Fix off-by-one. #243
Fix off-by-one. #243
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ordian
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ordian
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Nice catch!
I think in parity-ethereum we deny hex string of odd length before deserializing them.
The new behavior is to essentially pad it with leading 0 if it has an odd length, so e.g. 0x123 is treated as 0x0123. This seems reasonable to me, but should be documented somewhere.
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@ordian Indeed Parity Ethereum is following the jsonrpc spec from here: https://github.com/ethereum/wiki/wiki/JSON-RPC#hex-value-encoding and it clearly states what values are valid and what not. |
| let bytes_len = v.len() - 2; | ||
| let mut modulus = bytes_len % 2; | ||
| let mut bytes = vec![0u8; bytes_len / 2 + 1]; | ||
| let mut bytes = vec![0u8; (bytes_len + 1) / 2]; |
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why bother with this complex logic?
Isn't better to use Vec::new() / Vec::with_capacity() and Vec::push?
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Well, it's a performance optimization (hopefuly measureable), which is justified, since this code might be on a hot path.
Also this logic is not that complex imho, seems it was just untested properly.
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I for one kind of agree with Niklas here: it's a bit odd and I'm surprised to learn it's faster to init a vec with vec![0u8; 123] than Vec::with_capacity(123).
(No action needed here, I'm just curious)
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I'm about to add benches for Bytes to be continued :P
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Wow, thanks for making me realize this is actually a vec. I was pretty sure that we just allocate an array here (but obviously we don't cause it's not a constant size)
I'm really curious about the performance indeed, as just using push instead of direct access seems way less error prone, and with_capacity should ensure that there are no re-allocations.
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I really hope there's no difference in performance! :)
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