1 /*

     2  * Low-level protocol support for the IPC connection to the engine.

     3  */

     4 

     5 #ifndef IPCCONN_H_

     6 #define IPCCONN_H_

     7 

     8 #include "../util/buffer.h"

     9 

    10 #include <stddef.h>

    11 #include <stdbool.h>

    12 

    13 #define IPCCONN_MAPMSG_BYTES 4097

    14 

    15 typedef enum {IPC_NOT_CONNECTED, IPC_LISTENING, IPC_CONNECTED} IpcConnState;

    16 

    17 struct _flib_ipcconn;

    18 typedef struct _flib_ipcconn flib_ipcconn;

    19 

    20 /**

    21  * Start an engine connection by listening on a random port. The selected port can

    22  * be queried with flib_ipcconn_port and has to be passed to the engine.

    23  *

    24  * The parameter "recordDemo" can be used to control whether demo recording should

    25  * be enabled for this connection. The localPlayerName is needed for demo

    26  * recording purposes.

    27  *

    28  * Returns NULL on error. Destroy the created object with flib_ipcconn_destroy.

    29  *

    30  * We stop accepting new connections once a connection has been established, so you

    31  * need to create a new ipcconn in order to start a new connection.

    32  */

    33 flib_ipcconn *flib_ipcconn_create();

    34 

    35 uint16_t flib_ipcconn_port(flib_ipcconn *ipc);

    36 

    37 /**

    38  * Free resources and close sockets.

    39  */

    40 void flib_ipcconn_destroy(flib_ipcconn *ipc);

    41 

    42 /**

    43  * Determine the current connection state

    44  */

    45 IpcConnState flib_ipcconn_state(flib_ipcconn *ipc);

    46 

    47 /**

    48  * Receive a single message (up to 256 bytes) and copy it into the data buffer.

    49  * Returns the length of the received message, a negative value if no message could

    50  * be read.

    51  *

    52  * The first byte of a message is its content length, which is one less than the returned

    53  * value.

    54  *

    55  * Note: When a connection is closed, you probably want to call this function until

    56  * no further message is returned, to ensure you see all messages that were sent

    57  * before the connection closed.

    58  */

    59 int flib_ipcconn_recv_message(flib_ipcconn *ipc, void *data);

    60 

    61 /**

    62  * Try to receive 4097 bytes. This is the size of the reply the engine sends

    63  * when successfully queried for map data. The first 4096 bytes are a bit-packed

    64  * twocolor image of the map (256x128), the last byte is the number of hogs that

    65  * fit on the map.

    66  */

    67 int flib_ipcconn_recv_map(flib_ipcconn *ipc, void *data);

    68 

    69 int flib_ipcconn_send_raw(flib_ipcconn *ipc, const void *data, size_t len);

    70 

    71 /**

    72  * Write a single message (up to 255 bytes) to the engine. This call blocks until the

    73  * message is completely written or the connection is closed or an error occurs.

    74  *

    75  * Calling this function in a state other than IPC_CONNECTED will fail immediately.

    76  * Returns a negative value on failure.

    77  */

    78 int flib_ipcconn_send_message(flib_ipcconn *ipc, void *data, size_t len);

    79 

    80 /**

    81  * Convenience function for sending a 0-delimited string.

    82  */

    83 int flib_ipcconn_send_messagestr(flib_ipcconn *ipc, char *data);

    84 

    85 /**

    86  * Call regularly to allow background work to proceed

    87  */

    88 void flib_ipcconn_accept(flib_ipcconn *ipc);

    89 

    90 #endif /* IPCCONN_H_ */

    91