Updating lecctures and readme for relevancy

.gitlab-ci.yml

@@ -5,6 +5,6 @@ pages:
   - ./scripts/build-html.sh
  artifacts:
   paths:
-			-public
+   - public/
  only:
-		master
+  - master

311/lec/lec10.md

@@ -1,81 +1,51 @@
-# lec10
+lec1 
+=====
 
-## TCP Structue
+First we'll define some terminology.
 
-Sequence Numbers:
+> Hosts
-* byte stream _number_ of first byte in segment's data
 
-ACKS's: 
+End systems - typically don't bother with routing data through a network
-* seq # of next byte expected from other side
 
-Example: 
+> Communication Links
-```
-host a: user sends 'c'
-	seq=42, ack=79, data='c'
-host b: ACK recepit send to host a(echo's back ''c')
-	seq=72, ack=49, data='c'	; data sent back from host b
-```
 
-### Round trip time
+Typically the actual systems that connect things together.
 
-EstimatedRTT= (1-\alpha)*EstimatedRTT + \alpha*SampleRTT
+Network edges
+-------------
 
-> Lot's of stuff missing here
+Can be subdivided clients & servers and sometimes both at the same time.
 
-## TCP Reliable data transfer
+Access network: cable network
-
+-----------------------------
-Implements:
-
-* Pipeplined segments
-* cumulative `ACK`
-	* This just means that we assume that the highest sequenced ACK also means the previous segments have been received properly too
-* Single transmission timer
-
-### Sender Events
-
-1. First create segment w/ seq no.
-
-	a. Sequence number refers to byte in 
-
-2. Start timer if we don't already have one.
-	
-	a. Timer based off oldest UN-ACKED segment
-
-## Retransmission w/ TCP
-
-__Timout__: Usually it's pretty long so if there is a timeout on a packet.
-When this happens the receiver responds to sender with 3 ACK's for the last well received segment:
-
-Receiver gets `1 2 3 5` but not `4`. We respond with the ACK for `1` like normal, then 3 ACK's for `1` is sent to the sender before the time out and we start re-sending from `2`.
-This is what we call _fast retransmit_.
-
-_The main thing here is that the receiver controls the sender's "send rate" so that the receiver doesn't get inundated._
-Receiver will _advertise_ free buffer space in including `rwnd` value in TCP header.
-This just tells the sender how much space is available to accept at a time.
-
-Example: Transferring a large file from host to host.
-
-\alpha will send a file to \beta.
-Alpha sends some file data to \beta, who then ACK's the packet but includes in the header that their buffer is full.
-\alpha responds with a 1 byte packet to keep the connection alive.
-
-
-## Connection Management
-
-Before sender/receiver start exchanging anything we must perform a `handshake`.
-`SYN` is a special packet type under TCP which we can use to synchronize both client and server.
-
-### Closing 
-
-`FIN` bit inside the header.
-We send this off to a receiver and we enter a `close_wait` state.
-We only wait because there might be more data.
-Receiver enters the `close_wait` state as well, _but_, still sends any data left over.
-Once the last `ACK` is sent we send a `FIN` packet
 
+Typically when have to share one line we can change the frequency of the
+signal as one method to provide a distinguishment between different data
+which may sometimes come from different sources.
 
+### Home Network
 
+Let's start with the modem. All it does it take some signla and convert
+it to the proper IEEE data format(citation needed).
 
+Typically we would then pipe that data to a router which, given a
+scenario for most houses, would forward that input data to whichever
+machines requested the data.
 
+If you recall back to your discrete mathematics coursework various graph
+topologies were covered and you likely noted that *star* topologies were
+common for businesses since it makes it easist to send data from one
+outside node on the star to another. In practice this would just mean
+having the router/modem setup be one of the apendages of the star and
+switch be in the middle so that the data only has to make two hops to
+get anywhere in the network.
 
+> Doesn't that mean theres one node that could bring the whole network
+> down at any time?
 
+Absolutely, which is why if you have a *very* small network with a
+couple devices it's not really a problem but if you have an office full
+of employees all with their own machines and wireless, printers,
+servers, etc. then it's a huge problem. That's why typically a small
+business or shop might be more inclined to use such a setup because: \*
+It's easy to setup \* It's cheap to maintain

312/ciphers.md

@@ -1,77 +1,32 @@
-# Block Ciphers
+Active v Passive Attacks
+========================
 
-The main concept here is twofold:
+Base Definitions
+----------------
 
-* we take _blocks_ of data and cipher the _blocks_
+Passive: compromising a system but not necessarily doing anything apart
-* A given key is actually used to generate recursive keys to be further used on the data itself
+from *watching*
 
+Active: compromising a system while doing something to the system apart
+from infiltrating it
 
-_bs example ahead_
+Loosely speaking
+----------------
 
-Say we have a key 7 and some data 123456.
+*Passive* can be just like listening in on a conversation(eavesdropping)
-We take the whole data set and chunk it into blocks(for example): 12 34 56.
+where *active* is like jumping into the conversation and trying to do
+something to it.
 
