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Limited bptr decoding to lfs_file_* functions

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Bptrs really are a file concept, despite the name (bptr =>
block-pointer). Other bshrubs/btrees do not have bptrs.

Returning decoded bptrs from lfsr_bshrub_lookupnext and friends was a
bit of a hack to make bsprouts (single bptrs) work, but now that we
don't support bsprouts, we don't need this hack anymore.

To avoid code duplication, this does reroute mtree traversal through
lfsr_file_traverse_. Which is a bit weird, but not the worst thing this
codebase has ever done.

Code changes:

           code          stack          ctx
  before: 36492           2608          640
  after:  36460 (-0.1%)   2608 (+0.0%)  640 (+0.0%)
This commit is contained in:
Christopher Haster
2025-02-04 15:30:01 -06:00
parent 1259c170c4
commit b115ebbac0
2 changed files with 86 additions and 81 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lfs.c
+82 -77
View File
@@ -6212,79 +6212,23 @@ static lfs_ssize_t lfsr_bshrub_estimate(lfs_t *lfs,
static int lfsr_bshrub_lookupnext(lfs_t *lfs, const lfsr_bshrub_t *bshrub,
lfsr_bid_t bid,
lfsr_bid_t *bid_, lfsr_tag_t *tag_, lfsr_bid_t *weight_,
lfsr_bptr_t *bptr_) {
// out of bounds?
if (bid >= bshrub->shrub.weight) {
return LFS_ERR_NOENT;
}
lfsr_data_t *data_) {
return lfsr_btree_lookupnext(lfs, &bshrub->shrub, bid,
bid_, tag_, weight_, data_);
}
// bshrub/btree?
lfsr_bid_t bid__;
lfsr_rbyd_t rbyd;
lfsr_srid_t rid;
lfsr_tag_t tag;
lfsr_bid_t weight;
lfsr_data_t data;
int err = lfsr_btree_lookupnext_(lfs, &bshrub->shrub, bid,
&bid__, &rbyd, &rid, &tag, &weight, &data);
if (err) {
LFS_ASSERT(err != LFS_ERR_NOENT);
return err;
}
LFS_ASSERT(tag == LFSR_TAG_DATA
|| tag == LFSR_TAG_BLOCK);
if (bid_) {
*bid_ = bid__;
}
if (tag_) {
*tag_ = tag;
}
if (weight_) {
*weight_ = weight;
}
if (bptr_) {
// decode bptrs
if (tag == LFSR_TAG_DATA) {
bptr_->data = data;
} else {
err = lfsr_data_readbptr(lfs, &data, bptr_);
if (err) {
return err;
}
}
LFS_ASSERT(lfsr_data_size(bptr_->data) <= weight);
}
return 0;
static int lfsr_bshrub_lookup(lfs_t *lfs, const lfsr_bshrub_t *bshrub,
lfsr_bid_t bid,
lfsr_tag_t *tag_, lfsr_bid_t *weight_, lfsr_data_t *data_) {
return lfsr_btree_lookup(lfs, &bshrub->shrub, bid,
tag_, weight_, data_);
}
static int lfsr_bshrub_traverse(lfs_t *lfs, const lfsr_bshrub_t *bshrub,
lfsr_btraversal_t *bt,
lfsr_bid_t *bid_, lfsr_tag_t *tag_, lfsr_bptr_t *bptr_) {
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_btree_traverse(lfs, &bshrub->shrub, bt,
bid_, &tag, &data);
if (err) {
return err;
}
// decode bptrs
if (tag_) {
*tag_ = tag;
}
if (bptr_) {
if (tag == LFSR_TAG_BLOCK) {
err = lfsr_data_readbptr(lfs, &data,
bptr_);
if (err) {
return err;
}
} else {
bptr_->data = data;
}
}
return 0;
lfsr_bid_t *bid_, lfsr_tag_t *tag_, lfsr_data_t *data_) {
return lfsr_btree_traverse(lfs, &bshrub->shrub, bt,
bid_, tag_, data_);
}
// needed in lfsr_bshrub_commit_
@@ -9016,6 +8960,11 @@ static void lfsr_traversal_init(lfsr_traversal_t *t, uint32_t flags) {
t->gcksum = 0;
}
// needed in lfsr_mtree_traverse_
static int lfsr_file_traverse_(lfs_t *lfs, const lfsr_bshrub_t *bshrub,
lfsr_btraversal_t *bt,
lfsr_bid_t *bid_, lfsr_tag_t *tag_, lfsr_bptr_t *bptr_);
// low-level traversal _only_ finds blocks
static int lfsr_mtree_traverse_(lfs_t *lfs, lfsr_traversal_t *t,
lfsr_tag_t *tag_, lfsr_bptr_t *bptr_) {
@@ -9234,13 +9183,17 @@ static int lfsr_mtree_traverse_(lfs_t *lfs, lfsr_traversal_t *t,
LFSR_TSTATE_OBTREE);
continue;
