contrib/chg/hgclient.h

chgserver: truncate base address at "." for hash address

Previously, the hash address is just appending "-$HASH" to base address.
This patch makes it truncate the basename address at "." before appending
"-$HASH".

This makes it possible to spawn new servers in a racy situation and the
client could be sure the server it connects is the new server just spawned.

This is a step towards removing the lock.

One of the functionalities of the lock is to make sure the connect will
connect to a server it just created:

  1. start server --address foo
  2. connect to foo # wish "foo" is the server just started

With this change, the client could do:

  1. start server --address foo.tmp$PID
  2. connect to foo.tmp$PID # is the server just started
     (note: if it is not, it does not affect correctness - linux pid
      namespace is not a concern here)
  3. rename foo.tmp$PID to foo

Another functionality of the lock is to avoid starting multiple servers with
a same confighash in parallel. But that also prevents starting multiple
servers with different confighashes in parallel.

/*
 * A command server client that uses Unix domain socket
 *
 * 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.
 */

#ifndef HGCLIENT_H_
#define HGCLIENT_H_

#include <sys/types.h>

struct hgclient_tag_;
typedef struct hgclient_tag_ hgclient_t;

hgclient_t *hgc_open(const char *sockname);
void hgc_close(hgclient_t *hgc);

pid_t hgc_peerpgid(const hgclient_t *hgc);
pid_t hgc_peerpid(const hgclient_t *hgc);

const char **hgc_validate(hgclient_t *hgc, const char *const args[],
			  size_t argsize);
int hgc_runcommand(hgclient_t *hgc, const char *const args[], size_t argsize);
void hgc_attachio(hgclient_t *hgc);
const char *hgc_getpager(hgclient_t *hgc, const char *const args[],
			 size_t argsize);
void hgc_setenv(hgclient_t *hgc, const char *const envp[]);

#endif  /* HGCLIENT_H_ */