Truncate Logs - Reduce Log File to Size Limit by Dropping Oldest Entries

Question

## Problem

You have a list of log lines, each with a timestamp and a message. The log must be truncated to fit within `max_bytes` total size. Remove the oldest entries first (by timestamp). Each log line contributes `len(line) + 1` bytes (including newline).

Return the retained log lines in original order.

```python
def truncate_logs(
    lines: list[str],   # already sorted oldest-first
    max_bytes: int
) -> list[str]:
```

## Example

```
lines = [
  "2024-01-01 ERROR disk full",   # 26 bytes
  "2024-01-02 WARN retry",        # 22 bytes
  "2024-01-03 INFO ok",           # 19 bytes
]
max_bytes = 42
# total = 69; drop oldest: 69-27=42 after dropping first line
Output: ["2024-01-02 WARN retry", "2024-01-03 INFO ok"]
```

## Follow-ups

1. How would you handle truncation from the middle (remove entries matching a pattern) instead of the front?
2. What if logs must be truncated per-severity level (e.g., keep all `ERROR`, truncate `INFO` first)?
3. Implement this as a rotating log buffer class that auto-truncates on each `append` call.
4. If `max_bytes` is very large (e.g., 1 GB) and lines are on disk, how does your approach change?

Truncate Logs - Reduce Log File to Size Limit by Dropping Oldest Entries

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