git reimport

dcj/tool/includes/message.h

@@ -0,0 +1,68 @@
+// The contestant-available API for the Zeus distributed contest.
+#ifndef MESSAGE_H_  // NOLINT
+#define MESSAGE_H_  // NOLINT
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// The number of nodes on which the solution is running.
+int NumberOfNodes();
+
+// The number (in the range [0 .. NumberOfNodes()-1]) of the node on which this
+// process is running.
+int MyNodeId();
+
+// In all the methods below, if "target" or "source" is not in the valid range,
+// the behaviour is undefined.
+
+// The library internally has a message buffer for each of the nodes in
+// [0 .. NumberOfNodes()-1]. It accumulates the message in such a buffer through
+// the "Put" methods.
+
+// Append "value" to the message that is being prepared for the node with id
+// "target".
+void PutChar(int target, char value);
+void PutInt(int target, int value);
+void PutLL(int target, long long value);  // NOLINT
+
+// Sends the message that was accumulated in the appropriate buffer to the
+// "target" instance, and clear the buffer for this instance.
+//
+// This method is non-blocking - that is, it does not wait for the receiver to
+// call "Receive", it returns immediately after sending the message.
+void Send(int target);
+
+// The library also has a receiving buffer for each instance. When you call
+// "Receive" and retrieve a message from an instance, the buffer tied to this
+// instance is overwritten. You can then retrieve individual parts of the
+// message through the Get* methods. You must retrieve the contents of the
+// message in the order in which they were appended.
+//
+// This method is blocking - if there is no message to receive, it will wait for
+// the message to arrive.
+//
+// You can call Receive(-1) to retrieve a message from any source, or with with
+// source in [0 .. NumberOfNodes()-1] to retrieve a message from a particular
+// source.
+//
+// It returns the number of the instance which sent the message (which is equal
+// to source, unless source is -1).
+int Receive(int source);
+
+// Each of these methods returns and consumes one item from the buffer of the
+// appropriate instance. You must call these methods in the order in which the
+// elements were appended to the message (so, for instance, if the message was
+// created with PutChar, PutChar, PutLL, you must call GetChar, GetChar, GetLL
+// in this order).
+// If you call them in different order, or you call a Get* method after
+// consuming all the contents of the buffer, behaviour is undefined.
+char GetChar(int source);
+int GetInt(int source);
+long long GetLL(int source);  // NOLINT
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // MESSAGE_H_  // NOLINT