weaselab/conflict-set
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Track lcp as loop invariant

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This commit is contained in:
Andrew Noyes
2024-02-13 15:37:14 -08:00
parent 86978c057e
commit eef3c9e8d0
1 changed files with 41 additions and 11 deletions
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52
ConflictSet.cpp
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@@ -931,6 +931,35 @@ bytes:
return i;
}
__attribute__((always_inline)) inline void
ascend(int &depth, int &lcp, Node *oldNode, Vector<uint8_t> &searchPath) {
depth -= 1 + oldNode->partialKeyLen;
searchPath.resize(depth);
lcp = std::min(lcp, depth);
}
__attribute__((always_inline)) inline void
descend(int &depth, int &lcp, Node *newNode, std::span<const uint8_t> end,
Vector<uint8_t> &searchPath) {
if (depth == lcp) {
if (lcp < int(end.size()) && newNode->parentsIndex == end[lcp]) {
++lcp;
for (int i = 0; i < newNode->partialKeyLen && lcp < int(end.size());
++i) {
if (newNode->partialKey[i] == end[lcp]) {
++lcp;
} else {
break;
}
}
}
}
depth += 1 + newNode->partialKeyLen;
searchPath.push_back(newNode->parentsIndex);
searchPath.insert(searchPath.end(), newNode->partialKey,
newNode->partialKey + newNode->partialKeyLen);
}
bool checkRangeRead(Node *n, const std::span<const uint8_t> begin,
const std::span<const uint8_t> end, int64_t readVersion,
Arena &arena) {
@@ -980,10 +1009,15 @@ bool checkRangeRead(Node *n, const std::span<const uint8_t> begin,
return false;
}
int depth = searchPath.size();
lcp = longestCommonPrefix(searchPath.data(), end.data(),
std::min(searchPath.size(), end.size()));
bool first = true;
for (auto *iter = left.n; iter != nullptr; first = false) {
int cl = std::min(searchPath.size(), end.size());
int lcp = longestCommonPrefix(searchPath.data(), end.data(), cl);
assert(depth == int(searchPath.size()));
assert(lcp == longestCommonPrefix(searchPath.data(), end.data(), cl));
// if (searchPath >= end) break;
if ((cl == lcp ? searchPath.size() <=> end.size()
@@ -1005,7 +1039,7 @@ bool checkRangeRead(Node *n, const std::span<const uint8_t> begin,
fprintf(stderr, "Max version of keys starting with %s: %" PRId64 "\n",
printable(searchPath).c_str(), iter->maxVersion);
#endif
if (lcp == int(searchPath.size())) {
if (lcp == depth) {
// end starts with searchPath, so end < range
if (iter->maxVersion <= readVersion) {
return true;
@@ -1015,17 +1049,15 @@ bool checkRangeRead(Node *n, const std::span<const uint8_t> begin,
auto nextChild = getChildGeq(iter, index + 1);
if (nextChild >= 0) {
auto *result = getChildExists(iter, nextChild);
searchPath.push_back(nextChild);
searchPath.insert(searchPath.end(), result->partialKey,
result->partialKey + result->partialKeyLen);
iter = result;
descend(depth, lcp, iter, end, searchPath);
break;
}
if (iter->parent == nullptr) {
iter = nullptr;
break;
}
searchPath.resize(int(searchPath.size()) - 1 - iter->partialKeyLen);
ascend(depth, lcp, iter, searchPath);
index = iter->parentsIndex;
iter = iter->parent;
}
@@ -1043,15 +1075,13 @@ bool checkRangeRead(Node *n, const std::span<const uint8_t> begin,
}
auto next = getChildGeq(iter->parent, iter->parentsIndex + 1);
if (next < 0) {
searchPath.resize(int(searchPath.size()) - (1 + iter->partialKeyLen));
ascend(depth, lcp, iter, searchPath);
iter = iter->parent;
} else {
searchPath.resize(int(searchPath.size()) - (1 + iter->partialKeyLen));
ascend(depth, lcp, iter, searchPath);
auto *result = getChildExists(iter->parent, next);
searchPath.push_back(next);
searchPath.insert(searchPath.end(), result->partialKey,
result->partialKey + result->partialKeyLen);
iter = result;
descend(depth, lcp, iter, end, searchPath);
break;
}
}