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

transaction: actually delete file created during the transaction on rollback...

transaction: actually delete file created during the transaction on rollback Transaction currently has two modes: - one where file created during the transaction are deleted on rollback, - one where file created during the transaction are truncated to 0 on rollback. Before this change, `hg rollback` and `hg recover` are using the "delete" mode and transaction abort is using the "truncate" option. This difference is never really explained. A long time ago, there was two code paths, with this divergence existing for unclear reasons. When the two code paths got merged into a single one, a boolean argument have been added to preserve this divergence, mostly probably as a cargo cult. The divergence is weird and induce bad surprises, and the truncate behavior is a bit odds, introducing other bad surprises (e.g. 08ecbdba186f) So solve this, we stop using the "truncate" behavior and unify on the "delete" behavior. Despite being currently more "common", the truncate behavior seems less natural, resulting in the transaction leaving empty file around. This is landed on default, early in the cycle, to help us catch problems that could emerge.

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);
				}