Block number from getwork | Bitcointalksearch.org

lfm

full member

Activity: 196

Merit: 104

Quote from: geebus on March 01, 2011, 11:59:27 PM

I'm looking for a way to verify if the current getwork I'm on is from the current, or last block. Would I be able to do that by looking at "prev_block", and checking against a stored array of the "prev_block" from the previous two blocks?

Like, I have an array with the two last known prev_block values in it. If the prev_block value from the getwork matches the newest stored prev_block value, I know it's from the current block. If it matches the oldest prev_block value, it's from the block prior to the current. Correct?

You would need to get the hash of the current "top" block and compare it to prev-hash in the getwork block.

theymos

administrator

Activity: 5222

Merit: 13032

Quote from: geebus on March 01, 2011, 11:59:27 PM

I'm looking for a way to verify if the current getwork I'm on is from the current, or last block. Would I be able to do that by looking at "prev_block", and checking against a stored array of the "prev_block" from the previous two blocks?

Like, I have an array with the two last known prev_block values in it. If the prev_block value from the getwork matches the newest stored prev_block value, I know it's from the current block. If it matches the oldest prev_block value, it's from the block prior to the current. Correct?

That won't work unless your getwork is putting you back to a block you've already seen, which it shouldn't do. The problem is getting the hash for the most recent block, which you have never seen before.

If you only need to get this data once in a while, you could use this:
http://blockexplorer.com/q/latesthash
Otherwise, you could patch your Bitcoin to support jgarzik's getblockbycount and then combine getblockbycount with getblockcount to get the hash of the latest block. If you have access to Bitcoin's debug.log, you can search it to find the latest block hash.

geebus

sr. member

Activity: 258

Merit: 250

I'm looking for a way to verify if the current getwork I'm on is from the current, or last block. Would I be able to do that by looking at "prev_block", and checking against a stored array of the "prev_block" from the previous two blocks?

Like, I have an array with the two last known prev_block values in it. If the prev_block value from the getwork matches the newest stored prev_block value, I know it's from the current block. If it matches the oldest prev_block value, it's from the block prior to the current. Correct?

jgarzik

legendary

Activity: 1596

Merit: 1100

Quote from: geebus on March 01, 2011, 11:19:56 PM

How would one go about getting the current block number, in a readable format (i.e. the height of the block) from a getwork?

Current block chain height is not stored in the getwork data.

getwork data returns a block header, which includes things like previous-block-hash (forms the block chain). See this example of a block: http://blockexplorer.com/rawblock/000000000000aaa7a48683e8a184ebd4de700d3c7f29524d95a417b086793ac6

geebus

sr. member

Activity: 258

Merit: 250

How would one go about getting the current block number, in a readable format (i.e. the height of the block) from a getwork?

How could/would this be done in python?

Topic: Block number from getwork (Read 1598 times)