peco.peco/filter/filter.go
2026-02-20 10:55:49 +09:00

107 lines
2.7 KiB
Go

package filter
import (
"context"
"regexp"
"github.com/peco/peco/line"
"github.com/peco/peco/pipeline"
)
// Filter is the interface that all filter implementations must satisfy.
type Filter interface {
Apply(context.Context, []line.Line, pipeline.ChanOutput) error
BufSize() int
NewContext(context.Context, string) context.Context
String() string
// SupportsParallel returns true if this filter can safely be invoked
// concurrently on independent chunks of lines. Filters that require
// global state across all lines (e.g. sorted output) should return false.
SupportsParallel() bool
}
// Collector is an optional interface that filters can implement to return
// matched lines directly as a slice, bypassing channel-based output.
// This avoids per-chunk channel allocation and goroutine overhead in the
// parallel filter path.
type Collector interface {
ApplyCollect(context.Context, []line.Line) ([]line.Line, error)
}
// isExcluded reports whether text matches any of the given negative regexps.
func isExcluded(negRegexps []*regexp.Regexp, text string) bool {
for _, rx := range negRegexps {
if rx.MatchString(text) {
return true
}
}
return false
}
// newContext initializes the context so that it is suitable
// to be passed to `Run()`
func newContext(ctx context.Context, query string) context.Context {
return pipeline.NewQueryContext(ctx, query)
}
// checkCancelled returns ctx.Err() every 1000 iterations so that
// long-running filter loops can bail out promptly on cancellation
// without paying the cost of a channel receive on every single line.
func checkCancelled(ctx context.Context, i int) error {
if i%1000 == 0 {
select {
case <-ctx.Done():
return ctx.Err()
default:
}
}
return nil
}
// sort related stuff
type byMatchStart [][]int
func (m byMatchStart) Len() int {
return len(m)
}
func (m byMatchStart) Swap(i, j int) {
m[i], m[j] = m[j], m[i]
}
func (m byMatchStart) Less(i, j int) bool {
if m[i][0] < m[j][0] {
return true
}
if m[i][0] == m[j][0] {
return m[i][1]-m[i][0] < m[j][1]-m[j][0]
}
return false
}
// matchContains reports whether match range a fully contains match range b.
func matchContains(a []int, b []int) bool {
return a[0] <= b[0] && a[1] >= b[1]
}
// matchOverlaps reports whether two match ranges overlap.
func matchOverlaps(a []int, b []int) bool {
return a[0] <= b[0] && a[1] >= b[0] ||
a[0] <= b[1] && a[1] >= b[1]
}
// mergeMatches combines two overlapping match ranges into a single range
// spanning both.
func mergeMatches(a []int, b []int) []int {
ret := make([]int, 2)
// Note: In practice this should never happen
// because we're sorting by N[0] before calling
// this routine, but for completeness' sake...
ret[0] = min(a[0], b[0])
ret[1] = max(a[1], b[1])
return ret
}