Introduce poor man's hash.

This lookup array is helpful for adding fields parsed from the DEC file.

diff --git a/Makefile.am b/Makefile.am
index a9d3f7e..c823c67 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,2 +1,2 @@
 bin_PROGRAMS = rnetclient
-rnetclient_SOURCES = rnetclient.c decfile.c decfile.h
+rnetclient_SOURCES = rnetclient.c decfile.c decfile.h pmhash.c pmhash.h

diff --git a/pmhash.c b/pmhash.c
new file mode 100644 (file)
index 0000000..d228856
--- /dev/null
+++ b/pmhash.c
@@ -0,0 +1,97 @@
+/*
+ *  Copyright (C) 2012-2013  Thadeu Lima de Souza Cascardo <cascardo@minaslivre.org>
+ *
+ *  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 3 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 "pmhash.h"
+#include <stdlib.h>
+#include <string.h>
+
+struct item {
+       char *key;
+       void *val;
+};
+
+struct pmhash {
+       size_t len;
+       struct item items[];
+};
+
+struct pmhash * pmhash_new(void)
+{
+       struct pmhash *pmhash;
+       size_t len = 128;
+       pmhash = malloc(sizeof(*pmhash) + len * sizeof(struct item));
+       if (!pmhash)
+               return NULL;
+       pmhash->len = len;
+       memset(pmhash->items, 0, len * sizeof(struct item));
+       return pmhash;
+}
+
+int pmhash_add(struct pmhash **pmhash, char *key, void *val)
+{
+       int i;
+       struct pmhash *hash = *pmhash;
+       i = 0;
+repeat:
+       for (; i < hash->len; i++) {
+               if (hash->items[i].key == NULL) {
+                       hash->items[i].key = key;
+                       hash->items[i].val = val;
+                       break;
+               }
+       }
+       if (i == hash->len) {
+               struct pmhash *nhash;
+               size_t len = hash->len * sizeof(struct item);
+               size_t nlen = len * 2;
+               nhash = realloc(hash, sizeof(*nhash) + nlen);
+               if (!nhash)
+                       goto out;
+               *pmhash = hash = nhash;
+               memset(&hash->items[hash->len], 0, len);
+               hash->len = hash->len * 2;
+               goto repeat;
+       }
+       return 0;
+out:
+       return -1;
+}
+
+void * pmhash_get(struct pmhash *pmhash, char *key)
+{
+       int i;
+       for (i = 0; i < pmhash->len; i++) {
+               if (pmhash->items[i].key == NULL)
+                       return NULL;
+               if (!strcmp(pmhash->items[i].key, key))
+                       return pmhash->items[i].val;
+       }
+       return NULL;
+}
+
+void pmhash_del(struct pmhash *pmhash)
+{
+       int i;
+       for (i = 0; i < pmhash->len; i++) {
+               if (pmhash->items[i].key == NULL)
+                       break;
+               free(pmhash->items[i].key);
+               free(pmhash->items[i].val);
+       }
+       free(pmhash);
+}

diff --git a/pmhash.h b/pmhash.h
new file mode 100644 (file)
index 0000000..d1c0206
--- /dev/null
+++ b/pmhash.h
@@ -0,0 +1,29 @@
+/*
+ *  Copyright (C) 2012-2013  Thadeu Lima de Souza Cascardo <cascardo@minaslivre.org>
+ *
+ *  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 3 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.
+ */
+
+#ifndef _PMHASH_H
+#define _PMHASH_H
+
+struct pmhash;
+
+struct pmhash * pmhash_new(void);
+int pmhash_add(struct pmhash **pmhash, char *key, void *val);
+void * pmhash_get(struct pmhash *pmhash, char *key);
+void pmhash_del(struct pmhash *pmhash);
+
+#endif