-Let's say our function here is to just add 7 to each block so we do the first step: 
+When/How would either happen?
+-----------------------------
 
-```
+If the result of an attack is to actually trigger some code to run then
-12 + 7 = 19
+usually we need to first gather the information required to understand
-Unlike other ciphers we don't reuse 7; instead we use the new thing as both the new key and part of our cipher text
+how to make that happen. The reasoning is straightforward: if you don't
+know how some system works then it's much harder to exploit that system.
 
-19 + 34 = 53
+Random example: Using a keylogger to log keystroke before sending those
-Cipher: 1953..
+logs to a server for processing could be a passive attack since you're
-
+still in a *gathering data* sort of mode. Finally using that data to
-53 + 56 = 109 <= let's pretend that this rolls over 99 and back to 00
+trying logging into some service would be the active portion of a
-          09  <= like this
+full-scale attack.
-
-Final cipher: 195309
-```
-
-_It should be noted that in practice these functions usually take in huge keys and blocks_.
-
-> Deciphering
-
-Start from the back of the cipher not the front; if we used and xor function scheme (which is a symmetrical function) we would simply just xor the last block by itself and thus perform the same encryption scheme but in reverse.
-
-Example::Encryption
-
-```
-Key: 110
-Function scheme: xor
-Data: 101 001 111
-
-101 011 010
-110 001 111
-
-011 010 101 <= encrypted
-
-```
-
-Example::Decryption
-
-```
-Ciphered: 011 010 101
-Function scheme: xor
-
-...
-```
-
-# Feistal Cipher
-
-Two main components:
-
-1. each _thing_ in the data to cipher is replaced by a _ciphered thing_
-
-2. nothing is added or deleted or replaced in sequence, instead the order of _things_ is changed.
-
-Basically imagine that every _type of thing_ in our data maps to some other _type of thing/thing_ in the data and thus become swapped/reordered.
-
-# DES - Data Encryption Standard
-
-Widely used until about 2001 when AES surpassed it as the newer(ish(kinda)) standard.
-
-DEA was the actual algorithm tho:
-
-* 64 bit blocks
-* 56 bit keys
-* turns a 64-bit input into a 64-bit output (wew)
-* Steps in reverse also reverse the encryption itself

337/lec/lec10.md

@@ -1,41 +1,169 @@
-# lec11
+lec1
+====
 
-At this point I'l mention that just reading isn't going to get you anywhere, you have to try things, and give it a real earnest attempt.
+> What on earth?
 
-__ALU:__ Arithmetic Logic Unit
+The first lecture has bee 50% syllabus 25% videos, 25% simple
+terminology; expect nothing interesting for this section
 
-## Building a 1-bit ALU 
+General Performance Improvements in software
+--------------------------------------------
 
-![fig0](../img/alu.png)
+In general we have a few options to increase performace in software;
+pipelining, parallelism, prediction.
 
-First we'll create an example _ALU_ which implements choosing between an `and`, `or`, `xor`, or `add`.
+1.  Parallelism
-Whether or not our amazing _ALU_ is useful doesn't matter so we'll go one function at a time(besides `and/or`).
 
-First recognize that we need to choose between `and` or `or` against our two inputs A/B.
+If we have multiple tasks to accomplish or multiple sources of data we
-This means we have two inputs and/or, and we need to select between them.
+might instead find it better to work on multiple things at
-_Try to do this on your own first!_
+once\[e.g. multi-threading, multi-core rendering\]
 
-![fig1](../mg/fig1llec11.png)
+2.  Pipelining
 
-Next we'll add on the `xor`.
+Here we are somehow taking *data* and serializing it into a linear form.
-Try doing this on your own but as far as hints go: don't be afraid to make changes to the mux.
+We do things like this because it could make sense to things
+linearly\[e.g. taking data from a website response and forming it into a
+struct/class instance in C++/Java et al.\].
 
-![fig2](../img/fig2lec11.png)
+3.  Prediction
 
-Finally we'll add the ability to add and subtract. 
+If we can predict an outcome to avoid a bunch of computation then it
-You may have also noted that we can subtract two things to see if they are the same however, we can also `not` the result of the `xor` and get the same result.
+could be worth to take our prediction and proceed with that instead of
+the former. This happens **a lot** in cpu's where they use what's called
+[branch prediction](https://danluu.com/branch-prediction/) to run even
+faster.
 
