v0.1.0 initial commit

internal/filter/text.go

@@ -0,0 +1,86 @@
+package filter
+
+import "github.com/lixenwraith/vif-log/internal/logfile"
+
+func init() {
+	Register(Desc{Kind: "sub", Help: "subsystem regexp, e.g. sub:^(fsm|rec)$", New: newSub})
+	Register(Desc{Kind: "msg", Help: "message regexp, e.g. msg:transition", New: newMsg})
+}
+
+// Text matches one of the interned vocabulary columns. The pattern is applied
+// once per interned id into a bitset, so the per-record cost is a bit probe
+// and no line is ever read.
+type Text struct {
+	kind  string
+	Query string
+	pat   Pattern
+	mask  []uint64
+	n     int
+}
+
+func newSub(arg string) (Filter, error) { return newText("sub", arg) }
+func newMsg(arg string) (Filter, error) { return newText("msg", arg) }
+
+func newText(kind, arg string) (Filter, error) {
+	p, err := NewPattern(arg)
+	if err != nil {
+		return nil, err
+	}
+	return &Text{kind: kind, Query: arg, pat: p}, nil
+}
+
+func (f *Text) Kind() string { return f.kind }
+func (f *Text) Needs() Need  { return 0 }
+
+func (f *Text) Match(c *Ctx) bool {
+	if f.pat.Empty() {
+		return true
+	}
+	var id int
+	var tab []string
+	if f.kind == "sub" {
+		id, tab = int(c.Meta.Sub), c.Idx.Subs()
+	} else {
+		id, tab = int(c.Meta.Msg), c.Idx.Msgs()
+	}
+	f.ensure(tab)
+	if id < 0 || id >= f.n {
+		return false
+	}
+	return f.mask[id>>6]&(1<<uint(id&63)) != 0
+}
+
+// ensure rebuilds the bitset when the interned table has grown.
+func (f *Text) ensure(tab []string) {
+	if f.mask != nil && f.n == len(tab) {
+		return
+	}
+	need := (len(tab) + 63) / 64
+	if cap(f.mask) < need {
+		f.mask = make([]uint64, need)
+	} else {
+		f.mask = f.mask[:need]
+		clear(f.mask)
+	}
+	for i, s := range tab {
+		if f.pat.MatchString(s) {
+			f.mask[i>>6] |= 1 << uint(i&63)
+		}
+	}
+	f.n = len(tab)
+}
+
+func (f *Text) Label() string {
+	if f.pat.Empty() {
+		return ""
+	}
+	return f.kind + ":" + f.Query
+}
+
+// SubOf resolves the column a text filter binds to; used by the help overlay.
+func (f *Text) Column() logfile.Column {
+	if f.kind == "sub" {
+		return logfile.ColSub
+	}
+	return logfile.ColMsg
+}