view contrib/chg/util.c @ 39631:b9e453d683a1

exchangev2: fetch changeset revisions

All Mercurial repository data is derived from changesets:
you can't do anything unless you have changesets. Therefore,
it makes sense for changesets to be the first piece of data
that we transfer as part of pull.

To do this, we call our new "changesetdata" command, requesting
parents and revision data. This gives us all the data that a
changegroup delta group would give us. We simply normalize
this data into what addgroup() expects and call that API on
the changelog to bulk insert revisions into the changelog.

Code in this commit is heavily borrowed from
changegroup.cg1unpacker.apply().

Differential Revision: https://phab.mercurial-scm.org/D4482

/*
 * Utility functions
 *
 * Copyright (c) 2011 Yuya Nishihara <[e-mail]>
 *
 * 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 <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include "util.h"

static int colorenabled = 0;

static inline void fsetcolor(FILE *fp, const char *code)
{
	if (!colorenabled)
		return;
	fprintf(fp, "\033[%sm", code);
}

static void vabortmsgerrno(int no, const char *fmt, va_list args)
{
	fsetcolor(stderr, "1;31");
	fputs("chg: abort: ", stderr);
	vfprintf(stderr, fmt, args);
	if (no != 0)
		fprintf(stderr, " (errno = %d, %s)", no, strerror(no));
	fsetcolor(stderr, "");
	fputc('\n', stderr);
	exit(255);
}

void abortmsg(const char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	vabortmsgerrno(0, fmt, args);
	va_end(args);
}

void abortmsgerrno(const char *fmt, ...)
{
	int no = errno;
	va_list args;
	va_start(args, fmt);
	vabortmsgerrno(no, fmt, args);
	va_end(args);
}

static int debugmsgenabled = 0;
static double debugstart = 0;

static double now()
{
	struct timeval t;
	gettimeofday(&t, NULL);
	return t.tv_usec / 1e6 + t.tv_sec;
}

void enablecolor(void)
{
	colorenabled = 1;
}

void enabledebugmsg(void)
{
	debugmsgenabled = 1;
	debugstart = now();
}

void debugmsg(const char *fmt, ...)
{
	if (!debugmsgenabled)
		return;

	va_list args;
	va_start(args, fmt);
	fsetcolor(stderr, "1;30");
	fprintf(stderr, "chg: debug: %4.6f ", now() - debugstart);
	vfprintf(stderr, fmt, args);
	fsetcolor(stderr, "");
	fputc('\n', stderr);
	va_end(args);
}

void fchdirx(int dirfd)
{
	int r = fchdir(dirfd);
	if (r == -1)
		abortmsgerrno("failed to fchdir");
}

void fsetcloexec(int fd)
{
	int flags = fcntl(fd, F_GETFD);
	if (flags < 0)
		abortmsgerrno("cannot get flags of fd %d", fd);
	if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0)
		abortmsgerrno("cannot set flags of fd %d", fd);
}

void *mallocx(size_t size)
{
	void *result = malloc(size);
	if (!result)
		abortmsg("failed to malloc");
	return result;
}

void *reallocx(void *ptr, size_t size)
{
	void *result = realloc(ptr, size);
	if (!result)
		abortmsg("failed to realloc");
	return result;
}

/*
 * Execute a shell command in mostly the same manner as system(), with the
 * give environment variables, after chdir to the given cwd. Returns a status
 * code compatible with the Python subprocess module.
 */
int runshellcmd(const char *cmd, const char *envp[], const char *cwd)
{
	enum { F_SIGINT = 1, F_SIGQUIT = 2, F_SIGMASK = 4, F_WAITPID = 8 };
	unsigned int doneflags = 0;
	int status = 0;
	struct sigaction newsa, oldsaint, oldsaquit;
	sigset_t oldmask;

	/* block or mask signals just as system() does */
	memset(&newsa, 0, sizeof(newsa));
	newsa.sa_handler = SIG_IGN;
	newsa.sa_flags = 0;
	if (sigemptyset(&newsa.sa_mask) < 0)
		goto done;
	if (sigaction(SIGINT, &newsa, &oldsaint) < 0)
		goto done;
	doneflags |= F_SIGINT;
	if (sigaction(SIGQUIT, &newsa, &oldsaquit) < 0)
		goto done;
	doneflags |= F_SIGQUIT;

	if (sigaddset(&newsa.sa_mask, SIGCHLD) < 0)
		goto done;
	if (sigprocmask(SIG_BLOCK, &newsa.sa_mask, &oldmask) < 0)
		goto done;
	doneflags |= F_SIGMASK;

	pid_t pid = fork();
	if (pid < 0)
		goto done;
	if (pid == 0) {
		sigaction(SIGINT, &oldsaint, NULL);
		sigaction(SIGQUIT, &oldsaquit, NULL);
		sigprocmask(SIG_SETMASK, &oldmask, NULL);
		if (cwd && chdir(cwd) < 0)
			_exit(127);
		const char *argv[] = {"sh", "-c", cmd, NULL};
		if (envp) {
			execve("/bin/sh", (char **)argv, (char **)envp);
		} else {
			execv("/bin/sh", (char **)argv);
		}
		_exit(127);
	} else {
		if (waitpid(pid, &status, 0) < 0)
			goto done;
		doneflags |= F_WAITPID;
	}

done:
	if (doneflags & F_SIGINT)
		sigaction(SIGINT, &oldsaint, NULL);
	if (doneflags & F_SIGQUIT)
		sigaction(SIGQUIT, &oldsaquit, NULL);
	if (doneflags & F_SIGMASK)
		sigprocmask(SIG_SETMASK, &oldmask, NULL);

	/* no way to report other errors, use 127 (= shell termination) */
	if (!(doneflags & F_WAITPID))
		return 127;
	if (WIFEXITED(status))
		return WEXITSTATUS(status);
	if (WIFSIGNALED(status))
		return -WTERMSIG(status);
	return 127;
}