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Half-adopted upper/lower bounds in lookup and append

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This commit is contained in:
Christopher Haster
2023-01-01 15:22:15 -06:00
parent 55e9df571b
commit d78c4412b6
2 changed files with 232 additions and 187 deletions
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lfs.c
+112 -67
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@@ -469,6 +469,15 @@ enum lfs_rtag_pat {
#define LFS_MKRALT(color, dir, weight) \
LFS_MKRALT_(LFS_ALT_##color, LFS_ALT_##dir, weight)
#define LFS_MKRALT___(color, dir, weight) \
(LFS_TYPE1_ALT \
| ((0x1 & (lfs_rtag_t)(color)) << 0) \
| ((0x1 & (lfs_rtag_t)(dir)) << 1) \
| ((0x1ffffff8 & (lfs_rtag_t)(weight))))
#define LFS_MKRALT__(color, dir, weight) \
LFS_MKRALT___(LFS_ALT_##color, LFS_ALT_##dir, weight)
// tag operations
static inline bool lfs_rtag_isvalid(lfs_rtag_t tag) {
return !(tag & 0x80000000);
@@ -563,6 +572,10 @@ static inline lfs_srtag_t lfs_rtag_weight(lfs_rtag_t tag) {
return tag >> 3;
}
static inline lfs_rtag_t lfs_rtag_weight_(lfs_rtag_t tag) {
return tag & ~0x7;
}
static inline lfs_rtag_t lfs_rtag_merge(lfs_rtag_t a, lfs_rtag_t b) {
return a + (b & ~0x7);
}
@@ -585,6 +598,16 @@ static inline bool lfs_rtag_follow(lfs_rtag_t alt,
}
}
static inline bool lfs_rtag_follow_(lfs_rtag_t alt,
lfs_rtag_t lower, lfs_rtag_t upper, lfs_rtag_t tag) {
// TODO should we expect weight as an argument here?
if (lfs_rtag_isgt(alt)) {
return lfs_rtag_weight_(tag) >= upper - lfs_rtag_weight_(alt);
} else {
return lfs_rtag_weight_(tag) < lower + lfs_rtag_weight_(alt);
}
}
static inline lfs_rtag_t lfs_rtag_flip(
lfs_rtag_t alt, lfs_rtag_t lt, lfs_rtag_t gt) {
return LFS_MKRALT_(
@@ -593,6 +616,14 @@ static inline lfs_rtag_t lfs_rtag_flip(
(lt+gt+1) - lfs_rtag_weight(alt));
}
static inline lfs_rtag_t lfs_rtag_flip_(lfs_rtag_t alt,
lfs_rtag_t lower, lfs_rtag_t upper) {
return LFS_MKRALT___(
lfs_rtag_isred(alt),
!lfs_rtag_isgt(alt),
(upper-lower) - lfs_rtag_weight_(alt));
}
static inline void lfs_rtag_trim(lfs_rtag_t alt,
lfs_srtag_t *lt, lfs_srtag_t *gt) {
if (lfs_rtag_islt(alt)) {
@@ -602,6 +633,15 @@ static inline void lfs_rtag_trim(lfs_rtag_t alt,
}
}
static inline void lfs_rtag_trim_(lfs_rtag_t alt,
lfs_rtag_t *lower, lfs_rtag_t *upper) {
if (lfs_rtag_isgt(alt)) {
*upper -= lfs_rtag_weight_(alt);
} else {
*lower += lfs_rtag_weight_(alt);
}
}
static inline void lfs_rtag_untrim(lfs_rtag_t alt,
lfs_srtag_t *lt, lfs_srtag_t *gt) {
if (lfs_rtag_islt(alt)) {
@@ -611,6 +651,15 @@ static inline void lfs_rtag_untrim(lfs_rtag_t alt,
}
}
static inline void lfs_rtag_untrim_(lfs_rtag_t alt,
lfs_rtag_t *lower, lfs_rtag_t *upper) {
if (lfs_rtag_isgt(alt)) {
*upper += lfs_rtag_weight_(alt);
} else {
*lower -= lfs_rtag_weight_(alt);
}
}
// operations on attribute lists
struct lfs_mattr {
lfs_tag_t tag;
@@ -1230,10 +1279,9 @@ tryagain:;
return LFS_ERR_NOENT;
}
// weights for pruning
lfs_srtag_t lt = lfs_rtag_weight_lt(tag, rbyd->count+1);
lfs_srtag_t gt = lfs_rtag_weight_gt(tag, rbyd->count+1);
printf("lt, gt = (%x, %x)\n", lt, gt);
// keep track of bounds as we descend down the tree
lfs_rtag_t lower = 0;
lfs_rtag_t upper = (rbyd->count+1) << 15;
// descend down tree
while (true) {
@@ -1248,21 +1296,22 @@ tryagain:;
// found an alt?
