✨ Support LITERAL+ and LITERAL- non-synchronizing literals (RFC7888)#649
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This tests literal sending a lot more thoroughly. Most importantly, this tests both continuation rejection and continuation request. Added `literal_acceptor` proc to FakeServer, which returns if server accepts specific literal continuation, and can be varied per test.
This is internal only, for now. It is only used by `Literal` and `Literal8`, and only when `non_synchronizing` is _explicitly_ set to `true` or `false`. `CommandData` only has a single `#data` attr, so this updates `Literal` to no longer inherit from `CommandData`. `non_synchronizing` is optional. The intent is to make it tri-state: * `true` -> force non-synchronizing `LITERAL+`/`LITERAL-` behavior * `false` -> force normal synchronizing literal behavior * `nil` -> dynamic behavior, based on capabilities and literal size The `nil` behavior will be implemented in a separate commit.
I thought rdoc had fixed their endless method definition bugs with the upgrade to using prism?
This also adds a new config attribute: `max_non_synchronizing_literal`. By default, it is set rather conservatively to 16 KiB. But servers are much more likely to support `LITERAL-` than `LITERAL+`, so the practical limit will be 4096.
nevans
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enhancement
This was referenced Apr 22, 2026
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Non-synchronizing literals avoid the latency of waiting for the server to allow continuation. Non-synchronizing literals are only sent when the server's capabilities have been already been cached and include either
LITERAL+[RFC7888],LITERAL-[RFC7888], orIMAP4rev2[RFC9051].However, if a client sends a non-synchronizing literal that is too large for the server, the server may need to close the connection. Because
LITERAL+does not directly indicate the server's limits, it's best to avoid sending very large non-synchronized literals. This also addsConfig#max_non_synchronizing_literal: the maximum bytesize for non-synchronizing literals. To disable non-synchronizing literals, set the value to-1.For
LITERAL+,config.max_non_synchronizing_literalis the only limit on whether a literal value is sent as a non-synchronizing literal. ForLITERAL-andIMAP4rev2, non-synchronizing literals must also be smaller than4096bytes.By default,
config.max_non_synchronizing_literalis set to 16 KiB. But servers are much more likely to supportLITERAL-thanLITERAL+, so the practical limit will be 4096.