From d391b8d1912b9ce1254fb1fede13419aad66fe49 Mon Sep 17 00:00:00 2001
From: Thadeu Lima de Souza Cascardo <cascardo@cascardo.info>
Date: Tue, 11 Jun 2013 08:33:03 -0300
Subject: [PATCH] Introduce poor man's hash.

This lookup array is helpful for adding fields parsed from the DEC file.
---
 Makefile.am |  2 +-
 pmhash.c    | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 pmhash.h    | 29 ++++++++++++++++
 3 files changed, 127 insertions(+), 1 deletion(-)
 create mode 100644 pmhash.c
 create mode 100644 pmhash.h

diff --git a/Makefile.am b/Makefile.am
index a9d3f7e..c823c67 100644
--- 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
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
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
-- 
2.20.1