSE
meta.go is Copyright (C) 2017-2019 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
under the terms of the GNU General Public License as published by the
Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
It is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with revid in gpl.txt. If not, see http://www.gnu.org/licenses.
*/
package mts
import (
"errors"
"fmt"
"sync"
)
type Meta struct {
mu sync.RWMutex
data map[string]string
}
// Add adds metadata with key and val, if already exists return error
func (m *Meta) Add(key, val string) error {
m.mu.Lock()
if _, exists := m.data[key]; !exists {
return errors.New(fmt.Sprintf("Metadata for: %v already exists", key))
}
m.data[key] = val
m.mu.Unlock()
return nil
}
// All returns the a copy of the map containing the meta data
func (m *Meta) All() map[string]string {
var cpy map[string]string
for k, v := range m.data {
cpy[k] = v
}
return cpy
}
// Get returns the meta data for the passed key
func (m *Meta) Get(key string) (string, error) {
val, ok := m.data[key]
if !ok {
return "", errors.New("Key does not exist in metadata map")
}
return val, nil
}
// Remove deletes a meta entry in the map and returns error if it doesnt exist
func (m *Meta) Delete(key string) error {
if _, ok := m.data[key]; ok {
delete(m.data, key)
return nil
}
return errors.New("Trying to delete map entry that doesn't exist")
}
func (m *Meta) Format() []byte {
// TODO: complete this
return []byte("someData")
}