common_meta/ddl/
flow_meta.rs

1// Copyright 2023 Greptime Team
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use std::sync::Arc;
16
17use crate::error::Result;
18use crate::key::FlowId;
19use crate::peer::{NoopPeerAllocator, Peer, PeerAllocatorRef};
20use crate::sequence::SequenceRef;
21
22/// The reference of [FlowMetadataAllocator].
23pub type FlowMetadataAllocatorRef = Arc<FlowMetadataAllocator>;
24
25/// [FlowMetadataAllocator] provides the ability of:
26/// - [FlowId] Allocation.
27/// - [FlownodeId] Selection.
28#[derive(Clone)]
29pub struct FlowMetadataAllocator {
30    flow_id_sequence: SequenceRef,
31    peer_allocator: PeerAllocatorRef,
32}
33
34impl FlowMetadataAllocator {
35    /// Returns the [FlowMetadataAllocator] with [NoopPeerAllocator].
36    pub fn with_noop_peer_allocator(flow_id_sequence: SequenceRef) -> Self {
37        Self {
38            flow_id_sequence,
39            peer_allocator: Arc::new(NoopPeerAllocator),
40        }
41    }
42
43    pub fn with_peer_allocator(
44        flow_id_sequence: SequenceRef,
45        peer_allocator: PeerAllocatorRef,
46    ) -> Self {
47        Self {
48            flow_id_sequence,
49            peer_allocator,
50        }
51    }
52
53    /// Allocates a the [FlowId].
54    pub(crate) async fn allocate_flow_id(&self) -> Result<FlowId> {
55        let flow_id = self.flow_id_sequence.next().await? as FlowId;
56        Ok(flow_id)
57    }
58
59    /// Allocates the [FlowId] and [Peer]s.
60    pub async fn create(&self, partitions: usize) -> Result<(FlowId, Vec<Peer>)> {
61        let flow_id = self.allocate_flow_id().await?;
62        let peers = self.peer_allocator.alloc(partitions).await?;
63
64        Ok((flow_id, peers))
65    }
66}
common_meta/ddl/flow_meta.rs

common_meta/ddl/
flow_meta.rs
