1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/*
* dmucs_hosts_file.cc: code to read the hosts-info configuration file.
*
* Copyright (C) 2005, 2006 Victor T. Norman
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
* Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "dmucs.h"
#include "dmucs_hosts_file.h"
#include <fstream>
#include <iostream>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <exception>
#include <sys/stat.h>
DmucsHostsFile *DmucsHostsFile::instance_ = NULL;
DmucsHostsFile *DmucsHostsFile::getInstance(const std::string &file)
{
if (instance_ == NULL) {
instance_ = new DmucsHostsFile(file);
}
return instance_;
}
DmucsHostsFile::DmucsHostsFile(const std::string &hostsInfoFile) :
hostsInfoFile_(hostsInfoFile),
lastFileChangeTime_(0)
{
readFileIntoDb();
/* We know the file has changed since time 0 -- so just call this
to get the new time into lastFileChangeTime_. */
(void) hasFileChanged();
}
void
DmucsHostsFile::readFileIntoDb() const
{
db_.clear();
std::ifstream instr(hostsInfoFile_.c_str());
if (!instr) {
DMUCS_DEBUG((stderr, "Unable to open hosts-info file \"%s\"\n",
hostsInfoFile_.c_str()));
return;
}
for (int lineno = 1; ; lineno++) {
/*
* Each line is: machine-or-ipaddr numcpus power-index.
* Comment lines start with #, and these are skipped. Lines
* containing only whitespace are also skipped.
*/
char firstChar;
instr >> firstChar; // this will skip empty lines.
if (instr.eof()) {
break;
}
if (firstChar == '#') {
std::string junk;
std::getline(instr, junk);
continue;
} else if (! instr.good()) {
break;
} else {
instr.putback(firstChar);
}
std::string line;
std::getline(instr, line);
char machine[256];
int numcpus, powerIndex;
if (sscanf(line.c_str(), "%s %d %d", machine, &numcpus,
&powerIndex) != 3) {
std::cout << "Bad input in line " << lineno << " of file " <<
hostsInfoFile_ << std::endl;
break;
}
/*
* Convert the machine name into an ip address.
*/
unsigned long addr;
struct hostent *hostent;
if ((int)(addr = inet_addr(machine)) != -1) {
hostent = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET);
} else {
hostent = gethostbyname(machine);
}
if (hostent == NULL) {
std::cout << "Could not get IP address for machine: " << machine <<
". Skipping." << std::endl;
continue;
}
struct in_addr in;
memcpy(&in.s_addr, hostent->h_addr_list[0], sizeof(in.s_addr));
/* Insert the info into the database of host info. */
host_info_db_t::value_type object(in.s_addr,
info_t(numcpus, powerIndex));
db_.insert(object);
}
}
void
DmucsHostsFile::getDataForHost(const struct in_addr &ipAddr, int *numCpus,
int *powerIndex) const
{
if (hasFileChanged()) {
readFileIntoDb();
}
/*
* Be default, we'll assume 1 CPU and a very slow one at that.
*/
*numCpus = 1;
*powerIndex = 1;
host_info_db_iter_t itr = db_.find(ipAddr.s_addr);
if (itr != db_.end()) {
*numCpus = itr->second.numCpus_;
*powerIndex = itr->second.powerIndex_;
}
}
/* If the file modification time has changed since the last time this
was called, then return true AND update lastFileChangeTime_ to the
new modification time. */
bool
DmucsHostsFile::hasFileChanged() const
{
struct stat st;
if (stat(hostsInfoFile_.c_str(), &st) != 0) {
return true; // assume the file has changed...
}
if (lastFileChangeTime_ != st.st_ctime) {
lastFileChangeTime_ = st.st_ctime;
return true;
}
return false;
}
|
