// GlobPatternPrefix exracts the longest possible fixed-string
// prefix. Ex. `statsd.foo.*.bar` should return `statsd.foo.`.
func GlobPatternPrefix(pattern string) string {
conf := glob.Default()
conf.Separator = '.'
// Scan the pattern to find the longest prefix
var i = 0
for i = 0; i < len(pattern); i++ {
switch pattern[i] {
case '\\':
// Trailing backslash
if i+1 < len(pattern) {
i++
}
case conf.Range:
return pattern[:i]
case conf.RangeEnd:
return pattern[:i]
case conf.Star:
return pattern[:i]
case conf.Quest:
return pattern[:i]
}
}
return pattern
}
// Apply glob pattern to metrics from a backend
func GlobMetricsAsList(pattern string, backend Backend) ([]string, error) {
conf := glob.Default()
conf.Separator = '.'
globber, err := glob.New(conf)
if err != nil {
return nil, err
}
list := make([]string, 0)
out := make(chan string)
backend.GetMetricsList(out)
for name := range out {
match, err := globber.Match(pattern, name)
if err != nil {
return nil, err
}
if match {
list = append(list, name)
}
}
return list, nil
}