refactor: use std::vector instead of bespoke Array class

CMakeLists.txt

@@ -24,7 +24,7 @@ if(LIBUTP_STANDALONE_BUILD)
     endif()
 
     if(NOT CMAKE_CXX_STANDARD)
-        set(CMAKE_CXX_STANDARD 98)
+        set(CMAKE_CXX_STANDARD 17)
         set(CMAKE_CXX_STANDARD_REQUIRED ON)
         set(CMAKE_CXX_EXTENSIONS OFF)
     endif()

utp_hash.cpp

@@ -20,6 +20,8 @@
  * THE SOFTWARE.
  */
 
+#include <assert.h>
+
 #include "utp_hash.h"
 #include "utp_types.h"
 

utp_internal.cpp

@@ -667,21 +667,22 @@ struct UTPSocket {
 	size_t get_packet_size() const;
 };
 
-void removeSocketFromAckList(UTPSocket *conn)
+static void removeSocketFromAckList(UTPSocket *conn)
 {
-	if (conn->ida >= 0)
-	{
-		UTPSocket *last = conn->ctx->ack_sockets[conn->ctx->ack_sockets.GetCount() - 1];
+	auto const ida = conn->ida;
+	if (ida < 0)
+		return;
 
-		assert(last->ida < (int)(conn->ctx->ack_sockets.GetCount()));
-		assert(conn->ctx->ack_sockets[last->ida] == last);
-		last->ida = conn->ida;
-		conn->ctx->ack_sockets[conn->ida] = last;
-		conn->ida = -1;
+	auto& acks = conn->ctx->ack_sockets;
+	assert(acks[ida]->ida == ida);
 
-		// Decrease the count
-		conn->ctx->ack_sockets.SetCount(conn->ctx->ack_sockets.GetCount() - 1);
-	}
+	// fast-remove `conn` from acks by swapping w/last and resizing.
+	// update `ida` index for both swapped sockets.
+	// note the steps need to be safe even when conn == acks.back()
+	std::swap(acks[ida], acks.back());
+	acks[ida]->ida = ida;
+	acks.resize(acks.size() - 1U);
+	conn->ida = -1;
 }
 
 static void utp_register_sent_packet(utp_context *ctx, size_t length)
@@ -715,7 +716,8 @@ void UTPSocket::schedule_ack()
 		#if UTP_DEBUG_LOGGING
 		log(UTP_LOG_DEBUG, "schedule_ack");
 		#endif
-		ida = ctx->ack_sockets.Append(this);
+		ida = ctx->ack_sockets.size();
+		ctx->ack_sockets.push_back(this);
 	} else {
 		#if UTP_DEBUG_LOGGING
 		log(UTP_LOG_DEBUG, "schedule_ack: already in list");
@@ -2923,12 +2925,9 @@ int utp_process_udp(utp_context *ctx, const byte *buffer, size_t len, const stru
 	if (flags != ST_SYN) {
 		ctx->current_ms = utp_call_get_milliseconds(ctx, NULL);
 
-		for (size_t i = 0; i < ctx->rst_info.GetCount(); i++) {
-			if ((ctx->rst_info[i].connid == id)   &&
-				(ctx->rst_info[i].addr   == addr) &&
-				(ctx->rst_info[i].ack_nr == seq_nr))
-			{
-				ctx->rst_info[i].timestamp = ctx->current_ms;
+		for (auto& info : ctx->rst_info) {
+			if ((info.connid == id) && (info.addr == addr) && (info.ack_nr == seq_nr)) {
+				info.timestamp = ctx->current_ms;
 
 				#if UTP_DEBUG_LOGGING
 				ctx->log(UTP_LOG_DEBUG, NULL, "recv not sending RST to non-SYN (stored)");
@@ -2938,7 +2937,7 @@ int utp_process_udp(utp_context *ctx, const byte *buffer, size_t len, const stru
 			}
 		}
 
-		if (ctx->rst_info.GetCount() > RST_INFO_LIMIT) {
+		if (ctx->rst_info.size() > RST_INFO_LIMIT) {
 
 			#if UTP_DEBUG_LOGGING
 			ctx->log(UTP_LOG_DEBUG, NULL, "recv not sending RST to non-SYN (limit at %u stored)", (uint)ctx->rst_info.GetCount());
@@ -2951,11 +2950,7 @@ int utp_process_udp(utp_context *ctx, const byte *buffer, size_t len, const stru
 		ctx->log(UTP_LOG_DEBUG, NULL, "recv send RST to non-SYN (%u stored)", (uint)ctx->rst_info.GetCount());
 		#endif
 
-		RST_Info &r = ctx->rst_info.Append();
-		r.addr = addr;
-		r.connid = id;
-		r.ack_nr = seq_nr;
-		r.timestamp = ctx->current_ms;
+		ctx->rst_info.emplace_back(addr, id, seq_nr, ctx->current_ms);
 
 		UTPSocket::send_rst(ctx, addr, id, seq_nr, utp_call_get_random(ctx, NULL));
 		return 1;
@@ -3280,7 +3275,7 @@ void utp_issue_deferred_acks(utp_context *ctx)
 	assert(ctx);
 	if (!ctx) return;
 
-	for (size_t i = 0; i < ctx->ack_sockets.GetCount(); i++) {
+	for (size_t i = 0; i < ctx->ack_sockets.size(); i++) {
 		UTPSocket *conn = ctx->ack_sockets[i];
 		conn->send_ack();
 		i--;
@@ -3300,15 +3295,16 @@ void utp_check_timeouts(utp_context *ctx)
 
 	ctx->last_check = ctx->current_ms;
 
