Suraj Nath electron0zero

## latency.markdown

      
              2 files
            
          
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                hellerbarde
                / latency.markdown
            
            
              Created
              May 31, 2012 13:16
                — forked from jboner/latency.txt
            
              
                Latency numbers every programmer should know
              
          
    Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

  
## ffmpeg.md

      
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              293 forks
            
          
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              1225 stars
            
          
                protrolium
                / ffmpeg.md
            
            
              Last active
              May 2, 2024 12:02
            
              
                ffmpeg guide
              
          
    ffmpeg

Converting Audio into Different Formats / Sample Rates

Minimal example: transcode from MP3 to WMA:

ffmpeg -i input.mp3 output.wma
You can get the list of supported formats with:

ffmpeg -formats
You can get the list of installed codecs with:


## postgres_queries_and_commands.sql
-- show running queries (pre 9.2)
SELECT procpid, age(clock_timestamp(), query_start), usename, current_query
FROM pg_stat_activity
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%'
ORDER BY query_start desc;

-- show running queries (9.2)
SELECT pid, age(clock_timestamp(), query_start), usename, query
FROM pg_stat_activity
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%'

## postgres-cheatsheet.md

      
              1 file
            
          
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              3488 stars
            
          
                Kartones
                / postgres-cheatsheet.md
            
            
              Last active
              April 30, 2024 19:47
            
              
                PostgreSQL command line cheatsheet
              
          
    PSQL

Magic words:
psql -U postgres
Some interesting flags (to see all, use -h or --help depending on your psql version):

-E: will describe the underlaying queries of the \ commands (cool for learning!)
-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)


## sidekiq_monitoring
stats = Sidekiq::Stats.new

stats.queues

stats.enqueued

stats.processed

stats.failed

## learning-golang.md

      
              1 file
            
          
              5 forks
            
          
              1 comment
            
          
              34 stars
            
          
                johannaratliff
                / learning-golang.md
            
            
              Last active
              April 9, 2024 20:07
            
              
                Golang Rampup
              
          
    Context

This is for programmers who want to ramp on Go, without resources that reiterate programming fundamentals.
This would not be a good list of resources for folks who are learning to program using Go as their first language. Some resources that I dismiss here would be super valuable for newer folks.
This is a selection of resources for those who understand programming fundamentals in a different language already.
Advice


First steps = Tour of Go
Don't waste time on Go Fundamentals-type books - it all lives in tour of Go.
Consider joining the Gophers Slack
When you need help, the Go Playground allows you make a quick scratch file and share it. Others trying to help can run your code easily this way.


## pr.md

      
              1 file
            
          
              506 forks
            
          
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                piscisaureus
                / pr.md
            
            
              Created
              August 13, 2012 16:12
            
              
                Checkout github pull requests locally
              
          
    Locate the section for your github remote in the .git/config file. It looks like this:
[remote "origin"]
	fetch = +refs/heads/*:refs/remotes/origin/*
	url = git@github.com:joyent/node.git

Now add the line fetch = +refs/pull/*/head:refs/remotes/origin/pr/* to this section. Obviously, change the github url to match your project's URL. It ends up looking like this:

  
## p4merge4git.md

      
              1 file
            
          
              81 forks
            
          
              29 comments
            
          
              338 stars
            
          
                tony4d
                / p4merge4git.md
            
            
              Created
              August 24, 2012 19:00
            
              
                Setup p4merge as a visual diff and merge tool for git
              
          
    Download and install p4merge


Download the perforce visual tool suite from here: http://www.perforce.com/perforce/downloads/index.html
Copy only the p4merge.app file into your /Applications/ directory

Setup p4merge as a visual mergetool


## hash_array_to_csv.rb
class Array
  def to_csv(csv_filename="hash.csv")
    require 'csv'
    CSV.open(csv_filename, "wb") do |csv|
      csv << first.keys # adds the attributes name on the first line
      self.each do |hash|
        csv << hash.values
      end
    end
  end

## rspec_model_testing_template.rb
# This is a skeleton for testing models including examples of validations, callbacks,
# scopes, instance & class methods, associations, and more.
# Pick and choose what you want, as all models don't NEED to be tested at this depth.
#
# I'm always eager to hear new tips & suggestions as I'm still new to testing,
# so if you have any, please share!
#
# @kyletcarlson
#
# This skeleton also assumes you're using the following gems:
	-- show running queries (pre 9.2)
	SELECT procpid, age(clock_timestamp(), query_start), usename, current_query
	FROM pg_stat_activity
	WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%'
	ORDER BY query_start desc;

	-- show running queries (9.2)
	SELECT pid, age(clock_timestamp(), query_start), usename, query
	FROM pg_stat_activity
	WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%'
	stats = Sidekiq::Stats.new

	stats.queues

	stats.enqueued

	stats.processed

	stats.failed
	class Array
	def to_csv(csv_filename="hash.csv")
	require 'csv'
	CSV.open(csv_filename, "wb") do \|csv\|
	csv << first.keys # adds the attributes name on the first line
	self.each do \|hash\|
	csv << hash.values
	end
	end
	end
	# This is a skeleton for testing models including examples of validations, callbacks,
	# scopes, instance & class methods, associations, and more.
	# Pick and choose what you want, as all models don't NEED to be tested at this depth.
	#
	# I'm always eager to hear new tips & suggestions as I'm still new to testing,
	# so if you have any, please share!
	#
	# @kyletcarlson
	#
	# This skeleton also assumes you're using the following gems: