add playout service: HLS streaming, FFmpeg, SegmentStore port (#9)

crates/playout/src/segment_store/mod.rs

@@ -0,0 +1,28 @@
+pub mod filesystem;
+pub mod memory;
+
+use async_trait::async_trait;
+use bytes::Bytes;
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum SegmentStoreError {
+    #[error("segment not found: {0}")]
+    NotFound(String),
+    #[error("io error: {0}")]
+    Io(#[from] std::io::Error),
+}
+
+pub type SegmentStoreResult<T> = Result<T, SegmentStoreError>;
+
+#[async_trait]
+pub trait SegmentStore: Send + Sync {
+    async fn write_segment(&self, channel_id: &str, name: &str, data: Bytes)
+        -> SegmentStoreResult<()>;
+
+    async fn read_segment(&self, channel_id: &str, name: &str) -> SegmentStoreResult<Bytes>;
+
+    async fn list_segments(&self, channel_id: &str) -> SegmentStoreResult<Vec<String>>;
+
+    async fn delete_segment(&self, channel_id: &str, name: &str) -> SegmentStoreResult<()>;
+}