-![fig3](../img/fig3lec11.png)
+Cost of Such Improvements
+-------------------------
 
-At this point our _ALU_ can `and`, `or`, `xor`, and `add`/`sub`.
+As the saying goes: every decision you make as an engineer ultimately
-The mux will choose one which logic block to use; the carry-in line will tell the `add` logic block whether to add or subtract.
+has a cost, let's look at the cost of these improvements.
-Finally the A-invert and B-invert line allow us to determine if we want to invert either A or B (inputs).
 
-## N-bit ALU
+1.  Parallelism
 
-For sanity we'll use the following block for our new ALU.
+If we have a data set which has some form of inter-dependencies between
+its members then we could easily run into the issue of waiting on other
+things to finish.
 
-![fig4](../img/fig4lec11.png)
+Contrived Example:
 
-Note that we are chaining the carry-in's to the carry-out's just like a ripple adder.
+    Premise: output file contents -> search lines for some text -> sort the resulting lines
-also each ALU just works with `1` bit from our given 4-bit input.
+
+    We have to do the following processes:
+    print my-file.data 
+    search file
+    sort results of the search
+
+    In bash we might do: cat my-file.data | grep 'Text to search for' | sort
+
+Parallelism doesn't make sense here for one reason: this series of
+proccesses don't benefit from parallelism because the 2nd and 3rd tasks
+*must* wait until the previous ones finish first.
+
+2.  Pipelining
+
+Let's say we want to do the following:
+
+    Search file1 for some text : [search file1] 
+    Feed the results of the search into a sorting program [sort]
+
+    Search file2 for some text  [search file2]
+    Feed the results of the search into a reverse sorting program [reverse sort]
+
+    The resulting Directed Acyclic Graph looks like
+
+    [search file1] => [sort]
+
+    [search file2] => [reverse sort]
+
+Making the above linear means we effectively have to:
+
+    [search file1] => [sort] [search file2] => [reverse sort]
+    | proc2 waiting........| 
+
+Which wastes a lot of time if the previous process is going to take a
+long time. Bonus points if process 2 is extremely short.
+
+3.  Prediction
+
+Ok two things up front:
+
+-   First: prediction's fault is that we could be wrong and have to end
+    up doing hard computations.
+-   Second: *this course never covers branch prediction(something that
+    pretty much every cpu in the last 20 years out there does)* so I'm
+    gonna cover it here; ready, let's go.
+
+For starters let's say a basic cpu takes instructions sequentially in
+memory: `A B C D`. However this is kinda slow because there is *time*
+between getting instructions, decoding it to know what instruction it is
+and finally executing it proper. For this reason modern CPU's actually
+fetch, decode, and execute(and more!) instructions all at the same time.
+
+Instead of getting instructions like this:
+
+    0
+     AA
+       BB
+         CC
+           DD 
+
+We actually do something more like this
+
+    A
+     AB
+       BC
+         CD
+           D0
+
+If it doesn't seem like much remember this is half an instruction on a
+chip that is likely going to process thousands/millions of instructions
+so the savings scales really well.
+
+This scheme is fine if our instructions are all coming one after the
+other in memory, but if we need to branch then we likely need to jump to
+a new location like so.
+
+    ABCDEFGHIJKL
+    ^^^*     ^
+       |-----|
+
+Now say we have the following code:
+
+    if (x == 123) {
+        main_call();
+    }
+    else {
+        alternate_call();
+    }
+
+The (psuedo)assembly might look like
+
+``` {.asm}
+    cmp x, 123 
+    je second
+main_branch:    ; pointless label but nice for reading
+    call main_call
+    jmp end
+second:
+    call alternate_call
+end:
+    ; something to do here
+```
+
+Our problem comes when we hit the je. Once we've loaded that instruction
+and can start executing it, we have to make a decision, load the
+`call main_call` instruction or the `call alternate_call`? Chances are
+that if we guess we have a 50% change of saving time and 50% chance of
+tossing out our guess and starting the whole *get instruction =\> decode
+etc.* process over again from scratch.
+
+Solution 1:
+
+Try do determine what branches are taken prior to running the program
+and just always guess the more likely branches. If we find that the
+above branch calls `main_branch` more often then we should load that
+branch always; knowing that the loss from being wrong is offset by the
+gain from the statistically more often correct branches.
+
+...

337/lec/lec2.md

@@ -10,29 +10,76 @@ Most typically we deal with binary(when we do) in nibbles or 4 _bit_ chunks whic
 Ex:`0101 1100` is a basic random byte.
 For most sane solutions this is essentially the only way we __ever__ deal with binary.
 
