📅 Original date posted:2018-11-15
📝 Original message:
Hi ZmnSCPxj,
Precisely, something like that is what I had in mind.
Since the max message size is 65KB, one option could be to only allow
the varint to
be max 2 bytes where:
- if the 8th bit is not set, the lowest 7 bits of the first bytes
translate to 0 - 127
- if the 8th bit is set, this implies that the second byte is also
treated as part of the
length, and the total value is 0x7f & first byte + second byte << 7
This would be fairly straightforward to implement, at the cost of
limiting a particular
field to 2^15 bytes. I wonder, is this too restrictive?
At the same time, we could offer a varint that could extend up to the
three bytes.
The third byte would only come in to play if the length of the field
is greater than
2^14 - 1. The argument could be made that for values of this size, one
extra byte
is irrelevant compared to the size of these larger fields.
Cheers,
Conner
On Thu, Nov 15, 2018 at 1:45 AM ZmnSCPxj <ZmnSCPxj at protonmail.com> wrote:
>
> Good morning Conner et al,
>
> > > > 5. `len` - one byte or two? I believe we tend to use two bytes for various
> > > > lengths.
> > > >
> > >
> > > Maybe varint? One byte is not enough for all lengths, but two seems excessive
> > > for uint8 or even uint32.
> >
> > Given that messages are currently only up to 65536 bytes total, is that not a bit much?
>
> Sorry, I misunderstood.
>
> This is varint, correct? http://learnmeabitcoin.com/glossary/varint
>
> If so, I think this is good idea.
> It seems we do not have varint currently in Lightning (at least the parts I am familiar with).
> I suppose the t-l-v being in a different BOLT would let us make some section or part for describing `varint`.
>
> Regards,
> ZmnSCPxj
Conner Fromknecht [ARCHIVE] /
npub1za…uua2a
2023-06-09 12:52:54
in reply to nevent1q…jrz7
Author Public Key
npub1za0a9afyj7um5feva0d5xmhfsah3zxm252hna2duq0numa952frqvuua2aPublished at
2023-06-09 12:52:54Event JSON
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"content": "📅 Original date posted:2018-11-15\n📝 Original message:\nHi ZmnSCPxj,\n\nPrecisely, something like that is what I had in mind.\n\nSince the max message size is 65KB, one option could be to only allow\nthe varint to\nbe max 2 bytes where:\n - if the 8th bit is not set, the lowest 7 bits of the first bytes\ntranslate to 0 - 127\n - if the 8th bit is set, this implies that the second byte is also\ntreated as part of the\n length, and the total value is 0x7f \u0026 first byte + second byte \u003c\u003c 7\n\nThis would be fairly straightforward to implement, at the cost of\nlimiting a particular\nfield to 2^15 bytes. I wonder, is this too restrictive?\n\nAt the same time, we could offer a varint that could extend up to the\nthree bytes.\nThe third byte would only come in to play if the length of the field\nis greater than\n2^14 - 1. The argument could be made that for values of this size, one\nextra byte\nis irrelevant compared to the size of these larger fields.\n\nCheers,\nConner\n\nOn Thu, Nov 15, 2018 at 1:45 AM ZmnSCPxj \u003cZmnSCPxj at protonmail.com\u003e wrote:\n\u003e\n\u003e Good morning Conner et al,\n\u003e\n\u003e \u003e \u003e \u003e 5. `len` - one byte or two? I believe we tend to use two bytes for various\n\u003e \u003e \u003e \u003e lengths.\n\u003e \u003e \u003e \u003e\n\u003e \u003e \u003e\n\u003e \u003e \u003e Maybe varint? One byte is not enough for all lengths, but two seems excessive\n\u003e \u003e \u003e for uint8 or even uint32.\n\u003e \u003e\n\u003e \u003e Given that messages are currently only up to 65536 bytes total, is that not a bit much?\n\u003e\n\u003e Sorry, I misunderstood.\n\u003e\n\u003e This is varint, correct? http://learnmeabitcoin.com/glossary/varint\n\u003e\n\u003e If so, I think this is good idea.\n\u003e It seems we do not have varint currently in Lightning (at least the parts I am familiar with).\n\u003e I suppose the t-l-v being in a different BOLT would let us make some section or part for describing `varint`.\n\u003e\n\u003e Regards,\n\u003e ZmnSCPxj",
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