Add storage behind a trait

Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/aerogramme/pulls/32

1 files changed, 334 insertions, 0 deletions

diff --git a/src/storage/in_memory.rs b/src/storage/in_memory.rs
new file mode 100644
index 0000000..3c3a94c
--- /dev/null
+++ b/src/storage/in_memory.rs
@@ -0,0 +1,334 @@
+use crate::storage::*;
+use std::collections::{BTreeMap, HashMap};
+use std::ops::Bound::{self, Excluded, Included, Unbounded};
+use std::sync::{Arc, RwLock};
+use tokio::sync::Notify;
+
+/// This implementation is very inneficient, and not completely correct
+/// Indeed, when the connector is dropped, the memory is freed.
+/// It means that when a user disconnects, its data are lost.
+/// It's intended only for basic debugging, do not use it for advanced tests...
+
+#[derive(Debug, Default)]
+pub struct MemDb(tokio::sync::Mutex<HashMap<String, Arc<MemBuilder>>>);
+impl MemDb {
+    pub fn new() -> Self {
+        Self(tokio::sync::Mutex::new(HashMap::new()))
+    }
+
+    pub async fn builder(&self, username: &str) -> Arc<MemBuilder> {
+        let mut global_storage = self.0.lock().await;
+        global_storage
+            .entry(username.to_string())
+            .or_insert(MemBuilder::new(username))
+            .clone()
+    }
+}
+
+#[derive(Debug, Clone)]
+enum InternalData {
+    Tombstone,
+    Value(Vec<u8>),
+}
+impl InternalData {
+    fn to_alternative(&self) -> Alternative {
+        match self {
+            Self::Tombstone => Alternative::Tombstone,
+            Self::Value(x) => Alternative::Value(x.clone()),
+        }
+    }
+}
+
+#[derive(Debug)]
+struct InternalRowVal {
+    data: Vec<InternalData>,
+    version: u64,
+    change: Arc<Notify>,
+}
+impl std::default::Default for InternalRowVal {
+    fn default() -> Self {
+        Self {
+            data: vec![],
+            version: 1,
+            change: Arc::new(Notify::new()),
+        }
+    }
+}
+impl InternalRowVal {
+    fn concurrent_values(&self) -> Vec<Alternative> {
+        self.data.iter().map(InternalData::to_alternative).collect()
+    }
+
+    fn to_row_val(&self, row_ref: RowRef) -> RowVal {
+        RowVal {
+            row_ref: row_ref.with_causality(self.version.to_string()),
+            value: self.concurrent_values(),
+        }
+    }
+}
+
+#[derive(Debug, Default, Clone)]
+struct InternalBlobVal {
+    data: Vec<u8>,
+    metadata: HashMap<String, String>,
+}
+impl InternalBlobVal {
+    fn to_blob_val(&self, bref: &BlobRef) -> BlobVal {
+        BlobVal {
+            blob_ref: bref.clone(),
+            meta: self.metadata.clone(),
+            value: self.data.clone(),
+        }
+    }
+}
+
+type ArcRow = Arc<RwLock<HashMap<String, BTreeMap<String, InternalRowVal>>>>;
+type ArcBlob = Arc<RwLock<BTreeMap<String, InternalBlobVal>>>;
+
+#[derive(Clone, Debug)]
+pub struct MemBuilder {
+    unicity: Vec<u8>,
+    row: ArcRow,
+    blob: ArcBlob,
+}
+
+impl MemBuilder {
+    pub fn new(user: &str) -> Arc<Self> {
+        tracing::debug!("initialize membuilder for {}", user);
+        let mut unicity: Vec<u8> = vec![];
+        unicity.extend_from_slice(file!().as_bytes());
+        unicity.extend_from_slice(user.as_bytes());
+        Arc::new(Self {
+            unicity,
+            row: Arc::new(RwLock::new(HashMap::new())),
+            blob: Arc::new(RwLock::new(BTreeMap::new())),
+        })
+    }
+}
+
+#[async_trait]
+impl IBuilder for MemBuilder {
+    async fn build(&self) -> Result<Store, StorageError> {
+        Ok(Box::new(MemStore {
+            row: self.row.clone(),
+            blob: self.blob.clone(),
+        }))
+    }
+
+    fn unique(&self) -> UnicityBuffer {
