kafka-api 0.4.1

Manual implementation of Apache Kafka API in Rust.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206

// Copyright 2024 tison <wander4096@gmail.com>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::io::Cursor;

use byteorder::BigEndian;
use byteorder::ReadBytesExt;
use byteorder::WriteBytesExt;

use crate::codec::Decodable;
use crate::codec::Encodable;
use crate::codec::Encoder;
use crate::codec::Int32;
use crate::schemata::apikey::ApiMessageType;
use crate::schemata::request_header::RequestHeader;
use crate::schemata::response_header::ResponseHeader;
use crate::IoResult;

pub mod apikey;
#[allow(dead_code)]
pub mod error;

pub mod api_versions_request;
pub mod api_versions_response;
pub mod create_topic_request;
pub mod create_topic_response;
pub mod fetch_request;
pub mod fetch_response;
pub mod find_coordinator_request;
pub mod find_coordinator_response;
pub mod heartbeat_request;
pub mod heartbeat_response;
pub mod init_producer_id_request;
pub mod init_producer_id_response;
pub mod join_group_request;
pub mod join_group_response;
pub mod metadata_request;
pub mod metadata_response;
pub mod offset_fetch_request;
pub mod offset_fetch_response;
pub mod produce_request;
pub mod produce_response;
pub mod request_header;
pub mod response_header;
pub mod sync_group_request;
pub mod sync_group_response;

#[derive(Debug)]
pub enum Request {
    ApiVersionsRequest(api_versions_request::ApiVersionsRequest),
    CreateTopicRequest(create_topic_request::CreateTopicsRequest),
    FetchRequest(fetch_request::FetchRequest),
    FindCoordinatorRequest(find_coordinator_request::FindCoordinatorRequest),
    HeartbeatRequest(heartbeat_request::HeartbeatRequest),
    InitProducerIdRequest(init_producer_id_request::InitProducerIdRequest),
    JoinGroupRequest(join_group_request::JoinGroupRequest),
    MetadataRequest(metadata_request::MetadataRequest),
    OffsetFetchRequest(offset_fetch_request::OffsetFetchRequest),
    ProduceRequest(produce_request::ProduceRequest),
    SyncGroupRequest(sync_group_request::SyncGroupRequest),
}

impl Request {
    pub fn decode<T: AsRef<[u8]>>(buf: &mut Cursor<T>) -> IoResult<(RequestHeader, Request)> {
        let header_version = {
            let pos = buf.position();
            let api_key = buf.read_i16::<BigEndian>()?;
            let api_version = buf.read_i16::<BigEndian>()?;
            buf.set_position(pos);
            ApiMessageType::try_from(api_key)?.request_header_version(api_version)
        };

        let header = RequestHeader::read(buf, header_version)?;
        let api_type = ApiMessageType::try_from(header.request_api_key)?;
        let api_version = header.request_api_version;

        let request = match api_type {
            ApiMessageType::API_VERSIONS => {
                api_versions_request::ApiVersionsRequest::read(buf, api_version)
                    .map(Request::ApiVersionsRequest)
            }
            ApiMessageType::CREATE_TOPICS => {
                create_topic_request::CreateTopicsRequest::read(buf, api_version)
                    .map(Request::CreateTopicRequest)
            }
            ApiMessageType::FETCH => {
                fetch_request::FetchRequest::read(buf, api_version).map(Request::FetchRequest)
            }
            ApiMessageType::FIND_COORDINATOR => {
                find_coordinator_request::FindCoordinatorRequest::read(buf, api_version)
                    .map(Request::FindCoordinatorRequest)
            }
            ApiMessageType::INIT_PRODUCER_ID => {
                init_producer_id_request::InitProducerIdRequest::read(buf, api_version)
                    .map(Request::InitProducerIdRequest)
            }
            ApiMessageType::JOIN_GROUP => {
                join_group_request::JoinGroupRequest::read(buf, api_version)
                    .map(Request::JoinGroupRequest)
            }
            ApiMessageType::HEARTBEAT => {
                heartbeat_request::HeartbeatRequest::read(buf, api_version)
                    .map(Request::HeartbeatRequest)
            }
            ApiMessageType::METADATA => metadata_request::MetadataRequest::read(buf, api_version)
                .map(Request::MetadataRequest),
            ApiMessageType::OFFSET_FETCH => {
                offset_fetch_request::OffsetFetchRequest::read(buf, api_version)
                    .map(Request::OffsetFetchRequest)
            }
            ApiMessageType::PRODUCE => {
                produce_request::ProduceRequest::read(buf, api_version).map(Request::ProduceRequest)
            }
            ApiMessageType::SYNC_GROUP => {
                sync_group_request::SyncGroupRequest::read(buf, api_version)
                    .map(Request::SyncGroupRequest)
            }
            api_type => unreachable!("unknown api type {}", api_type),
        }?;

