Track event sequences globally, not per channel.

Per-channel event sequences were a cute idea, but it made reasoning about event resumption much, much harder (case in point: recovering the order of events in a partially-ordered collection is quadratic, since it's basically graph sort). The minor overhead of a global sequence number is likely tolerable, and this simplifies both the API and the internals.

12 files changed, 211 insertions, 119 deletions

diff --git a/.sqlx/query-023b1e263b68a483704ae5f6b07e69ab792b7365f2eb2831f7a2ac13e2ecf323.json b/.sqlx/query-023b1e263b68a483704ae5f6b07e69ab792b7365f2eb2831f7a2ac13e2ecf323.json
new file mode 100644
index 0000000..cc23359
--- /dev/null
+++ b/.sqlx/query-023b1e263b68a483704ae5f6b07e69ab792b7365f2eb2831f7a2ac13e2ecf323.json
@@ -0,0 +1,38 @@
+{
+  "db_name": "SQLite",
+  "query": "\n                insert\n                into channel (id, name, created_at, created_sequence)\n                values ($1, $2, $3, $4)\n                returning\n                    id as \"id: Id\",\n                    name,\n                    created_at as \"created_at: DateTime\",\n                    created_sequence as \"created_sequence: Sequence\"\n            ",
+  "describe": {
+    "columns": [
+      {
+        "name": "id: Id",
+        "ordinal": 0,
+        "type_info": "Text"
+      },
+      {
+        "name": "name",
+        "ordinal": 1,
+        "type_info": "Text"
+      },
+      {
+        "name": "created_at: DateTime",
+        "ordinal": 2,
+        "type_info": "Text"
+      },
+      {
+        "name": "created_sequence: Sequence",
+        "ordinal": 3,
+        "type_info": "Integer"
+      }
+    ],
+    "parameters": {
+      "Right": 4
+    },
+    "nullable": [
+      false,
+      false,
+      false,
+      false
+    ]
+  },
+  "hash": "023b1e263b68a483704ae5f6b07e69ab792b7365f2eb2831f7a2ac13e2ecf323"
+}
diff --git a/.sqlx/query-397bdfdb77651e3e65e9ec53cf075037c794cae08f79a689c7a037aa68d7c00c.json b/.sqlx/query-397bdfdb77651e3e65e9ec53cf075037c794cae08f79a689c7a037aa68d7c00c.json
deleted file mode 100644
index 5cb7282..0000000
--- a/.sqlx/query-397bdfdb77651e3e65e9ec53cf075037c794cae08f79a689c7a037aa68d7c00c.json
+++ /dev/null
@@ -1,20 +0,0 @@
-{
-  "db_name": "SQLite",
-  "query": "\n                update channel\n                set last_sequence = last_sequence + 1\n                where id = $1\n                returning last_sequence as \"next_sequence: Sequence\"\n            ",
-  "describe": {
-    "columns": [
-      {
-        "name": "next_sequence: Sequence",
-        "ordinal": 0,
-        "type_info": "Integer"
-      }
-    ],
-    "parameters": {
-      "Right": 1
-    },
-    "nullable": [
-      false
-    ]
-  },
-  "hash": "397bdfdb77651e3e65e9ec53cf075037c794cae08f79a689c7a037aa68d7c00c"
-}
diff --git a/.sqlx/query-2310fe5b8e88e314eb200d8f227b09c3e4b0c9c0202c7cbe3fba93213ea100cf.json b/.sqlx/query-4715007e2395ad30433b7405a144db4901c302bbcd3e76da6c61742ac44345c9.json
index 1bd4116..494e1db 100644
--- a/.sqlx/query-2310fe5b8e88e314eb200d8f227b09c3e4b0c9c0202c7cbe3fba93213ea100cf.json
+++ b/.sqlx/query-4715007e2395ad30433b7405a144db4901c302bbcd3e76da6c61742ac44345c9.json
@@ -1,6 +1,6 @@
 {
   "db_name": "SQLite",
