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| -rw-r--r-- | IBRAHIM_MKUSA.md | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/IBRAHIM_MKUSA.md b/IBRAHIM_MKUSA.md index 48a7ed1..e029534 100644 --- a/IBRAHIM_MKUSA.md +++ b/IBRAHIM_MKUSA.md @@ -13,8 +13,6 @@ The goal in building Hermes was to expose myself to several concepts integral to systems like networking, synchronization, and multitasking. -**Authorship note:** All of the code described here was written by myself. - # Libraries Used Most libraries and utilities used are part of base Drracket installation and therefore do not need to be imported. @@ -77,6 +75,7 @@ to ```make-connections``` object. (define connections-s (make-semaphore 1)) ;; control access to connections ``` + When the tcp-listener accepts a connection from a client, the associated input output ports along with username are added as an entry in ```make-connections``` via ```add``` function. External functions can operate on the connections by securing the semaphore, @@ -151,7 +150,7 @@ After the message is send, the message is removed from the "queue" via the The code snippet below creates a thread that iteratively calls ```broadcast``` every interval, where interval(in secs) is defined by ```sleep-t```. -** note ** : ```sleep``` is very important for making Hermes behave gracefully +```sleep``` is very important for making Hermes behave gracefully in a system. Without it, it would be called at the rate derived from cpu clock rate. This raises cpu temperatures substantially, and make cause a pre-mature system shutdown. @@ -172,7 +171,7 @@ the chat room. The whisper message is only sent to specified user. To implement this i used ```filter``` over the connections, where the predicate tested whether the current list item matched that of a specific user. -''' +``` (define whisper (regexp-match #px"(.*)/whisper\\s+(\\w+)\\s+(.*)" evt-t0)) [whisper @@ -198,7 +197,7 @@ current list item matched that of a specific user. (get-output-port (car that-user-ports))) (flush-output (get-output-port (car that-user-ports))))) (semaphore-post connections-s)] -''' +``` The snippet above is part of cond statement that tests contents of input from clients to determine what the client is trying wants/trying to do. The top-line @@ -211,10 +210,7 @@ is using regexes to determine whether the received message is a whisper or not. Below are are three selectors that help abstract the contents of a whisper message. - - ``` -; whisper selector for the username and message (define (whisper-info exp) (cadr exp)) @@ -223,12 +219,6 @@ message. (define (whisper-message exp) (cadddr exp)) -(define (list-all-folders folder-id) - (let ((this-level (list-folders folder-id))) - (begin - (display (length this-level)) (display "... ") - (append this-level - (flatten (map list-all-folders (map get-id this-level))))))) ``` ```whisper-info``` retrieves the date-time and username info. |