`PeerString` (and some others) are Non-encodable metadata: they're getting carried around there because they make sense at the same times as metadata, but they don't go out on the wire. So... being non-encodable Encode() skips them.
There's some logging helpers that will catch them, so they show up as debug
text, but they're not directly iterable right now.
On Thu, Oct 12, 2023 at 3:53 PM John Ousterhout <john.ousterh...@gmail.com>
wrote:
> In the Homa module for gRPC there are a few places where the code needs to
> iterate over all of the values in a grpc_metadata_batch, but there are
> currently cases where my code isn't seeing all of the values. Here is an
> example from my code that attempts to log all of the values in a batch. The
> code invokes the Encode method, passing it a MetataLogger object:
>
> grpc_metadata_batch *batch;
> MetadataLogger logger(separator);
> batch->Encode(&logger);
>
> Here is the definition of the logger object:
>
> class MetadataLogger {
> public:
> MetadataLogger(const char *separator) : separator(separator) {}
>
> void Encode(const grpc_core::Slice &key, const grpc_core::Slice &value)
> {
> uint32_t keyLength = key.length();
> uint32_t valueLength = value.length();
> Mock::logPrintf(separator, "metadata %.*s: %.*s", keyLength,
> key.data(), valueLength, value.data());
> }
>
> template <typename MetadataTrait>
> void Encode(MetadataTrait, const grpc_core::Slice &value)
> {
> absl::string_view key = MetadataTrait::key();
> uint32_t keyLength = key.length();
> uint32_t valueLength = value.length();
> Mock::logPrintf(separator, "metadata %.*s: %.*s", keyLength,
> key.data(), valueLength, value.data());
> }
>
> template <typename MetadataTrait>
> void Encode(MetadataTrait, const typename MetadataTrait::ValueType&
> value)
> {
> absl::string_view key = MetadataTrait::key();
> uint32_t keyLength = key.length();
> const grpc_core::Slice& slice =
> grpc_core::MetadataValueAsSlice<MetadataTrait>(value);
> uint32_t valueLength = slice.length();
> Mock::logPrintf(separator, "metadata %.*s: %.*s", keyLength,
> key.data(), valueLength, slice.data());
> }
>
> const char *separator;
> };
>
> The class has 3 different Encode methods, intended to catch all of the
> different variants of metadata. However, it doesn't seem to be catching
> absolutely all of them. In particular, if I set the PeerString value, where
> the key is grpc_core::PeerString(), none of these methods gets invoked. Are
> there other variants of Encode that I need to define to catch this key?
> What do I need to do to be sure I'm catching absolutely all of the metadata
> entries? Is there a better way I should be doing this?
>
> Thanks in advance for any help you can provide.
>
> -John-
>
> --
> You received this message because you are subscribed to the Google Groups "
> grpc.io" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to grpc-io+unsubscr...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/grpc-io/f14fe33f-5f76-4f6a-9066-b9c920ed9835n%40googlegroups.com
> <https://groups.google.com/d/msgid/grpc-io/f14fe33f-5f76-4f6a-9066-b9c920ed9835n%40googlegroups.com?utm_medium=email&utm_source=footer>
> .
>
--
You received this message because you are subscribed to the Google Groups
"grpc.io" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to grpc-io+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/grpc-io/CAAvp3oNCqybQj64r0f5RZ3FQBSL-ydVwDBpZRTk6C5Fdq5c4pw%40mail.gmail.com.
smime.p7s
Description: S/MIME Cryptographic Signature