+> Why can't we (((save bits))) and not use nibbles?
+
+In truth you can totally do that; but not really.
+To explain let's look at some higher level C/C++ code; say you had this structure: 
+
+```
+struct Point {
+	int x; // specifying width for clarity sake
+	int y;
+	unsigned int valid : 1;
+};
+```
+
+On a typical x86 system(and many x64 systems) with no compile time optimizations this structure might look like: 
+
+```
+32(int x) + 32(int y) + 1(unsigned int valid) + 7(bits of padding)
+```
+
+Why? Because while we can always calculate the address of a particular byte's address in memory we cant' or rather don't even try to do the same for bits.
+The reason is simple: a 32bit CPU can calulate any number inclusively between `0` and `0xffffffff` or `4294967295`. That means we have an entropy pool large enough to have 1 number per byte but not enough to include the bits as well.
+
+If we use that `valid` _bit-field_ in our code later like
+
+```
+if(point_ref->valid) {
+	/* do stuff */
+}
+```
+
+The machine code instructions generated will really just check if that byte(which contains the bit we care about) is a non-zero value.
+
+If the bit is set we have (for example) `0b0000 0001` thus a _true_ value.
 
 ## Two's Complement - aka Negate 
 
 To find the Negation of any bit-string: 
 
+i.e. `3 * -1=> -3` 
+
 1. Flip all bits in the bit-string
 2. Add 1 to the bitstring
 
+The case for 3:
+
+```
+start off: 0011 => 3
+
+flip bits: 1100 => -2
+
+add one: 1101 => -3
+
+```
+
 ### Signedness 
 
 > Why? 
 
 Because this matters for dealing with `signed` and `unsigned` values. _No it doesn't mean positive and negative numbers._
-Say we have 4 bytes to mess with. This means we have a range of 0000 to 1111. If we wanted pureley positive numbers in this range we could have 0000 to 1111... or 0 to 15.
+Say we have 4 bytes to mess with. This means we have a range of 0000 to 1111. If we wanted purely positive numbers in this range we could have 0000 to 1111... or 0 to 15.
-If we needed negative represenation however, we have to sacrifice some of our range.
+If we needed negative representation however, we have to sacrifice some of our range.
-Our new unsigned range is 0-7. We say it's unsigned because the first bit here is 0.
+Our new unsigned range is then `0-7` _or in binary_: `0000 - 0111`. We say unsigned for this range because the largest number we can represent without setting the first bit is `0111` => `7`.
-If it were 1 we would have a _signed_ number. 
+Our negative range is then `-8 -> -1` which in binary is `0b1000 -> 0b1111`
+
 
 ## Intro to hex
 
 > Hex Notation 0x... 
 
-x86 assemblersi(masm) will typically accept `...h`
+x86 assemblersi(masm) will typically accept `...h` as a postfix notation.
 
 More convinient than binary for obvious reasons; namely it doesn't look like spaghetti on the screen.
 
@@ -41,24 +88,29 @@ More pedantically our new hex range is 0x00 to 0xff.
 
 > Binary mapped 
 
-It happens that 1 nibble makes up 0x00 to 0xFF. 
+It happens that 1 nibble makes up 0x0 to 0xF. 
-So for now just get used to converting {0000-1111} to one of it's respective values in hex and evetually it should be second nature.
+So for now just get used to converting {0000-1111} to one of it's respective values in hex and eventually it should be second nature.
-Then just move on to using hex(like immediately after these lessons).
+Then just move on to using hex(like immediately after these lessons), because writing actual binary is actually awful.
-Even the most obfuscated binary files out there don't resort to architectural obfuscation; until they do.
+
+> Dude trust me hex is way better to read than decimal
+
+It may seem convenient at first but after a while you'll realized that hex has really easy to understand uses and makes this super clear + concise, especially when dealing with bit masks and bitsets.
+
 
 > Ascii in Hex Dumps 
 
-Kind of a side note but most ascii text is from 0x21 to 0x66ish[citation needed]
+Kind of a side note but most ascii text values range from 0x21 to 0x66 so if you're looking for text in a binary look for groupings of that value.
 
 ## 32 v 64 bit 
 
-For those with a 32 bit background know that these notes deal with 64-bit architecutres mostly. So some quick terminology which might randomly throw you off anyway.
+In case you come from an x86_64 ish background know that in MIPS terminology changes a bit(bun intended).
 
-> double-byte/ half-word 
+> x86 byte = mips byte
 
-The latter is dumb but soemtimes used so wtever.
+> x86 word = mips half word
 
-> word = 4 bytes
+> x86 dword = mips word
 
-Etc onward with doubles, quads...
+> x86/64 qword = mips mips dword
 
+So just keep those translations in mind...

