2.4
a collection of usefull functions
Repository
Current version released
11 months ago
Handy Helpers
this is a collection of useful functions
f_s_n_beautified
beautify/format a number, 12341234 becomes 12’341’234
f_assert_equals(
f_s_n_beautified(12341234),
"12'341'234"
)
f_assert_equals(
f_s_n_beautified(12345, '_'),
"12_345"
)
f_assert_equals(
f_s_n_beautified(111333222555, ' '),
"111 333 222 555"
)
f_a_a_v__combinations
get all possible combinations of all items without caring about the order
let a = f_a_a_v__combinations(['a','b','c','d'])
f_assert_equals(
JSON.stringify(a),
JSON.stringify([
["a"],
["b"],
["a","b"],
["c"],
["a","c"],
["b","c"],
["a","b","c"],
["d"],
["a","d"],
["b","d"],
["a","b","d"],
["c","d"],
["a","c","d"],
["b","c","d"],
["a","b","c","d"]
])
)
f_a_v__recursive
get a n-dimensional array with a value of choice
let a = f_a_v__recursive(3,3,function(n_x, n_y){return `${[n_x, n_y].join(',')}`})
console.log(a);
f_move_in_array
moves a value in an array, it does not swap the elements!
let a_n = [2,0,1,0,0]
f_move_in_array(a_n, 2, 0)
f_assert_equals(
JSON.stringify(a_n),
`[1,2,0,0,0]`
)
f_move_in_array(a_n, 1, a_n.length-1)
f_assert_equals(
JSON.stringify(a_n),
`[1,0,0,0,2]`
)
f_move_in_array(a_n, 2, a_n.length-1)
f_assert_equals(
JSON.stringify(a_n),
`[1,0,0,2,0]`
)
f_move_in_array(a_n, 0, -1)
f_assert_equals(
JSON.stringify(a_n),
`[0,0,2,0,1]`
)
f_move_in_array(a_n, -1, 0)
f_assert_equals(
JSON.stringify(a_n),
`[1,0,0,2,0]`
)
let o1 = {n:1}
let o2 = {n:2}
let o3 = {n:3}
let o4 = {n:4}
let o5 = {n:5}
let a_o = [o1,o2,o3,o4,o5];
var n_idx_from = 0;
var n_idx_to = 2;
var o_from = a_o[n_idx_from];
var o_to = a_o[n_idx_to];
f_move_in_array(a_o, n_idx_from, n_idx_to)
f_assert_equals(
a_o[n_idx_to],
o_from
)
f_swap_in_array
swaps two values in an array
let a_n = [2,0,1,0,0]
f_swap_in_array(a_n, 2, 0)
f_assert_equals(
JSON.stringify(a_n),
`[1,0,2,0,0]`
)
f_swap_in_array(a_n, 0, a_n.length-1)
f_assert_equals(
JSON.stringify(a_n),
`[0,0,2,0,1]`
)
f_swap_in_array(a_n, 2, a_n.length-1)
f_assert_equals(
JSON.stringify(a_n),
`[0,0,1,0,2]`
)
f_swap_in_array(a_n, -1, 2)
f_assert_equals(
JSON.stringify(a_n),
`[0,0,2,0,1]`
)
f_swap_in_array(a_n, 2, -1)
f_assert_equals(
JSON.stringify(a_n),
`[0,0,1,0,2]`
)
f_move_v_in_array
moves a value in an array by a index difference
let a_s = ["a","b","c","d"];
f_move_v_in_array(a_s, "a", 2)
f_assert_equals(
JSON.stringify(a_s),
'["b","c","a","d"]'
)
f_move_v_in_array(a_s, "d", -3)
f_assert_equals(
JSON.stringify(a_s),
'["d","b","c","a"]'
)
let o1 = {n:1}
let o2 = {n:2}
let o3 = {n:3}
let o4 = {n:4}
let o5 = {n:5}
let a_o = [o1,o2,o3,o4,o5];
f_move_v_in_array(a_o, o1, -1)
f_assert_equals(
a_o.at(-1) == o1,
true
)
f_swap_v_in_array
moves a value in an array by a index difference
let a_s = ["a","b","c","d"];
f_swap_v_in_array(a_s, "a", "d")
f_assert_equals(
JSON.stringify(a_s),
'["d","b","c","a"]'
)
f_swap_v_in_array(a_s, "b", "c")
f_assert_equals(
JSON.stringify(a_s),
'["d","c","b","a"]'
)
let o1 = {n:1}
let o2 = {n:2}
let o3 = {n:3}
let o4 = {n:4}
let o5 = {n:5}
let a_o = [o1,o2,o3,o4,o5];
f_swap_v_in_array(a_o, o1, o5)
f_assert_equals(
a_o.at(-1) == o1,
true
)
f_assert_equals(
a_o.at(0) == o5,
true
)f_sleep_ms
let n_ms = window.performance.now();
await f_sleep_ms(333);
f_assert_equals(
(window.performance.now() - n_ms) >= 333,
true
)Handy snippets
extend a file name by ‘_thumb’
// extend the prototype
f_assert_equals(
'some_image.png'
.split('.')
