📅 Original date posted:2011-07-03
🗒️ Summary of this message: Jan implemented a balance cache to speed up the Instawallet server, using a list of all account balances stored in a map.
📝 Original message:Hey!
John Smith wrote:
> I think the easiest way to speed this up would be to scan the wallet every
> time a block comes in or something else changes in the block chain (or, if
> you prefer, some pre-set interval of N minutes). Then go over the entire
> wallet and the accumulate balances for all accounts. This could be done in
> amortized linear time using a hash_map.
That was a good suggestion - thanks! I implemented it along these lines
and now the Instawallet server can breath again. Well, more or less at
least, as now "sendfrom" starts acting up and I have to look into that
next.
Here is a branch with the code for the cache:
https://github.com/javgh/bitcoin/tree/balancecache . It's currently based
on a somewhat old version of the codebase as I'm running with a number of
other modifications. So it won't easily apply to something newer. I hope
to be able to switch to a recent version at some point (mostly hoping for
some improvements in the fee handling area before I do that) and then I
can hopefully provide a cleaner version of this patch. For now, I just
document it here for anyone who might need this as well and can piece it
together themselves (I attached a patch file).
Basically I create a list of all account balances every time a new a new
block comes in or a transaction that affects my wallet appears. The list
is stored in a "map" right now. This seems fast enough for me. I didn't
use a hash map for now, because I'm fairly new to C++ and was a little
confused on what to use (is there a "standard" hash map to use in the STL?
or do people use boost or what?). But my VPS is low on memory anyway, so I
guess that's kind of a justification as well to go for a tree-based
implementation of map.
Cheers!
Jan
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Jan Vornberger [ARCHIVE] /
npub147…tnsv4
2023-06-07 02:02:18
in reply to nevent1q…0k7t
Author Public Key
npub147edljttlezv8m5dugzg4ka8cg3073j3t2hq4h8ncxaz9sm5swuq4tnsv4Seen on
wss://relay.nostr.bandPublished at
2023-06-07 02:02:18Event JSON
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"content": "📅 Original date posted:2011-07-03\n🗒️ Summary of this message: Jan implemented a balance cache to speed up the Instawallet server, using a list of all account balances stored in a map.\n📝 Original message:Hey!\n\nJohn Smith wrote:\n\u003e I think the easiest way to speed this up would be to scan the wallet every\n\u003e time a block comes in or something else changes in the block chain (or, if\n\u003e you prefer, some pre-set interval of N minutes). Then go over the entire\n\u003e wallet and the accumulate balances for all accounts. This could be done in\n\u003e amortized linear time using a hash_map.\n\nThat was a good suggestion - thanks! I implemented it along these lines\nand now the Instawallet server can breath again. Well, more or less at\nleast, as now \"sendfrom\" starts acting up and I have to look into that\nnext.\n\nHere is a branch with the code for the cache:\nhttps://github.com/javgh/bitcoin/tree/balancecache . It's currently based\non a somewhat old version of the codebase as I'm running with a number of\nother modifications. So it won't easily apply to something newer. I hope\nto be able to switch to a recent version at some point (mostly hoping for\nsome improvements in the fee handling area before I do that) and then I\ncan hopefully provide a cleaner version of this patch. For now, I just\ndocument it here for anyone who might need this as well and can piece it\ntogether themselves (I attached a patch file).\n\nBasically I create a list of all account balances every time a new a new\nblock comes in or a transaction that affects my wallet appears. The list\nis stored in a \"map\" right now. This seems fast enough for me. I didn't\nuse a hash map for now, because I'm fairly new to C++ and was a little\nconfused on what to use (is there a \"standard\" hash map to use in the STL?\nor do people use boost or what?). But my VPS is low on memory anyway, so I\nguess that's kind of a justification as well to go for a tree-based\nimplementation of map.\n\nCheers!\nJan\n-------------- next part --------------\nA non-text attachment was scrubbed...\nName: balancecache.patch\nType: text/x-patch\nSize: 8184 bytes\nDesc: not available\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20110703/16ead949/attachment.bin\u003e",
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