if (lfs_rtag_isalt(alt)) {
printf("follow %c%x (%x, %x)? => %d\n", lfs_rtag_isgt(alt) ? '>' : '<', lfs_rtag_weight(alt), lt, gt, lfs_rtag_follow(alt, lt, gt));
if (lfs_rtag_follow(alt, lt, gt)) {
lfs_rtag_trim(lfs_rtag_flip(alt, lt, gt), &lt, &gt);
printf("follow %c%x (%x, %x, %x)? => %d\n", lfs_rtag_isgt(alt) ? '>' : '<', lfs_rtag_weight_(alt), lower, upper, tag, lfs_rtag_follow_(alt, lower, upper, tag));
if (lfs_rtag_follow_(alt, lower, upper, tag)) {
lfs_rtag_trim_(lfs_rtag_flip_(alt, lower, upper), &lower, &upper);
branch = branch - jump;
} else {
lfs_rtag_trim(alt, &lt, &gt);
lfs_rtag_trim_(alt, &lower, &upper);
branch = branch + delta;
}
// found end of tree?
} else {
// update the tag id
lfs_rtag_t tag_ = lfs_rtag_setid(alt, lfs_rtag_id(tag));
//lfs_rtag_t tag_ = lfs_rtag_setid(alt, lfs_rtag_id(tag));
lfs_rtag_t tag_ = lfs_rtag_setid(alt, lfs_rtag_id(upper-1));
printf("lt, gt = (%x, %x)\n", lt, gt);
printf("lower, upper = (%x, %x)\n", lower, upper);
printf("lookup %08x => %08x (raw %08x)\n", tag, tag_, alt);
// not what we're looking for?
@@ -1270,6 +1319,7 @@ tryagain:;
return LFS_ERR_NOENT;
}
// TODO we should make this impossible
// was removed? go on to the next tag
if (lfs_rtag_isrm(tag_)) {
tag = lfs_rtag_inc(tag_);
@@ -1475,6 +1525,16 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
goto leaf;
}
// keep track of bounds as we descend down the tree
lfs_rtag_t lower = 0;
lfs_rtag_t upper = (rbyd_->count+1) << 15;
lfs_rtag_t tag__;
if (lfs_rtag_type1(tag) == LFS_TYPE1_CREATE) {
tag__ = (tag & ~0x7fff)-1;
} else {
tag__ = tag;
}
// weights for pruning
lfs_srtag_t lt;
lfs_srtag_t gt;
@@ -1520,6 +1580,7 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
lfs_rtag_t branch_ = branch + delta;
// prune?
assert((lfs_rtag_weight(alt) >= lt+gt+1) == (lfs_rtag_weight_(alt) >= (upper-lower)));
if (lfs_rtag_weight(alt) >= lt+gt+1) {
printf("prune!\n");
LFS_ASSERT(p_alts[0]);
@@ -1531,6 +1592,7 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
lfs_rbyd_p_pop(p_alts, p_jumps);
lfs_rtag_untrim(alt, &lt, &gt);
lfs_rtag_untrim_(alt, &lower, &upper);
}
// two reds makes a yellow, split?
@@ -1542,6 +1604,7 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
// if we take the red or yellow alt we can just point
// to the black alt, otherwise we need to point to the
// yellow alt and prune later
assert(lfs_rtag_follow_(alt, lower, upper, tag__) == lfs_rtag_follow(alt, lt, gt));
if (lfs_rtag_follow(alt, lt, gt)) {
printf("ysplit follow\n");
lfs_rtag_t alt_ = p_alts[0];
@@ -1554,7 +1617,9 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
jump = jump_;
lfs_rtag_untrim(alt, &lt, &gt);
lfs_rtag_untrim_(alt, &lower, &upper);
lfs_rtag_trim(p_alts[0], &lt, &gt);
lfs_rtag_trim_(p_alts[0], &lower, &upper);
lfs_rbyd_p_red(p_alts, p_jumps);
} else {
@@ -1565,6 +1630,7 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
p_jumps[0] = graft;
lfs_rtag_trim(alt, &lt, &gt);
lfs_rtag_trim_(alt, &lower, &upper);
lfs_rbyd_p_red(p_alts, p_jumps);
graft = 0;
@@ -1574,6 +1640,7 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
}
// should've taken red alt? needs a flip
assert((lt < 0 || gt < 0) == (tag__ < lower || tag__ >= upper));
if (lt < 0 || gt < 0) {
LFS_ASSERT(p_alts[0]);
LFS_ASSERT(lfs_rtag_isred(p_alts[0]));
@@ -1599,10 +1666,13 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
jump = jump_;
lfs_rtag_untrim(alt, &lt, &gt);
lfs_rtag_untrim_(alt, &lower, &upper);