.map((v, n_idx, a)=>{
return (n_idx == a.length-2) ? `${v}_thumb`: v
})
.join('.'),
'some_image_thumb.png'
)
f_o_resp__fetch_cached
makes a fetch but caches the response meta (status, statusText, headers) and data as a_n_u8
var o_resp = await f_o_resp__fetch_cached(
fetch, // f_fetch
[ // a_v_arg__for_f_fetch
'https://deno.com/',
{'headers': {'User-Agent': "Test 1.2/3"}}
],
true,// b_overwrite_cached_file
1000, // n_ms_diff__overwrite_cached_file
async (
s_url
)=>{ // f_s_name_file_cached
// available functions
// f_s_name_file_cached__base64encoded -> 'aHR0cHM6Ly9kZW5vLmNvbS8='
// f_s_name_file_cached__hashed -> 'd2a68e83cffd1f8dc53143c95006f862f199082b'
// f_s_name_file_cached__readable_ignore_fragment_and_getparams -> 'https______deno__com'
return `${s_url.split('?').shift().replaceAll('/', '--').replaceAll(':', '__')}}`
},
'./.cache'//a custom path to a folder for the cache
);
f_assert_equals(
o_resp?.b_from_disk,
undefined
);f_b_deno
check if script is running with https://deno.com/
f_assert_equals(f_b_denojs(), ("Deno" in window))f_o_html_element__from_s_tag
returns a html element browser: document.createElement denojs: using /x/deno_dom
f_assert_equals((await f_o_html_element__from_s_tag('h1')).tagName, 'H1');f_o_html__from_s_html
returns a html element browser: div.innerHTML = s_html denojs: using /x/deno_dom
f_assert_equals(
(await f_o_html__from_s_html('<div><h1>hello</h1><h1>world</h1></div>')).querySelectorAll('h1')[1].innerText,
'world'
);f_download_file__from_s_url
download a file, pass an optional callback, or let log the download state by default
await f_download_file__from_s_url(
// 'https://www.dwsamplefiles.com/?dl_id=409'
// 'https://images.unsplash.com/photo-1533144188434-eb0442504392?auto=format&fit=crop&q=80&w=3948&ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D',
// 'a_picture_in_bird_perspective.png'
'https://www.w3schools.com/html/pic_trulli.jpg',
'./.gitignored/lol/test.jpg'//if denojs we can pass a path
)
f_a_n_u8__from_s_url_with_download_speed_easy
get the response body as Uint8array (a_n_u8) from an url, while the download is pending a callback will be executed every nth millisecond in this callback one can print download speed, if the response header ‘content-length’ is present and its value is legit one can also print the download percentage
let a_n_u8 = await f_a_n_u8__from_s_url_with_download_speed_easy(
'https://www.dwsamplefiles.com/?dl_id=406',
function(
n_mb_downloaded,
n_mb_per_sec_domwnload_speed,
n_mb_to_download_total
){
let s_from_total = ''
if(n_mb_to_download_total != -1){
s_from_total = (`/${(n_mb_to_download_total).toFixed(0)}`)
}
console.log(`downloaded ${(n_mb_downloaded).toFixed(0)}${s_from_total}(MB) @ ${n_mb_per_sec_domwnload_speed.toFixed(2)} MB/s`)
},
555// callback gets called every 555 milliseconds
)
f_assert_equals(a_n_u8.length, 15944874)
Overwrite / ‘Monkey-Patch’ the fetch function
replace the original fetch function, with a custom fetch function, for example to change some headers
