plugin.c

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/* File: plugin.c
 *
 * Time-stamp: <Tue 02 Aug 2005-- 21:44:10 Paolo Frasconi>
 * $Id: plugin.c,v 1.1 2006/05/31 09:21:19 andrea Exp $
 *
 * Author: Alessio Ceroni and Paolo Frasconi
 *
 * Description: svm-Dlight - wrappers around customizable functions
 * 
 */
# include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dlfcn.h>
# include "plugin.h"
#include "sparsevector.h" /* Default data type is sparse vector */

static void *dl_library = NULL;


static void*(*plugin_null_fcn)(void) = NULL;
static void*(*plugin_copy_constructor_fcn)(void*) = NULL;
static void*(*plugin_parse_document_fcn)
  (char*, double*, long*, long*, double*, long*, long, char**) = NULL;
static double(*plugin_kernel_fcn)(void*,void*) = NULL;
static void(*plugin_write_fcn)(FILE*,void*) = NULL;
static void(*plugin_destructor_fcn)(void*) = NULL;
static void(*plugin_clip_fcn)(void*, int) = NULL;
static void(*plugin_kernel_setparm_fcn)(char*) = NULL;

void empty_function(char* a)
{
}

void plugin_init(char *plugin_file) {

  const char *error;
  plugin_exit();  /* Alessio: a che serve? */

  /* open library */
  if( plugin_file != NULL && strlen(plugin_file)>0 ) {
    dl_library = dlopen(plugin_file,RTLD_LAZY);
    if( dl_library==NULL ) {
      fprintf (stderr, "Cannot open plugin file <%s>, using default: %s\n",
               plugin_file, dlerror()); 
    }
  }
    
  if( dl_library!=NULL ) {
    /* clear errors */
    dlerror();
    
    /* load symbols */
    plugin_null_fcn = dlsym(dl_library, "plugin_null");
    if ((error = dlerror()) != NULL)  {
      fprintf (stderr, "Fatal plugin error: %s\n", error);
      exit(1);
    }

    plugin_copy_constructor_fcn = dlsym(dl_library, "plugin_copy_constructor");
    if ((error = dlerror()) != NULL)  {
      fprintf (stderr, "Fatal plugin error: %s\n", error);
      exit(1);
    }

    plugin_parse_document_fcn = dlsym(dl_library, "plugin_parse_document");
    if ((error = dlerror()) != NULL)  {
      fprintf (stderr, "Fatal plugin error: %s\n", error);
      exit(1);
    }

    plugin_kernel_fcn = dlsym(dl_library, "plugin_kernel");
    if ((error = dlerror()) != NULL)  {
      fprintf (stderr, "Fatal plugin error: %s\n", error);
      exit(1);
    }

    plugin_write_fcn = dlsym(dl_library, "plugin_write");
    if ((error = dlerror()) != NULL)  {
      fprintf (stderr, "Fatal plugin error: %s\n", error);
      exit(1);
    }

    plugin_destructor_fcn = dlsym(dl_library, "plugin_destructor");
    if ((error = dlerror()) != NULL)  {
      fprintf (stderr, "Fatal plugin error: %s\n", error);
      exit(1);
    }

    plugin_clip_fcn = dlsym(dl_library, "plugin_clip");
    if ((error = dlerror()) != NULL)  {
      fprintf (stderr, "Fatal plugin error: %s\n", error);
      exit(1);
    }

    plugin_kernel_setparm_fcn = dlsym(dl_library, "plugin_kernel_setparm");
    if ((error = dlerror()) != NULL)  {
      fprintf (stderr, "Fatal plugin error: %s\n", error);
      exit(1);
    }


  }
  else {
    /* default */
    plugin_null_fcn = sparsevector_null;
    plugin_copy_constructor_fcn = sparsevector_copy_constructor;
    plugin_parse_document_fcn = sparsevector_parse_document;
    plugin_kernel_fcn = sparsevector_kernel;
    plugin_write_fcn = sparsevector_write;
    plugin_destructor_fcn = sparsevector_destructor;
    plugin_clip_fcn = sparsevector_clip;
    plugin_kernel_setparm_fcn = empty_function;
  }
}

void plugin_exit() {
  plugin_null_fcn = NULL;
  plugin_copy_constructor_fcn = NULL;
  plugin_parse_document_fcn = NULL;
  plugin_kernel_fcn = NULL; 
  plugin_write_fcn = NULL;
  plugin_destructor_fcn = NULL;
  plugin_clip_fcn = NULL;
  
  if( dl_library!=NULL )
    dlclose(dl_library);
  dl_library = NULL;  
}



void* plugin_null(void) {
  return plugin_null_fcn();
}

void* plugin_copy_constructor(void *words) {
  return plugin_copy_constructor_fcn(words);
}

void* 
plugin_parse_document(char* line, 
                      double* alphay,
                      long int* queryid,
                      long int* slackid, 
                      double* costfactor,
                      /* long* wpos, */
                      long int* highest_feature, 
                      long int max_words, 
                      char** comment) 
{
  return plugin_parse_document_fcn(line, alphay, queryid, slackid, costfactor,
                                   highest_feature, max_words, comment);
}


double plugin_kernel(void *a, void *b) {
  return plugin_kernel_fcn(a,b);
}

void plugin_write(FILE *fl, void *words) {
  plugin_write_fcn(fl,words);
}

void plugin_destructor(void *words) {
  plugin_destructor_fcn(words);
}

void plugin_clip(void *words, int maxwords) {
  plugin_clip_fcn(words, maxwords);
}


void plugin_kernel_setparm(char* kernel_parm) {
  plugin_kernel_setparm_fcn(kernel_parm);
}

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