337/lec/lec3.md

@@ -1,22 +1,19 @@
-# lec3
+# Lecture 3
 
-## One's & Two's Complement
+## One's & Two's Complement (in depth(or something))
 
-_Previous lecture went over signedness of numbers so this section won't as much_.
+In order to change recall from last lecture that we wanted to represent `3` with a single nibble like so `0b0011`.
 
-First we'll deal with flipping bits: this is where you may hear the term _1's complement_.
+To make this into a `-3` we:
-While not very useful on it's own for most purposes it does help get closer to creating a seperation between _positive_ and _negative_ numbers.
 
-The only other step after flipping all the bits is just adding 1.
+1. Flipped all the bits : `value xor 0xff..`
 
-`1001 1110` becomes `0110 0010`.
+2. Added 1 to the result of step 1
 
-> shouldn't that last 2 bits be 01?
+> Ok, but like, why do I care? we're just multiplying things by -1 how does that matter at all?
 
-Close, the reason why we have `b10` is because if we: `b01 + b1` the `1` will carry over to the next bit.
+It matters because certain types operations _just suck_ on pretty much every general use platform.
-The actual term for this is just __negate__; the other way around is essentially cannon fodder.
 
->Ok, but what does that look like _assembly_ the thing I came here to learn.
 
 Most assemblers accept something like `neg targetValue` however you can also use an _exclusive or_[`xor targetValue, 0xFF`]. Keep in mind that the immediate value should be sign-extended to reflect the proper targetValue size.
 

363/lec/lec10.md

@@ -1,43 +1,47 @@
-# lec10
+lec1
+====
 
-This lecture has a corresponding lab excercise who's instructions can be found in `triggers-lab.pdf`.
+Databases introduction
+----------------------
 
-## What is a trigger
+First off why do we even need a database and what do they accomplish?
 
-Something that executes when _some operation_ is performed
+Generally a databse will have 3 core elements to it:
 
-## Structure 
+1.  querying
+    -   Finding things
+        -   Just as well structured data makes querying easier
+2.  access control
+    -   who can access which data segments and what they can do with
+        that data
+        -   reading, writing, sending, etc
+3.  corruption prevention
+    -   mirroring/raid/parity checking/checksums/etc as some examples
 
-```
+Modeling Data
-create trigger NAME before some_operation
+-------------
-when(condition)
-begin
-	do_something
-end;
-```
 
-To explain: First we `create trigger` followed by some trigger name.
+Just like other data problems we can choose what model we use to deal
-Then we have to denote that this trigger should fire whenever some operation happens.
+with data. In the case for sqlite3 the main data model we have are
-This trigger then executes everything in the `begin...end;` section _before_ the new operation happens.
+tables, where we store our pertinent data, and later we'll learn even
+data about our data is stored in tables.
 
-> `after`
+Because everything goes into a table, it means we also have to have a
+plan for *how* we want to lay out our data in the table. The **schema**
+is that design/structure for our databse. The **instance** is the
+occurance of that schema with some data inside the fields, i.e. we have
+a table sitting somewhere in the databse which follows the given
+structure of a aforemention schema.
 
-Likewise if we want to fire a trigger _after_ some operation we ccan just replace the before keyword with `after`.
+**Queries** are typically known to be declarative; typically we don't
-
+care about what goes on behind the scenes in practice since by this
-> `new.adsf`
+point we are assuming we have tools we trust and know to be somewhat
-
+efficient.
-Refers to _new_ value being added to a table.
-
-> `old.adsf` 
-
-Refers to _old_ vvalue being changed in a table.
-
-	
-## Trigger Metadata
-
-If you want to look at what triggers exist you can query the `sql_master` table.
-
-```
-select * from sql_master where name='trigger';
-```
 
+Finally we have **transactions** which are a set of operations who are
+not designed to only commit if they are completed successfully.
+Transactions are not alllowed to fail. If *anything* fails then
+everything should be undone and the state should revert to previous
+state. This is useful because if we are, for example, transferring money
+to another account we want to make sure that the exchange happens
+seamlessly otherwise we should back out of the operation altogether.

