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Typedefed lfsr_shrub_t -> lfsr_rbyd_t, replacing lfsr_bshrub_t union

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The lfsr_shrub_t/lfsr_btree_t union was _technically_ not undefined
behavior, because the relevant fields were all a part of the "common
initial sequence", but collapsing these to the same type certainly does
simplify things.

The only weirdness is that we now store shrub.estimate in shrub.eoff.

We could add a union here, but the extra noise is just not worth the
slighty better name. The shrub.estimate is a sort of "simulated
shrub.eoff" anyways.

---

This makes it so all of these types alias to the same core lfsr_rbyd_t
type, which I suppose actually reflects the on-disk format quite well:

  lfsr_shrub_t  => lfsr_rbyd_t
  lfsr_bshrub_t
  lfsr_btree_t

Code cost more-or-less unaffected:

           code          stack          ctx
  before: 36432           2608          640
  after:  36436 (+0.0%)   2608 (+0.0%)  640 (+0.0%)
This commit is contained in:
Christopher Haster
2025-02-03 02:17:52 -06:00
parent 192c58318f
commit 7c17be4dbe
3 changed files with 91 additions and 107 deletions
Download Patch File Download Diff File Expand all files Collapse all files
tests/test_files.toml
+7 -7
View File
@@ -1097,19 +1097,19 @@ code = '''
lfsr_mdir_commit(&lfs, &file.o.o.mdir, LFSR_RATS(
LFSR_RAT_SHRUBCOMMIT(
LFSR_TAG_SHRUBCOMMIT, 0,
&file.o.bshrub.u.bshrub, 0, ((lfsr_rat_t[]){
&file.o.bshrub, 0, ((lfsr_rat_t[]){
LFSR_RAT(LFSR_TAG_DATA, +1, LFSR_DATA_BUF("?", 1))}),
1))) => 0;
lfsr_mdir_commit(&lfs, &file.o.o.mdir, LFSR_RATS(
LFSR_RAT_SHRUBCOMMIT(
LFSR_TAG_SHRUBCOMMIT, 0,
&file.o.bshrub.u.bshrub, 0, ((lfsr_rat_t[]){
&file.o.bshrub, 0, ((lfsr_rat_t[]){
LFSR_RAT(LFSR_TAG_RM, -1, LFSR_DATA_NULL())}),
1))) => 0;
lfsr_mdir_commit(&lfs, &file.o.o.mdir, LFSR_RATS(
LFSR_RAT_SHRUBTRUNK(
LFSR_TAG_SUB | LFSR_TAG_SHRUBTRUNK, 0,
&file.o.bshrub.u.bshrub))) => 0;
&file.o.bshrub))) => 0;
lfsr_file_close(&lfs, &file) => 0;
@@ -1224,16 +1224,16 @@ code = '''
// create an empty btree
lfs_alloc_ckpoint(&lfs);
lfsr_rbyd_alloc(&lfs, &file.o.bshrub.u.btree) => 0;
lfsr_rbyd_commit(&lfs, &file.o.bshrub.u.btree, 0, LFSR_RATS(
lfsr_rbyd_alloc(&lfs, &file.o.bshrub) => 0;
lfsr_rbyd_commit(&lfs, &file.o.bshrub, 0, LFSR_RATS(
LFSR_RAT(LFSR_TAG_DATA, +1, LFSR_DATA_BUF("?", 1)))) => 0;
lfsr_rbyd_commit(&lfs, &file.o.bshrub.u.btree, 0, LFSR_RATS(
lfsr_rbyd_commit(&lfs, &file.o.bshrub, 0, LFSR_RATS(
LFSR_RAT(LFSR_TAG_RM, -1, LFSR_DATA_NULL()))) => 0;
uint8_t buf[LFSR_BTREE_DSIZE];
lfsr_mdir_commit(&lfs, &file.o.o.mdir, LFSR_RATS(
LFSR_RAT(
LFSR_TAG_SUB | LFSR_TAG_BTREE, 0,
LFSR_DATA_BTREE(&file.o.bshrub.u.btree, buf)))) => 0;
LFSR_DATA_BTREE(&file.o.bshrub, buf)))) => 0;
lfsr_file_close(&lfs, &file) => 0;