        Ok((header, request))
    }
}

#[derive(Debug)]
pub enum Response {
    ApiVersionsResponse(api_versions_response::ApiVersionsResponse),
    CreateTopicsResponse(create_topic_response::CreateTopicsResponse),
    FindCoordinatorResponse(find_coordinator_response::FindCoordinatorResponse),
    FetchResponse(fetch_response::FetchResponse),
    HeartbeatResponse(heartbeat_response::HeartbeatResponse),
    InitProducerIdResponse(init_producer_id_response::InitProducerIdResponse),
    JoinGroupResponse(join_group_response::JoinGroupResponse),
    MetadataResponse(metadata_response::MetadataResponse),
    OffsetFetchResponse(offset_fetch_response::OffsetFetchResponse),
    ProduceResponse(produce_response::ProduceResponse),
    SyncGroupResponse(sync_group_response::SyncGroupResponse),
}

impl Response {
    pub fn encode<B: WriteBytesExt>(&self, header: RequestHeader, buf: &mut B) -> IoResult<()> {
        let api_type = ApiMessageType::try_from(header.request_api_key)?;
        let api_version = header.request_api_version;
        let correlation_id = header.correlation_id;

        let response_header_version = api_type.response_header_version(api_version);
        let response_header = ResponseHeader {
            correlation_id,
            unknown_tagged_fields: vec![],
        };

        // 1. total size
        let size = self.calculate_size(api_version)
            + response_header.calculate_size(response_header_version);
        Int32.encode(buf, size as i32)?;

        // 2. response header
        response_header.write(buf, response_header_version)?;

        // 3. response body
        self.do_encode(buf, api_version)
    }

    fn calculate_size(&self, version: i16) -> usize {
        match self {
            Response::ApiVersionsResponse(resp) => resp.calculate_size(version),
            Response::CreateTopicsResponse(resp) => resp.calculate_size(version),
            Response::FindCoordinatorResponse(resp) => resp.calculate_size(version),
            Response::FetchResponse(resp) => resp.calculate_size(version),
            Response::HeartbeatResponse(resp) => resp.calculate_size(version),
            Response::InitProducerIdResponse(resp) => resp.calculate_size(version),
            Response::JoinGroupResponse(resp) => resp.calculate_size(version),
            Response::MetadataResponse(resp) => resp.calculate_size(version),
            Response::OffsetFetchResponse(resp) => resp.calculate_size(version),
            Response::ProduceResponse(resp) => resp.calculate_size(version),
            Response::SyncGroupResponse(resp) => resp.calculate_size(version),
        }
    }

    fn do_encode<B: WriteBytesExt>(&self, buf: &mut B, version: i16) -> IoResult<()> {
        match self {
            Response::ApiVersionsResponse(resp) => resp.write(buf, version),
            Response::CreateTopicsResponse(resp) => resp.write(buf, version),
            Response::FindCoordinatorResponse(resp) => resp.write(buf, version),
            Response::FetchResponse(resp) => resp.write(buf, version),
            Response::HeartbeatResponse(resp) => resp.write(buf, version),
            Response::InitProducerIdResponse(resp) => resp.write(buf, version),
            Response::JoinGroupResponse(resp) => resp.write(buf, version),
            Response::MetadataResponse(resp) => resp.write(buf, version),
            Response::OffsetFetchResponse(resp) => resp.write(buf, version),
            Response::ProduceResponse(resp) => resp.write(buf, version),
            Response::SyncGroupResponse(resp) => resp.write(buf, version),
        }
    }
}