370/homework/huffman.py

@@ -88,7 +88,7 @@ if __name__ == "__main__":
 
     # build up our heap to display info from
     heap = encode(frequencies)[0]
-    #print(heap)
+    print(heap)
 
     # decode the binary
     decode(heap, binary)

370/notes/adj-list.md

@@ -1,38 +1,35 @@
-# Adjacency list
+A\* Pathfinding
+===============
 
-Imagine 8 nodes with no connections
+There are 3 main values usedd in reference to A\*:
 
-To store this data in an _adjacency list_ we need __n__ items to store them.
+    f = how promisiing a new location is
-We'll have 0 __e__dges however so in total our space is (n+e) == (n)
+    g = distance from origin
+    h = estimate distance to goal
+    f = g + h
 
-# Adjacency matrix
+For a grid space our `h` is calculated by two straight shots to the goal
+from the current location(ignore barriers). The grid space `g` value is
+basiccally the number of steps we've taken from the origin. We maintain
+a list of potential nodes only, so if one of the seeking nodes gets us
+stuck we can freely remove that, because it succs.
 
-space: O(n^2)
+Time & Space Commplexities
-The convention for notation btw is [x,y] meaning:
+==========================
-	* _from x to y_
 
-# Breadth first search
+Best-First Search
+-----------------
 
-add neighbors of current to queue
+Time: O(VlogV + E)
-go through current's neighbors and add their neighbors to queue
-add neighbor's neighbors
-	keep going until there are no more neighbors to add
-go through queue and start popping members out of the queue
 
-# Depth first search 
+Dijkstra's
+----------
 
-Here we're going deeper into the neighbors
+O(V\^2 + E)
 
-_once we have a starting point_ 
+A\*
+---
 
-_available just means that node has a non-visited neighbor_
+Worst case is the same as Dijkstra's time
-if available go to a neighbor
-if no neighbors available visit
-goto 1
 
-# Kahn Sort
+O(V\^2 + E)
-
-
-# Graph Coloring
-
-When figuring out how many colors we need for the graph, we should note the degree of the graph

412/hardware-strats.md

@@ -1,69 +1,60 @@
-# Hardware deployment Strategies
+Data storage
+============
 
+Spinning Disks
+--------------
 
-## Virtual Desktop Interface
+Cheaper for more storage
 
-aka 0-Clients: network hosted OS is what each client would use.
+RAID - Redundant Array of Independent Disk
+------------------------------------------
 
-In some cases that network is a pool of servers which are tapped into.
+Raid 0: basically cramming multiple drives and treating them as one.
-Clients can vary in specs like explained below(context: university):
+Data is striped across the drives but if one fails then you literally
+lose a chunk of data.
 
-> Pool for a Library
+Raid 1: data is mirrored across the drives so it's completely redundant
+so if one fails the other is still alive. It's not a backup however
+since file updates will affect all the drives.
 
-Clients retain low hardware specs since most are just using office applications and not much else.
+Raid 5: parity. Combining multiple drives allows us to establish the
+parity of the data on other drives to recover that data if it goes
+missing.(min 3 drives)
 
-> Pool for an Engineering department
+Raid 6: same in principle as raid 5 but this time we have an extra drive
+for just parity.
 
-Clients connect to another pool where both clients and pool have better hardware specs/resources.
+Raid 10: 0 and 1 combined to have a set of drives in raid 0 and putting
+those together in raid 1 with another equally sized set of drives.
 
-The downside is that there is _1 point of failure_.
+Network Attached Storage - NAS
-The pool goes down and so does everyone else, meaning downtime is going to cost way more than a single machine going down.
+------------------------------
 
+Basically space stored on the local network.
 
+Storage Attached Network - SAN
+------------------------------
 
-# Server Hardware Strategies
+Applicable when we virtualise whole os's for users, we use a storage
+device attached to the network to use different operating systems
 
-> All eggs in one basket
+Managing Storage
+================
 
-Imagine just one server doing everything
+Outsourcing the storage for users to services like Onedrive because it
+becomes their problem and not ours.
 
-* Important to maintain redundancy in this case
+Storage as a Service
-* Upgrading is a pain sometimes
+====================
 
+Ensure that the OS gets its own space/partition on a drive and give the
+user their own partition to ruin. That way the OS(windows) will just
+fill its partition into another dimension.
 
-> Buy in bulk, allocate fractions
+Backup
+======
 
-Basically have a server that serves up varies virtual machines.
+Other people's data is in your hands so make sure that you backup data
-# Live migration
+in some way. Some external services can be nice if you find that you
-
+constantly need to get to your backups. Tape records are good for
-Allows us to move live running virtual machines onto new servers if that server is running out of resources.
+archival purposes; keep in mind that they are slow as hell.
-
-# Containers
-
-_docker_: Virtualize the service, not the whole operating system
-
-# Server Hardware Features
-
-> Things that server's benefit from
-
-* fast i/o
-* low latency cpu's(xeons > i series)
-* expansion slots
-* lots of network ports available
-* EC memory
-* Remote control
-
-Patch/Version control on server's
-
-Scheduling is usually slow/more lax so that server's don't just randomly break all the time.
-
-# Misc
-
-Uptime: more uptime is _going_ to be more expensive. Depending on what you're doing figure out how much downtime you can afford.
-
-
-# Specs
-
-Like before _ecc memory_ is basically required for servers, good number of network interfaces, and solid disks management.
-
-Remember that the main parameters for choosing hardware is going to be budget, and necessity; basically what can you get away with on the budget at hand.

