Merge pull request #542 from aboch/bs

Allow to set bits in a range in bitseq

libnetwork/bitseq/sequence.go

@@ -87,12 +87,12 @@ func (s *sequence) toString() string {
 }
 
 // GetAvailableBit returns the position of the first unset bit in the bitmask represented by this sequence
-func (s *sequence) getAvailableBit() (uint32, uint32, error) {
+func (s *sequence) getAvailableBit(from uint32) (uint32, uint32, error) {
 	if s.block == blockMAX || s.count == 0 {
-		return invalidPos, invalidPos, fmt.Errorf("no available bit")
+		return invalidPos, invalidPos, errNoBitAvailable
 	}
-	bits := uint32(0)
-	bitSel := blockFirstBit
+	bits := from
+	bitSel := blockFirstBit >> from
 	for bitSel > 0 && s.block&bitSel != 0 {
 		bitSel >>= 1
 		bits++
@@ -186,12 +186,23 @@ func (h *Handle) getCopy() *Handle {
 	}
 }
 
+// SetAnyInRange atomically sets the first unset bit in the specified range in the sequence and returns the corresponding ordinal
+func (h *Handle) SetAnyInRange(start, end uint32) (uint32, error) {
+	if end-start <= 0 || end >= h.bits {
+		return invalidPos, fmt.Errorf("invalid bit range [%d, %d]", start, end)
+	}
+	if h.Unselected() == 0 {
+		return invalidPos, errNoBitAvailable
+	}
+	return h.set(0, start, end, true, false)
+}
+
 // SetAny atomically sets the first unset bit in the sequence and returns the corresponding ordinal
 func (h *Handle) SetAny() (uint32, error) {
 	if h.Unselected() == 0 {
 		return invalidPos, errNoBitAvailable
 	}
-	return h.set(0, true, false)
+	return h.set(0, 0, h.bits-1, true, false)
 }
 
 // Set atomically sets the corresponding bit in the sequence
@@ -199,7 +210,7 @@ func (h *Handle) Set(ordinal uint32) error {
 	if err := h.validateOrdinal(ordinal); err != nil {
 		return err
 	}
-	_, err := h.set(ordinal, false, false)
+	_, err := h.set(ordinal, 0, 0, false, false)
 	return err
 }
 
@@ -208,7 +219,7 @@ func (h *Handle) Unset(ordinal uint32) error {
 	if err := h.validateOrdinal(ordinal); err != nil {
 		return err
 	}
-	_, err := h.set(ordinal, false, true)
+	_, err := h.set(ordinal, 0, 0, false, true)
 	return err
 }
 
@@ -225,7 +236,7 @@ func (h *Handle) IsSet(ordinal uint32) bool {
 }
 
 // set/reset the bit
-func (h *Handle) set(ordinal uint32, any bool, release bool) (uint32, error) {
+func (h *Handle) set(ordinal, start, end uint32, any bool, release bool) (uint32, error) {
 	var (
 		bitPos  uint32
 		bytePos uint32
@@ -240,8 +251,11 @@ func (h *Handle) set(ordinal uint32, any bool, release bool) (uint32, error) {
 			bytePos, bitPos = ordinalToPos(ordinal)
 		} else {
 			if any {
-				bytePos, bitPos, err = getFirstAvailable(h.head)
+				bytePos, bitPos, err = getFirstAvailable(h.head, start)
 				ret = posToOrdinal(bytePos, bitPos)
+				if end < ret {
+					err = errNoBitAvailable
+				}
 			} else {
 				bytePos, bitPos, err = checkIfAvailable(h.head, ordinal)
 				ret = ordinal
@@ -285,7 +299,7 @@ func (h *Handle) set(ordinal uint32, any bool, release bool) (uint32, error) {
 
 // checks is needed because to cover the case where the number of bits is not a multiple of blockLen
 func (h *Handle) validateOrdinal(ordinal uint32) error {
-	if ordinal > h.bits {
+	if ordinal >= h.bits {
 		return fmt.Errorf("bit does not belong to the sequence")
 	}
 	return nil
@@ -353,16 +367,24 @@ func (h *Handle) String() string {
 		h.app, h.id, h.dbIndex, h.bits, h.unselected, h.head.toString())
 }
 