+        UnicityBuffer(self.unicity.clone())
+    }
+}
+
+pub struct MemStore {
+    row: ArcRow,
+    blob: ArcBlob,
+}
+
+fn prefix_last_bound(prefix: &str) -> Bound<String> {
+    let mut sort_end = prefix.to_string();
+    match sort_end.pop() {
+        None => Unbounded,
+        Some(ch) => {
+            let nc = char::from_u32(ch as u32 + 1).unwrap();
+            sort_end.push(nc);
+            Excluded(sort_end)
+        }
+    }
+}
+
+impl MemStore {
+    fn row_rm_single(&self, entry: &RowRef) -> Result<(), StorageError> {
+        tracing::trace!(entry=%entry, command="row_rm_single");
+        let mut store = self.row.write().or(Err(StorageError::Internal))?;
+        let shard = &entry.uid.shard;
+        let sort = &entry.uid.sort;
+
+        let cauz = match entry.causality.as_ref().map(|v| v.parse::<u64>()) {
+            Some(Ok(v)) => v,
+            _ => 0,
+        };
+
+        let bt = store.entry(shard.to_string()).or_default();
+        let intval = bt.entry(sort.to_string()).or_default();
+
+        if cauz == intval.version {
+            intval.data.clear();
+        }
+        intval.data.push(InternalData::Tombstone);
+        intval.version += 1;
+        intval.change.notify_waiters();
+
+        Ok(())
+    }
+}
+
+#[async_trait]
+impl IStore for MemStore {
+    async fn row_fetch<'a>(&self, select: &Selector<'a>) -> Result<Vec<RowVal>, StorageError> {
+        tracing::trace!(select=%select, command="row_fetch");
+        let store = self.row.read().or(Err(StorageError::Internal))?;
+
+        match select {
+            Selector::Range {
+                shard,
+                sort_begin,
+                sort_end,
+            } => Ok(store
+                .get(*shard)
+                .unwrap_or(&BTreeMap::new())
+                .range((
+                    Included(sort_begin.to_string()),
+                    Excluded(sort_end.to_string()),
+                ))
+                .map(|(k, v)| v.to_row_val(RowRef::new(shard, k)))
+                .collect::<Vec<_>>()),
+            Selector::List(rlist) => {
+                let mut acc = vec![];
+                for row_ref in rlist {
+                    let maybe_intval = store
+                        .get(&row_ref.uid.shard)
+                        .map(|v| v.get(&row_ref.uid.sort))
+                        .flatten();
+                    if let Some(intval) = maybe_intval {
+                        acc.push(intval.to_row_val(row_ref.clone()));
+                    }
+                }
+                Ok(acc)
+            }
+            Selector::Prefix { shard, sort_prefix } => {
+                let last_bound = prefix_last_bound(sort_prefix);
+
+                Ok(store
+                    .get(*shard)
+                    .unwrap_or(&BTreeMap::new())
+                    .range((Included(sort_prefix.to_string()), last_bound))
+                    .map(|(k, v)| v.to_row_val(RowRef::new(shard, k)))
+                    .collect::<Vec<_>>())
+            }
+            Selector::Single(row_ref) => {
+                let intval = store
+                    .get(&row_ref.uid.shard)
+                    .ok_or(StorageError::NotFound)?
+                    .get(&row_ref.uid.sort)
+                    .ok_or(StorageError::NotFound)?;
+                Ok(vec![intval.to_row_val((*row_ref).clone())])
+            }
+        }
+    }
+
+    async fn row_rm<'a>(&self, select: &Selector<'a>) -> Result<(), StorageError> {
+        tracing::trace!(select=%select, command="row_rm");
+
+        let values = match select {
+            Selector::Range { .. } | Selector::Prefix { .. } => self
+                .row_fetch(select)
+                .await?
