Salvatore Sanfilippo antirez

## gist:924301
require 'rubygems'
require 'json'
require 'redis'

class RedisComments
    def initialize(redis,namespace,sort_proc=nil)
        @r = redis
        @namespace = namespace
        @sort_proc = sort_proc
    end

## TM.md

      
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                antirez
                / TM.md
            
            
              Created
              February 23, 2018 09:04
            
              
                TripMode TCP out of order bytes reproducing steps
              
          
    Generate a payload.txt file using this Ruby script:
(1..1000000).each{|i| print "#{i} "}
The file will trivially contain "1 2 3 4 5 ..." so that out of order violations are trivial to spot.

In one terminal open netcat in listen mode: nc -l 6379
In another terminal execute netcat like this: cat payload.txt | nc 127.0.0.1 6379
In the first terminal you should see like 20796 20797 20798 20799 20800... instead of 1 2 3 ...
Does not happen always, so kill the netcat instances, and GOTO 10 to retry until it happens.


## twitter.c
#define F float
F f[]={-.1,-.1,1.7,.8,-.11,-6,.4,-.6,.15,-.3,.22,-3.1,-.1,-.06,3.2,.57,-1.1,19,-176,-4.8,-7.2,43,-86,40,48,65,34,803,39,9.65,-17,-33,-33,16,1167,63,-23,41,-22,9,.56,-.08,4.76,-8,-.28,.63,-1182,-7.27,26.6,-1213,198,5.3,-8.25,38.4,.22,-.78,-903,-7.4,-.26,.42,47.5,33.7,36.5,-184,14.5,-90,3};F o[15];F R(F A,F U){o[0]=A;o[1]=U;F a=0;int k=2,m=3,n=0,z=0,l=1;for(int j=0;j<67;j++){if(j==18)n=2,z=3,m=7,l=-17;if(j==60)n=8,l=-59;if((j+l)%m){a+=f[j]*o[n+(j+z)%m];}else{o[k++]=(F)1/(1+exp(-(a+f[j])));a=0;}}return o[14];}main(){for(int i=0;i<2201;i++){putchar(R(i%55,i/55-5)>.5?58:32);if(!(i%55))putchar(10);}}

## streams_fields.md

      
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                antirez
                / streams_fields.md
            
            
              Last active
              February 2, 2018 14:15
            
              
                Why streams have elements that are actually like hashes?
              
          
    Why stream items are small hashes instead of single strings like many other Redis types elements is a good question indeed.
At the end it's just a design decision, so I don't have the definitive answer. However I can try to explain the design process leading to this design.
What I wanted "Streams" to be, was actually just an Abstract Log. I was not able to call the data structure "log" because it's confusing in many contexts, but that was the idea, and a log better represents what Redis Streams are.
Perhaps it's the consumer groups part of the Redis Streams that better characterize the streaming part, but the data structure itself is a log.
Now, what constitutes a log? In the original form, is just lines of text ending with "\n", one after the other, added in an append only fashion.
But in general is some data in append only mode.
XADD captures this append only mode of operation. While we have more powerful deletion mechanisms, and will add more, but that is the general idea.

  
## wft.md

      
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                antirez
                / wft.md
            
            
              Created
              February 1, 2018 21:55
            
          
    Hello!
That's the C function (you can find it inside the Redis source code, inside rax.c).
raxNode *raxRemoveChild(raxNode *parent, raxNode *child) {
    debugnode("raxRemoveChild before", parent);
    /* If parent is a compressed node (having a single child, as for definition
     * of the data structure), the removal of the child consists into turning
     * it into a normal node without children. */

  
## xmas.c

#include <stdio.h>
  #include <stdlib.h>
             int
            main()
           {int h=9,
          d=0,x;while
         (h--){for(x=0;
       x<39;x++){int a=x
     -6;if(a<0)a=-a;printf

## rax_iterator_api.c
void somefunc(rax *mytree) {
    raxIterator iter;
    raxStart(&iter,mytree);

    /* As seek operator you can use >, <, >=, <=, == */
    raxSeek(&iter,(unsigned char*)"chromo",6,"<="); /* Seek key <= "chromo" */
    while(raxNext(&iter,NULL,0,NULL)) { /* or raxPrev() */
        printf("Current key: %.*s, val %p\n",
            (int)iter.key_len, (char*)iter.key, iter.data);
    }

## streams.txt
# Let's add a few entries in our stream "mystream". Every entry in a stream is like
# an hash, composed of fields and values, but every entry can have different fields.
# XADD appends a new entry in a stream, and returns an unique ID which is guaranteed
# be incrementing.