-// getFirstAvailable looks for the first unset bit in passed mask
-func getFirstAvailable(head *sequence) (uint32, uint32, error) {
-	byteIndex := uint32(0)
-	current := head
+// getFirstAvailable looks for the first unset bit in passed mask starting from start
+func getFirstAvailable(head *sequence, start uint32) (uint32, uint32, error) {
+	// Find sequence which contains the start bit
+	byteStart, bitStart := ordinalToPos(start)
+	current, _, _, inBlockBytePos := findSequence(head, byteStart)
+
+	// Derive the this sequence offsets
+	byteOffset := byteStart - inBlockBytePos
+	bitOffset := inBlockBytePos*8 + bitStart
+
 	for current != nil {
 		if current.block != blockMAX {
-			bytePos, bitPos, err := current.getAvailableBit()
-			return byteIndex + bytePos, bitPos, err
+			bytePos, bitPos, err := current.getAvailableBit(bitOffset)
+			return byteOffset + bytePos, bitPos, err
 		}
-		byteIndex += current.count * blockBytes
+		// Moving to next block: Reset bit offset.
+		bitOffset = 0
+		byteOffset += current.count * blockBytes
 		current = current.next
 	}
 	return invalidPos, invalidPos, errNoBitAvailable
@@ -371,8 +393,7 @@ func getFirstAvailable(head *sequence) (uint32, uint32, error) {
 // checkIfAvailable checks if the bit correspondent to the specified ordinal is unset
 // If the ordinal is beyond the sequence limits, a negative response is returned
 func checkIfAvailable(head *sequence, ordinal uint32) (uint32, uint32, error) {
-	bytePos := ordinal / 8
-	bitPos := ordinal % 8
+	bytePos, bitPos := ordinalToPos(ordinal)
 
 	// Find the sequence containing this byte
 	current, _, _, inBlockBytePos := findSequence(head, bytePos)

libnetwork/bitseq/sequence_test.go

@@ -9,58 +9,75 @@ import (
 func TestSequenceGetAvailableBit(t *testing.T) {
 	input := []struct {
 		head    *sequence
+		from    uint32
 		bytePos uint32
 		bitPos  uint32
 	}{
-		{&sequence{block: 0x0, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0x0, count: 1}, 0, 0},
-		{&sequence{block: 0x0, count: 100}, 0, 0},
+		{&sequence{block: 0x0, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0x0, count: 1}, 0, 0, 0},
+		{&sequence{block: 0x0, count: 100}, 0, 0, 0},
+
+		{&sequence{block: 0x80000000, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0x80000000, count: 1}, 0, 0, 1},
+		{&sequence{block: 0x80000000, count: 100}, 0, 0, 1},
 
-		{&sequence{block: 0x80000000, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0x80000000, count: 1}, 0, 1},
-		{&sequence{block: 0x80000000, count: 100}, 0, 1},
+		{&sequence{block: 0xFF000000, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFF000000, count: 1}, 0, 1, 0},
+		{&sequence{block: 0xFF000000, count: 100}, 0, 1, 0},
 
-		{&sequence{block: 0xFF000000, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0xFF000000, count: 1}, 1, 0},
-		{&sequence{block: 0xFF000000, count: 100}, 1, 0},
+		{&sequence{block: 0xFF800000, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFF800000, count: 1}, 0, 1, 1},
+		{&sequence{block: 0xFF800000, count: 100}, 0, 1, 1},
 
-		{&sequence{block: 0xFF800000, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0xFF800000, count: 1}, 1, 1},
-		{&sequence{block: 0xFF800000, count: 100}, 1, 1},
+		{&sequence{block: 0xFFC0FF00, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFC0FF00, count: 1}, 0, 1, 2},
+		{&sequence{block: 0xFFC0FF00, count: 100}, 0, 1, 2},
 
-		{&sequence{block: 0xFFC0FF00, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0xFFC0FF00, count: 1}, 1, 2},
-		{&sequence{block: 0xFFC0FF00, count: 100}, 1, 2},
+		{&sequence{block: 0xFFE0FF00, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFE0FF00, count: 1}, 0, 1, 3},
+		{&sequence{block: 0xFFE0FF00, count: 100}, 0, 1, 3},
 
