Adds a new skip_instructions() reader iterator interface. It is a linear walk for every type of reader except a chunked zipfile walking a single thread.
Adds a drcachesim command line option -skip_instrs which triggers the analyzer to skip from the start before passing anything to the tool.
Refactors the reader_t++ to provide a process_input_entry to update state while skipping.
Adds a unit test with an added trace file with a small chunk size. The test checks the view output for every skip value from 0 to over double the chunk size.
Leaves several pieces for future work:
- Recording the record count in each chunk so we have an accurate count after skipping.
- Presenting global headers skipped over as memtrace_stream_t values that tools can query.
- Reading the schedule files for serial skipping (or the planned cpu iterator and skipping).
- Repeating the timestamp+cpu for non-zipfile skipping.
Issue: #5538