gitlab-page/index.md

@@ -0,0 +1,23 @@
+# Alejandro's Notes
+
+Here you will find all the notes in reference book format below.
+
+If some of this information is inaccurate or missing details please feel free to submit a merge request or contact me via Email/Discord:
+
+* Email: alejandros714@protonmail.com
+
+* Discord: shockrah#2647
+
+* Public Repository: [gitlab.com/shockrah/csnotes](https://gitlab.com/shockrah/csnotes/)
+
+[Intro to Networking](intro-to-networking-311.html)
+
+[Networking Administration](network-administration-412.html)
+
+[Networking and Security Concepts](network-security-concepts-312.html)
+
+[Intro to Databases](intro-to-databases-363.html)
+
+[Advanced Algorithms](advanced-algorithms-370.html)
+
+[Computer Architecture with MIPS](computer-architecture-337.html)

gitlab-page/style.css

@@ -0,0 +1,328 @@
+/*
+ * I add this to html files generated with pandoc.
+ */
+
+html {
+  font-size: 100%;
+  overflow-y: scroll;
+  -webkit-text-size-adjust: 100%;
+  -ms-text-size-adjust: 100%;
+}
+
+body {
+  color: #444;
+  font-family: Georgia, Palatino, 'Palatino Linotype', Times, 'Times New Roman', serif;
+  font-size: 12px;
+  line-height: 1.7;
+  padding: 1em;
+  margin: auto;
+  max-width: 42em;
+  background: #fefefe;
+}
+
+a {
+  color: #0645ad;
+  text-decoration: none;
+}
+
+a:visited {
+  color: #0b0080;
+}
+
+a:hover {
+  color: #06e;
+}
+
+a:active {
+  color: #faa700;
+}
+
+a:focus {
+  outline: thin dotted;
+}
+
+*::-moz-selection {
+  background: rgba(255, 255, 0, 0.3);
+  color: #000;
+}
+
+*::selection {
+  background: rgba(255, 255, 0, 0.3);
+  color: #000;
+}
+
+a::-moz-selection {
+  background: rgba(255, 255, 0, 0.3);
+  color: #0645ad;
+}
+
+a::selection {
+  background: rgba(255, 255, 0, 0.3);
+  color: #0645ad;
+}
+
+p {
+  margin: 1em 0;
+}
+
+img {
+  max-width: 100%;
+}
+
+h1, h2, h3, h4, h5, h6 {
+  color: #111;
+  line-height: 125%;
+  margin-top: 2em;
+  font-weight: normal;
+}
+
+h4, h5, h6 {
+  font-weight: bold;
+}
+
+h1 {
+  font-size: 2.5em;
+}
+
+h2 {
+  font-size: 2em;
+}
+
+h3 {
+  font-size: 1.5em;
+}
+
+h4 {
+  font-size: 1.2em;
+}
+
+h5 {
+  font-size: 1em;
+}
+
+h6 {
+  font-size: 0.9em;
+}
+
+blockquote {
+  color: #666666;
+  margin: 0;
+  padding-left: 3em;
+  border-left: 0.5em #EEE solid;
+}
+
+hr {
+  display: block;
+  height: 2px;
+  border: 0;
+  border-top: 1px solid #aaa;
+  border-bottom: 1px solid #eee;
+  margin: 1em 0;
+  padding: 0;
+}
+
+pre, code, kbd, samp {
+  color: #000;
+  font-family: monospace, monospace;
+  _font-family: 'courier new', monospace;
+  font-size: 0.98em;
+}
+
+pre {
+  white-space: pre;
+  white-space: pre-wrap;
+  word-wrap: break-word;
+}
+
+b, strong {
+  font-weight: bold;
+}
+
+dfn {
+  font-style: italic;
+}
+
+ins {
+  background: #ff9;
+  color: #000;
+  text-decoration: none;
+}
+
+mark {
+  background: #ff0;
+  color: #000;
+  font-style: italic;
+  font-weight: bold;
+}
+
+sub, sup {
+  font-size: 75%;
+  line-height: 0;
+  position: relative;
+  vertical-align: baseline;
+}
+
+sup {
+  top: -0.5em;
+}
+
+sub {
+  bottom: -0.25em;
+}
+
+ul, ol {
+  margin: 1em 0;
+  padding: 0 0 0 2em;
+}
+
+li p:last-child {
+  margin-bottom: 0;
+}
+
+ul ul, ol ol {
+  margin: .3em 0;
+}
+
+dl {
+  margin-bottom: 1em;
+}
+
+dt {
+  font-weight: bold;
+  margin-bottom: .8em;
+}
+
+dd {
+  margin: 0 0 .8em 2em;
+}
+
+dd:last-child {
+  margin-bottom: 0;
+}
+
+img {
+  border: 0;
+  -ms-interpolation-mode: bicubic;
+  vertical-align: middle;
+}
+
+figure {
+  display: block;
+  text-align: center;
+  margin: 1em 0;
+}
+
+figure img {
+  border: none;
+  margin: 0 auto;
+}
+
+figcaption {
+  font-size: 0.8em;
+  font-style: italic;
+  margin: 0 0 .8em;
+}
+
+table {
+  margin-bottom: 2em;
+  border-bottom: 1px solid #ddd;
+  border-right: 1px solid #ddd;
+  border-spacing: 0;
+  border-collapse: collapse;
+}
+
+table th {
+  padding: .2em 1em;
+  background-color: #eee;
+  border-top: 1px solid #ddd;
+  border-left: 1px solid #ddd;
+}
+
+table td {
+  padding: .2em 1em;
+  border-top: 1px solid #ddd;
+  border-left: 1px solid #ddd;
+  vertical-align: top;
+}
+
+.author {
+  font-size: 1.2em;
+  text-align: center;
+}
+
+@media only screen and (min-width: 480px) {
+  body {
+    font-size: 14px;
+  }
+}
+@media only screen and (min-width: 768px) {
+  body {
+    font-size: 16px;
+  }
+}
+@media print {
+  * {
+    background: transparent !important;
+    color: black !important;
+    filter: none !important;
+    -ms-filter: none !important;
+  }
+
+  body {
+    font-size: 12pt;
+    max-width: 100%;
+  }
+
+  a, a:visited {
+    text-decoration: underline;
+  }
+
+  hr {
+    height: 1px;
+    border: 0;
+    border-bottom: 1px solid black;
+  }
+
+  a[href]:after {
+    content: " (" attr(href) ")";
+  }
+
+  abbr[title]:after {
+    content: " (" attr(title) ")";
+  }
+
+  .ir a:after, a[href^="javascript:"]:after, a[href^="#"]:after {
+    content: "";
+  }
+
+  pre, blockquote {
+    border: 1px solid #999;
+    padding-right: 1em;
+    page-break-inside: avoid;
+  }
+
+  tr, img {
+    page-break-inside: avoid;
+  }
+
+  img {
+    max-width: 100% !important;
+  }
+
+  @page :left {
+    margin: 15mm 20mm 15mm 10mm;
+}
+
+  @page :right {
+    margin: 15mm 10mm 15mm 20mm;
+}
+
+  p, h2, h3 {
+    orphans: 3;
+    widows: 3;
+  }
+
+  h2, h3 {
+    page-break-after: avoid;
+  }
+}

