From dadfff98d9c50c4c98edc3cc50ab8afa08e7d47e Mon Sep 17 00:00:00 2001
From: Alex Hultman <alexhultman@gmail.com>
Date: Wed, 2 Dec 2020 04:26:14 +0100
Subject: [PATCH] Add BloomFilter test

---
 tests/BloomFilter.cpp | 109 ++++++++++++++++++++++++++++++++++++++++++
 tests/Makefile        |   8 ++--
 2 files changed, 114 insertions(+), 3 deletions(-)
 create mode 100644 tests/BloomFilter.cpp

diff --git a/tests/BloomFilter.cpp b/tests/BloomFilter.cpp
new file mode 100644
index 0000000..26db9b4
--- /dev/null
+++ b/tests/BloomFilter.cpp
@@ -0,0 +1,109 @@
+#include "../src/BloomFilter.h"
+
+#include <cassert>
+#include <vector>
+#include <string>
+#include <algorithm>
+#include <iostream>
+
+/* From Wikipedia */
+std::vector<std::string> commonHeaders = {
+    "A-IM",
+    "Accept",
+    "Accept-Charset",
+    "Accept-Datetime",
+    "Accept-Encoding",
+    "Accept-Language",
+    "Access-Control-Request-Method",
+    "Access-Control-Request-Headers",
+    "Authorization",
+    "Cache-Control",
+    "Connection",
+    "Content-Encoding",
+    "Content-Length",
+    "Content-MD5",
+    "Content-Type",
+    "Cookie",
+    "Date",
+    "Expect",
+    "Forwarded",
+    "From",
+    "Host",
+    "HTTP2-Settings",
+    "If-Match",
+    "If-Modified-Since",
+    "If-None-Match",
+    "If-Range",
+    "If-Unmodified-Since",
+    "Max-Forwards",
+    "Origin",
+    "Pragma",
+    "Proxy-Authorization",
+    "Range",
+    "Referer",
+    "TE",
+    "Trailer",
+    "Transfer-Encoding",
+    "User-Agent",
+    "Upgrade",
+    "Via",
+    "Warning",
+
+    /* Put common non-standard ones here */
+};
+
+int main() {
+
+    /* Lowercase everything */
+    std::transform(commonHeaders.begin(), commonHeaders.end(), commonHeaders.begin(), [](std::string &header) {
+        std::transform(header.begin(), header.end(), header.begin(), ::tolower);
+        return header;
+    });
+
+    uWS::BloomFilter bf;
+    unsigned int totalCollisions = 0;
+
+    /* One on one */
+    for (int i = 0; i < commonHeaders.size(); i++) {
+        bf.reset();
+        assert(bf.mightHave(commonHeaders[i]) == false);
+
+        bf.add(commonHeaders[i]);
+        assert(bf.mightHave(commonHeaders[i]) == true);
+
+        for (int j = i + 1; j < commonHeaders.size(); j++) {
+            if (bf.mightHave(commonHeaders[j])) {
+                std::cout << commonHeaders[i] << " collides with " << commonHeaders[j] << std::endl;
+                totalCollisions++;
+            }
+        }
+    }
+
+    /* We don't want any direct one-one-one collisions (please) */
+    std::cout << "Total collisions: " << totalCollisions << std::endl;
+    assert(totalCollisions == 0);
+
+    unsigned int totalFalsePositives = 0;
+
+    /* Add all except the one we test */
+    for (int i = 0; i < commonHeaders.size(); i++) {
+        bf.reset();
+
+        /* Add all headers but our */
+        for (int j = 0; j < commonHeaders.size(); j++) {
+            if (j != i) {
+                bf.add(commonHeaders[j]);
+            }
+        }
+
+        /* Do we have false positives? */
+        if (bf.mightHave(commonHeaders[i])) {
+            std::cout << commonHeaders[i] << " has false positives" << std::endl;
+            totalFalsePositives++;
+        }
+    }
+
+    /* It is totally fine to have a few false positives */
+    std::cout << "Total false positives: " << totalFalsePositives << std::endl;
+    assert(totalFalsePositives == 1);
+}
\ No newline at end of file
diff --git a/tests/Makefile b/tests/Makefile
index 7c9acff..238a7e8 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -1,5 +1,7 @@
 default:
-	$(CXX) -std=c++17 -fsanitize=address TopicTree.cpp -o TopicTree
-	./TopicTree
+	#$(CXX) -std=c++17 -fsanitize=address TopicTree.cpp -o TopicTree
+	#./TopicTree
 	$(CXX) -std=c++17 -fsanitize=address HttpRouter.cpp -o HttpRouter
-	./HttpRouter
\ No newline at end of file
+	./HttpRouter
+	$(CXX) -std=c++17 -fsanitize=address BloomFilter.cpp -o BloomFilter
+	./BloomFilter
\ No newline at end of file