-  "query": "\n\t\t\t\tinsert into message\n\t\t\t\t\t(id, channel, sequence, sender, body, sent_at)\n\t\t\t\tvalues ($1, $2, $3, $4, $5, $6)\n\t\t\t\treturning\n\t\t\t\t\tid as \"id: message::Id\",\n                    sequence as \"sequence: Sequence\",\n\t\t\t\t\tsender as \"sender: login::Id\",\n\t\t\t\t\tbody,\n\t\t\t\t\tsent_at as \"sent_at: DateTime\"\n\t\t\t",
+  "query": "\n\t\t\t\tinsert into message\n\t\t\t\t\t(id, channel, sender, sent_at, sent_sequence, body)\n\t\t\t\tvalues ($1, $2, $3, $4, $5, $6)\n\t\t\t\treturning\n\t\t\t\t\tid as \"id: message::Id\",\n\t\t\t\t\tsender as \"sender: login::Id\",\n                    sent_at as \"sent_at: DateTime\",\n                    sent_sequence as \"sent_sequence: Sequence\",\n\t\t\t\t\tbody\n\t\t\t",
   "describe": {
     "columns": [
       {
@@ -9,22 +9,22 @@
         "type_info": "Text"
       },
       {
-        "name": "sequence: Sequence",
+        "name": "sender: login::Id",
         "ordinal": 1,
-        "type_info": "Integer"
+        "type_info": "Text"
       },
       {
-        "name": "sender: login::Id",
+        "name": "sent_at: DateTime",
         "ordinal": 2,
         "type_info": "Text"
       },
       {
-        "name": "body",
+        "name": "sent_sequence: Sequence",
         "ordinal": 3,
-        "type_info": "Text"
+        "type_info": "Integer"
       },
       {
-        "name": "sent_at: DateTime",
+        "name": "body",
         "ordinal": 4,
         "type_info": "Text"
       }
@@ -40,5 +40,5 @@
       false
     ]
   },
-  "hash": "2310fe5b8e88e314eb200d8f227b09c3e4b0c9c0202c7cbe3fba93213ea100cf"
+  "hash": "4715007e2395ad30433b7405a144db4901c302bbcd3e76da6c61742ac44345c9"
 }
diff --git a/.sqlx/query-df3656771c3cb6851e0c54a2d368676f279af866d0840d6c2c093b87b1eadd8c.json b/.sqlx/query-5244f04bc270fc8d3cd4116854398e2151ba2dba10c03a9d2d93184141f1425c.json
index 87e478e..820b43f 100644
--- a/.sqlx/query-df3656771c3cb6851e0c54a2d368676f279af866d0840d6c2c093b87b1eadd8c.json
+++ b/.sqlx/query-5244f04bc270fc8d3cd4116854398e2151ba2dba10c03a9d2d93184141f1425c.json
@@ -1,6 +1,6 @@
 {
   "db_name": "SQLite",
-  "query": "\n                select\n                    channel.id as \"channel_id: channel::Id\",\n                    channel.name as \"channel_name\",\n                    channel.created_at as \"channel_created_at: DateTime\",\n                    message.id as \"message: message::Id\"\n                from message\n                    join channel on message.channel = channel.id\n                    join login as sender on message.sender = sender.id\n                where sent_at < $1\n            ",
+  "query": "\n                select\n                    channel.id as \"channel_id: channel::Id\",\n                    channel.name as \"channel_name\",\n                    channel.created_at as \"channel_created_at: DateTime\",\n                    channel.created_sequence as \"channel_created_sequence: Sequence\",\n                    message.id as \"message: message::Id\"\n                from message\n                    join channel on message.channel = channel.id\n                    join login as sender on message.sender = sender.id\n                where sent_at < $1\n            ",
   "describe": {
     "columns": [
       {
@@ -19,8 +19,13 @@
         "type_info": "Text"
       },
       {
-        "name": "message: message::Id",
+        "name": "channel_created_sequence: Sequence",
