huangwenwei.com wenweih

The following example demonstrates the creation of a raw Omni transaction, which transfers 0.1 Test Omni with token identifier 2 from 1K6JtSvrHtyFmxdtGZyZEF7ydytTGqasNc to 1Njbpr7EkLA1R8ag8bjRN7oks7nv5wUn3o, with a transaction fee of 0.0006 BTC. For the sake of a demonstration, more than one unspent output was consumed.

1) List unspent outputs

List unspent outputs for 1K6JtSvrHtyFmxdtGZyZEF7ydytTGqasNc.

omnicore-cli "listunspent" 0 999999 '["1K6JtSvrHtyFmxdtGZyZEF7ydytTGqasNc"]'

How to convert private key to WIF

0. Overview

WIF = base58check encode ([version byte][private key][checksum])

version byte = 80 for mainnet, ef for testnet and regtest

checksum = first 4 bytes of double SHA256 of private key

# referecing: # https://www.digitalocean.com/community/tutorials/how-to-install-apache-kafka-on-ubuntu-14-04 # https://chongyaorobin.wordpress.com/2015/07/08/step-by-step-of-install-apache-kafka-on-ubuntu-standalone-mode/

Add 'kafka' user:

$ sudo useradd kafka -m

Install Java:

Optimizing postgresql table for more than 100K inserts per second

Create UNLOGGED table. This reduces the amount of data written to persistent storage by up to 2x.
Set WITH (autovacuum_enabled=false) on the table. This saves CPU time and IO bandwidth on useless vacuuming of the table (since we never DELETE or UPDATE the table).
Insert rows with COPY FROM STDIN. This is the fastest possible approach to insert rows into table.
Minimize the number of indexes in the table, since they slow down inserts. Usually an index on time timestamp with time zone is enough.
Add synchronous_commit = off to postgresql.conf.
Use table inheritance for fast removal of old data:

	package main

	import (
	"encoding/json"
	"fmt"
	"net/http"
	"time"

	"github.com/hashicorp/vault/api"
	"github.com/hashicorp/vault/builtin/credential/aws"

	package ciphers

	import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/sha512"
	"crypto/x509"
	"encoding/pem"
	"log"
	)

	FROM ruby:2.3.1

	# Install dependencies
	RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs

	# Set an environment variable where the Rails app is installed to inside of Docker image:
	ENV RAILS_ROOT /var/www/app_name
	RUN mkdir -p $RAILS_ROOT

	# Set working directory, where the commands will be ran:

	/*
	references:
	- https://dev.mysql.com/doc/refman/5.7/en/insert-on-duplicate.html
	- https://stackoverflow.com/questions/32777081/bulk-insert-and-update-in-mysql
	- https://thewebfellas.com/blog/conditional-duplicate-key-updates-with-mysql
	*/

	/* create a new database and use it */
	drop database if exists test_upsert;
	create database test_upsert;

	package main

	import (
	"bytes"
	"fmt"
	"strings"

	"io/ioutil"
	"os"
	"path"

	/*
	* Genarate rsa keys.
	*/

	package main

	import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"