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Ivan Ivanoff ivanljutyj

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ivanljutyj / blockchain.md
Created July 18, 2018 02:10 — forked from joepie91/blockchain.md
Is my blockchain a blockchain?

Your blockchain must have all of the following properties:

  • It's a merkle tree, or a construct with equivalent properties.
  • There is no single point of trust or authority; nodes are operated by different parties.
  • Multiple 'forks' of the blockchain may exist - that is, nodes may disagree on what the full sequence of blocks looks like.
  • In the case of such a fork, there must exist a deterministic consensus algorithm of some sort to decide what the "real" blockchain looks like (ie. which fork is "correct").
  • The consensus algorithm must be executable with only the information contained in the blockchain (or its forks), and no external input (eg. no decisionmaking from a centralized 'trust node').

If your blockchain is missing any of the above properties, it is not a blockchain, it is just a ledger.

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ivanljutyj / ncurses_stl.cpp
Created May 3, 2018 17:50 — forked from daleobrien/ncurses_stl.cpp
A general purpose example of using ncurses in C++ e.g. with STL strings. Note: copied from http://pastebin.com/jRK9C129
/* ncurses C++
*
* A general purpose example of using ncurses in C++ e.g. with STL strings.
* I guess whatever license ncurses uses applies, otherwise public domain.
*/
# include <algorithm>
# include <iostream>
# include <fstream>
# include <iterator>
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ivanljutyj / jobs_copy.sql
Created January 3, 2018 14:57 — forked from heathdutton/jobs_copy.sql
Laravel jobs concurrency untangling
DROP TABLE IF EXISTS jobs_copy;
CREATE TABLE `jobs_copy` ( `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `queue` varchar(255) COLLATE utf8_unicode_ci NOT NULL, `payload` text COLLATE utf8_unicode_ci NOT NULL, `attempts` tinyint(3) unsigned NOT NULL, `reserved` tinyint(3) unsigned NOT NULL, `reserved_at` int(10) unsigned DEFAULT NULL, `available_at` int(10) unsigned NOT NULL, `created_at` int(10) unsigned NOT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=29972441 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
INSERT INTO `jobs_copy` SELECT * FROM `jobs`;
DELETE FROM jobs WHERE `reserved` != 1 AND `id` IN (SELECT `id` FROM jobs_copy ORDER BY `id` DESC);
# Repeat ad nauseam:
INSERT INTO `jobs` (SELECT * FROM `jobs_copy` ORDER BY `id` ASC LIMIT 500); DELETE FROM `jobs_copy` ORDER BY `id` ASC LIMIT 500; SELECT SLEEP(18); SELECT COUNT(*) FROM `jobs`;