Add C API

include/zaprus.h

@@ -0,0 +1,33 @@
+#ifndef ZAPRUS_H
+#define ZAPRUS_H
+
+#include <stdint.h>
+#include <stdlib.h>
+
+typedef void* zaprus_client;
+typedef void* zaprus_connection;
+
+// Returns NULL if there was an error.
+zaprus_client zaprus_init_client(void);
+
+void zaprus_deinit_client(zaprus_client client);
+
+// Returns 0 on success, else returns 1.
+int zaprus_client_send_relay(zaprus_client client, const char* payload, size_t payload_len, const char dest[4]);
+
+// Returns NULL if there was an error.
+// Caller should call zaprus_deinit_connection when done with the connection.
+zaprus_connection zaprus_connect(zaprus_client client, const char* payload, size_t payload_len);
+
+void zaprus_deinit_connection(zaprus_connection connection);
+
+// Capacity is the maximum length of the output buffer.
+// out_len is modified to specify how much of the capacity is used by the response.
+// Blocks until the next message is available, or returns 1 if the underlying socket times out.
+// Returns 0 on success, else returns 1.
+int zaprus_connection_next(zaprus_connection connection, char *out, size_t capacity, size_t *out_len);
+
+// Returns 0 on success, else returns 1.
+int zaprus_connection_send(zaprus_connection connection, const char *payload, size_t payload_len);
+
+#endif // ZAPRUS_H