IsNegtive exist bug

[ChicChip]

When using roaring64.BSI, due to value type is *big.Int , bsi's bitCount is Variable length even if some negative value is set. Thus there is a bug, when bsi's min negative value's bitLen is less than max positive num, GetValue will get wrong error.

testcode
bsi := roaring64.NewDefaultBSI()
for i:=-100;i<100;i++ {
bsi.SetValue(uint64(i+100),int64(i))
}
fmt.Println(bsi.GetValue(0))
result is -100, true

bsi := roaring64.NewDefaultBSI()
for i:=-100;i<1000;i++ {
bsi.SetValue(uint64(i+100),int64(i))
}
fmt.Println(bsi.GetValue(0))
result is 156, true

So if code uses len(b.bA) as sign bit may not work

[guymolinari]

Hello, Can you add a unit test that reproduces the issue?

…

On Wed, Nov 27, 2024 at 3:45 AM ChicChip ***@***.***> wrote: When using roaring64.BSI, due to value type is *big.Int , bsi's bitCount is Variable length even if some negative value is set. Thus there is a bug, when bsi's min negative value's bitLen is less than max positive num, GetValue will get wrong error. — Reply to this email directly, view it on GitHub <#462>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADZZAUXHT3GSMFANPE7NJV32CWICZAVCNFSM6AAAAABSSM5VLKVHI2DSMVQWIX3LMV43ASLTON2WKOZSGY4TOOBZGY2DGNI> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[ChicChip]

1. unit test will pass

func TestGetNegativeValue(t *testing.T) {
num := int64(14)
bsi := NewDefaultBSI()
for i:=-num; i<=num;i++ {
bsi.SetValue(uint64(i+num), i)
}
val, _ := bsi.GetValue(0)
assert.Equal(t, -num, val)
bsi.SetValue(uint64((num+1)+num), num+1)
val, _ = bsi.GetValue(0)
assert.Equal(t, -num, val)
}

2. unit test will fail, when set value 16 to bsi, bsi's higthest bit is not sign bit
   func TestGetNegativeValue(t *testing.T) {
num := int64(15)
bsi := NewDefaultBSI()
for i:=-num; i<=num;i++ {
bsi.SetValue(uint64(i+num), i)
}
val, _ := bsi.GetValue(0)
assert.Equal(t, -num, val)
bsi.SetValue(uint64((num+1)+num), num+1)
val, _ = bsi.GetValue(0)
assert.Equal(t, -num, val)
}
   Error: Not equal:
   expected: -15
   actual : 17
   Test: TestGetNegativeValue
   --- FAIL: TestGetNegativeValue (0.00s)

[guymolinari]

Are you attempting to set columnId to a negative value?

…

On Wed, Nov 27, 2024 at 8:02 AM ChicChip ***@***.***> wrote: 1. unit test will pass func TestGetNegativeValue(t *testing.T) { num := int64(14) bsi := NewDefaultBSI() for i:=-num; i<=num;i++ { bsi.SetValue(uint64(i+num), i) } val, _ := bsi.GetValue(0) assert.Equal(t, -num, val) bsi.SetValue(uint64((num+1)+num), num+1) val, _ = bsi.GetValue(0) assert.Equal(t, -num, val) } 2. unit test will fail, when set value 16 to bsi, bsi's higthest bit is not sign bit func TestGetNegativeValue(t *testing.T) { num := int64(15) bsi := NewDefaultBSI() for i:=-num; i<=num;i++ { bsi.SetValue(uint64(i+num), i) } val, _ := bsi.GetValue(0) assert.Equal(t, -num, val) bsi.SetValue(uint64((num+1)+num), num+1) val, _ = bsi.GetValue(0) assert.Equal(t, -num, val) } Error: Not equal: expected: -15 actual : 17 Test: TestGetNegativeValue --- FAIL: TestGetNegativeValue (0.00s) — Reply to this email directly, view it on GitHub <#462 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADZZAUTPTVSHT53FOZJRTDD2CXGHNAVCNFSM6AAAAABSSM5VLKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKMBTHE2TQMRWGM> . You are receiving this because you commented.Message ID: ***@***.***>

[ChicChip]

Are you attempting to set columnId to a negative value?
…
On Wed, Nov 27, 2024 at 8:02 AM ChicChip @.**> wrote: 1. unit test will pass func TestGetNegativeValue(t testing.T) { num := int64(14) bsi := NewDefaultBSI() for i:=-num; i<=num;i++ { bsi.SetValue(uint64(i+num), i) } val, _ := bsi.GetValue(0) assert.Equal(t, -num, val) bsi.SetValue(uint64((num+1)+num), num+1) val, _ = bsi.GetValue(0) assert.Equal(t, -num, val) } 2. unit test will fail, when set value 16 to bsi, bsi's higthest bit is not sign bit func TestGetNegativeValue(t testing.T) { num := int64(15) bsi := NewDefaultBSI() for i:=-num; i<=num;i++ { bsi.SetValue(uint64(i+num), i) } val, _ := bsi.GetValue(0) assert.Equal(t, -num, val) bsi.SetValue(uint64((num+1)+num), num+1) val, _ = bsi.GetValue(0) assert.Equal(t, -num, val) } Error: Not equal: expected: -15 actual : 17 Test: TestGetNegativeValue --- FAIL: TestGetNegativeValue (0.00s) — Reply to this email directly, view it on GitHub <#462 (comment)>, or unsubscribe https://github.com/notifications/unsubscribe-auth/ADZZAUTPTVSHT53FOZJRTDD2CXGHNAVCNFSM6AAAAABSSM5VLKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKMBTHE2TQMRWGM . You are receiving this because you commented.Message ID: @.>

no, in this code, you can see columnId is >=0, only value may a negtive number