upstream/mercurial-mirror Files · rust/chg/src/sendfds.c

dirstate-tree: Add tree traversal/iteration...

dirstate-tree: Add tree traversal/iteration Like Python’s, Rust’s iterators are "external" in that they are driven by a caller who calls a `next` method. This is as opposed to "internal" iterators who drive themselves and call a callback for each item. Writing an internal iterator traversing a tree is easy with recursion, but internal iterators cannot rely on the call stack in that way, they must save in an explicit object all state that they need to be preserved across two `next` calls. This algorithm uses a `Vec` as a stack that contains what would be local variables on the call stack if we could use recursion. Differential Revision: https://phab.mercurial-scm.org/D10370

Yuya Nishihara - - Load All Authors

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      /*

       * Utility to send fds via Unix domain socket

       *

       * Copyright 2011, 2018 Yuya Nishihara <yuya@tcha.org>

       *

       * This software may be used and distributed according to the terms of the

       * GNU General Public License version 2 or any later version.

       */

      #include <errno.h>

      #include <stdlib.h>

      #include <string.h>

      #include <sys/socket.h>

      #include <sys/types.h>

      #define MAX_FD_LEN 10

      /*

       * Sends the given fds with 1-byte dummy payload.

       *

       * Returns the number of bytes sent on success, -1 on error and errno is set

       * appropriately.

       */

      ssize_t sendfds(int sockfd, const int *fds, size_t fdlen)

      {

      	char dummy[1] = {0};

      	struct iovec iov = {dummy, sizeof(dummy)};

      	char fdbuf[CMSG_SPACE(sizeof(fds[0]) * MAX_FD_LEN)];

      	struct msghdr msgh;

      	struct cmsghdr *cmsg;

      	/* just use a fixed-size buffer since we'll never send tons of fds */

      	if (fdlen > MAX_FD_LEN) {

      		errno = EINVAL;

      		return -1;

      	}

      	memset(&msgh, 0, sizeof(msgh));

      	msgh.msg_iov = &iov;

      	msgh.msg_iovlen = 1;

      	msgh.msg_control = fdbuf;

      	msgh.msg_controllen = CMSG_SPACE(sizeof(fds[0]) * fdlen);

      	cmsg = CMSG_FIRSTHDR(&msgh);

      	cmsg->cmsg_level = SOL_SOCKET;

      	cmsg->cmsg_type = SCM_RIGHTS;

      	cmsg->cmsg_len = CMSG_LEN(sizeof(fds[0]) * fdlen);

      	memcpy(CMSG_DATA(cmsg), fds, sizeof(fds[0]) * fdlen);

      	msgh.msg_controllen = cmsg->cmsg_len;

      	return sendmsg(sockfd, &msgh, 0);

      }

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				/*
				* Utility to send fds via Unix domain socket
				*
				* Copyright 2011, 2018 Yuya Nishihara <yuya@tcha.org>
				*
				* This software may be used and distributed according to the terms of the
				* GNU General Public License version 2 or any later version.
				*/

				#include <errno.h>
				#include <stdlib.h>
				#include <string.h>
				#include <sys/socket.h>
				#include <sys/types.h>

				#define MAX_FD_LEN 10

				/*
				* Sends the given fds with 1-byte dummy payload.
				*
				* Returns the number of bytes sent on success, -1 on error and errno is set
				* appropriately.
				*/
				ssize_t sendfds(int sockfd, const int *fds, size_t fdlen)
				{
				char dummy[1] = {0};
				struct iovec iov = {dummy, sizeof(dummy)};
				char fdbuf[CMSG_SPACE(sizeof(fds[0]) * MAX_FD_LEN)];
				struct msghdr msgh;
				struct cmsghdr *cmsg;

				/* just use a fixed-size buffer since we'll never send tons of fds */
				if (fdlen > MAX_FD_LEN) {
				errno = EINVAL;
				return -1;
				}

				memset(&msgh, 0, sizeof(msgh));
				msgh.msg_iov = &iov;
				msgh.msg_iovlen = 1;
				msgh.msg_control = fdbuf;
				msgh.msg_controllen = CMSG_SPACE(sizeof(fds[0]) * fdlen);

				cmsg = CMSG_FIRSTHDR(&msgh);
				cmsg->cmsg_level = SOL_SOCKET;
				cmsg->cmsg_type = SCM_RIGHTS;
				cmsg->cmsg_len = CMSG_LEN(sizeof(fds[0]) * fdlen);
				memcpy(CMSG_DATA(cmsg), fds, sizeof(fds[0]) * fdlen);
				msgh.msg_controllen = cmsg->cmsg_len;
				return sendmsg(sockfd, &msgh, 0);
				}