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Rbyd trees with 4-leaves now working, fixed lfs_rtag_flip bug

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- This is when flips starts happening during lfs_rbyd_append
- lfs_rtag_flip had an off-by-one math mistake
This commit is contained in:
Christopher Haster
2022-12-23 12:28:13 -06:00
parent c5fec90465
commit fe28837861
3 changed files with 165 additions and 31 deletions
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lfs.c
+34 -20
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@@ -1095,7 +1095,7 @@ static inline lfs_rtag_t lfs_rbyd_flip(
return LFS_MKRALT_(
lfs_rtag_isred(alt),
!lfs_rtag_isgt(alt),
(lt+gt-1) - lfs_rtag_weight(alt));
(lt+gt+1) - lfs_rtag_weight(alt));
// TODO
}
@@ -1227,6 +1227,9 @@ static lfs_srtag_t lfs_rbyd_lookup(lfs_t *lfs, const lfs_rbyd_t *rbyd,
lfs_rtag_type2(alt),
lfs_rtag_id(tag));
printf("lt, gt = (%x, %x)\n", lt, gt);
printf("lookup %08x => %08x (raw %08x)\n", tag, tag_, alt);
// not what we're looking for?
if (tag_ < tag) {
return LFS_ERR_NOENT;
@@ -1236,8 +1239,6 @@ static lfs_srtag_t lfs_rbyd_lookup(lfs_t *lfs, const lfs_rbyd_t *rbyd,
*off = branch + delta;
*size = jump;
printf("lt, gt = (%x, %x)\n", lt, gt);
printf("lookup %08x => %08x (raw %08x)\n", tag, tag_, alt);
//return alt; // TODO adjust
//return lt << 3;
//return lfs_rtag_setid(alt, lt >> 12);
@@ -1458,7 +1459,7 @@ static int lfs_rbyd_commit(lfs_t *lfs, lfs_rbyd_t *rbyd,
// queue of pending alts we can emulate rotations with
lfs_rtag_t p_alts[3] = {0, 0, 0};
lfs_off_t p_jumps[3] = {0, 0, 0};
lfs_rtag_t stump = 0;
lfs_rtag_t xylem = 0;
// descend down tree, building alt pointers
while (true) {
@@ -1524,7 +1525,7 @@ static int lfs_rbyd_commit(lfs_t *lfs, lfs_rbyd_t *rbyd,
// } else {
// lfs_rtag_t alt_ = p_alts[0];
// p_alts[0] = lfs_rtag_black(alt);
// p_jumps[0] = stump;
// p_jumps[0] = xylem;
//
// lfs_rbyd_trim(alt_, &lt, &gt);
// lfs_rbyd_trim(alt, &lt, &gt);
@@ -1535,9 +1536,13 @@ static int lfs_rbyd_commit(lfs_t *lfs, lfs_rbyd_t *rbyd,
// }
// should've taken red alt?
if (lt < 0 || gt < 0) {
LFS_ASSERT(p_alts[0] && lfs_rtag_isred(p_alts[0]));
printf("lt,gt = (%x,%x)\n", lt, gt);
printf("p = %08x %d\n", p_alts[0], lfs_rtag_isred(p_alts[0]));
if (p_alts[0]
&& lfs_rtag_isred(p_alts[0])
&& (lt < 0 || gt < 0)) {
LFS_ASSERT(lfs_rtag_isblack(alt));
printf("???\n");
if (lfs_rtag_parallel(alt, p_alts[0])) {
printf("rflip parallel (%x,%x)\n", lt, gt);
@@ -1560,6 +1565,7 @@ static int lfs_rbyd_commit(lfs_t *lfs, lfs_rbyd_t *rbyd,
lfs_rbyd_untrim(alt, &lt, &gt);
lfs_rbyd_trim(p_alts[0], &lt, &gt);
printf("=> (%x, %x)\n", lt, gt);
}
@@ -1596,7 +1602,7 @@ static int lfs_rbyd_commit(lfs_t *lfs, lfs_rbyd_t *rbyd,
// off += delta;
//
// lfs_rbyd_trim(alt_, &lt, &gt);
// stump = branch_;
// xylem = branch_;
// branch = jump_;
//
// } else if (p_alts[0]
@@ -1621,7 +1627,7 @@ static int lfs_rbyd_commit(lfs_t *lfs, lfs_rbyd_t *rbyd,
// }
// off += delta;
//
// stump = branch_;
// xylem = branch_;
// branch = jump_;
// take black alt?
@@ -1638,8 +1644,8 @@ static int lfs_rbyd_commit(lfs_t *lfs, lfs_rbyd_t *rbyd,
}
off += delta;
lfs_rbyd_trim(lfs_rbyd_flip(alt, lt, gt), &lt, &gt);
stump = branch_;
lfs_rbyd_trim(p_alts[0], &lt, &gt);
xylem = branch_;
branch = jump;
// continue down current path
@@ -1656,20 +1662,28 @@ static int lfs_rbyd_commit(lfs_t *lfs, lfs_rbyd_t *rbyd,
off += delta;
lfs_rbyd_trim(alt, &lt, &gt);
stump = branch_;
xylem = branch_;
}
// found end of tree?
} else {
// update the tag id
// TODO should this be a function? maybe see what create/delete need
// TODO alternatively can we do this a bit more directly here
lfs_rtag_t tag_ = LFS_MKRTAG_(
lfs_rtag_type1(alt),
lfs_rtag_type2(alt),
lfs_rtag_id(attr->tag));
// split leaf?
if (alt != attr->tag) {
if (tag_ != attr->tag) {
// bias the weights so that lookups always find the
// next biggest tag
lfs_rtag_t alt_;
if (lfs_rtag_weight(alt) < lfs_rtag_weight(attr->tag)) {
// bias the weights so that lookups always find the
// next biggest tag
alt_ = LFS_MKRALT(B, LT, lt+1 - (
lfs_rtag_weight(attr->tag)
- lfs_rtag_weight(alt)));
if (lfs_rtag_weight(tag_) < lfs_rtag_weight(attr->tag)) {
alt_ = LFS_MKRALT(B, LT, lt+1
+ lfs_rtag_weight(tag_)
- lfs_rtag_weight(attr->tag));
} else {
alt_ = LFS_MKRALT(B, GT, gt);
}
@@ -1684,7 +1698,7 @@ static int lfs_rbyd_commit(lfs_t *lfs, lfs_rbyd_t *rbyd,
}
off += delta;
lfs_rbyd_p_red(p_alts, p_jumps);
//lfs_rbyd_p_red(p_alts, p_jumps);
}
// flush any pending alts