lfs_rtag_trim(p_alts[0], &lt, &gt);
lfs_rtag_trim_(p_alts[0], &lower, &upper);
}
// take black alt? needs a flip
assert(lfs_rtag_follow_(alt, lower, upper, tag__) == lfs_rtag_follow(alt, lt, gt));
if (lfs_rtag_isblack(alt) && lfs_rtag_follow(alt, lt, gt)) {
printf("bflip\n");
alt = lfs_rtag_flip(alt, lt, gt);
@@ -1621,6 +1691,7 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
// continue to next alt
lfs_rtag_trim(alt, &lt, &gt);
lfs_rtag_trim_(alt, &lower, &upper);
graft = branch;
branch = branch_;
@@ -1631,11 +1702,13 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
// TODO alternatively can we do this a bit more directly here
// lfs_rtag_t tag_ = lfs_rtag_setid(alt,
// lfs_min(lfs_rtag_id(attr->tag), count));
lfs_rtag_t tag_ = lfs_rtag_setid(alt, lfs_rtag_id(tag));
//lfs_rtag_t tag_ = lfs_rtag_setid(alt, lfs_rtag_id(tag));
// TODO I don't really know why this works
if (lfs_rtag_type1(tag) == LFS_TYPE1_CREATE && gt == 0) {
tag_ = lfs_rtag_decid(tag_);
}
// if (lfs_rtag_type1(tag) == LFS_TYPE1_CREATE && gt == 0) {
// tag_ = lfs_rtag_decid(tag_);
// }
lfs_rtag_t tag_ = lfs_rtag_setid(alt, lfs_rtag_id(upper-1));
//gt == 0 ? lfs_rtag_id(attr->tag)-1 : lfs_rtag_id(attr->tag));
printf("found %x (%d, %d)\n", tag_, lt >> 12, gt >> 12);
@@ -1645,66 +1718,38 @@ static int lfs_rbyd_append(lfs_t *lfs, lfs_rbyd_t *rbyd_,
|| tag_ != tag) {
// inserting a new id?
if (lfs_rtag_type1(tag) == LFS_TYPE1_CREATE) {
// bias the weights so that lookups always find the
// next biggest tag
// note we bias the weights here so that lfs_rbyd_lookup
// always finds the next biggest tag
if (lfs_rtag_weight(tag_)
< lfs_rtag_weight(tag & ~0x7fff)) {
printf("lt insert\n");
//
// lt gt
// .----'---. .-'.
// alt
// .--'--.
// <---+------+---|--+--|---+------+--->
// a old new d e
//
alt = LFS_MKRALT(B, LT, lt
- (lfs_rtag_weight(tag & ~0x7fff)-1
- lfs_rtag_weight(tag_))
+ 1);
assert(
((lt
- (lfs_rtag_weight(tag & ~0x7fff)-1
- lfs_rtag_weight(tag_))
+ 1) << 3)
== (lfs_rtag_weight_(tag_)+0x8) - lower);
alt = LFS_MKRALT__(B, LT,
(lfs_rtag_weight_(tag_)+0x8) - lower);
} else {
printf("gt insert\n");
printf("hmmm? %08x %08x\n", lfs_rtag_weight(tag_), lfs_rtag_weight(tag & ~0x7fff));
//
// lt gt
// .-----'--. .-'.
// alt
// .--'--.
// <---+------+---|--+--|---+------+--->
// a b new old e
//
alt = LFS_MKRALT(B, GT,
alt = LFS_MKRALT__(B, GT,
// TODO hm, can this be done differently?
lfs_rtag_weight(lfs_rtag_incid(tag_))
- lfs_rtag_weight(tag));
lfs_rtag_weight_(lfs_rtag_incid(tag_))
- lfs_rtag_weight_(tag));
}
} else {
// bias the weights so that lookups always find the
// next biggest tag
if (lfs_rtag_weight(tag_)
< lfs_rtag_weight(tag)) {
//
// lt gt
// .-----'-----. .--'--.
// alt
// .--'--.
// <---+------+------+------+------+--->
// a old new d e
//
alt = LFS_MKRALT(B, LT, lt
+ 1
- (lfs_rtag_weight(tag)
- lfs_rtag_weight(tag_)));
// note we bias the weights here so that lfs_rbyd_lookup
// always finds the next biggest tag
if (lfs_rtag_weight_(tag_) < lfs_rtag_weight_(tag)) {
assert(((lt
+ 1
- (lfs_rtag_weight(tag)
- lfs_rtag_weight(tag_))) << 3) == lfs_rtag_weight_(tag_) - lower + 0x8);
alt = LFS_MKRALT__(B, LT,
(lfs_rtag_weight_(tag_)+0x8) - lower);
} else {
//
// lt gt
// .-----'-----. .--'--.
// alt
// .--'--.
// <---+------+------+------+------+--->
// a b new old e
//
alt = LFS_MKRALT(B, GT, gt);
assert((gt << 3) == upper - lfs_rtag_weight_(tag) - 0x8);
alt = LFS_MKRALT__(B, GT,
upper - (lfs_rtag_weight_(tag)+0x8));
}
}