Implement snowflake IDs for some models.

Still needs fixes to the client API paginator.

activities/migrations/0001_initial.py

@@ -10,6 +10,7 @@ import activities.models.fan_out
 import activities.models.post
 import activities.models.post_attachment
 import activities.models.post_interaction
+import core.snowflake
 import core.uploads
 import stator.models
 
@@ -28,11 +29,10 @@ class Migration(migrations.Migration):
             fields=[
                 (
                     "id",
-                    models.BigAutoField(
-                        auto_created=True,
+                    models.BigIntegerField(
+                        default=core.snowflake.Snowflake.generate_post,
                         primary_key=True,
                         serialize=False,
-                        verbose_name="ID",
                     ),
                 ),
                 ("state_ready", models.BooleanField(default=True)),
@@ -111,11 +111,10 @@ class Migration(migrations.Migration):
             fields=[
                 (
                     "id",
-                    models.BigAutoField(
-                        auto_created=True,
+                    models.BigIntegerField(
+                        default=core.snowflake.Snowflake.generate_post_interaction,
                         primary_key=True,
                         serialize=False,
-                        verbose_name="ID",
                     ),
                 ),
                 ("state_ready", models.BooleanField(default=True)),

activities/models/post.py

@@ -30,6 +30,7 @@ from core.ld import (
     get_value_or_map,
     parse_ld_date,
 )
+from core.snowflake import Snowflake
 from stator.exceptions import TryAgainLater
 from stator.models import State, StateField, StateGraph, StatorModel
 from users.models.follow import FollowStates
@@ -215,6 +216,8 @@ class Post(StatorModel):
         question = "Question"
         video = "Video"
 
+    id = models.BigIntegerField(primary_key=True, default=Snowflake.generate_post)
+
     # The author (attributedTo) of the post
     author = models.ForeignKey(
         "users.Identity",
@@ -998,7 +1001,7 @@ class Post(StatorModel):
             "id": self.pk,
             "uri": self.object_uri,
             "created_at": format_ld_date(self.published),
-            "account": self.author.to_mastodon_json(),
+            "account": self.author.to_mastodon_json(include_counts=False),
             "content": self.safe_content_remote(),
             "visibility": visibility_mapping[self.visibility],
             "sensitive": self.sensitive,

activities/models/post_interaction.py

@@ -4,6 +4,7 @@ from django.utils import timezone
 from activities.models.fan_out import FanOut
 from activities.models.post import Post
 from core.ld import format_ld_date, get_str_or_id, parse_ld_date
+from core.snowflake import Snowflake
 from stator.models import State, StateField, StateGraph, StatorModel
 from users.models.identity import Identity
 
@@ -125,6 +126,11 @@ class PostInteraction(StatorModel):
         like = "like"
         boost = "boost"
 
+    id = models.BigIntegerField(
+        primary_key=True,
+        default=Snowflake.generate_post_interaction,
+    )
+
     # The state the boost is in
     state = StateField(PostInteractionStates)
 
@@ -327,13 +333,13 @@ class PostInteraction(StatorModel):
             raise ValueError(
                 f"Cannot make status JSON for interaction of type {self.type}"
             )
-        # Grab our subject post JSON, and just return it if we're a post
+        # Make a fake post for this boost (because mastodon treats boosts as posts)
         post_json = self.post.to_mastodon_json(interactions=interactions)
         return {
-            "id": f"interaction-{self.pk}",
+            "id": f"{self.pk}",
             "uri": post_json["uri"],
             "created_at": format_ld_date(self.published),
-            "account": self.identity.to_mastodon_json(),
+            "account": self.identity.to_mastodon_json(include_counts=False),
             "content": "",
             "visibility": post_json["visibility"],
             "sensitive": post_json["sensitive"],

core/snowflake.py

@@ -0,0 +1,81 @@
+import secrets
+import time
+
+
+class Snowflake:
+    """
+    Snowflake ID generator and parser.
+    """
+
+    # Epoch is 2022/1/1 at midnight, as these are used for _created_ times in our
+    # own database, not original publish times (which would need an earlier one)
+    EPOCH = 1641020400
+
+    TYPE_POST = 0b000
+    TYPE_POST_INTERACTION = 0b001
+    TYPE_IDENTITY = 0b010
+    TYPE_REPORT = 0b011
+    TYPE_FOLLOW = 0b100
+
+    @classmethod
+    def generate(cls, type_id: int) -> int:
+        """
+        Generates a snowflake-style ID for the given "type". They are designed
+        to fit inside 63 bits (a signed bigint)
+
+        ID layout is:
+        * 41 bits of millisecond-level timestamp (enough for EPOCH + 69 years)
+        * 19 bits of random data (1% chance of clash at 10000 per millisecond)
+        * 3 bits of type information
+
+        We use random data rather than a sequence ID to try and avoid pushing
+        this job onto the DB - we may do that in future. If a clash does
+        occur, the insert will fail and Stator will retry the work for anything
+        that's coming in remotely, leaving us to just handle that scenario for
+        our own posts, likes, etc.
+        """
+        # Get the current time in milliseconds
+        now: int = int((time.time() - cls.EPOCH) * 1000)
+        # Generate random data
+        rand_seq: int = secrets.randbits(19)
+        # Compose them together
+        return (now << 22) | (rand_seq << 3) | type_id
+
+    @classmethod
+    def get_type(cls, snowflake: int) -> int:
+        """
+        Returns the type of a given snowflake ID
+        """
+        if snowflake < (1 << 22):
+            raise ValueError("Not a valid Snowflake ID")
+        return snowflake & 0b111
+
+    @classmethod
+    def get_time(cls, snowflake: int) -> float:
+        """
+        Returns the generation time (in UNIX timestamp seconds) of the ID
+        """
+        if snowflake < (1 << 22):
+            raise ValueError("Not a valid Snowflake ID")
+        return ((snowflake >> 22) / 1000) + cls.EPOCH
+
+    # Handy pre-baked methods for django model defaults
+    @classmethod
+    def generate_post(cls) -> int:
+        return cls.generate(cls.TYPE_POST)
+
+    @classmethod
+    def generate_post_interaction(cls) -> int:
+        return cls.generate(cls.TYPE_POST_INTERACTION)
+
+    @classmethod
+    def generate_identity(cls) -> int:
+        return cls.generate(cls.TYPE_IDENTITY)
+
+    @classmethod
+    def generate_report(cls) -> int:
+        return cls.generate(cls.TYPE_REPORT)
+
+    @classmethod
+    def generate_follow(cls) -> int:
+        return cls.generate(cls.TYPE_FOLLOW)

