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Tweaked SHRUBCOMMIT to infer alloc from block address

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Turns out we don't need SHRUBALLOC, as we can infer if we need to reset
the shrub based on if it already exists in our mdir. Not in mdir =>
needs to alloc/reset.

This saves an internal tag and a bit of code:

           code          stack
  before: 33770           2600 (+0.0%)
  after:  33746 (-0.1%)   2600 (+0.0%)
This commit is contained in:
Christopher Haster
2024-06-07 00:44:32 -05:00
parent 2402e108db
commit f7165f3176
1 changed files with 15 additions and 21 deletions
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lfs.c
+15 -21
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@@ -836,9 +836,8 @@ enum lfsr_tag {
// in-device only tags, these should never get written to disk
LFSR_TAG_INTERNAL = 0x0800,
LFSR_TAG_MOVE = 0x0800,
LFSR_TAG_SHRUBALLOC = 0x0801,
LFSR_TAG_SHRUBCOMMIT = 0x0802,
LFSR_TAG_SHRUBTRUNK = 0x0803,
LFSR_TAG_SHRUBCOMMIT = 0x0801,
LFSR_TAG_SHRUBTRUNK = 0x0802,
// some in-device only tag modifiers
LFSR_TAG_RM = 0x8000,
@@ -6146,7 +6145,7 @@ static int lfsr_mdir_commit__(lfs_t *lfs, lfsr_mdir_t *mdir,
return err;
}
// compact our bshrub
// compact our shrub
err = lfsr_shrub_compact(lfs, &rbyd_, &shrub,
&shrub);
if (err) {
@@ -6224,24 +6223,21 @@ static int lfsr_mdir_commit__(lfs_t *lfs, lfsr_mdir_t *mdir,
// shrub tags append a set of attributes to an unrelated trunk
// in our rbyd
} else if (attrs[i].tag == LFSR_TAG_SHRUBALLOC
|| attrs[i].tag == LFSR_TAG_SHRUBCOMMIT) {
const lfsr_shrubcommit_t *bshrubcommit = attrs[i].cat;
} else if (attrs[i].tag == LFSR_TAG_SHRUBCOMMIT) {
const lfsr_shrubcommit_t *shrubcommit = attrs[i].cat;
// SHRUBALLOC is roughly the same as SHRUBCOMMIT but also
// resets the shrub, we need to do this here so bshrub root
// extensions are atomic
if (attrs[i].tag == LFSR_TAG_SHRUBALLOC) {
bshrubcommit->shrub->blocks[0] = rbyd_.blocks[0];
bshrubcommit->shrub->trunk = LFSR_RBYD_ISSHRUB | 0;
bshrubcommit->shrub->weight = 0;
// reset shrub if it doesn't live in our block, this happens
// when converting from a btree
if (shrubcommit->shrub->blocks[0] != rbyd_.blocks[0]) {
shrubcommit->shrub->blocks[0] = rbyd_.blocks[0];
shrubcommit->shrub->trunk = LFSR_RBYD_ISSHRUB | 0;
shrubcommit->shrub->weight = 0;
}
// commit to shrub
int err = lfsr_shrub_commit(lfs, &rbyd_,
bshrubcommit->shrub,
bshrubcommit->rid,
bshrubcommit->attrs,
bshrubcommit->attr_count);
shrubcommit->shrub, shrubcommit->rid,
shrubcommit->attrs, shrubcommit->attr_count);
if (err) {
return err;
}
@@ -10559,9 +10555,7 @@ static int lfsr_bshrub_commit(lfs_t *lfs, lfsr_file_t *file,
// commit to shrub
int err = lfsr_mdir_commit(lfs, &file->o.mdir, LFSR_ATTRS(
LFSR_ATTR_SHRUBCOMMIT(
(alloc)
? LFSR_TAG_SHRUBALLOC
: LFSR_TAG_SHRUBCOMMIT, 0,
LFSR_TAG_SHRUBCOMMIT, 0,
&file->bshrub_.u.bshrub, bid,
attrs, attr_count)));
if (err) {