1 files changed, 192 insertions, 0 deletions
diff --git a/src/queue.c b/src/queue.c
new file mode 100644
index 0000000..16b0a0f
--- /dev/null
+++ b/src/queue.c
@@ -0,0 +1,192 @@
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "db.h"
+
+#define DROP 0
+#define SET  1
+
+/**
+ * Queue
+ */
+struct queue
+{
+	uint32_t read, write, capacity;
+	void *queue;
+};
+typedef struct queue queue_t;
+
+/** the queue */
+static queue_t queue;
+
+static
+bool
+qread(
+	void *data,
+	uint32_t length
+) {
+	if (queue.read + length > queue.write)
+		return false;
+
+	memcpy(data, queue.queue + queue.read, length);
+	queue.read += length;
+	return true;
+}
+
+static
+bool
+qget_char(
+	char *value
+) {
+	return qread(value, sizeof *value);
+}
+
+static
+bool
+qget_uint32(
+	uint32_t *value
+) {
+	return qread(value, sizeof *value);
+}
+
+static
+bool
+qget_string(
+	const char **text
+) {
+	char *p = queue.queue + queue.read;
+	uint32_t length = (uint32_t)strlen(p);
+	if (queue.read + length >= queue.write)
+		return false;
+	*text = p;
+	queue.read += length + 1;
+	return true;
+}
+
+static
+bool
+qwrite(
+	const void *data,
+	uint32_t length
+) {
+	uint32_t c;
+	void *b;
+
+	c = queue.capacity;
+	while (c < queue.write + length)
+		c += 4096;
+	if (c != queue.capacity) {
+		b = realloc(queue.queue, c);
+		if (b == NULL)
+			return false;
+		queue.queue = b;
+		queue.capacity = c;
+	}
+	memcpy(queue.queue + queue.write, data, length);
+	queue.write += length;
+	return true;
+}
+
+static
+bool
+qput_char(
+	char value
+) {
+	return qwrite(&value, sizeof value);
+}
+
+static
+bool
+qput_uint32(
+	uint32_t value
+) {
+	return qwrite(&value, sizeof value);
+}
+
+static
+bool
+qput_string(
+	const char *text
+) {
+	size_t len;
+	text = text ?: "";
+	/* check length */
+	len = strnlen(text, MAX_NAME_LENGTH + 1);
+	if (len > MAX_NAME_LENGTH)
+		return false;
+	return qwrite(text, 1 + (uint32_t)len);
+}
+
+int
+queue_drop(
+	const char *client,
+	const char *session,
+	const char *user,
+	const char *permission
+) {
+	return qput_char(DROP)
+		&& qput_string(client)
+		&& qput_string(session)
+		&& qput_string(user)
+		&& qput_string(permission)
+			? 0 : -(errno = ENOMEM);
+}
+
+int
+queue_set(
+	const char *client,
+	const char *session,
+	const char *user,
+	const char *permission,
+	uint32_t value
+) {
+	return qput_char(SET)
+		&& qput_string(client)
+		&& qput_string(session)
+		&& qput_string(user)
+		&& qput_string(permission)
+		&& qput_uint32(value)
+			? 0 : -(errno = ENOMEM);
+}
+
+
+void
+queue_clear(
+) {
+	queue.write = 0;
+}
+
+int
+queue_play(
+) {
+	int rc, rc2;
+	char op;
+	const char *client;
+	const char *session;
+	const char *user;
+	const char *permission;
+	uint32_t value;
+
+	rc = 0;
+	queue.read = 0;
+	while (queue.read < queue.write) {
+		rc2 = -EINVAL;
+		if (qget_char(&op)
+		 && qget_string(&client)
+		 && qget_string(&session)
+		 && qget_string(&user)
+		 && qget_string(&permission)) {
+			if (op == DROP)
+				rc2 = db_drop(client, session, user, permission);
+			else if (qget_uint32(&value))
+				rc2 = db_set(client, session, user, permission, value);
+		}
+		if (rc2 != 0 && rc == 0)
+			rc = rc2;
+	}
+	return rc;
+}
+