// traverse any btrees we see, this includes the mtree and any file
// btrees/bshrubs
// traverse any bshrubs/btrees we see, this includes the mtree
// and any file btrees/bshrubs
case LFSR_TSTATE_MTREE:;
case LFSR_TSTATE_BTREE:;
case LFSR_TSTATE_OBTREE:;
// traverse through our file
err = lfsr_bshrub_traverse(lfs, &t->b, &t->u.bt,
// traverse through our bshrub/btree
//
// it probably looks a bit weird to go through
// lfsr_file_traverse_, but this gets us bptr decoding
// for free
err = lfsr_file_traverse_(lfs, &t->b, &t->u.bt,
NULL, &tag, bptr_);
if (err) {
if (err == LFS_ERR_NOENT) {
@@ -11116,11 +11069,34 @@ int lfsr_file_close(lfs_t *lfs, lfsr_file_t *file) {
// low-level file reading
static int lfsr_file_lookupnext(lfs_t *lfs, const lfsr_file_t *file,
lfs_off_t pos,
lfsr_bid_t bid,
lfsr_bid_t *bid_, lfsr_tag_t *tag_, lfsr_bid_t *weight_,
lfsr_bptr_t *bptr_) {
return lfsr_bshrub_lookupnext(lfs, &file->b, pos,
bid_, tag_, weight_, bptr_);
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_bshrub_lookupnext(lfs, &file->b, bid,
bid_, &tag, weight_, &data);
if (err) {
return err;
}
LFS_ASSERT(tag == LFSR_TAG_DATA
|| tag == LFSR_TAG_BLOCK);
// decode bptrs
if (tag_) {
*tag_ = tag;
}
if (bptr_) {
if (tag == LFSR_TAG_DATA) {
bptr_->data = data;
} else {
err = lfsr_data_readbptr(lfs, &data, bptr_);
if (err) {
return err;
}
}
}
return 0;
}
static lfs_ssize_t lfsr_file_readnext(lfs_t *lfs, const lfsr_file_t *file,
@@ -12714,16 +12690,45 @@ failed:;
// file check functions
static int lfsr_file_traverse_(lfs_t *lfs, const lfsr_bshrub_t *bshrub,
lfsr_btraversal_t *bt,
lfsr_bid_t *bid_, lfsr_tag_t *tag_, lfsr_bptr_t *bptr_) {
lfsr_tag_t tag;
lfsr_data_t data;
int err = lfsr_bshrub_traverse(lfs, bshrub, bt,
bid_, &tag, &data);
if (err) {
return err;
}
// decode bptrs
if (tag_) {
*tag_ = tag;
}
if (bptr_) {
if (tag == LFSR_TAG_BLOCK) {
err = lfsr_data_readbptr(lfs, &data,
bptr_);
if (err) {
return err;
}
} else {
bptr_->data = data;
}
}
return 0;
}
static int lfsr_file_traverse(lfs_t *lfs, const lfsr_file_t *file,
lfsr_btraversal_t *bt,
lfsr_bid_t *bid_, lfsr_tag_t *tag_, lfsr_bptr_t *bptr_) {
return lfsr_bshrub_traverse(lfs, &file->b, bt,
return lfsr_file_traverse_(lfs, &file->b, bt,
bid_, tag_, bptr_);
}
static int lfsr_file_ck(lfs_t *lfs, const lfsr_file_t *file,
uint32_t flags) {
// traverse the file's btree
// traverse the file's bshrub/btree
lfsr_btraversal_t bt;
lfsr_btraversal_init(&bt);
while (true) {
tests/test_fwrite.toml
+4 -4
View File
@@ -189,7 +189,7 @@ code = '''
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bptr_t bptr;
int err = lfsr_bshrub_traverse(&lfs, &file.b, &bt,
int err = lfsr_file_traverse(&lfs, &file, &bt,
&bid, &tag, &bptr);
assert(!err || err == LFS_ERR_NOENT);
if (err == LFS_ERR_NOENT) {
@@ -329,7 +329,7 @@ code = '''
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bptr_t bptr;
int err = lfsr_bshrub_traverse(&lfs, &file.b, &bt,
int err = lfsr_file_traverse(&lfs, &file, &bt,
&bid, &tag, &bptr);
assert(!err || err == LFS_ERR_NOENT);
if (err == LFS_ERR_NOENT) {
@@ -587,7 +587,7 @@ code = '''
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bptr_t bptr;
int err = lfsr_bshrub_traverse(&lfs, &file.b, &bt,
int err = lfsr_file_traverse(&lfs, &file, &bt,
&bid, &tag, &bptr);
assert(!err || err == LFS_ERR_NOENT);
if (err == LFS_ERR_NOENT) {
@@ -742,7 +742,7 @@ code = '''
lfsr_bid_t bid;
lfsr_tag_t tag;
lfsr_bptr_t bptr;
int err = lfsr_bshrub_traverse(&lfs, &file.b, &bt,
int err = lfsr_file_traverse(&lfs, &file, &bt,
&bid, &tag, &bptr);
assert(!err || err == LFS_ERR_NOENT);
if (err == LFS_ERR_NOENT) {