[PATCH 0/7] Sparse Index: integrate with reset

This series integrates the sparse index with git reset and provides miscellaneous fixes and improvements to the command in sparse checkouts. This includes:

 1. tests added to t1092 and p2000 to establish the baseline functionality
    of the command
 2. repository settings to enable the sparse index with ensure_full_index
    guarding any code paths that break tests without other compatibility
    updates.
 3. modifications to remove or reduce the scope in which ensure_full_index
    must be called.

The sparse index updates are predicated on a fix originating from the microsoft/git fork [1], correcting how git reset --mixed handles resetting entries outside the sparse checkout definition. Additionally, a performance "bug" in next_cache_entry with sparse index is corrected, preventing repeatedly looping over already-searched entries.

The p2000 tests demonstrate an overall ~70% execution time reduction across all tested usages of git reset using a sparse index:

Test before after ------------------------------------------------------------------------ 2000.22: git reset (full-v3) 0.48 0.51 +6.3% 2000.23: git reset (full-v4) 0.47 0.50 +6.4% 2000.24: git reset (sparse-v3) 0.93 0.30 -67.7% 2000.25: git reset (sparse-v4) 0.94 0.29 -69.1% 2000.26: git reset --hard (full-v3) 0.69 0.68 -1.4% 2000.27: git reset --hard (full-v4) 0.75 0.68 -9.3% 2000.28: git reset --hard (sparse-v3) 1.29 0.34 -73.6% 2000.29: git reset --hard (sparse-v4) 1.31 0.34 -74.0% 2000.30: git reset -- does-not-exist (full-v3) 0.54 0.51 -5.6% 2000.31: git reset -- does-not-exist (full-v4) 0.54 0.52 -3.7% 2000.32: git reset -- does-not-exist (sparse-v3) 1.02 0.31 -69.6% 2000.33: git reset -- does-not-exist (sparse-v4) 1.07 0.30 -72.0%

[1] microsoft@6b8a074

Thanks! -Victoria

Kevin Willford (1):
  reset: behave correctly with sparse-checkout

Victoria Dye (6):
  sparse-index: update command for expand/collapse test
  reset: expand test coverage for sparse checkouts
  reset: integrate with sparse index
  reset: make sparse-aware (except --mixed)
  reset: make --mixed sparse-aware
  unpack-trees: improve performance of next_cache_entry

 builtin/reset.c                          |  77 ++++++++++++-
 cache-tree.c                             |  43 ++++++-
 cache.h                                  |  10 ++
 read-cache.c                             |  22 ++--
 t/perf/p2000-sparse-operations.sh        |   3 +
 t/t1092-sparse-checkout-compatibility.sh | 139 ++++++++++++++++++++++-
 t/t7114-reset-sparse-checkout.sh         |  61 ++++++++++
 unpack-trees.c                           |  23 +++-
 8 files changed, 353 insertions(+), 25 deletions(-)
 create mode 100755 t/t7114-reset-sparse-checkout.sh

base-commit: cefe983a320c03d7843ac78e73bd513a27806845
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1048%2Fvdye%2Fvdye%2Fsparse-index-part1-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1048/vdye/vdye/sparse-index-part1-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1048