1 files changed, 63 insertions, 0 deletions
diff --git a/bin/edi/log.c b/bin/edi/log.c
new file mode 100644
index 00000000..b0bd117e
--- /dev/null
+++ b/bin/edi/log.c
@@ -0,0 +1,63 @@
+/* Copyright (C) 2018  June McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <err.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <sysexits.h>
+
+#include "edi.h"
+
+struct Log logAlloc(size_t cap) {
+	assert(cap);
+	struct State *states = malloc(sizeof(*states) * cap);
+	if (!states) err(EX_OSERR, "malloc");
+	states[0] = (struct State) {
+		.table = NULL,
+		.prev = 0,
+		.next = 0,
+	};
+	return (struct Log) {
+		.cap = cap,
+		.len = 1,
+		.index = 0,
+		.states = states,
+	};
+}
+
+void logFree(struct Log *log) {
+	for (size_t i = 0; i < log->len; ++i) {
+		free(log->states[i].table);
+	}
+	free(log->states);
+}
+
+void logPush(struct Log *log, struct Table *table) {
+	if (log->len == log->cap) {
+		log->cap *= 2;
+		log->states = realloc(log->states, sizeof(*log->states) * log->cap);
+		if (!log->states) err(EX_OSERR, "realloc");
+	}
+	size_t next = log->len++;
+	log->states[next] = (struct State) {
+		.table = table,
+		.prev = log->index,
+		.next = next,
+	};
+	log->states[log->index].next = next;
+	log->index = next;
+}