comparison src/fftw-3.3.3/api/import-wisdom-from-file.c @ 10:37bf6b4a2645

Add FFTW3

+/*
+ * Copyright (c) 2003, 2007-11 Matteo Frigo
+ * Copyright (c) 2003, 2007-11 Massachusetts Institute of Technology
+ *
+ * This program 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 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include "api.h"
+#include <stdio.h>
+
+/* getc()/putc() are *unbelievably* slow on linux.  Looks like glibc
+   is grabbing a lock for each call to getc()/putc(), or something
+   like that.  You pay the price for these idiotic posix threads
+   whether you use them or not.
+
+   So, we do our own buffering.  This completely defeats the purpose
+   of having stdio in the first place, of course.
+*/
+  
+#define BUFSZ 256
+
+typedef struct {
+     scanner super;
+     FILE *f;
+     char buf[BUFSZ];
+     char *bufr, *bufw;
+} S;
+
+static int getchr_file(scanner * sc_)
+{
+     S *sc = (S *) sc_;
+
+     if (sc->bufr >= sc->bufw) {
+	  sc->bufr = sc->buf;
+	  sc->bufw = sc->buf + fread(sc->buf, 1, BUFSZ, sc->f);
+	  if (sc->bufr >= sc->bufw)
+	       return EOF;
+     }
+
+     return *(sc->bufr++);
+}
+
+static scanner *mkscanner_file(FILE *f)
+{
+     S *sc = (S *) X(mkscanner)(sizeof(S), getchr_file);
+     sc->f = f;
+     sc->bufr = sc->bufw = sc->buf;
+     return &sc->super;
+}
+
+int X(import_wisdom_from_file)(FILE *input_file)
+{
+     scanner *s = mkscanner_file(input_file);
+     planner *plnr = X(the_planner)();
+     int ret = plnr->adt->imprt(plnr, s);
+     X(scanner_destroy)(s);
+     return ret;
+}
+
+int X(import_wisdom_from_filename)(const char *filename)
+{
+     FILE *f = fopen(filename, "r");
+     int ret;
+     if (!f) return 0; /* error opening file */
+     ret = X(import_wisdom_from_file)(f);
+     if (fclose(f)) ret = 0; /* error closing file */
+     return ret;
+}