Prefixer sub prefix #215
Prefixer sub prefix #215
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Elide explicit parameter types lifetimes
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| @@ -38,8 +40,9 @@ impl<'a> PrimaryKey<'a> for &'a [u8] { | |||
| // Provide a string version of this to raw encode strings | |||
| impl<'a> PrimaryKey<'a> for &'a str { | |||
| type Prefix = (); | |||
| type SubPrefix = (); | |||
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Simple. Just add the 2-step variant rather than some generic N-step construction. Should be plenty for any case I can think of.
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| fn key<'b>(&'b self) -> Vec<&'b [u8]> { | ||
| fn key(&self) -> Vec<&[u8]> { |
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And all that was unneeded?
Looks like a better clippy/linter got this working well
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This is something the idea built-in linter recommends. These are called "elided lifetimes", and the linter's recommendation is to remove them.
| all, | ||
| vec![ | ||
| ( | ||
| [to_length_prefixed(b"\x09"), b"recipient".to_vec()].concat(), |
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Ah, the big-endian encoding of U8key manually...
This is fine for now. It would be interesting to see how to auto-parse these keys, but the caller should know how in the end
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Yes. It could be handled automatically by the deserialization function (returning a vec! of (properly deserialized) tuples). But, for that we need to know if the sub-prefix is composed by one or more keys... if all the keys where length-prefixed that would be straightforward: we just honour the length-prefixed information. But currently, the last key is not length-prefixed. So, this introduces ambiguity.
I think an easy fix would be to make all keys length-prefixed, and for the deserialization fn to handle that directly.
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We could also consider reducing the max length of each length-prefixed key to one byte (255) (which is more than enough for a prefix), to save some bytes / processing.
Implemented first variant for #214.
Update: This turned out to be simpler, as the same
prefix()method can be used for both, prefixes and sub-prefixes, after signalling which one through its related type alias / helper function.Only missing piece is de-serialization of remaining keys, as they are being returned encoded. This can be tricky, as we don't have a regular format for keys, i. e. the first ones are length prefixed, but the last one isn't.
I think we can live with this: it's an issue only for
Map, and probablyIndexedMap. ForUniqueIndex, and upcomingMultiIndexwith sub-prefixes, this is already taken care of by the custom de-serialization function.