-		{&sequence{block: 0xFFE0FF00, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0xFFE0FF00, count: 1}, 1, 3},
-		{&sequence{block: 0xFFE0FF00, count: 100}, 1, 3},
+		{&sequence{block: 0xFFFEFF00, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFEFF00, count: 1}, 0, 1, 7},
+		{&sequence{block: 0xFFFEFF00, count: 100}, 0, 1, 7},
 
-		{&sequence{block: 0xFFFEFF00, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0xFFFEFF00, count: 1}, 1, 7},
-		{&sequence{block: 0xFFFEFF00, count: 100}, 1, 7},
+		{&sequence{block: 0xFFFFC0FF, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFFC0FF, count: 1}, 0, 2, 2},
+		{&sequence{block: 0xFFFFC0FF, count: 100}, 0, 2, 2},
 
-		{&sequence{block: 0xFFFFC0FF, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0xFFFFC0FF, count: 1}, 2, 2},
-		{&sequence{block: 0xFFFFC0FF, count: 100}, 2, 2},
+		{&sequence{block: 0xFFFFFF00, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFFFF00, count: 1}, 0, 3, 0},
+		{&sequence{block: 0xFFFFFF00, count: 100}, 0, 3, 0},
 
-		{&sequence{block: 0xFFFFFF00, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0xFFFFFF00, count: 1}, 3, 0},
-		{&sequence{block: 0xFFFFFF00, count: 100}, 3, 0},
+		{&sequence{block: 0xFFFFFFFE, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFFFFFE, count: 1}, 0, 3, 7},
+		{&sequence{block: 0xFFFFFFFE, count: 100}, 0, 3, 7},
 
-		{&sequence{block: 0xFFFFFFFE, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0xFFFFFFFE, count: 1}, 3, 7},
-		{&sequence{block: 0xFFFFFFFE, count: 100}, 3, 7},
+		{&sequence{block: 0xFFFFFFFF, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFFFFFF, count: 1}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFFFFFF, count: 100}, 0, invalidPos, invalidPos},
 
-		{&sequence{block: 0xFFFFFFFF, count: 0}, invalidPos, invalidPos},
-		{&sequence{block: 0xFFFFFFFF, count: 1}, invalidPos, invalidPos},
-		{&sequence{block: 0xFFFFFFFF, count: 100}, invalidPos, invalidPos},
+		// now test with offset
+		{&sequence{block: 0x0, count: 0}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0x0, count: 0}, 31, invalidPos, invalidPos},
+		{&sequence{block: 0x0, count: 0}, 32, invalidPos, invalidPos},
+		{&sequence{block: 0x0, count: 1}, 0, 0, 0},
+		{&sequence{block: 0x0, count: 1}, 1, 0, 1},
+		{&sequence{block: 0x0, count: 1}, 31, 3, 7},
+		{&sequence{block: 0xF0FF0000, count: 1}, 0, 0, 4},
+		{&sequence{block: 0xF0FF0000, count: 1}, 8, 2, 0},
+		{&sequence{block: 0xFFFFFFFF, count: 1}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFFFFFF, count: 1}, 16, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFFFFFF, count: 1}, 31, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFFFFFE, count: 1}, 0, 3, 7},
+		{&sequence{block: 0xFFFFFFFF, count: 2}, 0, invalidPos, invalidPos},
+		{&sequence{block: 0xFFFFFFFF, count: 2}, 32, invalidPos, invalidPos},
 	}
 
 	for n, i := range input {
-		b, bb, err := i.head.getAvailableBit()
+		b, bb, err := i.head.getAvailableBit(i.from)
 		if b != i.bytePos || bb != i.bitPos {
-			t.Fatalf("Error in sequence.getAvailableBit() (%d).\nExp: (%d, %d)\nGot: (%d, %d), err: %v", n, i.bytePos, i.bitPos, b, bb, err)
+			t.Fatalf("Error in sequence.getAvailableBit(%d) (%d).\nExp: (%d, %d)\nGot: (%d, %d), err: %v", i.from, n, i.bytePos, i.bitPos, b, bb, err)
 		}
 	}
 }
@@ -140,7 +157,7 @@ func TestGetFirstAvailable(t *testing.T) {
 	}
 
