netpoll: factor out a bunch of search checks

diff --git a/src/netpoll.cpp b/src/netpoll.cpp
index 3de7569..c12b4a7 100644 (file)
--- a/src/netpoll.cpp
+++ b/src/netpoll.cpp
@@ -4,6 +4,7 @@
 #include "util.h"
 
 #include <uv.h>
+#include <algorithm>
 
 namespace netpoll {
 #define NETPOLL_MAXFDS 1024
@@ -127,42 +128,34 @@ int get(struct net_pollfd *out)
        return ev;
 }
 
-static int search(SOCKET fd) {
-       int l = 0, r = nfds;
-       while (l != r) {
-               int m = (l+r)/2;
-               if (fds[m].fd < fd)
-                       l = m+1;
-               else if (fd < fds[m].fd)
-                       r = m;
-               else
-                       l = r = m;
+static int search(SOCKET fd, bool add) {
+       if (fd == INVALID_SOCKET)
+               abortf("netpoll::search: INVALID_SOCKET\n");
+       auto it = std::partition_point(fds, fds+nfds, [fd](const auto &p){ return p.fd < fd; });
+       bool found = it != fds+nfds && it->fd == fd;
+       if (found == add)
+               abortf("netpoll::search: duplicate or missing socket\n");
+       if (add) {
+               if (nfds == NETPOLL_MAXFDS)
+                       abortf("netpoll::add: NETPOLL_MAXFDS limit\n");
+               memmove(it+1, it, sizeof(fds[0])*(fds+nfds-it));
+               nfds++;
+               *it = net_pollfd{};
+               it->fd = fd;
        }
-       return l;
+       return it - fds;
 }
-#define IS_FOUND(i, f) ((i) < nfds && fds[i].fd == (f))
 
 void add(SOCKET fd, int type, void *assoc)
 {
-       if (fd == INVALID_SOCKET)
-               abortf("netpoll::add: INVALID_SOCKET\n");
-       int i = search(fd);
-       if (IS_FOUND(i, fd))
-               abortf("netpoll::add: socket already added\n");
-       if (nfds == NETPOLL_MAXFDS)
-               abortf("netpoll::add: NETPOLL_MAXFDS limit\n");
-       memmove(fds+i+1, fds+i, sizeof(fds[0])*(nfds-i));
-       nfds++;
-       fds[i] = (struct net_pollfd){ .assoc = assoc, .fd = fd, .type = type };
+       int i = search(fd, true);
+       fds[i].assoc = assoc;
+       fds[i].type = type;
        add_impl(i);
 }
 void del_and_close(SOCKET fd)
 {
-       if (fd == INVALID_SOCKET)
-               abortf("netpoll::del_and_close: INVALID_SOCKET\n");
-       int i = search(fd);
-       if (!IS_FOUND(i, fd))
-               abortf("netpoll::del_and_close: socket not added\n");
+       int i = search(fd, false);
        reg_impl(i, 0);
        del_impl(i);
        memmove(fds+i, fds+i+1, sizeof(fds[0])*(nfds-(i+1)));
@@ -170,20 +163,10 @@ void del_and_close(SOCKET fd)
 }
 void reg(SOCKET fd, int ev)
 {
-       if (fd == INVALID_SOCKET)
-               abortf("netpoll::reg: INVALID_SOCKET\n");
-       int i = search(fd);
-       if (!IS_FOUND(i, fd))
-               abortf("netpoll::reg: socket not added\n");
-       reg_impl(i, ev);
+       reg_impl(search(fd, false), ev);
 }
 void change_type(SOCKET fd, int type)
 {
-       if (fd == INVALID_SOCKET)
-               abortf("netpoll::change_type: INVALID_SOCKET\n");
-       int i = search(fd);
-       if (!IS_FOUND(i, fd))
-               abortf("netpoll::change_type: socket not added\n");
-       fds[i].type = type;
+       fds[search(fd, false)].type = type;
 }
 }