.

wcfs/internal/xbtree/rangeset.go

@@ -22,7 +22,7 @@ package xbtree
 
 import (
 	"fmt"
-//	"sort"
+	"sort"
 )
 
 // Range represents [lo,hi) Key range.
@@ -58,7 +58,63 @@ func (S *RangeSet) AddRange(r Range) {
 	S.verify()
 	defer S.verify()
 
-	panic("TODO")	// XXX
+	// find first ilo: r.lo < [ilo].hi
+	l := len(S.rangev)
+	ilo := sort.Search(l, func(i int) bool {
+		 return r.lo <= S.rangev[i].hi_
+	})
+
+	if ilo == l { // not found
+		// XXX append r; l++
+		// XXX check & merge with prev
+	}
+
+	// find firt jhi: r.hi > =(?) [jhi].lo
+	jhi := ilo
+	for ; jhi < l; jhi++ {
+		if r.hi_ >= S.rangev[jhi].lo {
+			break
+		}
+	}
+
+	// entries in [ilo:jhi) ∈ [r.lo,r.hi) and should be merged into one
+	if ilo < jhi {
+		lo  := S.rangev[ilo].lo
+		hi_ := S.rangev[jhi-1].hi_
+		S.rangev = append(
+			S.rangev[:ilo],
+			Range{lo, hi_},
+			S.rangev[jhi:]...)
+	}
+
+	// if [r.lo,r.hi) was outside of any entry - create new entry
+	if r.hi_ <= S.rangev[ilo].lo {
+		S.rangev = append(
+			S.rangev[:ilo],
+			r,
+			S.rangev[ilo:])
+	}
+
+	// now we have covered entries merged as needed into [ilo]
+	// extend this entry if r coverage is wider
+	if r.lo < S.rangev[ilo].lo {
+		S.rangev[ilo].lo = r.lo
+	}
+	if r.hi_ > S.rangev[ilo].hi_ {
+		S.rangev[ilo].hi_ = r.hi_
+	}
+
+	// and check if we should merge it with right/left neighbours
+	if ilo < len(S.rangev) {
+		if S.rangev[ilo].hi_ == S.rangev[ilo+1].lo {
+			S.rangev = append(
+				S.rangev[:ilo],
+				Range{S.rangev[ilo].lo, S.rangev[ilo+1].hi_},
+				S.rangev[ilo+2:]...)
+		}
+	}
+
+	// done
 }
 
 // Del removes Range r from the set.
@@ -66,6 +122,7 @@ func (S *RangeSet) DelRange(r Range) {
 	S.verify()
 	defer S.verify()
 
+	return // XX temp
 	panic("TODO")	// XXX
 }
 

wcfs/internal/xbtree/rangeset_test.go

@@ -93,6 +93,16 @@ func TestRangeSet(t *testing.T) {
 			S(noo, oo),          // B
 				S(1,3, 5,7, 11,100), // U
 				S()),                // D
+
+		// [1,3) [5,7) + insert [3,5) -> [1,7)
+		E(
+			S(1,3, 5,7),	// A
+			S(3,5),		// B
+				S(1,7),		// U
+				S(1,3, 5,7)),	// D
+
+		// XXX Add to left  - merge
+		// XXX Add to right - merge
 	}
 
 	for _, tt := range testv {