Added comments

git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@2338 e03df62e-2008-0410-955e-edbf42e46eb7

1 files changed, 81 insertions, 6 deletions

diff --git a/include/socketengine.h b/include/socketengine.h
index a499b4282..caccd9b3f 100644
--- a/include/socketengine.h
+++ b/include/socketengine.h
@@ -32,37 +32,112 @@
 #include <sys/time.h>
 #endif
 
+/**
+ * Each of these values represents a socket
+ * type in our reference table (the reference
+ * table itself is only accessible to
+ * socketengine.cpp)
+ */
 const char X_EMPTY_SLOT		= 0;
 const char X_LISTEN             = 1;
 const char X_ESTAB_CLIENT       = 2;
 const char X_ESTAB_MODULE       = 3;
 const char X_ESTAB_DNS          = 4;
 
+/**
+ * To indicate that a socket is readable, we
+ * mask its top bit with this X_READBIT value.
+ * The socket engine can handle two types of
+ * socket, readable and writeable (error sockets
+ * are dealt with when read() and write() return
+ * negative or zero values).
+ */
 const char X_READBIT            = 0x80;
 
+/**
+ * The actual socketengine class presents the
+ * same interface on all operating systems, but
+ * its private members and internal behaviour
+ * should be treated as blackboxed, and vary
+ * from system to system and upon the config
+ * settings chosen by the server admin. The current
+ * version supports select, epoll and kqueue.
+ */
 class SocketEngine {
 
-	std::vector<int> fds;
-	int EngineHandle;
+	std::vector<int> fds;			/* List of file descriptors being monitored */
+	int EngineHandle;			/* Handle to the socket engine if needed */
 #ifdef USE_SELECT
-	fd_set wfdset, rfdset;
+	fd_set wfdset, rfdset;			/* Readable and writeable sets for select() */
 #endif
 #ifdef USE_KQUEUE
-	struct kevent ke_list[65535];
-	struct timespec ts;
+	struct kevent ke_list[65535];		/* Up to 64k sockets for kqueue */
+	struct timespec ts;			/* kqueue delay value */
 #endif
 #ifdef USE_EPOLL
-	struct epoll_event events[65535];
+	struct epoll_event events[65535];	/* Up to 64k sockets for epoll */
 #endif
 
 public:
 
+	/** Constructor
+	 * The constructor transparently initializes
+	 * the socket engine which the ircd is using.
+	 * Please note that if there is a catastrophic
+	 * failure (for example, you try and enable
+	 * epoll on a 2.4 linux kernel) then this
+	 * function may bail back to the shell.
+	 */
 	SocketEngine();
+
+	/** Destructor
+	 * The destructor transparently tidies up
+	 * any resources used by the socket engine.
+	 */
 	~SocketEngine();
+
+	/** Add a file descriptor to the engine
+	 * Use AddFd to add a file descriptor to the
+	 * engine and have the socket engine monitor
+	 * it. You must provide a type (see the consts
+	 * in socketengine.h) and a boolean flag to
+	 * indicate wether to watch this fd for read
+	 * or write events (there is currently no
+	 * need for support of both).
+	 */
 	bool AddFd(int fd, bool readable, char type);
+
+	/** Returns the type value for this file descriptor
+	 * This function masks off the X_READBIT value
+	 * so that the type of the socket can be obtained.
+	 * The core uses this to decide where to dispatch
+	 * the event to. Please note that some engines
+	 * such as select() have an upper limit of 1024
+	 * descriptors which may be active at any one time,
+	 * where others such as kqueue have no practical
+	 * limits at all.
+	 */
 	char GetType(int fd);
+
+	/** Delete a file descriptor f rom the engine
+	 * This function call deletes a file descriptor
+	 * from the engine, returning true if it succeeded
+	 * and false if it failed.
+	 */
 	bool DelFd(int fd);
+
+	/** Waits for an event.
+	 * Please note that this doesnt wait long, only
+	 * a couple of milliseconds. It returns a list
+	 * of active file descriptors in the vector
+	 * fdlist which the core may then act upon.
+	 */
 	bool Wait(std::vector<int> &fdlist);
+
+	/** Returns the socket engines name
+	 * This returns the name of the engine for use
+	 * in /VERSION responses.
+	 */
 	std::string GetName();
 };