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Tweaked lfsr_btree_carve to take bptr+becksum instead of attr-list

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This avoids a hacky shoehorning of our attr-list while also making
lfsr_btree_carve a nice reflection of lfsr_ftree_lookupnext.

I'm kind of surprised how little this impacts code size, maybe const
propagation already pushed the attr bounds through?

            code          stack
  before:  32124           2888
  after:   32128 (+0.0%)   2880 (-0.3%)
This commit is contained in:
Christopher Haster
2023-12-14 01:35:45 -06:00
parent 490938b8ca
commit 34b1e3ef00
1 changed files with 26 additions and 26 deletions
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lfs.c
+26 -26
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@@ -9419,10 +9419,7 @@ static int lfsr_ftree_lookupnext(lfs_t *lfs,
static int lfsr_ftree_carve(lfs_t *lfs,
lfsr_mdir_t *mdir, lfsr_ftree_t *ftree,
lfs_off_t pos, lfs_off_t weight, lfs_soff_t delta,
const lfsr_attr_t *attrs, lfs_size_t attr_count) {
// only <=2 attrs currently supported (bptr+becksum)
LFS_ASSERT(attr_count <= 2);
lfsr_tag_t tag, const lfsr_bptr_t *bptr, const lfsr_ecksum_t *becksum) {
// Note! This function has some rather special constraints:
//
// 1. We must never allow our btree size to overflow, even temporarily.
@@ -9472,7 +9469,7 @@ static int lfsr_ftree_carve(lfs_t *lfs,
// try to merge commits where possible
lfsr_attr_t attrs_[5];
lfs_size_t attr_count_ = 0;
uint8_t buf[2*LFSR_BPTR_DSIZE+LFSR_ECKSUM_DSIZE];
uint8_t buf[3*LFSR_BPTR_DSIZE+2*LFSR_ECKSUM_DSIZE];
lfs_size_t buf_size = 0;
// try to carve any existing data
@@ -9663,22 +9660,33 @@ static int lfsr_ftree_carve(lfs_t *lfs,
// finally append our data
if (weight + delta > 0) {
// can we coalesce a hole?
if (pos > 0 && attr_count == 0) {
if ((!bptr || lfsr_data_size(&bptr->data) == 0) && pos > 0) {
attrs_[attr_count_++] = LFSR_ATTR(pos-1,
GROW, +(weight + delta), NULL());
// need a new hole?
} else if (attr_count == 0) {
} else if (!bptr || lfsr_data_size(&bptr->data) == 0) {
attrs_[attr_count_++] = LFSR_ATTR(pos,
DATA, +(weight + delta), NULL());
// append new data
} else {
for (lfs_size_t i = 0; i < attr_count; i++) {
attrs_[attr_count_++] = LFSR_ATTR(
(i == 0) ? pos : pos+weight+delta-1,
TAG(attrs[i].tag), (i == 0) ? +(weight + delta) : 0,
DATA(attrs[i].data));
// append new fragment?
} else if (tag == LFSR_TAG_DATA) {
attrs_[attr_count_++] = LFSR_ATTR(pos,
DATA, +(weight + delta), DATA(bptr->data));
// append a new block?
} else if (tag == LFSR_TAG_BLOCK) {
attrs_[attr_count_++] = LFSR_ATTR(pos,
BLOCK, +(weight + delta),
FROMBPTR(bptr, &buf[buf_size]));
buf_size += LFSR_BPTR_DSIZE;
// append becksum?
if (becksum && becksum->size != -1) {
attrs_[attr_count_++] = LFSR_ATTR(pos+weight+delta-1,
BECKSUM, 0,
FROMECKSUM(becksum, &buf[buf_size]));
buf_size += LFSR_ECKSUM_DSIZE;
}
}
}
@@ -10050,16 +10058,9 @@ static int lfsr_ftree_flush(lfs_t *lfs,
}
// and write it into our tree
uint8_t bptr_buf[LFSR_BPTR_DSIZE];
uint8_t becksum_buf[LFSR_ECKSUM_DSIZE];
err = lfsr_ftree_carve(lfs, mdir, ftree,
block_start, block_end - block_start, 0,
LFSR_ATTRS(
LFSR_ATTR(0, BLOCK, 0, FROMBPTR(&bptr, bptr_buf)),
(becksum.size != -1)
? LFSR_ATTR(0,
BECKSUM, 0, FROMECKSUM(&becksum, becksum_buf))
: LFSR_ATTR_NOOP()));
LFSR_TAG_BLOCK, &bptr, &becksum);
if (err) {
return err;
}
@@ -10166,8 +10167,7 @@ static int lfsr_ftree_flush(lfs_t *lfs,
// our tree
int err = lfsr_ftree_carve(lfs, mdir, ftree,
fragment_start, fragment_end - fragment_start, 0,
LFSR_ATTRS(
LFSR_ATTR(-1, DATA, 0, DATA(data))));
LFSR_TAG_DATA, &(const lfsr_bptr_t){.data=data}, NULL);
if (err && err != LFS_ERR_RANGE) {
return err;
}
@@ -10586,7 +10586,7 @@ int lfsr_file_truncate(lfs_t *lfs, lfsr_file_t *file, lfs_off_t size) {
lfs_min32(file->size, size),
file->size - lfs_min32(file->size, size),
+size - file->size,
NULL, 0);
LFSR_TAG_DATA, NULL, NULL);
if (err) {
goto failed;
}
@@ -10648,7 +10648,7 @@ int lfsr_file_fruncate(lfs_t *lfs, lfsr_file_t *file, lfs_off_t size) {
0,
lfs_smax32(file->size - size, 0),
+size - file->size,
NULL, 0);
LFSR_TAG_DATA, NULL, NULL);
if (err) {
goto failed;
}