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

dirstate-tree: optimize HashMap lookups with raw_entry_mut...

dirstate-tree: optimize HashMap lookups with raw_entry_mut This switches to using `HashMap` from the hashbrown crate, in order to use its `raw_entry_mut` method. The standard library’s `HashMap` is also based on this same crate, but `raw_entry_mut` is not yet stable there: https://github.com/rust-lang/rust/issues/56167 Using version 0.9 because 0.10 is yanked and 0.11 requires Rust 1.49 This replaces in `DirstateMap::get_or_insert_node` a call to `HashMap<K, V>::entry` with `K = WithBasename<Cow<'on_disk, HgPath>>`. `entry` takes and consumes an "owned" `key: K` parameter, in case a new entry ends up inserted. This key is converted by `to_cow` from a value that borrows the `'path` lifetime. When this function is called by `Dirstate::new_v1`, `'path` is in fact the same as `'on_disk` so `to_cow` can return an owned key that contains `Cow::Borrowed`. For other callers, `to_cow` needs to create a `Cow::Owned` and thus make a costly heap memory allocation. This is wasteful if this key was already present in the map. Even when inserting a new node this is typically the case for its ancestor nodes (assuming most directories have numerous descendants). Differential Revision: https://phab.mercurial-scm.org/D12317

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);
				}