Se emprolija un poco los archivos de indices.

[z.facultad/75.06/emufs.git] / emufs / fsc.c

diff --git a/emufs/fsc.c b/emufs/fsc.c
index b8e0db4b7101042407387f9c97f3ea2334ad8edc..c0c026f726e6977c16ff51b26983808aa41e0cac 100644 (file)
--- a/emufs/fsc.c
+++ b/emufs/fsc.c
@@ -1,45 +1,144 @@
+/* vim: set noexpandtab tabstop=4 shiftwidth=4:
+ *----------------------------------------------------------------------------
+ *                                  emufs
+ *----------------------------------------------------------------------------
+ * This file is part of emufs.
+ *
+ * emufs 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.
+ *
+ * emufs 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 emufs; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place, Suite 330, Boston, MA  02111-1307  USA
+ *----------------------------------------------------------------------------
+ * Creado:  vie abr  9 16:17:50 ART 2004
+ * Autores: Nicolás Dimov <sagardua@uolsinectis.com.ar>
+ *----------------------------------------------------------------------------
+ *
+ * $Id$
+ *
+ */
+
+/** \file
+ *
+ * Archivo para administrar el espacio libre disponible.
+ * 
+ * Implementación del archivo para administrar el espacio libre disponible.
+ *
+ */
+
 #include "fsc.h"
-#include "tipo3.h"
+#include <string.h>
+#include <unistd.h>
+
+#define EMUFS_FSC_EXT ".fsc"
+
+typedef struct emufs_fsc_t {
+       int block;
+       int free_space;
+} EMUFS_FSC;
 
 int emufs_fsc_agregar(EMUFS *emu, int num_bloque, int fs)
 {
        FILE *f_fsc;
-       BLOCK_FREE_T reg;
+       EMUFS_FSC reg;
        char name_f_fsc[255];
        
        strcpy(name_f_fsc,emu->nombre);
-       strcat(name_f_fsc,".fsc");
+       strcat(name_f_fsc, EMUFS_FSC_EXT);
        
        /*cargo el registro*/
-       reg.block = num_bloque; /*no incremento cant, porque grabe el nuevo bloque antes y no lo conte!!*/
+       reg.block = num_bloque; 
        reg.free_space = fs;
        /*lo guardo en el archivo al final  "a+"*/
        if ( (f_fsc = fopen(name_f_fsc,"a+"))==NULL ) return -1;
-       fwrite(&reg,sizeof(BLOCK_FREE_T),1,f_fsc);
+       fwrite(&reg,sizeof(EMUFS_FSC),1,f_fsc);
        fclose(f_fsc);
        return 0;
 }
 
+/* busca el bloque y le resta fs de espacio libre */
 int emufs_fsc_actualizar(EMUFS *emu, int num_bloque, int fs)
 {
        FILE *f_fsc;
-       BLOCK_FREE_T reg;
+       EMUFS_FSC reg;
        char name_f_fsc[255];
        
        strcpy(name_f_fsc,emu->nombre);
-       strcat(name_f_fsc,".fsc");
+       strcat(name_f_fsc, EMUFS_FSC_EXT);
 
        /*busco el bloque que modifique*/
        if ( (f_fsc = fopen(name_f_fsc,"r+")) == NULL) return -1; 
        while ( !feof(f_fsc) ){
-               if ( fread(&reg,sizeof(BLOCK_FREE_T),1,f_fsc) != 1) continue;
+               if ( fread(&reg,sizeof(EMUFS_FSC),1,f_fsc) != 1) continue;
                if ( reg.block == num_bloque ){
-                       reg.free_space -= fs;
-                       fseek(f_fsc,-sizeof(BLOCK_FREE_T),SEEK_CUR);
-                       fwrite(&reg,sizeof(BLOCK_FREE_T),1,f_fsc);
+                       reg.free_space = fs;
+                       fseek(f_fsc,-sizeof(EMUFS_FSC),SEEK_CUR);
+                       fwrite(&reg,sizeof(EMUFS_FSC),1,f_fsc);
                        break;
                }
        }
        fclose(f_fsc);
        return 0;
 }
+
+/* me devuelve el ID del bloque donde quepa un registro, y guarda en fs el espacio libre que queda en el bloque */
+int emufs_fsc_buscar_lugar(EMUFS *emu, unsigned long tam, int *fs)
+{
+       FILE *f_fsc;
+       EMUFS_FSC reg;
+       char name_f_fsc[255];
+       
+       strcpy(name_f_fsc,emu->nombre);
+       strcat(name_f_fsc, EMUFS_FSC_EXT);
+
+       if ( (f_fsc = fopen(name_f_fsc,"r"))==NULL ) return -1;
+
+       /* Inicializo la estructura para evitar que si el archivo esta vacio
+        * el resultado sea correcto
+        */
+       reg.block = -1;
+       *fs = emu->tam_bloque;
+       while( !feof(f_fsc) ){
+               if (fread(&reg,sizeof(EMUFS_FSC),1,f_fsc) != 1) continue;
+               if ( reg.free_space >= tam+sizeof(int)) 
+                       break;
+               else {
+                       reg.block = -1;
+                       *fs = emu->tam_bloque;
+               }
+       }
+       
+       fclose(f_fsc);
+       if (reg.block != -1)
+               *fs = reg.free_space;
+       return reg.block;
+}
+
+int emufs_fsc_get_fs(EMUFS *emu, int num_bloque)
+{
+       FILE *f_fsc;
+       EMUFS_FSC reg;
+       char name_f_fsc[255];
+       
+       strcpy(name_f_fsc,emu->nombre);
+       strcat(name_f_fsc, EMUFS_FSC_EXT);
+
+       if ( (f_fsc = fopen(name_f_fsc,"r"))==NULL ) return -1;
+
+       while ( !feof(f_fsc) ){
+               if ( fread(&reg,sizeof(EMUFS_FSC),1,f_fsc) != 1 ) continue;
+               if ( reg.block == num_bloque )
+                       break;
+       }
+               
+       fclose(f_fsc);
+       return reg.free_space;
+}