Hash table bug fix, and add copy constructor and assignment operator for principle of least surprise.

node/Hashtable.hpp

@@ -29,6 +29,7 @@
 #include <stdlib.h>
 
 #include <stdexcept>
+#include <vector>
 
 namespace ZeroTier {
 
@@ -47,9 +48,11 @@ private:
 	{
 		_Bucket(const K &k,const V &v) : k(k),v(v) {}
 		_Bucket(const K &k) : k(k),v() {}
+		_Bucket(const _Bucket &b) : k(b.k),v(b.v) {}
+		inline _Bucket &operator=(const _Bucket &b) { k = b.k; v = b.v; return *this; }
 		K k;
 		V v;
-		_Bucket *next;
+		_Bucket *next; // must be set manually for each _Bucket
 	};
 
 public:
@@ -115,12 +118,47 @@ public:
 			_t[i] = (_Bucket *)0;
 	}
 
+	Hashtable(const Hashtable<K,V> &ht) :
+		_t(reinterpret_cast<_Bucket **>(::malloc(sizeof(_Bucket *) * ht._bc))),
+		_bc(ht._bc),
+		_s(ht._s)
+	{
+		if (!_t)
+			throw std::bad_alloc();
+		for(unsigned long i=0;i<_bc;++i)
+			_t[i] = (_Bucket *)0;
+		for(unsigned long i=0;i<_bc;++i) {
+			const _Bucket *b = ht._t[i];
+			while (b) {
+				_Bucket *nb = new _Bucket(*b);
+				nb->next = _t[i];
+				_t[i] = nb;
+				b = b->next;
+			}
+		}
+	}
+
 	~Hashtable()
 	{
-		clear();
+		this->clear();
 		::free(_t);
 	}
 
+	inline Hashtable &operator=(const Hashtable<K,V> &ht)
+	{
+		this->clear();
+		if (ht._s) {
+			for(unsigned long i=0;i<ht._bc;++i) {
+				const _Bucket *b = ht._t[i];
+				while (b) {
+					this->set(b->k,b->v);
+					b = b->next;
+				}
+			}
+		}
+		return *this;
+	}
+
 	/**
 	 * Erase all entries
 	 */
@@ -140,6 +178,24 @@ public:
 		}
 	}
 
+	/**
+	 * @return Vector of all keys
+	 */
+	inline typename std::vector<K> keys()
+	{
+		typename std::vector<K> k;
+		if (_s) {
+			for(unsigned long i=0;i<_bc;++i) {
+				_Bucket *b = _t[i];
+				while (b) {
+					k.push_back(b->k);
+					b = b->next;
+				}
+			}
+		}
+		return k;
+	}
+
 	/**
 	 * @param k Key
 	 * @return Pointer to value or NULL if not found
@@ -187,7 +243,8 @@ public:
 	 */
 	inline V &set(const K &k,const V &v)
 	{
-		const unsigned long bidx = _hc(k) % _bc;
+		const unsigned long h = _hc(k);
+		unsigned long bidx = h % _bc;
 
 		_Bucket *b = _t[bidx];
 		while (b) {
@@ -198,8 +255,10 @@ public:
 			b = b->next;
 		}
 
-		if (_s >= _bc)
+		if (_s >= _bc) {
 			_grow();
+			bidx = h % _bc;
+		}
 
 		b = new _Bucket(k,v);
 		b->next = _t[bidx];
@@ -215,7 +274,8 @@ public:
 	 */
 	inline V &operator[](const K &k)
 	{
-		const unsigned long bidx = _hc(k) % _bc;
+		const unsigned long h = _hc(k);
+		unsigned long bidx = h % _bc;
 
 		_Bucket *b = _t[bidx];
 		while (b) {
@@ -224,8 +284,10 @@ public:
 			b = b->next;
 		}
 
-		if (_s >= _bc)
+		if (_s >= _bc) {
 			_grow();
+			bidx = h % _bc;
+		}
 
 		b = new _Bucket(k);
 		b->next = _t[bidx];

selftest.cpp

@@ -581,31 +581,60 @@ static int testOther()
 {
 	std::cout << "[other] Testing Hashtable... "; std::cout.flush();
 	{
-		Hashtable<uint64_t,std::string> ht(128);
+		Hashtable<uint64_t,std::string> ht;
+		Hashtable<uint64_t,std::string> ht2;
 		std::map<uint64_t,std::string> ref; // assume std::map works correctly :)
 		for(int x=0;x<2;++x) {
 			for(int i=0;i<25000;++i) {
 				uint64_t k = rand();
 				while ((k == 0)||(ref.count(k) > 0))
 					++k;
-				std::string v;
+				std::string v("!");
 				for(int j=0;j<(int)(k % 64);++j)
 					v.push_back("0123456789"[rand() % 10]);
 				ht.set(k,v);
 				ref[k] = v;
 			}
 			if (ht.size() != ref.size()) {
-				std::cout << "FAILED! (size mismatch)" << std::endl;
+				std::cout << "FAILED! (size mismatch, original)" << std::endl;
+				return -1;
+			}
+			ht2 = ht;
+			Hashtable<uint64_t,std::string> ht3(ht2);
+			if (ht2.size() != ref.size()) {
+				std::cout << "FAILED! (size mismatch, assigned)" << std::endl;
+				return -1;
+			}
+			if (ht3.size() != ref.size()) {
+				std::cout << "FAILED! (size mismatch, copied)" << std::endl;
 				return -1;
 			}
 			for(std::map<uint64_t,std::string>::iterator i(ref.begin());i!=ref.end();++i) {
 				std::string *v = ht.get(i->first);
 				if (!v) {
-					std::cout << "FAILED! (key not found)" << std::endl;
+					std::cout << "FAILED! (key " << i->first << " not found, original)" << std::endl;
 					return -1;
 				}
 				if (*v != i->second) {
-					std::cout << "FAILED! (key not equal)" << std::endl;
+					std::cout << "FAILED! (key " << i->first << "  not equal, original)" << std::endl;
+					return -1;
+				}
+				v = ht2.get(i->first);
+				if (!v) {
+					std::cout << "FAILED! (key " << i->first << "  not found, assigned)" << std::endl;
+					return -1;
+				}
+				if (*v != i->second) {
+					std::cout << "FAILED! (key " << i->first << "  not equal, assigned)" << std::endl;
+					return -1;
+				}
+				v = ht3.get(i->first);
+				if (!v) {
+					std::cout << "FAILED! (key " << i->first << "  not found, copied)" << std::endl;
+					return -1;
+				}
+				if (*v != i->second) {
+					std::cout << "FAILED! (key " << i->first << "  not equal, copied)" << std::endl;
 					return -1;
 				}
 			}