Add queueing and rendering util

migrations/0.py

@@ -6,7 +6,7 @@ async def migrate(conn):
                     moderated INTEGER, 
                     remote_ip TEXT,
                     timestamp_received TEXT DEFAULT (datetime('now')),
-                    timestamp_displayed TEXT DEFAULT NULL
+                    timestamp_displayed TEXT DEFAULT NULL,
                  )''')
 
     await conn.execute('''CREATE TABLE IF NOT EXISTS shitlist (

queue.py

@@ -0,0 +1,130 @@
+#!/usr/bin/env python3
+
+import math
+import time
+import sqlite3
+from datetime import datetime
+
+import serial
+import click
+
+seg_map = {
+        " ": 0x00,
+        "a": 0x2e,
+        "b": 0xd6,
+        "c": 0xd0,
+        "d": 0xc5,
+        "e": 0x59,
+        "f": 0x98,
+        "g": 0xd4,
+        "h": 0x8c,
+        "i": 0x5c,
+        "j": 0x78,
+        "k": 0x8e,
+        "l": 0xc0,
+        "m": 0xa3,
+        "n": 0xa5,
+        "o": 0xf0,
+        "p": 0x93,
+        "q": 0xf4,
+        "r": 0x9e,
+        "s": 0x55,
+        "t": 0xc8,
+        "u": 0xe0,
+        "v": 0x8a,
+        "w": 0xac,
+        "x": 0x0f,
+        "y": 0x0b,
+        "z": 0x5a,
+        "0": 0x13,
+        "1": 0x20,
+        "2": 0x16,
+        "3": 0x56,
+        "4": 0x23,
+        "5": 0x1c,
+        "6": 0x4e,
+        "7": 0x1a,
+        "8": 0x5f,
+        "9": 0x33,
+        "/": 0x0a,
+        "\\": 0x05,
+        ".": 0x04,
+        ",": 0x08,
+        "_": 0x40,
+        "!": 0x53,
+        "?": 0x52,
+        "*": 0x0f,
+        ":": 0x50,
+        "(": 0x06,
+        "<": 0x06,
+        "[": 0xd0,
+        ")": 0x09,
+        ">": 0x09,
+        "]": 0x70,
+        "|": 0x20,
+        "#": 0xff,
+    }
+
+
+@click.command()
+@click.option('-b', '--baudrate', type=int, default=9600)
+@click.option('-w', '--display-width', type=int, default=32)
+@click.option('-i', '--message-interval', type=float, default=30)
+@click.argument('database')
+@click.argument('port')
+def cli(database, port, baudrate, message_interval, display_width):
+    db = sqlite3.connect(database)
+    ser = serial.Serial(port, baudrate)
+
+    discard = 0
+    while True:
+        count, = db.execute('''
+                SELECT COUNT(*) FROM messages
+                WHERE suppress_display = 0 AND timestamp_displayed IS NULL
+                ORDER BY timestamp_received''').fetchone()
+
+        if count == 0:
+            print(f'Queue is empty. Sleeping.')
+            time.sleep(1)
+            continue
+
+        queue_pressure = max(0, min((math.log10(max(1, count-3)) - 0.3) * message_interval*2/3, message_interval*1/3))
+        interval = message_interval - queue_pressure
+
+        rowid, message, timestamp, remote_ip, suppress_display = db.execute('''
+                SELECT rowid, message, timestamp_received, remote_ip, suppress_display FROM messages
+                WHERE timestamp_displayed IS NULL
+                ORDER BY timestamp_received LIMIT 1
+                ''').fetchone()
+        timestamp = datetime.fromisoformat(timestamp)
+        delta = (datetime.utcnow() - timestamp).total_seconds()
+
+        db.execute('UPDATE messages SET timestamp_displayed = datetime("now") WHERE rowid=?', (rowid,)) 
+        db.commit()
+
+        if suppress_display:
+            discard += 1
+
+        else:
+            if discard > 0:
+                print(f'Discarded {discard} messages.')
+            discard = 0
+
+            print(f'Queueing message by {remote_ip} received at {timestamp} ({delta//60:.0f}m {delta%60:.0f}s ago):')
+            print('   ', repr(message))
+
+            lines = [ line for line in message.splitlines() if line.strip() ]
+            interval = max(5, interval/len(lines))
+            for i, line in enumerate(lines):
+                print(f'    [Line {i+1}/{len(lines)}] Waiting interval of {message_interval:.1f} s with queue pressure {queue_pressure:.1f} from n={count} items for a total of {interval:.1f} s')
+
+                line = line.center(display_width)[:display_width]
+                line_mapped = [seg_map.get(c, seg_map['#']) for c in line]
+                formatted = ''.join(f'{d:02x}' for d in line_mapped) + '\n'
+                time.sleep(interval)
+                ser.write(formatted)
+                ser.flush()
+
+
+if __name__ == '__main__':
+    cli()