A0-1766: Sketch out the pricing script

scripts/pricing/README.md

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+Pricing script
+==============
+
+The `./run.py` script in this directory will deploy some contracts and print a summary of how much some basic operations
+on them cost.
+
+It requires `python3` and an Ink 4-compatible version of `cargo contract`, to install:
+
+```bash
+$ cargo install cargo-contract --version 2.0.0-beta.1
+```
+
+Afterwards, install the python deps and run the script:
+
+```bash
+$ pip install -r requirements.txt
+$ ./run.py
+```
+
+For more info on options see:
+
+```bash
+$ ./run.py --help
+```

scripts/pricing/requirements.txt

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+tabulate==0.9.0

scripts/pricing/run.py

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+#!/usr/bin/python3
+
+import argparse
+import random
+import subprocess
+import json
+from subprocess import PIPE
+from tabulate import tabulate
+import urllib.request
+
+AZERO = 1_000_000_000_000
+
+
+parser = argparse.ArgumentParser(
+    description='Check the prices of some common contract operations')
+parser.add_argument('--url', type=str,
+                    default='ws://localhost:9944', help='URL of the node to connect to')
+parser.add_argument('--suri', type=str, default='//Alice',
+                    help='Secret key URI to use for calls')
+parser.add_argument('--adder-dir', type=str,
+                    help='Directory of the adder contract', default='../../contracts/adder')
+
+args = parser.parse_args()
+
+COMMON_ARGS = ['--suri', args.suri, '--url',
+               args.url, '--skip-confirm', '--output-json']
+
+
+def random_salt():
+    return ''.join(random.choice('0123456789abcdef') for _ in range(10))
+
+
+def deploy(directory):
+    res = subprocess.run(['cargo', 'contract', 'instantiate', '--salt',
+                          random_salt()] + COMMON_ARGS, cwd=directory, check=True, stdout=PIPE)
+    return json.loads(res.stdout.decode('utf-8'))
+
+
+def call(directory, contract, message, *args):
+    args = [x for a in args for x in ['--args', a]]
+    res = subprocess.run(['cargo', 'contract', 'call', '--contract', contract,
+                          '--message', message] + args + COMMON_ARGS, cwd=directory, check=True, stdout=PIPE)
+    return json.loads(res.stdout.decode('utf-8'))
+
+
+def event_field(event, field):
+    for f in [f for f in event['fields'] if f['name'] == field]:
+        return f['value']
+
+
+def account_id(value):
+    match value:
+        case {'Literal': account_id}: return account_id
+        case _: raise ValueError(f'Invalid account id: {value}')
+
+
+def uint(value):
+    match value:
+        case {'UInt': value}: return value
+        case _: raise ValueError(f'Invalid uint: {value}')
+
+
+def find_fee(events, by_whom):
+    fee_event = next(filter(lambda e: e['name'] == 'TransactionFeePaid' and account_id(
+        event_field(e, 'who')) == by_whom, events), None)
+    return uint(event_field(fee_event, 'actual_fee'))
+
+
+with urllib.request.urlopen('https://api.coingecko.com/api/v3/simple/price?ids=aleph-zero&vs_currencies=usd') as response:
+    data = json.load(response)
+    aleph_usd = data['aleph-zero']['usd']
+
+
+def format_fee(fee):
+    return "%f AZERO ($%f)" % (fee / AZERO, fee / AZERO * aleph_usd)
+
+
+deploy_result = deploy(args.adder_dir)
+
+adder_address = deploy_result['contract']
+setup_event = next(filter(
+    lambda e: e['name'] == 'Transfer' and account_id(event_field(e, 'to')) == adder_address, deploy_result['events']), None)
+
+suri_address = account_id(event_field(setup_event, 'from'))
+instantiate_fee = find_fee(deploy_result['events'], suri_address)
+
+events = call(args.adder_dir, adder_address, 'add', '42')
+add_fee = find_fee(events, suri_address)
+
+headers = ['Operation', 'Fee']
+prices = [
+    ["Instantiate contract with single storage value",
+        format_fee(instantiate_fee)],
+    ["Call contract with single storage update", format_fee(add_fee)]
+]
+print(tabulate(prices, headers=headers, tablefmt="github"))