/
distinct_string_collector.go
84 lines (70 loc) · 2.13 KB
/
distinct_string_collector.go
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/*
* Copyright (C) 2023 Intergral GmbH
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package util
import (
"sort"
"strings"
)
type DistinctStringCollector struct {
values map[string]struct{}
maxLen int
currLen int
totalLen int
}
// NewDistinctStringCollector with the given maximum data size. This is calculated
// as the total length of the recorded strings. For ease of use, maximum=0
// is interpreted as unlimited.
func NewDistinctStringCollector(maxDataSize int) *DistinctStringCollector {
return &DistinctStringCollector{
values: make(map[string]struct{}),
maxLen: maxDataSize,
}
}
func (d *DistinctStringCollector) Collect(s string) {
if _, ok := d.values[s]; ok {
// Already present
return
}
// New entry
d.totalLen += len(s)
// Can it fit?
if d.maxLen > 0 && d.currLen+len(s) > d.maxLen {
// No
return
}
// Clone instead of referencing original
s = strings.Clone(s)
d.values[s] = struct{}{}
d.currLen += len(s)
}
// Strings returns the final list of distinct values collected and sorted.
func (d *DistinctStringCollector) Strings() []string {
ss := make([]string, 0, len(d.values))
for k := range d.values {
ss = append(ss, k)
}
sort.Strings(ss)
return ss
}
// Exceeded indicates if some values were lost because the maximum size limit was met.
func (d *DistinctStringCollector) Exceeded() bool {
return d.totalLen > d.currLen
}
// TotalDataSize is the total size of all distinct strings encountered.
func (d *DistinctStringCollector) TotalDataSize() int {
return d.totalLen
}