dbclient.c

bonddb 是一个源于PostgreSQL封装包的对象。它是一个由C/C++编写的快速数据提取层应用软件

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include <glob.h>
#include <dlfcn.h>

#include "dbclient.h"

#include "debug.h"
#include "dbgather.h"
#include "dbobject.h"
#include "dbwrapper.h"
#include "dbtoliet.h"
#include "dbbureaucrat.h"
#include "dblog.h"

#define NUMPLUGINPATHS 4
#define NUMBONDCONFSEARCH 5
static gchar *plugin_search_path[NUMPLUGINPATHS] = { "./.libs/", "./", "/usr/local/lib/",
      "/usr/lib/"
                                            };

gchar *bondconffilesearch[NUMBONDCONFSEARCH] = { "../etc/bond/", "/usr/local/etc/bond/",
      "/etc/bond/", "/etc/", "/usr/local/etc/"
                                               };

/* startup database connections. This is principle init function for bonddb */
/**
 *
 * Look for @searchforstr in @parentstr, return 0 if true.
 */
static gint
db_strcontain(gchar *parentstr, gchar *searchforstr)
	{
	gint i, pass=0;
	if (searchforstr == NULL || parentstr == NULL)
		return 0;
	for (i=0;i<strlen(parentstr);i++)
		{
		if (parentstr[i] == searchforstr[pass])
			pass++;
		else
			pass = 0;
		if (pass == strlen(searchforstr))
			return 0;
		}
	
	return 1;
	}

/**
 * db_init:
 * @conninfo: standard postgresql database connection string or the name of the application
 *
 * Establishes database connection to postgresql, and extracts all the 
 * information postgresql needs to work with the database.  If @conninfo 
 * is NULL then the bond.conf configuration files will 
 * be read to get the database initialising string.
 *
 * @conninfo can be either the name of the config file (ie appname.conf)
 * or a database connection string. It looks for the string dbname
 * in @conninfo and if present it assumes its a database connection
 * string else it assumes its not and is a filename.
 * 
 * Returns: non-zero on failure.
 */
gint
db_init(gchar * conninfo)
   {
   gchar *c;

   /*	if (conninfo == NULL)
   		{
   		errormsg("The API for db_init() has changed. You can no longer pass in NULL\n"
   					"as a valid input for db_init().  You need to pass in a database\n"
   					"connection string or the name of the application (argv[0]).\n");
   		return -2;
   		}
   */
	/* debugmsg("passing in conninfo of %s",conninfo); */
	/* this is a tad complex and can cause a few bugs. If conninfo is a db
	 * string then initialise it else do a read on a config file 
	 */
   if (conninfo == NULL || db_strcontain(conninfo,"dbname") != 0)
      c = db_readconfigfile(conninfo);
   else
      c = mem_strdup_printf("%s", conninfo);
	if (c == NULL)
		{
		errormsg("Error creating connection string from %s. Aborting",conninfo);
		}
   if (globaldbconn != NULL)
      db_cleanup();

   debug_init();
   /* dont you hate it when code you write goes missing? */
   globaldbconn = db_dbconnect(c);

   if (db_dbstatus(globaldbconn) != 0)
      {
		 db_dbfinish(globaldbconn);
		 errormsg("Connection to database failed with %s argument.\nerror msg %s", c, db_dberrormsg(globaldbconn));
		 mem_free(c);
		 exit(-1);
      }
   globaldb = db_builddef();
   globaldb->connstr = mem_strdup(c);
   mem_free(c);
   return 0;
   }

static gchar *
db_findbondconffile_ensurefine(gchar * appfile)
   {
   gint i, num;

   g_assert(appfile);
   num = strlen(appfile);
   for (i = num - 1; i >= 0; i--)
      {
      if (appfile[i] == '/')
         {
         debugmsg("returning %s", appfile + (i + 1));
         return appfile + (i + 1);
         }
      }
   return appfile;
   }

