Start work on storing channel buffers

crates/collab/src/db/queries/buffers.rs

@@ -0,0 +1,271 @@
+use super::*;
+use prost::Message;
+
+pub struct Buffer {
+    pub base_text: String,
+    pub operations: Vec<proto::Operation>,
+}
+
+impl Database {
+    pub async fn create_buffer(&self) -> Result<BufferId> {
+        self.transaction(|tx| async move {
+            let buffer = buffer::ActiveModel::new().insert(&*tx).await?;
+            Ok(buffer.id)
+        })
+        .await
+    }
+
+    pub async fn update_buffer(
+        &self,
+        buffer_id: BufferId,
+        operations: &[proto::Operation],
+    ) -> Result<()> {
+        self.transaction(|tx| async move {
+            let buffer = buffer::Entity::find_by_id(buffer_id)
+                .one(&*tx)
+                .await?
+                .ok_or_else(|| anyhow!("no such buffer"))?;
+            buffer_operation::Entity::insert_many(operations.iter().filter_map(|operation| {
+                match operation.variant.as_ref()? {
+                    proto::operation::Variant::Edit(operation) => {
+                        let value =
+                            serialize_edit_operation(&operation.ranges, &operation.new_text);
+                        let version = serialize_version(&operation.version);
+                        Some(buffer_operation::ActiveModel {
+                            buffer_id: ActiveValue::Set(buffer_id),
+                            epoch: ActiveValue::Set(buffer.epoch),
+                            replica_id: ActiveValue::Set(operation.replica_id as i32),
+                            lamport_timestamp: ActiveValue::Set(operation.lamport_timestamp as i32),
+                            local_timestamp: ActiveValue::Set(operation.local_timestamp as i32),
+                            is_undo: ActiveValue::Set(false),
+                            version: ActiveValue::Set(version),
+                            value: ActiveValue::Set(value),
+                        })
+                    }
+                    proto::operation::Variant::Undo(operation) => {
+                        let value = serialize_undo_operation(&operation.counts);
+                        let version = serialize_version(&operation.version);
+                        Some(buffer_operation::ActiveModel {
+                            buffer_id: ActiveValue::Set(buffer_id),
+                            epoch: ActiveValue::Set(buffer.epoch),
+                            replica_id: ActiveValue::Set(operation.replica_id as i32),
+                            lamport_timestamp: ActiveValue::Set(operation.lamport_timestamp as i32),
+                            local_timestamp: ActiveValue::Set(operation.local_timestamp as i32),
+                            is_undo: ActiveValue::Set(true),
+                            version: ActiveValue::Set(version),
+                            value: ActiveValue::Set(value),
+                        })
+                    }
+                    proto::operation::Variant::UpdateSelections(_) => None,
+                    proto::operation::Variant::UpdateDiagnostics(_) => None,
+                    proto::operation::Variant::UpdateCompletionTriggers(_) => None,
+                }
+            }))
+            .exec(&*tx)
+            .await?;
+
+            Ok(())
+        })
+        .await
+    }
+
+    pub async fn get_buffer(&self, id: BufferId) -> Result<Buffer> {
+        self.transaction(|tx| async move {
+            let buffer = buffer::Entity::find_by_id(id)
+                .one(&*tx)
+                .await?
+                .ok_or_else(|| anyhow!("no such buffer"))?;
+
+            let base_text = if buffer.epoch > 0 {
+                buffer_snapshot::Entity::find()
+                    .filter(
+                        buffer_snapshot::Column::BufferId
+                            .eq(id)
+                            .and(buffer_snapshot::Column::Epoch.eq(buffer.epoch)),
+                    )
+                    .one(&*tx)
+                    .await?
+                    .ok_or_else(|| anyhow!("no such snapshot"))?