         "ordinal": 3,
+        "type_info": "Integer"
+      },
+      {
+        "name": "message: message::Id",
+        "ordinal": 4,
         "type_info": "Text"
       }
     ],
@@ -31,8 +36,9 @@
       false,
       false,
       false,
+      false,
       false
     ]
   },
-  "hash": "df3656771c3cb6851e0c54a2d368676f279af866d0840d6c2c093b87b1eadd8c"
+  "hash": "5244f04bc270fc8d3cd4116854398e2151ba2dba10c03a9d2d93184141f1425c"
 }
diff --git a/.sqlx/query-6a782686e163e65f5e03e4aaf423b1fd14ed9e252d7d9c5323feafb0b9159259.json b/.sqlx/query-74f0bad30dcec743d77309b8df33083c2da765dfda3023c78c25c06735670457.json
index ae298d6..b34443f 100644
--- a/.sqlx/query-6a782686e163e65f5e03e4aaf423b1fd14ed9e252d7d9c5323feafb0b9159259.json
+++ b/.sqlx/query-74f0bad30dcec743d77309b8df33083c2da765dfda3023c78c25c06735670457.json
@@ -1,6 +1,6 @@
 {
   "db_name": "SQLite",
-  "query": "\n                select\n                    channel.id as \"id: Id\",\n                    channel.name,\n                    channel.created_at as \"created_at: DateTime\"\n                from channel\n                    left join message\n                where created_at < $1\n                    and message.id is null\n            ",
+  "query": "\n                select\n                    channel.id as \"id: Id\",\n                    channel.name,\n                    channel.created_at as \"created_at: DateTime\",\n                    channel.created_sequence as \"created_sequence: Sequence\"\n                from channel\n                    left join message\n                where created_at < $1\n                    and message.id is null\n            ",
   "describe": {
     "columns": [
       {
@@ -17,6 +17,11 @@
         "name": "created_at: DateTime",
         "ordinal": 2,
         "type_info": "Text"
+      },
+      {
+        "name": "created_sequence: Sequence",
+        "ordinal": 3,
+        "type_info": "Integer"
       }
     ],
     "parameters": {
@@ -25,8 +30,9 @@
     "nullable": [
       false,
       false,
+      false,
       false
     ]
   },
-  "hash": "6a782686e163e65f5e03e4aaf423b1fd14ed9e252d7d9c5323feafb0b9159259"
+  "hash": "74f0bad30dcec743d77309b8df33083c2da765dfda3023c78c25c06735670457"
 }
diff --git a/.sqlx/query-760d3532e1613fd9f79ac98cb132479c6e7a2301d576af298da570f3effdc106.json b/.sqlx/query-760d3532e1613fd9f79ac98cb132479c6e7a2301d576af298da570f3effdc106.json
deleted file mode 100644
index beb9234..0000000
--- a/.sqlx/query-760d3532e1613fd9f79ac98cb132479c6e7a2301d576af298da570f3effdc106.json
+++ /dev/null
@@ -1,50 +0,0 @@
-{
-  "db_name": "SQLite",
-  "query": "\n\t\t\t\tselect\n\t\t\t\t\tmessage.id as \"id: message::Id\",\n                    sequence as \"sequence: Sequence\",\n\t\t\t\t\tlogin.id as \"sender_id: login::Id\",\n\t\t\t\t\tlogin.name as sender_name,\n\t\t\t\t\tmessage.body,\n\t\t\t\t\tmessage.sent_at as \"sent_at: DateTime\"\n\t\t\t\tfrom message\n\t\t\t\t\tjoin login on message.sender = login.id\n\t\t\t\twhere channel = $1\n\t\t\t\t\tand coalesce(sequence > $2, true)\n\t\t\t\torder by sequence asc\n\t\t\t",
-  "describe": {
-    "columns": [
-      {
-        "name": "id: message::Id",
-        "ordinal": 0,
-        "type_info": "Text"
-      },
-      {
-        "name": "sequence: Sequence",
-        "ordinal": 1,