/**
 * db_findbondconffile:
 * @appfile: name of the application been run (argc[0])
 * 
 * Search for the configuration files in a number of different locations before
 * running.  Please note, this is hardcoded to the local directory, /usr/local/etc
 * and /etc.
 */
FILE *
db_findbondconffile(gchar * appfile)
   {
   FILE *file;
   gint i, count;
   glob_t g;
   gchar *pattern;
	gchar *filename = NULL;

	if (db_strcontain(appfile,".conf") != 0) 
		filename = mem_strdup_printf("%s.conf",appfile);
	else
		filename = mem_strdup(appfile);

   if ((file = fopen(filename, "r")) != NULL)
		{
		mem_free(filename);
      return file;
		}
	mem_free(filename);
   if ((file = fopen(DEFAULTCONFIGFILE, "r")) != NULL)
      return file;
   if ((file = fopen(".bond", "r")) != NULL)
      return file;
	debugmsg("i still can't find it.");
   if (appfile == NULL)
      errormsg("No arguments were passed into db_init() or bond_init() and application was unable"
               "to work out its roots. Arr i'm lost.  Try copying bond.conf to your working directory, or ensure\n"	       
	       "/etc/bond/appname.conf exists.");

   g_assert(appfile);
   appfile = db_findbondconffile_ensurefine(appfile);

   pattern = mem_strdup_printf("%s", appfile);

   if ((file = fopen(pattern, "r")) != NULL)
      {
      mem_free(pattern);
      return file;
      }
   mem_free(pattern);

   for (i = 0; i < NUMBONDCONFSEARCH; i++)
      {
      pattern = mem_strdup_printf("%s%s", bondconffilesearch[i], appfile);
      debugmsg("looking for a match on %s", pattern);
      if (glob(pattern, 0, NULL, &g) == 0)
         for (count = 0; count < g.gl_pathc; count++)
            if ((file = fopen(g.gl_pathv[count], "r")) != NULL)
               {
               globfree(&g);
               mem_free(pattern);
               return file;
               }
      mem_free(pattern);
      }
   globfree(&g);

   return NULL;
   }

/* shutdown database connection */

/**
 * db_cleanup:
 *
 * Frees up all memory used by db_init(). Will flush all write ahead caches to make sure data is 
 * saved and then close database connections.  Make sure you call this else your last record entered
 * maybe lost.
 *
 * Returns: non-zero on failure.
 */
gint
db_cleanup()
   {
   extern DbDatabaseDef *globaldb;

   /* flush everything outstanding */
   db_toliet_flushall();
	/* clear out the bureaucrat */
	db_bureaucrat_cleanup();
	/* empty the logs */
	db_lomem_free();
   /* free tables up */
   db_freedatabasedef(globaldb);
   /* close connections */
   db_dbfinish(globaldbconn);
   globaldbconn = NULL;
   debug_cleanup();

   return 0;
   }

/**
 * db_restart:
 * 
 * Restart database connection, incase it either dies.
 *
 * Returns: non-zero on failure.
 */
gint
db_restart()
   {
   db_dbreset(globaldbconn);
   return 0;
   }

/**
 * db_readconfigfile:
 * @appfile: Name of application to load
 *
 * Read a configuration file for database etc settings.  This may need readapting at some
 * point to a more powerful and standard configuration method.
 *
 * Returns: NULL on failure, else the db configuration connection string.
 */

/** \todo{ look for code from someone else possible. read config files} */
gchar *
db_readconfigfile(gchar * appfile)
   {
   gchar *gladexmlfile, *dbstring = NULL, *uiplugin;
   gint debuginfo, debuglineinfo;

   db_readallconfig(appfile, &gladexmlfile, &dbstring, &uiplugin, &debuginfo, &debuglineinfo);
   if (gladexmlfile != NULL)
      mem_free(gladexmlfile);
   if (uiplugin != NULL)
      mem_free(uiplugin);
   return dbstring;
   }

/**
 * db_readallconfig:
 * @appfile: Name of application been run
 * @uiplugin: User interface widget set plugin to be used. (uigtk, uihtml, uiwx etc), returned string
 * @dbstring: Database connection string, returned string
 * @gladexmlfile: Glade xml file to use.
 *
 * Liam write me
 */
void
db_readallconfig(gchar * appfile, gchar ** gladexmlfile, gchar ** dbstring, gchar ** uiplugin , gint * debuginfo, gint * debuglineinfo)
   {
   FILE *configfile = NULL;
   gchar *buffer = (gchar *) mem_alloc(1000);
   gchar *value;
   gint slen;

