Drizzled Public API Documentation

error_message.cc
1 /* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
2  * vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
3  *
4  * Copyright (C) 2008 Sun Microsystems, Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2 of the License.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 
20 #include <config.h>
21 
22 #include <drizzled/error.h>
23 #include <drizzled/gettext.h>
24 #include <drizzled/plugin/error_message.h>
25 
26 #include <cstdio>
27 #include <algorithm>
28 #include <vector>
29 
30 namespace drizzled
31 {
32 
33 std::vector<plugin::ErrorMessage *> all_errmsg_handler;
34 
35 bool plugin::ErrorMessage::addPlugin(plugin::ErrorMessage *handler)
36 {
37  all_errmsg_handler.push_back(handler);
38  return false;
39 }
40 
41 void plugin::ErrorMessage::removePlugin(plugin::ErrorMessage *)
42 {
43  all_errmsg_handler.clear();
44 }
45 
46 
47 class Print : public std::unary_function<plugin::ErrorMessage *, bool>
48 {
49  error::priority_t priority;
50  const char *format;
51  va_list ap;
52 
53 public:
54  Print(error::priority_t priority_arg,
55  const char *format_arg, va_list ap_arg) :
56  std::unary_function<plugin::ErrorMessage *, bool>(),
57  priority(priority_arg), format(format_arg)
58  {
59  va_copy(ap, ap_arg);
60  }
61 
62  ~Print() { va_end(ap); }
63 
64  inline result_type operator()(argument_type handler)
65  {
66  va_list handler_ap;
67  va_copy(handler_ap, ap);
68  if (handler->errmsg(priority, format, handler_ap))
69  {
70  /* we're doing the errmsg plugin api,
71  so we can't trust the errmsg api to emit our error messages
72  so we will emit error messages to stderr */
73  /* TRANSLATORS: The leading word "errmsg" is the name
74  of the plugin api, and so should not be translated. */
75  fprintf(stderr,
76  _("errmsg plugin '%s' errmsg() failed"),
77  handler->getName().c_str());
78  va_end(handler_ap);
79 
80  return true;
81  }
82  va_end(handler_ap);
83  return false;
84  }
85 };
86 
87 
88 bool plugin::ErrorMessage::vprintf(error::priority_t priority, char const *format, va_list ap)
89 {
90  if (priority > error::verbosity())
91  {
92  return false;
93  }
94 
95  /*
96  Check to see if any errmsg plugin has been loaded
97  if not, just fall back to emitting the message to stderr.
98  */
99  if (all_errmsg_handler.size() == 0)
100  {
101  /* if it turns out that the vfprintf doesnt do one single write
102  (single writes are atomic), then this needs to be rewritten to
103  vsprintf into a char buffer, and then write() that char buffer
104  to stderr
105  */
106  vfprintf(stderr, format, ap);
107  fputc('\n', stderr);
108 
109  return false;
110  }
111 
112  /* Use find_if instead of foreach so that we can collect return codes */
113  std::vector<plugin::ErrorMessage *>::iterator iter=
114  std::find_if(all_errmsg_handler.begin(), all_errmsg_handler.end(),
115  Print(priority, format, ap));
116 
117  /* If iter is == end() here, that means that all of the plugins returned
118  * false, which in this case means they all succeeded. Since we want to
119  * return false on success, we return the value of the two being !=
120  */
121  return iter != all_errmsg_handler.end();
122 }
123 
124 } /* namespace drizzled */
TODO: Rename this file - func.h is stupid.