From 0e9470119ea56635ea096777f4656f75138b5ed1 Mon Sep 17 00:00:00 2001 From: Paul Grosu Date: Wed, 7 Dec 2016 16:36:41 -0500 Subject: submit --- chapter/1/gRPC.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'chapter') diff --git a/chapter/1/gRPC.md b/chapter/1/gRPC.md index fceeaa6..f6c47b7 100644 --- a/chapter/1/gRPC.md +++ b/chapter/1/gRPC.md @@ -81,7 +81,7 @@ Since many streams will compete for the bandwidth of a connection, in order to p

2 Protocol Buffers with RPC

-Though gRPC was built on top of HTTP/2, an IDL had to be used to perform the communication between endpoints. The natural direction was to use Protocol Buffers is the method of stucturing data for serialization between a server and client. At the time of the start of gRPC development only version 2.0 (proto2) was available, which only implemented data structures without any request/response mechanism. An example of a Protocol Buffer data structure would look something like this: +Though gRPC was built on top of HTTP/2, an IDL had to be used to perform the communication between endpoints. The natural direction was to use Protocol Buffers is the method of stucturing key-value-based data for serialization between a server and client. At the time of the start of gRPC development only version 2.0 (proto2) was available, which only implemented data structures without any request/response mechanism. An example of a Protocol Buffer data structure would look something like this: ``` // A message containing the user's name. @@ -100,7 +100,7 @@ This message will also be encoded for highest compression when sent over the wir Table 1: Tag values for Protocol Buffer types.

-One will notice that there is a number associated with each field element in the Protocol Buffer definition, which represents its tag. In Figure 3, the field `name` has a tag of `1`. When a message gets encoded each field will start with a one byte value (8 bits), where the least-significant 3-bit value encode the type and the rest the tag. In this case tag which is `1`, with a type of 2. Thus the encoding will be `00001 010`, which has a hexdecimal value of `A`. The following byte is the length of the string which is `2`, followed by the string as `48` and `69` representing `H` and `i`. Thus the whole tranmission will look as follows: +One will notice that there is a number associated with each field element in the Protocol Buffer definition, which represents its tag. In Figure 3, the field `name` has a tag of `1`. When a message gets encoded each field (key) will start with a one byte value (8 bits), where the least-significant 3-bit value encode the type and the rest the tag. In this case tag which is `1`, with a type of 2. Thus the encoding will be `00001 010`, which has a hexdecimal value of `A`. The following byte is the length of the string which is `2`, followed by the string as `48` and `69` representing `H` and `i`. Thus the whole tranmission will look as follows: ``` A 2 48 69 -- cgit v1.2.3