   *gladexmlfile = NULL;
   *dbstring = NULL;
	*uiplugin = NULL;
   *debuginfo = 1;
   *debuglineinfo = 0;

   configfile = db_findbondconffile(appfile);
   if (configfile == NULL)
      {
      errormsg("Unable to find a config file for %s\nEnsure there is a %s.conf file"
               "in your /etc/bond/ directory or /usr/local/etc/bond directory.", appfile, appfile);
      exit( -1);
      }

   fgets(buffer, 1000, configfile);
   value = strstr(buffer, "=");
   if (value && strcasecmp(value + 1, "yes\n") == 0)
      *debuginfo = 1;
   else
      *debuginfo = 0;

   fgets(buffer, 1000, configfile);
   value = strstr(buffer, "=");
   if (value && strcasecmp(value + 1, "yes\n") == 0)
      *debuglineinfo = 1;
   else
      *debuglineinfo = 0;

   fgets(buffer, 1000, configfile);
   value = strstr(buffer, "=");
   if (!value)
      value = buffer;							 /* support old-style configs */
   if (value)
      {
      *gladexmlfile = mem_strdup(value + 1);
      slen = strlen(*gladexmlfile);
      (*gladexmlfile)[slen - 1] = 0;	 /* strip off CR ??? */
      }
   else
      {
      mem_free(buffer);
      return ;
      }

   fgets(buffer, 1000, configfile);
	if (buffer == NULL || strlen(buffer) == 0)
		return ;
   *dbstring = mem_strdup(strstr(buffer, "=") + 1);
   slen = strlen(*dbstring);
   (*dbstring)[slen - 1] = 0;
   /* printf("%s\n", *dbstring); */
   mem_free(buffer);
	if (feof(configfile))
		{
		fgets(buffer, 1000, configfile);
		*uiplugin = mem_strdup(strstr(buffer, "=") + 1);
		slen = strlen(*uiplugin);
		(*uiplugin)[slen - 1] = 0;
		/* printf("%s\n", *uiplugin); */
		}
	
   }

/* load that library eh */
static void *
check_shared_library(char *so)
   {
   void *handle;
   void *sym;

   if ((handle = dlopen(so, RTLD_LAZY)) == 0)
      {
      errormsg("An error occured while reading the shared library %s\n%s", so, dlerror());
      return NULL;
      }

   if ((sym = dlsym(handle, "plugin_init")) == 0)
      {
      dlclose(handle);
      return NULL;
      }
   return handle;
   }

gint
db_loadbindings(gchar * driver)
   {

   return 0;
   }

/*
static void*
db_load_library(gchar *so);
	{
	gint i, count;
	glob_t g;
	gchar *pattern;
 
	g_assert(library);
	
	plugin = mem_alloc(sizeof(Plugin));
	if (args != NULL) 
		args = mem_strdup(args);
	if (library!= NULL) 
		library = mem_strdup(library);
	
	plugin->name = library;
	plugin->args = args;
	plugin->func = NULL;
	plugin->numfunctions = 0; 
 
	for (i = 0; i < NUMPLUGINPATHS; i++)
		{
		pattern = mem_strdup_printf("%s*.so", plugin_search_path [i]);
		
		if (glob (pattern, 0, NULL, &g) == 0)
			{
			for (count = 0; count < g.gl_pathc; count++)
				{
				debugmsg ("Checking library: %s", g.gl_pathv[count]);
				
				plugin->dlhandle = check_shared_library (g.gl_pathv[count]);
				
				if (plugin->dlhandle!=NULL)
					{
					plugin->sym = dlsym (plugin->dlhandle, "plugin_init");
					g_assert (plugin->sym);
					if (plugin->sym (plugin) == 0)
						{
						globfree (&g);
						debugmsg("Plugin successfully loaded.");
						return plugin;
						}
					}
				}
			}
		mem_free (pattern);
		}
	warningmsg("Failed to load plugin\n");
	mem_free (plugin->name);
	mem_free (plugin->args);
	mem_free (plugin);
	} */