feat(flow): flow worker

src/flow/Cargo.toml

@@ -27,6 +27,7 @@ futures = "0.3"
 # it is the same with upstream repo
 async-trait.workspace = true
 common-meta.workspace = true
+enum-as-inner = "0.6.0"
 greptime-proto.workspace = true
 hydroflow = { git = "https://github.com/GreptimeTeam/hydroflow.git", branch = "main" }
 itertools.workspace = true

src/flow/src/adapter.rs

@@ -18,4 +18,8 @@
 pub(crate) mod error;
 pub(crate) mod node_context;
 
-pub(crate) use node_context::FlownodeContext;
+pub(crate) use node_context::{FlowId, FlownodeContext, TableName};
+
+mod worker;
+
+pub const PER_REQ_MAX_ROW_CNT: usize = 8192;

src/flow/src/adapter/error.rs

@@ -24,6 +24,7 @@ use datatypes::value::Value;
 use servers::define_into_tonic_status;
 use snafu::{Location, Snafu};
 
+use crate::adapter::FlowId;
 use crate::expr::EvalError;
 
 /// This error is used to represent all possible errors that can occur in the flow module.
@@ -39,7 +40,11 @@ pub enum Error {
     },
 
     #[snafu(display("Internal error"))]
-    Internal { location: Location, reason: String },
+    Internal {
+        reason: String,
+        #[snafu(implicit)]
+        location: Location,
+    },
 
     /// TODO(discord9): add detailed location of column
     #[snafu(display("Failed to eval stream"))]
@@ -71,6 +76,20 @@ pub enum Error {
         location: Location,
     },
 
+    #[snafu(display("Flow not found, id={id}"))]
+    FlowNotFound {
+        id: FlowId,
+        #[snafu(implicit)]
+        location: Location,
+    },
+
+    #[snafu(display("Flow already exist, id={id}"))]
+    FlowAlreadyExist {
+        id: FlowId,
+        #[snafu(implicit)]
+        location: Location,
+    },
+
     #[snafu(display("Failed to join task"))]
     JoinTask {
         #[snafu(source)]
@@ -168,10 +187,12 @@ impl ErrorExt for Error {
             Self::Eval { .. } | &Self::JoinTask { .. } | &Self::Datafusion { .. } => {
                 StatusCode::Internal
             }
-            &Self::TableAlreadyExist { .. } => StatusCode::TableAlreadyExists,
-            Self::TableNotFound { .. } | Self::TableNotFoundMeta { .. } => {
-                StatusCode::TableNotFound
+            &Self::TableAlreadyExist { .. } | Self::FlowAlreadyExist { .. } => {
+                StatusCode::TableAlreadyExists
             }
+            Self::TableNotFound { .. }
+            | Self::TableNotFoundMeta { .. }
+            | Self::FlowNotFound { .. } => StatusCode::TableNotFound,
             Self::InvalidQueryPlan { .. }
             | Self::InvalidQuerySubstrait { .. }
             | Self::InvalidQueryProst { .. }