1 files changed, 79 insertions, 0 deletions
diff --git a/mq.h b/mq.h
new file mode 100644
index 0000000..b5af78f
--- /dev/null
+++ b/mq.h
@@ -0,0 +1,79 @@
+#include <limits.h>  // for definition of SSIZE_MAX
+
+typedef struct {
+    PyObject_HEAD
+    key_t key;
+    int id;
+    unsigned long max_message_size;
+} MessageQueue;
+
+/* Message queue message struct for send() & receive() 
+On many systems this is defined in sys/msg.h already, but it's better
+for me to define it here. Name it something other than msgbuf to avoid 
+conflict with the struct that the OS header file might define.
+*/
+struct queue_message {
+    long type;
+    char message[];
+};
+
+/* Maximum message size is limited by (a) the largest Python string I can
+create and (b) SSIZE_T_MAX. The latter restriction comes from the spec which
+says, "If the value of msgsz is greater than {SSIZE_MAX}, the result is 
+implementation-defined."
+ref: http://www.opengroup.org/onlinepubs/000095399/functions/msgrcv.html
+*/
+#if SSIZE_MAX > PY_STRING_LENGTH_MAX
+#define QUEUE_MESSAGE_SIZE_MAX  PY_STRING_LENGTH_MAX
+#else
+#define QUEUE_MESSAGE_SIZE_MAX  SSIZE_MAX
+#endif
+
+/* The max message size is probably a very big number, and since a 
+max-sized buffer is allocated every time receive() is called, it would be
+ugly if the default message size for new queues was the same as the max.
+In addition, many operating systems limit the entire queue to 2048 bytes,
+so defaulting the max message to something larger seems a bit stupid.
+
+This value is also present in numeric form in ReadMe.html, so if you 
+change it here, change it there too.
+*/
+#define QUEUE_MESSAGE_SIZE_MAX_DEFAULT 2048
+
+/* Object methods */
+PyObject *MessageQueue_new(PyTypeObject *, PyObject *, PyObject *);
+int MessageQueue_init(MessageQueue *, PyObject *, PyObject *);
+void MessageQueue_dealloc(MessageQueue *);
+PyObject *MessageQueue_send(MessageQueue *, PyObject *, PyObject *);
+PyObject *MessageQueue_receive(MessageQueue *, PyObject *, PyObject *);
+PyObject *MessageQueue_remove(MessageQueue *);
+
+/* Object attributes (read-write & read-only) */
+PyObject *mq_get_mode(MessageQueue *);
+int mq_set_mode(MessageQueue *, PyObject *);
+
+PyObject *mq_get_uid(MessageQueue *);
+int mq_set_uid(MessageQueue *, PyObject *);
+
+PyObject *mq_get_gid(MessageQueue *);
+int mq_set_gid(MessageQueue *, PyObject *);
+
+PyObject *mq_get_max_size(MessageQueue *);
+int mq_set_max_size(MessageQueue *, PyObject *);
+
+PyObject *mq_get_key(MessageQueue *);
+PyObject *mq_get_last_send_time(MessageQueue *);
+PyObject *mq_get_last_receive_time(MessageQueue *);
+PyObject *mq_get_last_change_time(MessageQueue *);
+PyObject *mq_get_last_send_pid(MessageQueue *);
+PyObject *mq_get_last_receive_pid(MessageQueue *);
+PyObject *mq_get_current_messages(MessageQueue *);
+PyObject *mq_get_c_uid(MessageQueue *);
+PyObject *mq_get_c_gid(MessageQueue *);
+
+PyObject *mq_str(MessageQueue *);
+PyObject *mq_repr(MessageQueue *);
+
+/* Misc. */
+PyObject *mq_remove(int);
+