php_library/fboprime/sguid.inc

<?php
//$Header: /hl/cvsroots/gpl01/gpl01/webprojs/fboprime/sw/phplib/sguid.inc,v 1.4 2006/04/10 22:48:02 dashley Exp $
//********************************************************************************
//Copyright (C) 2006 David T. Ashley
//********************************************************************************
//This program or source file 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 or source file 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 may 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
//********************************************************************************
//Dave Ashley, 04/06
//
//This source file provides the code to create server globally-unique identifiers.
//The rationale is that since no process can have the same PID at the same
//time as another process, using the PID concatenated with a guaranteed
//unique time should provide an identifier that can never recur in the lifetime
//of the server.
//
//The format of the SGUID is documented in the FBO-Prime manual.
//
require_once("strfunc.inc");     //Necesssary for zero padding.
require_once("timeraw.inc");     //Necessary to get raw time.
//
//
//--------------------------------------------------------------------------------
//Returns the full generated SGUID as described in the documentation.
//
//Unit-tested 20060408.
//
function SGUID_sguid()
   {
   return("SG" . SGUID_sguid_raw());
   }
//
//
//--------------------------------------------------------------------------------
//Returns the raw form of an SGUID (without the "SG" prefix).
//
//Unit-tested 20060408.
//
function SGUID_sguid_raw()
  {
   //Get the reference timestamp.
   $reftime = TIMERAW_time_precision_mixed_array_2();

   //Get the PID.  This may also chew up some time and hopefully let the
   //server time change.
   $pid = getmypid();

   //Form the SGUID proper.  Hopefully this will also chew up more time.
   $reftime_whole  = $reftime[0];
   $reftime_frac   = sprintf("%d", $reftime[1]);
   $pid_string     = sprintf("%d", $pid       );
   $rv =    STRFUNC_pad_left_zero($reftime_whole, 11)
          . STRFUNC_pad_left_zero($reftime_frac,   9)
          . STRFUNC_pad_left_zero($pid_string,    10);

   //Spin-lock until the time has changed.  With any luck, the statements
   //above have done that for us.  It is hard to judge without some data
   //whether microsleep would make things more efficient ... let's just leave
   //it as a pure spin-lock.
   do
      {
      $comptime = TIMERAW_time_precision_mixed_array_2();
      } 
   while (($reftime[1] == $comptime[1]) && ($reftime[0] == $comptime[0]));

   //Return the value to the caller.
   return($rv);
  }
//
//
//--------------------------------------------------------------------------------
//Returns the length of a SGUID (in characters).
//
//Unit-tested 20060408.
//
function SGUID_sguid_len()
   {
   return(32);
   }
//
//
//--------------------------------------------------------------------------------
//Returns 1 if the SGUID is syntactically valid or 0 otherwise.
//
//Unit-tested 20060408.
//
function SGUID_is_syntactically_valid($sguid_to_check)
   {
   //Must be a string data type.
   if (! is_string($sguid_to_check))
      return(0);

   //Must be of appropriate length.
   if (strlen($sguid_to_check) != 32)
      return(0);

   //First two characters must be "SG".
   if (substr($sguid_to_check, 0, 2) !== "SG")
      return(0);
  
   //The remainder of the string must be digits only.
   if (! STRFUNC_is_pure_digits(SubStr($sguid_to_check, 2, 30)))
      return(0);

   //If we're here, nothing obvious wrong with it.
   return(1);
   }
//--------------------------------------------------------------------------------
?>
1	dashley	35	<?php
2			//$Header: /hl/cvsroots/gpl01/gpl01/webprojs/fboprime/sw/phplib/sguid.inc,v 1.4 2006/04/10 22:48:02 dashley Exp $
3			//********************************************************************************
4			//Copyright (C) 2006 David T. Ashley
5			//********************************************************************************
6			//This program or source file is free software; you can redistribute it and/or
7			//modify it under the terms of the GNU General Public License as published by
8			//the Free Software Foundation; either version 2 of the License, or (at your
9			//option) any later version.
10			//
11			//This program or source file is distributed in the hope that it will
12			//be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
13			//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			//GNU General Public License for more details.
15			//
16			//You may have received a copy of the GNU General Public License
17			//along with this program; if not, write to the Free Software
18			//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19			//********************************************************************************
20			//Dave Ashley, 04/06
21			//
22			//This source file provides the code to create server globally-unique identifiers.
23			//The rationale is that since no process can have the same PID at the same
24			//time as another process, using the PID concatenated with a guaranteed
25			//unique time should provide an identifier that can never recur in the lifetime
26			//of the server.
27			//
28			//The format of the SGUID is documented in the FBO-Prime manual.
29			//
30			require_once("strfunc.inc"); //Necesssary for zero padding.
31			require_once("timeraw.inc"); //Necessary to get raw time.
32			//
33			//
34			//--------------------------------------------------------------------------------
35			//Returns the full generated SGUID as described in the documentation.
36			//
37			//Unit-tested 20060408.
38			//
39			function SGUID_sguid()
40			{
41			return("SG" . SGUID_sguid_raw());
42			}
43			//
44			//
45			//--------------------------------------------------------------------------------
46			//Returns the raw form of an SGUID (without the "SG" prefix).
47			//
48			//Unit-tested 20060408.
49			//
50			function SGUID_sguid_raw()
51			{
52			//Get the reference timestamp.
53			$reftime = TIMERAW_time_precision_mixed_array_2();
54
55			//Get the PID. This may also chew up some time and hopefully let the
56			//server time change.
57			$pid = getmypid();
58
59			//Form the SGUID proper. Hopefully this will also chew up more time.
60			$reftime_whole = $reftime[0];
61			$reftime_frac = sprintf("%d", $reftime[1]);
62			$pid_string = sprintf("%d", $pid );
63			$rv = STRFUNC_pad_left_zero($reftime_whole, 11)
64			. STRFUNC_pad_left_zero($reftime_frac, 9)
65			. STRFUNC_pad_left_zero($pid_string, 10);
66
67			//Spin-lock until the time has changed. With any luck, the statements
68			//above have done that for us. It is hard to judge without some data
69			//whether microsleep would make things more efficient ... let's just leave
70			//it as a pure spin-lock.
71			do
72			{
73			$comptime = TIMERAW_time_precision_mixed_array_2();
74			}
75			while (($reftime[1] == $comptime[1]) && ($reftime[0] == $comptime[0]));
76
77			//Return the value to the caller.
78			return($rv);
79			}
80			//
81			//
82			//--------------------------------------------------------------------------------
83			//Returns the length of a SGUID (in characters).
84			//
85			//Unit-tested 20060408.
86			//
87			function SGUID_sguid_len()
88			{
89			return(32);
90			}
91			//
92			//
93			//--------------------------------------------------------------------------------
94			//Returns 1 if the SGUID is syntactically valid or 0 otherwise.
95			//
96			//Unit-tested 20060408.
97			//
98			function SGUID_is_syntactically_valid($sguid_to_check)
99			{
100			//Must be a string data type.
101			if (! is_string($sguid_to_check))
102			return(0);
103
104			//Must be of appropriate length.
105			if (strlen($sguid_to_check) != 32)
106			return(0);
107
108			//First two characters must be "SG".
109			if (substr($sguid_to_check, 0, 2) !== "SG")
110			return(0);
111
112			//The remainder of the string must be digits only.
113			if (! STRFUNC_is_pure_digits(SubStr($sguid_to_check, 2, 30)))
114			return(0);
115
116			//If we're here, nothing obvious wrong with it.
117			return(1);
118			}
119			//--------------------------------------------------------------------------------
120			?>