-        "type_info": "Integer"
-      },
-      {
-        "name": "sender_id: login::Id",
-        "ordinal": 2,
-        "type_info": "Text"
-      },
-      {
-        "name": "sender_name",
-        "ordinal": 3,
-        "type_info": "Text"
-      },
-      {
-        "name": "body",
-        "ordinal": 4,
-        "type_info": "Text"
-      },
-      {
-        "name": "sent_at: DateTime",
-        "ordinal": 5,
-        "type_info": "Text"
-      }
-    ],
-    "parameters": {
-      "Right": 2
-    },
-    "nullable": [
-      false,
-      false,
-      false,
-      false,
-      false,
-      false
-    ]
-  },
-  "hash": "760d3532e1613fd9f79ac98cb132479c6e7a2301d576af298da570f3effdc106"
-}
diff --git a/.sqlx/query-7e816ede017bc2635c11ab72b18b7af92ac1f1faed9df41df90f57cb596cfe7c.json b/.sqlx/query-7e816ede017bc2635c11ab72b18b7af92ac1f1faed9df41df90f57cb596cfe7c.json
new file mode 100644
index 0000000..f546438
--- /dev/null
+++ b/.sqlx/query-7e816ede017bc2635c11ab72b18b7af92ac1f1faed9df41df90f57cb596cfe7c.json
@@ -0,0 +1,74 @@
+{
+  "db_name": "SQLite",
+  "query": "\n\t\t\t\tselect\n\t\t\t\t\tmessage.id as \"id: message::Id\",\n                    channel.id as \"channel_id: channel::Id\",\n                    channel.name as \"channel_name\",\n                    channel.created_at as \"channel_created_at: DateTime\",\n                    channel.created_sequence as \"channel_created_sequence: Sequence\",\n\t\t\t\t\tsender.id as \"sender_id: login::Id\",\n\t\t\t\t\tsender.name as sender_name,\n                    message.sent_at as \"sent_at: DateTime\",\n                    message.sent_sequence as \"sent_sequence: Sequence\",\n                    message.body\n\t\t\t\tfrom message\n                    join channel on message.channel = channel.id\n\t\t\t\t\tjoin login as sender on message.sender = sender.id\n\t\t\t\twhere coalesce(message.sent_sequence > $1, true)\n\t\t\t\torder by sent_sequence asc\n\t\t\t",
+  "describe": {
+    "columns": [
+      {
+        "name": "id: message::Id",
+        "ordinal": 0,
+        "type_info": "Text"
+      },
+      {
+        "name": "channel_id: channel::Id",
+        "ordinal": 1,
+        "type_info": "Text"
+      },
+      {
+        "name": "channel_name",
+        "ordinal": 2,
+        "type_info": "Text"
+      },
+      {
+        "name": "channel_created_at: DateTime",
+        "ordinal": 3,
+        "type_info": "Text"
+      },
+      {
+        "name": "channel_created_sequence: Sequence",
+        "ordinal": 4,
+        "type_info": "Integer"
+      },
+      {
+        "name": "sender_id: login::Id",
+        "ordinal": 5,
+        "type_info": "Text"
+      },
+      {
+        "name": "sender_name",
+        "ordinal": 6,
+        "type_info": "Text"
+      },
+      {
+        "name": "sent_at: DateTime",
+        "ordinal": 7,
+        "type_info": "Text"
+      },
+      {
+        "name": "sent_sequence: Sequence",
+        "ordinal": 8,
+        "type_info": "Integer"
+      },
+      {
+        "name": "body",
+        "ordinal": 9,
+        "type_info": "Text"
+      }
+    ],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": [
+      false,
+      false,
+      false,
+      false,
+      false,
+      false,
+      false,
+      false,
+      false,
+      false
+    ]
+  },