this can be used in combination with f_o_resp__fetch_cached, f_download_file__from_s_url
let f_fetch_original = window.fetch
window.fetch = async function(){
let a_v_arg = Array.from(arguments);
let s_url = a_v_arg?.[0];
if(s_url?.includes('httbin_non_existing_lol.org')){
a_v_arg[0] = s_url.replace('httbin_non_existing_lol.org', 'httpbin.org')
}
// we can cache some sites
if(s_url == 'https://httpbin.org/status/418'){
return f_o_resp__fetch_cached(
f_fetch_original,
a_v_arg
);
}
// we could ignore the patching on some fetch calls
if(s_url.includes('#dont_monkey_patch')){
return f_fetch_original(...a_v_arg)
}
return f_fetch_original(
a_v_arg[0],
{
headers: {
'User-Agent': [
`Gozilla/${(Math.random()*5+1).toFixed(1)}`,
`(Dingos TN 2.1; Din64; x128; rv:27.0)`,
`Lizzard/20100101 Waterwhale/42.0`
].join(' ')
}
}
)
}
var o_data = await (await fetch('https://httpbin.org/headers')).json();
f_assert_equals(o_data.headers['User-Agent'].includes('Gozilla/'),true)
var o_data = await (await fetch('https://httbin_non_existing_lol.org/headers')).json();
f_assert_equals(o_data.headers['User-Agent'].includes('Gozilla/'),true)
var o_data = await (await fetch('https://httpbin.org/headers#dont_monkey_patch')).json();
f_assert_equals(o_data.headers['User-Agent'].includes('Deno/'),true)
var o_data = await fetch('https://httpbin.org/status/418');
var o_data = await fetch('https://httpbin.org/status/418');
f_assert_equals(o_data.b_from_disk, true)
// restore the original function
window.fetch = f_fetch_original
// test the restored function
var o_data = await (await fetch('https://httpbin.org/headers')).json();
f_assert_equals(
o_data.headers['User-Agent'].includes('Deno/'),
true
)
f_o_html__from_s_url
a handy function to directly get a js object html document from a url, works in deno and browser
let o_doc = (await f_o_html__from_s_url(
`https://deno.land`
))
f_assert_equals(
typeof o_doc.body.querySelectorAll,
'function'
)
f_s_hashed
hash a string, using the window.crypto.subtle API, available functions at the moment are ‘sha-1’, ‘sha-256’, ‘sha-384’, ‘sha-512’
f_assert_equals(
await f_s_hashed('lol this is a text', 'SHA-1'),
'd2a68e83cffd1f8dc53143c95006f862f199082b'
)
f_o_cpu_stats
get information about the cpu this will parse /proc/stat so we have to await it
let o_cpu_stats = await f_o_cpu_stats();the number of cpus is in fact the length of the cpu core stats
console.log(o_cpu_stats.n_cpus == o_cpu_stats.a_o_cpu_core_stats.length);more infos about the cpu cores can be found here
console.log(o_cpu_stats.a_o_cpu_core_stats)
f_o_cpu_stats__diff
this will returna difference to the last call of f_o_cpu_stats__diff
the important and usefull value here is o_cpu_stats__diff.a_o_cpu_core_stats__diff[0].n_usage_nor
which is the normalized usage 0.0-1.0 of the cpu core
this will parse /proc/stat so we have to await it
var o_cpu_stats__diff = await f_o_cpu_stats__diff();
