Offset Commit Advancement

A consumer has already committed offset committed. It has processed a set of additional offsets (unordered). It can only advance the commit to the highest contiguous offset starting from committed + 1.

Given the current committed offset and the set of processed offsets, compute the new committed offset.

Function signature

func AdvanceCommitOffset(committed int, processed []int) int

Example

committed = 4
processed = [6,5,8]
output = 6

Constraints

• committed >= 0
• 0 <= len(processed) <= 200000
• processed may include duplicates

Exact rules

• Offsets <= committed do not change the result.
• processed is unordered and may contain duplicates.
• Commit may advance only through a contiguous run:
  • committed+1, committed+2, ...
• Stop at the first missing offset.

Implementation recipe (near-answer)

1. Build a set of processed offsets greater than committed.
2. Start cur := committed.
3. While cur+1 exists in set:
   • increment cur
4. Return cur.

Complexity target

• Time: O(len(processed))
• Memory: O(len(processed))

Edge-case reminders

• Empty processed returns the original committed.
• A large offset without preceding contiguous offsets cannot advance commit.