neomantra’s gists

neomantra / top_exch_by_volume.sql

Last active September 6, 2025 01:36

Find exchange with top volume for each ticker with DataBento, dbn-go, and DuckDB

	# within DuckDB run these commands
	# load the parquet ohlcv files, which start with syms
	CREATE TABLE ohlcvs AS SELECT * FROM './syms*.parquet';

	# load the publishers parquet
	CREATE TABLE publishers AS SELECT * FROM './publishers.parquet';

	# query for the top publisher_id for each date,ticker
	# QUALIFY is DuckDB dialect
	SELECT date(ts_event),symbol,volume,close,P.dataset FROM ohlcvs O

neomantra / gist:6f87bbc719232dd4c50d24fb74398def

Created May 21, 2025 12:54

	events {
	worker_connections 4096; ## Default: 1024
	}

	http {
	# DEBUG:
	map $uri $proxy_uri_base {
	"~/crypto-proxy/(?<proxy_base>[^/]*)" $proxy_base;
	default $uri;
	}

neomantra / grafana-pdc.nomad.tpl

Last active July 12, 2024 19:44

pdc-agent with HashiCorp Nomad

	# Grafana PDC -- private network tunnel
	# This is templated by Terraform templatefile()
	# https://grafana.com/docs/grafana-cloud/connect-externally-hosted/private-data-source-connect/configure-pdc/

	job "grafana-pdc" {
	region = "global"
	datacenters = ["${NOMAD_DATACENTER}"]
	namespace = "${NOMAD_NAMESPACE}"
	type = "service"

neomantra / compressed_reader_writer.go

Created May 28, 2024 20:14

Compression wrappers for io.Reader and io.Writer

	// Copyright (c) 2024 Neomantra BV
	//
	// Opinionated Reader/Writer wrappers

	package nmio

	import (
	"compress/gzip"
	"io"
	"os"

neomantra / directory.go

Created May 21, 2024 22:45

VerifyDirectoryExists

	func VerifyDirectoryExists(dirPath string) error {
	if fileInfo, err := os.Stat(dirPath); err != nil {
	if os.IsNotExist(err) {
	return fmt.Errorf("directory '%s' does not exist", dirPath)
	} else {
	return fmt.Errorf("error filestat on '%s': %w", dirPath, err)
	}
	} else if !fileInfo.IsDir() {
	return fmt.Errorf("'%s' exists but is not a directory", dirPath)
	}

neomantra / pointerValueMap.go

Created March 31, 2023 13:31

NewPointerValueMap converts a map[string]*T to a map[string]T, omitting nil pointers.

	// NewPointerValueMap converts a map[string]*T to a map[string]T, omitting nil pointers.
	func NewPointerValueMap[K comparable, V any](src map[K]*V) map[K]V {
	dst := make(map[K]V)
	for k, ptr := range src {
	if ptr != nil {
	dst[k] = *ptr
	}
	}
	return dst
	}

neomantra / install_onload.sh

Created February 2, 2023 12:45

Installing OpenOnload on Ubuntu 22.04 Jammy

	# adapted from https://github.com/neomantra/docker-onload/blob/master/jammy/Dockerfile

	# install dependencies
	sudo apt-get update -y
	sudo apt-get install -y --no-install-recommends \
	autoconf \
	automake \
	ca-certificates \
	coreutils \
	curl \

neomantra / drillhead.vt100

Created January 16, 2023 14:51

neomantra / sleepy-cat.pl

Created January 16, 2023 14:25

sleepy-cat - like cat, except delay a little bit to emulate the # behavior of an old terminal

	#!/usr/bin/env perl
	# From: https://klipkyle.gitlab.io/blog/2017-10-22-vt100-ani.html
	#
	# scat
	#
	# sleepy-cat - like cat, except delay a little bit to emulate the
	# behavior of an old terminal
	#
	# By default a delay is inserted after every line feed (to emulate
	# screen refresh), and a smaller delay is inserted between every

neomantra / cnum.lua

Created December 7, 2022 13:51

Lua function to convert thousands-separated numbers into plain numbers

	-- converts thousands-separated numbers into plain numbers
	-- for example:
	-- cnum(0) == 0
	-- cnum(1,000) == 1000
	-- cnum(3,141,593) == 3141593
	-- cnum(-9,001) == -9001
	function cnum(...)
	local superbase = 1000
	local sign = 1
	local result = 0

Evan neomantra