await f_sleep_ms(1000/60);
var o_cpu_stats__diff = await f_o_cpu_stats__diff();
console.log(
[
`cpu usage (in the last ${parseInt(o_cpu_stats__diff.n_diff_n_ms_window_performance_now)} milliseconds)`,
...o_cpu_stats__diff.a_o_cpu_core_stats__diff.map(
(o_cpu_core_stats__diff,n_idx)=>{
return [
`CPU ${(n_idx+1).toString().padStart(3,' ')}`,
`${(o_cpu_core_stats__diff.n_usage_nor.toFixed(2)*100).toString().padStart(4, ' ')}%`
].join(':')
}
)
].join('\n')
)
let n_ms_duration = 1000;
let n_ms_window_performance_now = window.performance.now();
let f_print = async function(){
let n = window.performance.now();
var o_cpu_stats__diff = await f_o_cpu_stats__diff();
// console.log(`ms:${window.performance.now()-n}`)
// console.log()
let s_sep = '.';
let s_cpu = '|'
let s = o_cpu_stats__diff.a_o_cpu_core_stats__diff.map(
o_cpu_core_stats__diff=>{
// console.log(o_cpu_core_stats__diff)
return [
`${o_cpu_core_stats__diff.n_usage_nor.toFixed(1)}|`,
`${s_sep}${s_cpu.repeat(parseInt(o_cpu_core_stats__diff.n_usage_nor*5)).padEnd(5,' ')}`
] .join(' ')
}
).join('')
console.log(s)
await f_sleep_ms(1000/60);
if(Math.abs(window.performance.now() - n_ms_window_performance_now) < n_ms_duration){
f_print();
}
}
f_print()
f_s_type__from_typed_array
get a string matching the typed array type the default string is how a type in rust looks like so Uint8Array ->’u8’, Float32Array -> ‘f32 …
f_assert_equals(
f_s_type__from_typed_array(Uint16Array),
'u16'
);
f_assert_equals(
f_s_type__from_typed_array(Array),
'unknown'
);
let o_error = null;
try {
f_s_type__from_typed_array(
Array,
true // b_throw_error
)
} catch (o_e) {
o_error = o_e
}
f_assert_equals(
typeof o_error,
'object'
);
f_assert_equals(
f_s_type__from_typed_array(
BigUint64Array,
false,//b_throw_error
{u64:'uint64'}
),
'uint64'
);
f_download_text_file
download a text file
await f_download_text_file
('A'.repeat(1_000_000_000),
'my_hello_file.txt'
)
f_s_type_mime__from_s_extension
get a mime type from an extension
f_assert_equals(
f_s_type_mime__from_s_extension('webm'),
'video/webm'
)
f_assert_equals(
f_s_type_mime__from_s_extension('.ogg'),
'audio/ogg'
)
f_assert_equals(
f_s_type_mime__from_s_extension('.ogg'),
'audio/ogg'
)
f_assert_equals(
f_s_type_mime__from_s_extension('compiled.wasm'),
'application/wasm'
)
return true
f_o_meminfo
linux only , get info about the RAM usage
let o = await f_o_meminfo()
console.log(o)
console.log(o.o_meminfo_property_MemTotal.n_gigabytes); // 31GB on my ssytem
// the normalized number of currently used memory 1.0 = all ram is in use, no free memory :()
console.log(o.o_meminfo_property_memory_used_calculated.n_nor_by_mem_total);//0.3, currently on my system
let n_ms_duration = 4000;
let n_ms_window_performance_now = window.performance.now();
let a_a_n_u8 = []
let f_print = async function(){
let n_ms_diff_abs_nor = Math.abs(window.performance.now() - n_ms_window_performance_now) / n_ms_duration;
if(n_ms_diff_abs_nor > 0.5){
a_a_n_u8 = [] // de-allocate ?
