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Made btree commit track bids correctly during recursion

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This doesn't have that big an impact at the moment, but limiting the
bids/rids to well intentioned values helps development and debugging.

As we tail-recurse up the btree, the current bid always indicates the
left-most/least id in the current rbyd. This contrasts with pid, which
is the right-most id in the current rbyd. Before this the bid was
somewhat arbitrary after the first leaf, which risks confusion later.

This also implies bid=0 when we reach the root, which is a useful debug
assertion.
This commit is contained in:
Christopher Haster
2023-08-14 18:37:55 -05:00
parent f5436caf24
commit 2abc61c49c
1 changed files with 13 additions and 5 deletions
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lfs.c
+13 -5
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@@ -3916,6 +3916,7 @@ static int lfsr_btree_commit(lfs_t *lfs,
// done?
if (pid == -1) {
LFS_ASSERT(bid == 0);
break;
}
@@ -3928,6 +3929,7 @@ static int lfsr_btree_commit(lfs_t *lfs,
//
// note that since we defer merges to compaction time, we can
// end up removing an rbyd here
bid -= pid - (pweight-1);
if (rbyd->weight == 0) {
scratch_attrs[0] = LFSR_ATTR(
bid+pid, RM, +rbyd->weight-pweight,
@@ -4010,6 +4012,7 @@ static int lfsr_btree_commit(lfs_t *lfs,
// done?
if (pid == -1) {
LFS_ASSERT(bid == 0);
break;
}
@@ -4022,6 +4025,7 @@ static int lfsr_btree_commit(lfs_t *lfs,
//
// note that since we defer merges to compaction time, we can
// end up removing an rbyd here
bid -= pid - (pweight-1);
if (rbyd->weight == 0) {
scratch_attrs[0] = LFSR_ATTR(
bid+pid, RM, +rbyd->weight-pweight,
@@ -4144,20 +4148,21 @@ static int lfsr_btree_commit(lfs_t *lfs,
}
// prepare commit to parent, tail recursing upwards
LFS_ASSERT(bid == 0);
scratch_attrs[0] = LFSR_ATTR(
bid, BRANCH, +rbyd_.weight,
0, BRANCH, +rbyd_.weight,
BUF(scratch1_buf, scratch1_dsize));
scratch_attrs[1] = (lfsr_tag_suptype(stag) == LFSR_TAG_NAME
? LFSR_ATTR(
bid+rbyd_.weight, BNAME, +sibling.weight,
rbyd_.weight, BNAME, +sibling.weight,
DATA(sdata))
: LFSR_ATTR_NOOP);
scratch_attrs[2] = (lfsr_tag_suptype(stag) == LFSR_TAG_NAME
? LFSR_ATTR(
bid+rbyd_.weight+sibling.weight-1, BRANCH, 0,
rbyd_.weight+sibling.weight-1, BRANCH, 0,
BUF(scratch2_buf, scratch2_dsize))
: LFSR_ATTR(
bid+rbyd_.weight, BRANCH, +sibling.weight,
rbyd_.weight, BRANCH, +sibling.weight,
BUF(scratch2_buf, scratch2_dsize)));
attrs = scratch_attrs;
attr_count = 3;
@@ -4165,6 +4170,7 @@ static int lfsr_btree_commit(lfs_t *lfs,
// yes parent? push up split
} else {
// prepare commit to parent, tail recursing upwards
bid -= pid - (pweight-1);
scratch_attrs[0] = LFSR_ATTR(
bid+pid, GROW(RM), +rbyd_.weight-pweight, NULL);
scratch_attrs[1] = LFSR_ATTR(
@@ -4371,6 +4377,9 @@ static int lfsr_btree_commit(lfs_t *lfs,
break;
} else {
// prepare commit to parent, tail recursing upwards
bid -= pid - (pweight-1);
// make pid the lower child so the following math is easier
if (pid > sid) {
lfs_sswap32(&pid, &sid);
@@ -4383,7 +4392,6 @@ static int lfsr_btree_commit(lfs_t *lfs,
return scratch_dsize;
}
// prepare commit to parent, tail recursing upwards
scratch_attrs[0] = LFSR_ATTR(
bid+sid, RM, -sweight, NULL);
scratch_attrs[1] = LFSR_ATTR(