+  "hash": "7e816ede017bc2635c11ab72b18b7af92ac1f1faed9df41df90f57cb596cfe7c"
+}
diff --git a/.sqlx/query-7ccae3dde1aba5f22cf9e3926096285d50afb88a326cff0ecab96058a2f6d93a.json b/.sqlx/query-7f6b9c7d4ef3f540d594318a7a66fa8f9e3ddcf6d041be8d834db58f66a5aa88.json
index 4ec7118..3cc33cf 100644
--- a/.sqlx/query-7ccae3dde1aba5f22cf9e3926096285d50afb88a326cff0ecab96058a2f6d93a.json
+++ b/.sqlx/query-7f6b9c7d4ef3f540d594318a7a66fa8f9e3ddcf6d041be8d834db58f66a5aa88.json
@@ -1,6 +1,6 @@
 {
   "db_name": "SQLite",
-  "query": "\n                select\n                    id as \"id: Id\",\n                    name,\n                    created_at as \"created_at: DateTime\"\n                from channel\n                order by channel.name\n            ",
+  "query": "\n                select\n                    id as \"id: Id\",\n                    name,\n                    created_at as \"created_at: DateTime\",\n                    created_sequence as \"created_sequence: Sequence\"\n                from channel\n                order by channel.name\n            ",
   "describe": {
     "columns": [
       {
@@ -17,6 +17,11 @@
         "name": "created_at: DateTime",
         "ordinal": 2,
         "type_info": "Text"
+      },
+      {
+        "name": "created_sequence: Sequence",
+        "ordinal": 3,
+        "type_info": "Integer"
       }
     ],
     "parameters": {
@@ -25,8 +30,9 @@
     "nullable": [
       false,
       false,
+      false,
       false
     ]
   },
-  "hash": "7ccae3dde1aba5f22cf9e3926096285d50afb88a326cff0ecab96058a2f6d93a"
+  "hash": "7f6b9c7d4ef3f540d594318a7a66fa8f9e3ddcf6d041be8d834db58f66a5aa88"
 }
diff --git a/.sqlx/query-7fc3094944d5133fd8b2d80aace35b06db0071c5f257b7f71349966bcdadfcb5.json b/.sqlx/query-7fc3094944d5133fd8b2d80aace35b06db0071c5f257b7f71349966bcdadfcb5.json
new file mode 100644
index 0000000..b5bc371
--- /dev/null
+++ b/.sqlx/query-7fc3094944d5133fd8b2d80aace35b06db0071c5f257b7f71349966bcdadfcb5.json
@@ -0,0 +1,20 @@
+{
+  "db_name": "SQLite",
+  "query": "\n                update event_sequence\n                set last_value = last_value + 1\n                returning last_value as \"next_value: Sequence\"\n            ",
+  "describe": {
+    "columns": [
+      {
+        "name": "next_value: Sequence",
+        "ordinal": 0,
+        "type_info": "Integer"
+      }
+    ],
+    "parameters": {
+      "Right": 0
+    },
+    "nullable": [
+      false
+    ]
+  },
+  "hash": "7fc3094944d5133fd8b2d80aace35b06db0071c5f257b7f71349966bcdadfcb5"
+}
diff --git a/.sqlx/query-9386cdaa2cb41f5a7e19d2fc8c187294a4661c18c2d820f4379dfd82138a8f77.json b/.sqlx/query-9386cdaa2cb41f5a7e19d2fc8c187294a4661c18c2d820f4379dfd82138a8f77.json
new file mode 100644
index 0000000..e9c3967
--- /dev/null
+++ b/.sqlx/query-9386cdaa2cb41f5a7e19d2fc8c187294a4661c18c2d820f4379dfd82138a8f77.json
@@ -0,0 +1,38 @@
+{
+  "db_name": "SQLite",
+  "query": "\n                select\n                    id as \"id: Id\",\n                    name,\n                    created_at as \"created_at: DateTime\",\n                    created_sequence as \"created_sequence: Sequence\"\n                from channel\n                where coalesce(created_sequence > $1, true)\n            ",
+  "describe": {
+    "columns": [
+      {
+        "name": "id: Id",
+        "ordinal": 0,
+        "type_info": "Text"
+      },
