oh my God ...
发自我的 iPhone
> 在 2015年5月27日，19:26，Tier Nolan 写道：
>
>
>
>> On Wed, May 27, 2015 at 11:15 AM, Peter Todd wrote:
>> The median time mechanism is basically a way for hashing power to show
>> what time they think it is. Equally, the nVersion soft-fork mechanism is
>> a way for hashing power to show what features they want to support.
>
> Fair enough. It means slightly more processing, but the median time could be
> cached in the header index, so no big deal.
>
>> Block counts are inconvenient for planning, as there's no guarantee
>> they'll actually happen in any particular time frame, forward and back.
>
> I don't think the deadline needs to be set that accurately. A roughly 6
> month deadline should be fine, but as you say a majority of miners is needed
> to abuse the median time and it is already a miner poll.
>
> Perhaps the number of blocks used in the median could be increased to reduce
> "noise".
>
> The median time could be median of the last 144 blocks plus 12 hours.
>
>> If you assume no large reorganizations, your table of known BIPs can
>> just as easily be a list of block heights even if the median time
>> mechanism is used.
>
> I think it makes it easier to write the code. It reduced the state that
> needs to be stored per BIP. You don't need to check if the previous bips
> were all accepted.
>
> Each bit is assigned to a particular BIP for a particular range of times (or
> blocks).
>
> If block numbers were used for the deadline, you just need to check the block
> index for the deadline block.
>
> enum {
> BIP_INACTIVE = 0,
> BIP_ACTIVE,
> BIP_LOCKED
> BIP_INVALID_BLOCK,
> }
>
> int GetBIPState(block, bip)
> {
> if (block.height == bip.deadline) // Bit must be set to match
> locked/unlocked at deadline
> {
> int bipState = check_supermajority(...);
> if (bipState == BIP_LOCKED && (block.nVersion & bip.bit)
> return BIP_LOCKED;
>
> if (bipState != BIP_LOCKED && (block.nVersion & (~bip.bit)))
> return BIP_INACTIVE;
>
> return BIP_INVALID_BLOCK;
> }
>
> if (block.height > deadline) // Look at the deadline block to determine
> if the BIP is locked
> return (block_index[deadline].nVersion & bip_bit) != 0 ? BIP_LOCKED :
> BIP_INACTIVE;
>
> if (block.height < startline + I) // BIP cannot activate/lock until
> startline + implicit window size
> return INACTIVE;
>
> return check_supermajority() // Check supermajority of bit
> }
>
> The block at height deadline would indicate if the BIP was locked in.
>
> Block time could still be used as long as the block height was set after
> that. The deadline_time could be in six months. The startline height could
> be the current block height and the deadline_height could be startline +
> 35000.
>
> The gives roughly
>
> start time = now
> deadline time = now + six months
> deadline height = now + eight months
>
> The deadline height is the block height when the bit is returned to the pool
> but the deadline time is when the BIP has to be accepted.
>
> It also helps with the warning system. For each block height, there is a set
> of known BIP bits that are allowed. Once the final deadline is passed, the
> expected mask is zeros.
>
>> On Wed, May 27, 2015 at 11:15 AM, Jorge Timón wrote:
>> On May 27, 2015 11:35 AM, "Tier Nolan" wrote:
>>
>> > Was the intention to change the 95% rule. You need 750 of the last 1000
>> > to activate and then must wait at least 1000 for implication?
>>
>> You need 75% to start applying it, 95% to start rejecting blocks that don't
>> apply it.
>
> I think the phrasing is ambiguous. I was just asking for clarification.
>
> "Whenever I out of any W subsequent blocks (regardless of the block itself)
> have bit B set,"
>
> That suggests that the I of W blocks for the 95% rule must happen after
> activation. This makes the rule checking harder. Easier to use the current
> system, where blocks that were part of the 750 rule also count towards the
> 95% rule.
> --
>
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