readme.md

@@ -1,3 +1,12 @@
+# Holy Moly
+
+
+These notes are ancient but I like keeping them around because it reminds of
+my college days when I didn't really know much :3
+
+Not sure who will find value from these but here's some random tidbits of knowledge
+
+
 # Everyone else
 
 To some degree these notes are personal so there are a few mistakes that I just can't be bothered dealing with.

scripts/build-html.sh

@@ -1,10 +1,18 @@
-#!/bin/sh
+mkdir -p public/img
+cp gitlab-page/style.css public/style.css
 
-# Locations of important md files to build
+md() {
+	pandoc -s --css style.css `ls -v $1`
+}
 
-lecture_dirs='311/lec/ 312/ 337/lec/ 363/lec/ 370/notes/ 412/'
+md "311/lec/*.md" 	> public/intro-to-networking-311.html
-mkdir -p public
+md "312/*.md" 		> public/network-security-concepts-312.html
-for d in $lecture_dirs;do
+
-	echo $d;
+md "337/lec/*.md" 	> public/computer-architecture-337.html
-	pandoc `ls --sort=version $d` -o "public/$d.html"
+cp 337/img/* 		public/img/
-done
+
+md "363/lec/*.md" 	> public/intro-to-databases-363.html
+md "370/notes/*.md" 	> public/advanced-algorithms-370.html
+md "412/*.md"			> public/network-administration-412.html
+
+md gitlab-page/index.md > public/index.html

scripts/server.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+cd public
+python -m SimpleHTTPServer