+      {
+        "name": "name",
+        "ordinal": 1,
+        "type_info": "Text"
+      },
+      {
+        "name": "created_at: DateTime",
+        "ordinal": 2,
+        "type_info": "Text"
+      },
+      {
+        "name": "created_sequence: Sequence",
+        "ordinal": 3,
+        "type_info": "Integer"
+      }
+    ],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": [
+      false,
+      false,
+      false,
+      false
+    ]
+  },
+  "hash": "9386cdaa2cb41f5a7e19d2fc8c187294a4661c18c2d820f4379dfd82138a8f77"
+}
diff --git a/.sqlx/query-aeafe536f36593bfd1080ee61c4b10c6f90b1221e963db69c8e6d23e99012ecf.json b/.sqlx/query-aeafe536f36593bfd1080ee61c4b10c6f90b1221e963db69c8e6d23e99012ecf.json
deleted file mode 100644
index 5c27826..0000000
--- a/.sqlx/query-aeafe536f36593bfd1080ee61c4b10c6f90b1221e963db69c8e6d23e99012ecf.json
+++ /dev/null
@@ -1,32 +0,0 @@
-{
-  "db_name": "SQLite",
-  "query": "\n                insert\n                into channel (id, name, created_at, last_sequence)\n                values ($1, $2, $3, $4)\n                returning\n                    id as \"id: Id\",\n                    name,\n                    created_at as \"created_at: DateTime\"\n            ",
-  "describe": {
-    "columns": [
-      {
-        "name": "id: Id",
-        "ordinal": 0,
-        "type_info": "Text"
-      },
-      {
-        "name": "name",
-        "ordinal": 1,
-        "type_info": "Text"
-      },
-      {
-        "name": "created_at: DateTime",
-        "ordinal": 2,
-        "type_info": "Text"
-      }
-    ],
-    "parameters": {
-      "Right": 4
-    },
-    "nullable": [
-      false,
-      false,
-      false
-    ]
-  },
-  "hash": "aeafe536f36593bfd1080ee61c4b10c6f90b1221e963db69c8e6d23e99012ecf"
-}
diff --git a/.sqlx/query-22f313d9afcdd02df74a8b8c64a38a3f73b112e74b7318ee8e52e475866d8cfd.json b/.sqlx/query-f6909336ab05b7ad423c7b96a0e7b12a920f9827aff2b05ee0364ff7688a38ae.json
index 3d5d06c..ded48e1 100644
--- a/.sqlx/query-22f313d9afcdd02df74a8b8c64a38a3f73b112e74b7318ee8e52e475866d8cfd.json
+++ b/.sqlx/query-f6909336ab05b7ad423c7b96a0e7b12a920f9827aff2b05ee0364ff7688a38ae.json
@@ -1,6 +1,6 @@
 {
   "db_name": "SQLite",
-  "query": "\n                select\n                    id as \"id: Id\",\n                    name,\n                    created_at as \"created_at: DateTime\"\n                from channel\n                where id = $1\n            ",
+  "query": "\n                select\n                    id as \"id: Id\",\n                    name,\n                    created_at as \"created_at: DateTime\",\n                    created_sequence as \"created_sequence: Sequence\"\n                from channel\n                where id = $1\n            ",
   "describe": {
     "columns": [
       {
@@ -17,6 +17,11 @@
         "name": "created_at: DateTime",
         "ordinal": 2,
         "type_info": "Text"
+      },
+      {
+        "name": "created_sequence: Sequence",
+        "ordinal": 3,
+        "type_info": "Integer"
       }
     ],
     "parameters": {
@@ -25,8 +30,9 @@
     "nullable": [
       false,
       false,
+      false,
       false
     ]
   },
-  "hash": "22f313d9afcdd02df74a8b8c64a38a3f73b112e74b7318ee8e52e475866d8cfd"
+  "hash": "f6909336ab05b7ad423c7b96a0e7b12a920f9827aff2b05ee0364ff7688a38ae"
 }