+                    .text
+            } else {
+                String::new()
+            };
+
+            let mut rows = buffer_operation::Entity::find()
+                .filter(
+                    buffer_operation::Column::BufferId
+                        .eq(id)
+                        .and(buffer_operation::Column::Epoch.eq(buffer.epoch)),
+                )
+                .stream(&*tx)
+                .await?;
+            let mut operations = Vec::new();
+            while let Some(row) = rows.next().await {
+                let row = row?;
+                let version = deserialize_version(&row.version)?;
+                let operation = if row.is_undo {
+                    let counts = deserialize_undo_operation(&row.value)?;
+                    proto::operation::Variant::Undo(proto::operation::Undo {
+                        replica_id: row.replica_id as u32,
+                        local_timestamp: row.local_timestamp as u32,
+                        lamport_timestamp: row.lamport_timestamp as u32,
+                        version,
+                        counts,
+                    })
+                } else {
+                    let (ranges, new_text) = deserialize_edit_operation(&row.value)?;
+                    proto::operation::Variant::Edit(proto::operation::Edit {
+                        replica_id: row.replica_id as u32,
+                        local_timestamp: row.local_timestamp as u32,
+                        lamport_timestamp: row.lamport_timestamp as u32,
+                        version,
+                        ranges,
+                        new_text,
+                    })
+                };
+                operations.push(proto::Operation {
+                    variant: Some(operation),
+                })
+            }
+
+            Ok(Buffer {
+                base_text,
+                operations,
+            })
+        })
+        .await
+    }
+}
+
+mod storage {
+    #![allow(non_snake_case)]
+
+    use prost::Message;
+
+    pub const VERSION: usize = 1;
+
+    #[derive(Message)]
+    pub struct VectorClock {
+        #[prost(message, repeated, tag = "1")]
+        pub entries: Vec<VectorClockEntry>,
+    }
+
+    #[derive(Message)]
+    pub struct VectorClockEntry {
+        #[prost(uint32, tag = "1")]
+        pub replica_id: u32,
+        #[prost(uint32, tag = "2")]
+        pub timestamp: u32,
+    }
+
+    #[derive(Message)]
+    pub struct TextEdit {
+        #[prost(message, repeated, tag = "1")]
+        pub ranges: Vec<Range>,
+        #[prost(string, repeated, tag = "2")]
+        pub texts: Vec<String>,
+    }
+
+    #[derive(Message)]
+    pub struct Range {
+        #[prost(uint64, tag = "1")]
+        pub start: u64,
+        #[prost(uint64, tag = "2")]
+        pub end: u64,
+    }
+
+    #[derive(Message)]
+    pub struct Undo {
+        #[prost(message, repeated, tag = "1")]
+        pub entries: Vec<UndoCount>,
+    }
+
+    #[derive(Message)]
+    pub struct UndoCount {
+        #[prost(uint32, tag = "1")]
+        pub replica_id: u32,
+        #[prost(uint32, tag = "2")]
+        pub local_timestamp: u32,
+        #[prost(uint32, tag = "3")]
+        pub count: u32,
+    }
+}
+
+fn serialize_version(version: &Vec<proto::VectorClockEntry>) -> Vec<u8> {
+    storage::VectorClock {
+        entries: version
+            .iter()
+            .map(|entry| storage::VectorClockEntry {
+                replica_id: entry.replica_id,
+                timestamp: entry.timestamp,
+            })
+            .collect(),
+    }
+    .encode_to_vec()
+}
+
+fn deserialize_version(bytes: &[u8]) -> Result<Vec<proto::VectorClockEntry>> {
+    let clock = storage::VectorClock::decode(bytes).map_err(|error| anyhow!("{}", error))?;
+    Ok(clock
+        .entries
+        .into_iter()
+        .map(|entry| proto::VectorClockEntry {
+            replica_id: entry.replica_id,
+            timestamp: entry.timestamp,
+        })
+        .collect())
+}
+
+fn serialize_edit_operation(ranges: &[proto::Range], texts: &[String]) -> Vec<u8> {
+    storage::TextEdit {
+        ranges: ranges
+            .iter()
+            .map(|range| storage::Range {
+                start: range.start,
+                end: range.end,
+            })
+            .collect(),
+        texts: texts.to_vec(),
+    }
+    .encode_to_vec()
+}
+
+fn deserialize_edit_operation(bytes: &[u8]) -> Result<(Vec<proto::Range>, Vec<String>)> {
+    let edit = storage::TextEdit::decode(bytes).map_err(|error| anyhow!("{}", error))?;
+    let ranges = edit
+        .ranges
+        .into_iter()
+        .map(|range| proto::Range {
+            start: range.start,
+            end: range.end,
+        })
+        .collect();
+    Ok((ranges, edit.texts))
+}
+
+fn serialize_undo_operation(counts: &Vec<proto::UndoCount>) -> Vec<u8> {
+    storage::Undo {
+        entries: counts
+            .iter()
+            .map(|entry| storage::UndoCount {
+                replica_id: entry.replica_id,
+                local_timestamp: entry.local_timestamp,
+                count: entry.count,
+            })
+            .collect(),
+    }
+    .encode_to_vec()
+}
+
+fn deserialize_undo_operation(bytes: &[u8]) -> Result<Vec<proto::UndoCount>> {
+    let undo = storage::Undo::decode(bytes).map_err(|error| anyhow!("{}", error))?;
+    Ok(undo
+        .entries
+        .iter()
+        .map(|entry| proto::UndoCount {
+            replica_id: entry.replica_id,
+            local_timestamp: entry.local_timestamp,
+            count: entry.count,
+        })
+        .collect())
+}