users/migrations/0001_initial.py

@@ -6,6 +6,7 @@ import django.db.models.deletion
 from django.conf import settings
 from django.db import migrations, models
 
+import core.snowflake
 import core.uploads
 import stator.models
 import users.models.follow
@@ -216,11 +217,10 @@ class Migration(migrations.Migration):
             fields=[
                 (
                     "id",
-                    models.BigAutoField(
-                        auto_created=True,
+                    models.BigIntegerField(
+                        default=core.snowflake.Snowflake.generate_identity,
                         primary_key=True,
                         serialize=False,
-                        verbose_name="ID",
                     ),
                 ),
                 ("state_ready", models.BooleanField(default=True)),
@@ -350,11 +350,10 @@ class Migration(migrations.Migration):
             fields=[
                 (
                     "id",
-                    models.BigAutoField(
-                        auto_created=True,
+                    models.BigIntegerField(
+                        default=core.snowflake.Snowflake.generate_follow,
                         primary_key=True,
                         serialize=False,
-                        verbose_name="ID",
                     ),
                 ),
                 ("state_ready", models.BooleanField(default=True)),

users/migrations/0005_report.py

@@ -3,6 +3,7 @@
 import django.db.models.deletion
 from django.db import migrations, models
 
+import core.snowflake
 import stator.models
 import users.models.report
 
@@ -20,11 +21,10 @@ class Migration(migrations.Migration):
             fields=[
                 (
                     "id",
-                    models.BigAutoField(
-                        auto_created=True,
+                    models.BigIntegerField(
+                        default=core.snowflake.Snowflake.generate_report,
                         primary_key=True,
                         serialize=False,
-                        verbose_name="ID",
                     ),
                 ),
                 ("state_ready", models.BooleanField(default=True)),

users/models/follow.py

@@ -4,6 +4,7 @@ import httpx
 from django.db import models, transaction
 
 from core.ld import canonicalise, get_str_or_id
+from core.snowflake import Snowflake
 from stator.models import State, StateField, StateGraph, StatorModel
 from users.models.identity import Identity
 
@@ -101,6 +102,8 @@ class Follow(StatorModel):
     When one user (the source) follows other (the target)
     """
 
+    id = models.BigIntegerField(primary_key=True, default=Snowflake.generate_follow)
+
     source = models.ForeignKey(
         "users.Identity",
         on_delete=models.CASCADE,

users/models/identity.py

@@ -22,6 +22,7 @@ from core.ld import (
 )
 from core.models import Config
 from core.signatures import HttpSignature, RsaKeys
+from core.snowflake import Snowflake
 from core.uploads import upload_namer
 from core.uris import (
     AutoAbsoluteUrl,
@@ -149,6 +150,8 @@ class Identity(StatorModel):
 
     ACTOR_TYPES = ["person", "service", "application", "group", "organization"]
 
+    id = models.BigIntegerField(primary_key=True, default=Snowflake.generate_identity)
+
     # The Actor URI is essentially also a PK - we keep the default numeric
     # one around as well for making nice URLs etc.
     actor_uri = models.CharField(max_length=500, unique=True)
@@ -862,9 +865,9 @@ class Identity(StatorModel):
                 self.created.replace(hour=0, minute=0, second=0, microsecond=0)
             ),
             "last_status_at": None,  # TODO: populate
-            "statuses_count": self.posts.count(),
-            "followers_count": self.inbound_follows.count(),
-            "following_count": self.outbound_follows.count(),
+            "statuses_count": self.posts.count() if include_counts else 0,
+            "followers_count": self.inbound_follows.count() if include_counts else 0,
+            "following_count": self.outbound_follows.count() if include_counts else 0,
         }
 
     ### Cryptography ###

users/models/report.py

@@ -10,6 +10,7 @@ from django.template.loader import render_to_string
 
 from core.ld import canonicalise, get_list
 from core.models import Config
+from core.snowflake import Snowflake
 from stator.models import State, StateField, StateGraph, StatorModel
 from users.models import Domain
 
@@ -84,6 +85,8 @@ class Report(StatorModel):
         remote = "remote"
         other = "other"
 
+    id = models.BigIntegerField(primary_key=True, default=Snowflake.generate_report)
+
     state = StateField(ReportStates)
 
     subject_identity = models.ForeignKey(