# The first part of the ID is the millisecond unixtime during the
# addition (or the time of the last entry in the stream, if greater than the current time).
# The second part of an entry is a 64 bit counter for entries added in the same ms.

127.0.0.1:6379> XADD mystream name pamela nicknake kill-9

## rdbcheck.txt
36143:M 27 Jun 11:18:39.096 # Server initialized
36143:M 27 Jun 11:18:39.096 # Internal error in RDB reading function at rdb.c:1378 -> Unknown RDB encoding type 7
[offset 0] Checking RDB file dump.rdb
[offset 32] AUX FIELD redis-ver = '999.999.999'
[offset 46] AUX FIELD redis-bits = '64'
[offset 58] AUX FIELD ctime = '1498554991'
[offset 73] AUX FIELD used-mem = '1014768'
[offset 89] AUX FIELD aof-preamble = '0'
[offset 139] AUX FIELD repl-id = 'f7a20a009964381cdcc61f401f91f9b228801647'
[offset 154] AUX FIELD repl-offset = '0'

## slowlog_new_output.txt
127.0.0.1:6379> client setname worker-502
OK
127.0.0.1:6379> debug sleep 1
OK
(1.00s)
127.0.0.1:6379> slowlog get
1) 1) (integer) 0
   2) (integer) 1497523890
   3) (integer) 1002448
   4) 1) "debug"
	require 'rubygems'
	require 'json'
	require 'redis'

	class RedisComments
	def initialize(redis,namespace,sort_proc=nil)
	@r = redis
	@namespace = namespace
	@sort_proc = sort_proc
	end

	#include <stdio.h>
	#include <stdlib.h>
	int
	main()
	{int h=9,
	d=0,x;while
	(h--){for(x=0;
	x<39;x++){int a=x
	-6;if(a<0)a=-a;printf
	void somefunc(rax *mytree) {
	raxIterator iter;
	raxStart(&iter,mytree);

	/* As seek operator you can use >, <, >=, <=, == */
	raxSeek(&iter,(unsigned char)"chromo",6,"<="); / Seek key <= "chromo" */
	while(raxNext(&iter,NULL,0,NULL)) { /* or raxPrev() */
	printf("Current key: %.*s, val %p\n",
	(int)iter.key_len, (char*)iter.key, iter.data);
	}
	# Let's add a few entries in our stream "mystream". Every entry in a stream is like
	# an hash, composed of fields and values, but every entry can have different fields.
	# XADD appends a new entry in a stream, and returns an unique ID which is guaranteed
	# be incrementing.

	# The first part of the ID is the millisecond unixtime during the
	# addition (or the time of the last entry in the stream, if greater than the current time).
	# The second part of an entry is a 64 bit counter for entries added in the same ms.

	127.0.0.1:6379> XADD mystream name pamela nicknake kill-9
	36143:M 27 Jun 11:18:39.096 # Server initialized
	36143:M 27 Jun 11:18:39.096 # Internal error in RDB reading function at rdb.c:1378 -> Unknown RDB encoding type 7
	[offset 0] Checking RDB file dump.rdb
	[offset 32] AUX FIELD redis-ver = '999.999.999'
	[offset 46] AUX FIELD redis-bits = '64'
	[offset 58] AUX FIELD ctime = '1498554991'
	[offset 73] AUX FIELD used-mem = '1014768'
	[offset 89] AUX FIELD aof-preamble = '0'
	[offset 139] AUX FIELD repl-id = 'f7a20a009964381cdcc61f401f91f9b228801647'
	[offset 154] AUX FIELD repl-offset = '0'
	127.0.0.1:6379> client setname worker-502
	OK
	127.0.0.1:6379> debug sleep 1
	OK
	(1.00s)
	127.0.0.1:6379> slowlog get
	1) 1) (integer) 0
	2) (integer) 1497523890
	3) (integer) 1002448
	4) 1) "debug"