}else{
a_a_n_u8.push(new Float64Array(1024*1024*4).fill(0))
}
// allocate some memory to see usage
let n = window.performance.now();
let o = await f_o_meminfo()
// console.log(o.o_meminfo_property_MemFree)
let n_max = 80;
let s_used_gb = `${o.o_meminfo_property_memory_used_calculated.n_gigabytes.toFixed(0).padStart(2, ' ')}GB/`
let s_total_gb = `${o.o_meminfo_property_MemTotal.n_gigabytes.toFixed(0).padStart(2, ' ')}GB`
let s = [
`RAM Memory usage: `,
`${'|'.repeat(o.o_meminfo_property_memory_used_calculated.n_nor_by_mem_total*n_max-5)}`,
`${s_used_gb}`,
`${' '.repeat(o.o_meminfo_property_MemFree.n_nor_by_mem_total*n_max)}${s_total_gb}`
].join('')
console.log(s)
await f_sleep_ms(1000/60);
if(n_ms_diff_abs_nor< 1.){
await f_print();
}
}
await f_print()
return true;
f_v_s__between
get a string between strings
f_assert_equals(
f_v_s__between(
'hello world ! yes',
'world',
'yes'
),
" ! "
)
f_assert_equals(
f_v_s__between(
'hello not found 404',
'not',
'500'
),
null
)
f_assert_equals(
f_v_s__between(
'hello not found 404',
':)',
'404'
),
null
)to get info about the gpu you first have to get all available properties
let o_nvidia_smi_help_info = await f_o_nvidia_smi_help_info();
console.log(o_nvidia_smi_help_info.a_o_nvidia_smi_metric)
let a_o_metric = o_nvidia_smi_help_info.a_o_nvidia_smi_metric.filter(
o=>{
return o.a_s_name.includes('memory.used') ||
o.a_s_name.includes('memory.total')
}
);
// if the metric is available we can not get information
let o_nvidia_smi_info = await f_o_nvidia_smi_info(
a_o_metric
);
o_nvidia_smi_info['memory.used']
let n_ms_duration = 200000;
let n_ms_window_performance_now = window.performance.now();
let a_a_n_u8 = []
let f_print = async function(){
let n_ms_diff_abs_nor = Math.abs(window.performance.now() - n_ms_window_performance_now) / n_ms_duration;
if(n_ms_diff_abs_nor > 0.5){
a_a_n_u8 = [] // de-allocate ?
}else{
a_a_n_u8.push(new Float64Array(1024*1024*4).fill(0))
}
// allocate some memory to see usage
let n = window.performance.now();
let n_max = 80;
let o_nvidia_smi_info = await f_o_nvidia_smi_info(
a_o_metric
);
let s_used_gb = `${o_nvidia_smi_info['memory.used'].n_gigabytes.toFixed(0).padStart(2, ' ')}GB/`
let s_total_gb = `${o_nvidia_smi_info['memory.total'].n_gigabytes.toFixed(0).padStart(2, ' ')}GB`
let n_used_nor = o_nvidia_smi_info['memory.used'].n_gigabytes / o_nvidia_smi_info['memory.total'].n_gigabytes
let n_free_nor = 1.-n_used_nor
let s = [
`GPU Memory usage: `,
`${'|'.repeat(n_used_nor*n_max-5)}`,
`${s_used_gb}`,
`${' '.repeat(n_free_nor*n_max)}${s_total_gb}`
].join('')
console.log(s)
await f_sleep_ms(1000/60);
if(n_ms_diff_abs_nor< 1.){
await f_print();
}
}
await f_print()
// we can also parse the value
// console.log(o_nvidia_smi_info['o_memory.used'])
create a small canvas with a shader
oh how i hate it to write 100+ lines of code ‘just’ to get a small shader running this function is a shortcut
if(f_b_denojs()){
console.log('f_o_canvas_from_vertex_shader is not supported yet on denojs just in the browser')
}else{
let o_canvas = f_o_canvas_from_vertex_shader(
`
precision mediump float;
varying vec2 o_trn_pixel_nor;
uniform float n_t;
void main() {
float n_dist = length(o_trn_pixel_nor-0.5);
float n1 = sin(n_dist*3.*3.+n_t*0.003)*.5+.5;
float n2 = sin(n_dist*6.*3.+n_t*0.003)*.5+.5;
float n3 = sin(n_dist*9.*3.+n_t*0.003)*.5+.5;
gl_FragColor = vec4(
n1,
n2,
n3,
1.
);
}
`,
500,
500
)
document.body.appendChild(o_canvas);
window.setInterval(
function(){
o_canvas.f_render(window.performance.now())
},
1000/60
)
}