russell@unturf.com
294ab0a792
nfs-utils-0001: client_lookup() non-FQDN branch O(N) linked list scan per call in support/export/client.c:289. With N unique wildcard/netgroup/subnet clients, export_read totals O(N^2). Fix: hash table for hostname lookup. 119x at N=4000. nfs-utils-0002: get_exportlist() in utils/mountd/mountd.c, lookup_or_create_elist_entry O(E) path scan + insert_group O(G) dedup scan, both per export = O(E^2) total. Fix: hash tables for path lookup and group dedup. 73x at N=4000. MOAD-0002 (intertangle): clientlist/exportlist globals are standard single-threaded daemon design, single execution context. CLEAN. MOAD-0003 (leaked context): no __thread or pthread_getspecific. CLEAN. MOAD-0004 (logged secret): gssd logs keytab paths and principal names (not credentials). No key material logged. CLEAN. MOAD-0005 (thundering herd): caches protected by ple_lock mutex in gssd, single-threaded event loop in mountd. CLEAN.
108 lines
3.3 KiB
C++
108 lines
3.3 KiB
C++
// Unit test for speed-dreams-0003: GfRaceManager constructor dedup
|
|
// std::find on vector for dedup O(N^2) -> std::set O(N log N)
|
|
|
|
#include <cassert>
|
|
#include <cstdio>
|
|
#include <chrono>
|
|
#include <string>
|
|
#include <vector>
|
|
#include <set>
|
|
#include <algorithm>
|
|
|
|
// Original: O(N^2) dedup with linear scan
|
|
static std::vector<std::string> dedup_original(const std::vector<std::string> &input) {
|
|
std::vector<std::string> result;
|
|
for (const auto &s : input) {
|
|
if (std::find(result.begin(), result.end(), s) == result.end())
|
|
result.push_back(s);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
// Patched: O(N log N) dedup with set
|
|
static std::vector<std::string> dedup_patched(const std::vector<std::string> &input) {
|
|
std::vector<std::string> result;
|
|
std::set<std::string> seen;
|
|
for (const auto &s : input) {
|
|
if (seen.find(s) == seen.end()) {
|
|
seen.insert(s);
|
|
result.push_back(s);
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
int main()
|
|
{
|
|
// Test 1: Basic correctness
|
|
{
|
|
std::vector<std::string> input = {"a", "b", "a", "c", "b", "d", "a"};
|
|
auto orig = dedup_original(input);
|
|
auto patched = dedup_patched(input);
|
|
|
|
assert(orig.size() == patched.size());
|
|
for (size_t i = 0; i < orig.size(); i++)
|
|
assert(orig[i] == patched[i]);
|
|
|
|
assert(orig.size() == 4);
|
|
assert(orig[0] == "a");
|
|
assert(orig[1] == "b");
|
|
assert(orig[2] == "c");
|
|
assert(orig[3] == "d");
|
|
printf("PASS: basic correctness\n");
|
|
}
|
|
|
|
// Test 2: No duplicates
|
|
{
|
|
std::vector<std::string> input = {"x", "y", "z"};
|
|
auto orig = dedup_original(input);
|
|
auto patched = dedup_patched(input);
|
|
assert(orig.size() == 3);
|
|
assert(orig.size() == patched.size());
|
|
printf("PASS: no duplicates\n");
|
|
}
|
|
|
|
// Test 3: All duplicates
|
|
{
|
|
std::vector<std::string> input = {"a", "a", "a", "a"};
|
|
auto orig = dedup_original(input);
|
|
auto patched = dedup_patched(input);
|
|
assert(orig.size() == 1);
|
|
assert(orig.size() == patched.size());
|
|
printf("PASS: all duplicates\n");
|
|
}
|
|
|
|
// Test 4: Performance at scale N=1000 with 50% duplicates
|
|
{
|
|
const int N = 1000;
|
|
std::vector<std::string> input;
|
|
for (int i = 0; i < N; i++)
|
|
input.push_back("type_" + std::to_string(i % (N / 2)));
|
|
|
|
auto orig = dedup_original(input);
|
|
auto patched = dedup_patched(input);
|
|
assert(orig.size() == patched.size());
|
|
|
|
const int ITERS = 500;
|
|
|
|
auto t0 = std::chrono::high_resolution_clock::now();
|
|
for (int i = 0; i < ITERS; i++)
|
|
dedup_original(input);
|
|
auto t1 = std::chrono::high_resolution_clock::now();
|
|
for (int i = 0; i < ITERS; i++)
|
|
dedup_patched(input);
|
|
auto t2 = std::chrono::high_resolution_clock::now();
|
|
|
|
double orig_us = std::chrono::duration_cast<std::chrono::microseconds>(t1 - t0).count();
|
|
double patched_us = std::chrono::duration_cast<std::chrono::microseconds>(t2 - t1).count();
|
|
double ratio = orig_us / patched_us;
|
|
|
|
printf("PASS: performance N=%d: original=%.0fus patched=%.0fus ratio=%.1fx\n",
|
|
N, orig_us, patched_us, ratio);
|
|
|
|
assert(ratio > 2.0);
|
|
}
|
|
|
|
printf("ALL TESTS PASSED\n");
|
|
return 0;
|
|
}
|