Thanks Doug,
That affirms the direction that I was heading. Should I assume that metadata
is unique to each message? Here is what I have done so far for the code
generator portion. Should I worry about generating code that looks like
example 1 where I pass along a dictionary for metadata? Or should I look at
something like example 2 where I don't pass along the metadata. I could also
do a combination of both.
Example 1
[System.CodeDom.Compiler.GeneratedCodeAttribute("Avro.CodeGen.AvroGen",
"1.0")]
public interface Simple
{
/// <summary>
/// Send a greeting
/// </summary>
string hello(System.Collections.Generic.IDictionary<string, byte[]>
metadata, string greeting);
/// <summary>
/// Pretend you're in a cave!
/// </summary>
TestRecord echo(System.Collections.Generic.IDictionary<string,
byte[]> metadata, TestRecord record);
int add(System.Collections.Generic.IDictionary<string, byte[]>
metadata, int arg1, int arg2);
byte[] echoBytes(System.Collections.Generic.IDictionary<string,
byte[]> metadata, byte[] data);
/// <summary>
/// Always throws an error.
/// </summary>
void error(System.Collections.Generic.IDictionary<string, byte[]>
metadata);
}
Example 2
[System.CodeDom.Compiler.GeneratedCodeAttribute("Avro.CodeGen.AvroGen",
"1.0")]
public interface Simple
{
/// <summary>
/// Send a greeting
/// </summary>
string hello(string greeting);
/// <summary>
/// Pretend you're in a cave!
/// </summary>
TestRecord echo(TestRecord record);
int add(int arg1, int arg2);
byte[] echoBytes(byte[] data);
/// <summary>
/// Always throws an error.
/// </summary>
void error();
}
On Mon, Jun 7, 2010 at 5:03 PM, Doug Cutting <[email protected]> wrote:
> On 06/07/2010 02:25 PM, Jeremy Custenborder wrote:
>
>> This will be my last question for at least the next day or two. :) I just
>> want to double check my interpretation of the message framing.
>>
>
> Framing is mostly orthogonal to payload structure. It just says that the
> bytes that make up a payload are broken into length-prefixed frames. Those
> frames may or may not align with the payload's structure. When they do line
> up, optimizations are possible, so implementations should try to line them
> up when sending largish binary objects.
>
> Request payloads are of the form <metadata><messageName><parameters> and
> response payloads are of the form <metadata><boolean><errorOrResponse>.
> These may be delivered in one or more frames. A good framing might be to
> use a single frame unless a parameter has a bytes value that's larger than
> 4k, in which case that buffer might be transmitted as a distinct frame, so
> that it can be potentially processed in zerocopy style. I.e., if it
> contains file data, then the sendfile system call could be used to copy data
> from file to socket.
>
> Does that help?
>
> Doug
>