 	for n, i := range input {
-		bytePos, bitPos, _ := getFirstAvailable(i.mask)
+		bytePos, bitPos, _ := getFirstAvailable(i.mask, 0)
 		if bytePos != i.bytePos || bitPos != i.bitPos {
 			t.Fatalf("Error in (%d) getFirstAvailable(). Expected (%d, %d). Got (%d, %d)", n, i.bytePos, i.bitPos, bytePos, bitPos)
 		}
@@ -487,11 +504,134 @@ func TestSetUnset(t *testing.T) {
 	}
 	// set and unset all one by one
 	for hnd.Unselected() > 0 {
-		hnd.SetAny()
+		if _, err := hnd.SetAny(); err != nil {
+			t.Fatal(err)
+		}
 	}
 	i := uint32(0)
 	for hnd.Unselected() < numBits {
-		hnd.Unset(i)
+		if err := hnd.Unset(i); err != nil {
+			t.Fatal(err)
+		}
 		i++
 	}
 }
+
+func TestSetInRange(t *testing.T) {
+	numBits := uint32(1024 * blockLen)
+	hnd, err := NewHandle("", nil, "", numBits)
+	if err != nil {
+		t.Fatal(err)
+	}
+	hnd.head = getTestSequence()
+
+	firstAv := uint32(100*blockLen + blockLen - 1)
+
+	if o, err := hnd.SetAnyInRange(4, 3); err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+
+	if o, err := hnd.SetAnyInRange(5, 5); err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+
+	if o, err := hnd.SetAnyInRange(0, numBits); err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+
+	o, err := hnd.SetAnyInRange(100*blockLen, 101*blockLen)
+	if err != nil {
+		t.Fatalf("Unexpected failure: (%d, %v)", o, err)
+	}
+	if o != firstAv {
+		t.Fatalf("Unexpected ordinal: %d", o)
+	}
+
+	if o, err := hnd.SetAnyInRange(0, blockLen); err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+
+	if o, err := hnd.SetAnyInRange(0, firstAv-1); err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+
+	if o, err := hnd.SetAnyInRange(111*blockLen, 161*blockLen); err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+
+	o, err = hnd.SetAnyInRange(161*blockLen, 162*blockLen)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if o != 161*blockLen+30 {
+		t.Fatalf("Unexpected ordinal: %d", o)
+	}
+
+	o, err = hnd.SetAnyInRange(161*blockLen, 162*blockLen)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if o != 161*blockLen+31 {
+		t.Fatalf("Unexpected ordinal: %d", o)
+	}
+
+	o, err = hnd.SetAnyInRange(161*blockLen, 162*blockLen)
+	if err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+
+	if _, err := hnd.SetAnyInRange(0, numBits-1); err != nil {
+		t.Fatalf("Unexpected failure: %v", err)
+	}
+
+	// create a non multiple of 32 mask
+	hnd, err = NewHandle("", nil, "", 30)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// set all bit in the first range
+	for hnd.Unselected() > 22 {
+		if o, err := hnd.SetAnyInRange(0, 7); err != nil {
+			t.Fatalf("Unexpected failure: (%d, %v)", o, err)
+		}
+	}
+	// try one more set, which should fail
+	o, err = hnd.SetAnyInRange(0, 7)
+	if err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+	if err != errNoBitAvailable {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	// set all bit in a second range
+	for hnd.Unselected() > 14 {
+		if o, err := hnd.SetAnyInRange(8, 15); err != nil {
+			t.Fatalf("Unexpected failure: (%d, %v)", o, err)
+		}
+	}
+
+	// try one more set, which should fail
+	o, err = hnd.SetAnyInRange(0, 15)
+	if err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+	if err != errNoBitAvailable {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	// set all bit in a range which includes the last bit
+	for hnd.Unselected() > 12 {
+		if o, err := hnd.SetAnyInRange(28, 29); err != nil {
+			t.Fatalf("Unexpected failure: (%d, %v)", o, err)
+		}
+	}
+	o, err = hnd.SetAnyInRange(28, 29)
+	if err == nil {
+		t.Fatalf("Expected failure. Got success with ordinal:%d", o)
+	}
+	if err != errNoBitAvailable {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+}