-	for (size_t i = 0; i < ctx->rst_info.GetCount(); i++) {
-		if ((int)(ctx->current_ms - ctx->rst_info[i].timestamp) >= RST_INFO_TIMEOUT) {
-			ctx->rst_info.MoveUpLast(i);
+	auto& infos = ctx->rst_info;
+	for (size_t i = 0; i < infos.size(); i++) {
+		if ((int)(ctx->current_ms - infos[i].timestamp) >= RST_INFO_TIMEOUT) {
+			// fast-remove from `infos` by swapping w/last and resizing
+			std::swap(infos[i], infos.back());
+			infos.resize(infos.size() - 1U);
 			i--;
 		}
 	}
-	if (ctx->rst_info.GetCount() != ctx->rst_info.GetAlloc()) {
-		ctx->rst_info.Compact();
-	}
+	infos.shrink_to_fit();
 
 	utp_hash_iterator_t it;
 	UTPSocketKeyData* keyData;

utp_internal.h

@@ -28,6 +28,8 @@
 #include <assert.h>
 #include <stdio.h>
 
+#include <vector>
+
 #include "utp.h"
 #include "utp_callbacks.h"
 #include "utp_templates.h"
@@ -59,6 +61,16 @@ enum bandwidth_type_t {
 #endif
 
 struct PACKED_ATTRIBUTE RST_Info {
+	RST_Info() = default;
+
+  RST_Info(PackedSockAddr _addr, uint32 _connid, uint16 _ack_nr, uint64 _timestamp)
+		: addr{ _addr }
+		, connid{ _connid }
+		, ack_nr{ _ack_nr }
+		, timestamp{ _timestamp }
+	{
+	}
+
 	PackedSockAddr addr;
 	uint32 connid;
 	uint16 ack_nr;
@@ -117,8 +129,8 @@ struct struct_utp_context {
 	uint64 current_ms;
 	utp_context_stats context_stats;
 	UTPSocket *last_utp_socket;
-	Array<UTPSocket*> ack_sockets;
-	Array<RST_Info> rst_info;
+	std::vector<UTPSocket*> ack_sockets;
+	std::vector<RST_Info> rst_info;
 	UTPSocketHT *utp_sockets;
 	size_t target_delay;
 	size_t opt_sndbuf;

utp_templates.h

@@ -24,7 +24,6 @@
 #define __TEMPLATES_H__
 
 #include "utp_types.h"
-#include <assert.h>
 
 #if defined(POSIX)
 /* Allow over-writing FORCEINLINE from makefile because gcc 3.4.4 for buffalo
@@ -95,101 +94,4 @@ typedef big_endian<uint16> uint16_big;
 
 template<typename T> static inline void zeromem(T *a, size_t count = 1) { memset(a, 0, count * sizeof(T)); }
 
-typedef int SortCompareProc(const void *, const void *);
-
-template<typename T> static FORCEINLINE void QuickSortT(T *base, size_t num, int (*comp)(const T *, const T *)) { qsort(base, num, sizeof(T), (SortCompareProc*)comp); }
-
-
-// WARNING: The template parameter MUST be a POD type!
-template <typename T, size_t minsize = 16> class Array {
-protected:
-	T *mem;
-	size_t alloc,count;
-
-public:
-	Array(size_t init) { Init(init); }
-	Array() { Init(); }
-	~Array() { Free(); }
-
-	void inline Init() { mem = NULL; alloc = count = 0; }
-	void inline Init(size_t init) { Init(); if (init) Resize(init); }
-	size_t inline GetCount() const { return count; }
-	size_t inline GetAlloc() const { return alloc; }
-	void inline SetCount(size_t c) { count = c; }
-
-	inline T& operator[](size_t offset) { assert(offset ==0 || offset<alloc); return mem[offset]; }
-	inline const T& operator[](size_t offset) const { assert(offset ==0 || offset<alloc); return mem[offset]; }
-
-	void inline Resize(size_t a) {
-		if (a == 0) { free(mem); Init(); }
-		else { mem = (T*)realloc(mem, (alloc=a) * sizeof(T)); }
-	}
-
-	void Grow() { Resize(::max<size_t>(minsize, alloc * 2)); }
-
-	inline size_t Append(const T &t) {
-		if (count >= alloc) Grow();
-		size_t r=count++;
-		mem[r] = t;
-		return r;
-	}
-
-	T inline &Append() {
-		if (count >= alloc) Grow();
-		return mem[count++];
-	}
-
-	void inline Compact() {
-		Resize(count);
-	}
-
-	void inline Free() {
-		free(mem);
-		Init();
-	}
-
-	void inline Clear() {
-		count = 0;
-	}
-
-	bool inline MoveUpLast(size_t index) {
-		assert(index < count);
-		size_t c = --count;
-		if (index != c) {
-			mem[index] = mem[c];
-			return true;
-		}
-		return false;
-	}
-
-	bool inline MoveUpLastExist(const T &v) {
-		return MoveUpLast(LookupElementExist(v));
-	}
-
-	size_t inline LookupElement(const T &v) const {
-		for(size_t i = 0; i != count; i++)
-			if (mem[i] == v)
-				return i;
-		return (size_t) -1;
-	}
-
-	bool inline HasElement(const T &v) const {
-		return LookupElement(v) != -1;
-	}
-
-	typedef int SortCompareProc(const T *a, const T *b);
-
-	void Sort(SortCompareProc* proc, size_t start, size_t end) {
-		QuickSortT(&mem[start], end - start, proc);
-	}
-
-	void Sort(SortCompareProc* proc, size_t start) {
-		Sort(proc, start, count);
-	}
-
-	void Sort(SortCompareProc* proc) {
-		Sort(proc, 0, count);
-	}
-};
-
 #endif //__TEMPLATES_H__