[DISPATCH-1403] Consolidate chained qd_buffer_t field handling code

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.8.0, 1.9.0
• Fix Version/s: 1.19.0
• Component/s: Router Node
• Labels: refactor
• Assignee: Ken Giusti
• Reporter: Ken Giusti
• Created: 28/Aug/19 13:33
• Updated: 22/Mar/22 19:12
• Resolved: 17/Feb/22 21:05

Description

There are many places in the router's C codebase where we need to work with data spanning a chained qd_buffer_t list. In particular the low level operations such as:

• advance N bytes
• compare N bytes
• copy N bytes
  are common throughout the code.

Here are examples from the iterator.c library:
copy bytes
advance cursor
compare

Similar logic is implemented in message.c and parse.c.

We should de-duplicate this code by providing a common implementation as part of the buffer handling code.