+                .into_iter()
+                .map(|rv| rv.row_ref)
+                .collect::<Vec<_>>(),
+            Selector::List(rlist) => rlist.clone(),
+            Selector::Single(row_ref) => vec![(*row_ref).clone()],
+        };
+
+        for v in values.into_iter() {
+            self.row_rm_single(&v)?;
+        }
+        Ok(())
+    }
+
+    async fn row_insert(&self, values: Vec<RowVal>) -> Result<(), StorageError> {
+        tracing::trace!(entries=%values.iter().map(|v| v.row_ref.to_string()).collect::<Vec<_>>().join(","), command="row_insert");
+        let mut store = self.row.write().or(Err(StorageError::Internal))?;
+        for v in values.into_iter() {
+            let shard = v.row_ref.uid.shard;
+            let sort = v.row_ref.uid.sort;
+
+            let val = match v.value.into_iter().next() {
+                Some(Alternative::Value(x)) => x,
+                _ => vec![],
+            };
+
+            let cauz = match v.row_ref.causality.map(|v| v.parse::<u64>()) {
+                Some(Ok(v)) => v,
+                _ => 0,
+            };
+
+            let bt = store.entry(shard).or_default();
+            let intval = bt.entry(sort).or_default();
+
+            if cauz == intval.version {
+                intval.data.clear();
+            }
+            intval.data.push(InternalData::Value(val));
+            intval.version += 1;
+            intval.change.notify_waiters();
+        }
+        Ok(())
+    }
+    async fn row_poll(&self, value: &RowRef) -> Result<RowVal, StorageError> {
+        tracing::trace!(entry=%value, command="row_poll");
+        let shard = &value.uid.shard;
+        let sort = &value.uid.sort;
+        let cauz = match value.causality.as_ref().map(|v| v.parse::<u64>()) {
+            Some(Ok(v)) => v,
+            _ => 0,
+        };
+
+        let notify_me = {
+            let mut store = self.row.write().or(Err(StorageError::Internal))?;
+            let bt = store.entry(shard.to_string()).or_default();
+            let intval = bt.entry(sort.to_string()).or_default();
+
+            if intval.version != cauz {
+                return Ok(intval.to_row_val(value.clone()));
+            }
+            intval.change.clone()
+        };
+
+        notify_me.notified().await;
+
+        let res = self.row_fetch(&Selector::Single(value)).await?;
+        res.into_iter().next().ok_or(StorageError::NotFound)
+    }
+
+    async fn blob_fetch(&self, blob_ref: &BlobRef) -> Result<BlobVal, StorageError> {
+        tracing::trace!(entry=%blob_ref, command="blob_fetch");
+        let store = self.blob.read().or(Err(StorageError::Internal))?;
+        store
+            .get(&blob_ref.0)
+            .ok_or(StorageError::NotFound)
+            .map(|v| v.to_blob_val(blob_ref))
+    }
+    async fn blob_insert(&self, blob_val: BlobVal) -> Result<(), StorageError> {
+        tracing::trace!(entry=%blob_val.blob_ref, command="blob_insert");
+        let mut store = self.blob.write().or(Err(StorageError::Internal))?;
+        let entry = store.entry(blob_val.blob_ref.0.clone()).or_default();
+        entry.data = blob_val.value.clone();
+        entry.metadata = blob_val.meta.clone();
+        Ok(())
+    }
+    async fn blob_copy(&self, src: &BlobRef, dst: &BlobRef) -> Result<(), StorageError> {
+        tracing::trace!(src=%src, dst=%dst, command="blob_copy");
+        let mut store = self.blob.write().or(Err(StorageError::Internal))?;
+        let blob_src = store.entry(src.0.clone()).or_default().clone();
+        store.insert(dst.0.clone(), blob_src);
+        Ok(())
+    }
+    async fn blob_list(&self, prefix: &str) -> Result<Vec<BlobRef>, StorageError> {
+        tracing::trace!(prefix = prefix, command = "blob_list");
+        let store = self.blob.read().or(Err(StorageError::Internal))?;
+        let last_bound = prefix_last_bound(prefix);
+        let blist = store
+            .range((Included(prefix.to_string()), last_bound))
+            .map(|(k, _)| BlobRef(k.to_string()))
+            .collect::<Vec<_>>();
+        Ok(blist)
+    }
+    async fn blob_rm(&self, blob_ref: &BlobRef) -> Result<(), StorageError> {
+        tracing::trace!(entry=%blob_ref, command="blob_rm");
+        let mut store = self.blob.write().or(Err(StorageError::Internal))?;
+        store.remove(&blob_ref.0);
+        Ok(())
+    }
+}