krafka 0.10.0

A pure Rust, async-native Apache Kafka client
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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259

use bytes::{Buf, BufMut};

use super::{VersionedDecode, VersionedEncode, non_nullable_string};
use crate::error::{ErrorCode, Result};
use crate::protocol::primitives::{Decode, Encode, KafkaString, TaggedFields, TryEncode};
use crate::protocol::{
    array_len_i32, check_compact_array_len, check_decode_array_len, encode_compact_array_len,
};

// ============================================================================
// CreatePartitions API (Key 37)
// ============================================================================

/// CreatePartitions request.
#[derive(Debug, Clone)]
pub struct CreatePartitionsRequest {
    /// Topics to create partitions for.
    pub topics: Vec<CreatePartitionsTopic>,
    /// Timeout in milliseconds.
    pub timeout_ms: i32,
    /// If true, validate the request without actually creating partitions.
    pub validate_only: bool,
}

/// Topic in CreatePartitions request.
#[derive(Debug, Clone)]
pub struct CreatePartitionsTopic {
    /// Topic name.
    pub name: String,
    /// New total partition count.
    pub count: i32,
    /// Assignment of new partitions to brokers.
    pub assignments: Option<Vec<CreatePartitionsAssignment>>,
}

/// Partition assignment in CreatePartitions request.
#[derive(Debug, Clone)]
pub struct CreatePartitionsAssignment {
    /// Broker IDs to assign the partition replicas to.
    pub broker_ids: Vec<i32>,
}

impl CreatePartitionsRequest {
    /// Create a simple partition increase request.
    pub fn new(topic: impl Into<String>, count: i32, timeout: std::time::Duration) -> Self {
        Self {
            topics: vec![CreatePartitionsTopic {
                name: topic.into(),
                count,
                assignments: None,
            }],
            timeout_ms: crate::util::duration_to_millis_i32(timeout),
            validate_only: false,
        }
    }

    /// Encode for version 0–1 (non-flexible).
    pub fn encode_v0(&self, buf: &mut impl BufMut) -> Result<()> {
        // Array of topics
        array_len_i32(self.topics.len())?.encode(buf);
        for topic in &self.topics {
            KafkaString::new(&topic.name).try_encode(buf)?;
            topic.count.encode(buf);

            // Assignments (nullable array)
            match &topic.assignments {
                None => (-1i32).encode(buf),
                Some(assignments) => {
                    array_len_i32(assignments.len())?.encode(buf);
                    for assignment in assignments {
                        array_len_i32(assignment.broker_ids.len())?.encode(buf);
                        for &broker_id in &assignment.broker_ids {
                            broker_id.encode(buf);
                        }
                    }
                }
            }
        }
        self.timeout_ms.encode(buf);
        buf.put_u8(if self.validate_only { 1 } else { 0 });
        Ok(())
    }

    /// Encode for version 2–3 (flexible encoding).
    pub fn encode_v2(&self, buf: &mut impl BufMut) -> Result<()> {
        encode_compact_array_len(self.topics.len(), buf)?;
        for topic in &self.topics {
            KafkaString::new(&topic.name).try_encode_compact(buf)?;
            topic.count.encode(buf);

            // Assignments (nullable compact array)
            match &topic.assignments {
                None => {
                    crate::util::varint::encode_unsigned_varint(0, buf);
                }
                Some(assignments) => {
                    encode_compact_array_len(assignments.len(), buf)?;
                    for assignment in assignments {
                        encode_compact_array_len(assignment.broker_ids.len(), buf)?;
                        for &broker_id in &assignment.broker_ids {
                            broker_id.encode(buf);
                        }
                        TaggedFields::default().try_encode(buf)?;
                    }
                }
            }
            TaggedFields::default().try_encode(buf)?; // per-topic tagged fields
        }
        self.timeout_ms.encode(buf);
        buf.put_u8(if self.validate_only { 1 } else { 0 });
        TaggedFields::default().try_encode(buf)?;
        Ok(())
    }
}

/// CreatePartitions response.
#[derive(Debug, Clone)]
pub struct CreatePartitionsResponse {
    /// Throttle time in milliseconds.
    pub throttle_time_ms: i32,
    /// Results per topic.
    pub results: Vec<CreatePartitionsTopicResult>,
}

/// Result for a topic in CreatePartitions response.
#[derive(Debug, Clone)]
pub struct CreatePartitionsTopicResult {
    /// Topic name.
    pub name: String,
    /// Error code.
    pub error_code: ErrorCode,
    /// Error message.
    pub error_message: Option<String>,
}

impl CreatePartitionsResponse {
    /// Decode from version 0–1 (non-flexible).
    pub fn decode_v0(buf: &mut impl Buf) -> Result<Self> {
        let throttle_time_ms = i32::decode(buf)?;
        let result_count = check_decode_array_len(i32::decode(buf)?)?;
        let mut results = Vec::with_capacity(result_count);

        for _ in 0..result_count {
            let name = non_nullable_string("topic name", KafkaString::decode(buf)?.0)?;
            let error_code = ErrorCode::from_i16(i16::decode(buf)?);
            let error_message = KafkaString::decode(buf)?.0;

            results.push(CreatePartitionsTopicResult {
                name,
                error_code,
                error_message,
            });
        }

        Ok(Self {
            throttle_time_ms,
            results,
        })
    }

    /// Decode from version 2–3 (flexible encoding).
    pub fn decode_v2(buf: &mut impl Buf) -> Result<Self> {
        let throttle_time_ms = i32::decode(buf)?;
        let raw = crate::util::varint::decode_unsigned_varint(buf)?;
        let result_count = check_compact_array_len(raw)?;
        let mut results = Vec::with_capacity(result_count);

        for _ in 0..result_count {
            let name = non_nullable_string("topic name", KafkaString::decode_compact(buf)?.0)?;
            let error_code = ErrorCode::from_i16(i16::decode(buf)?);
            let error_message = KafkaString::decode_compact(buf)?.0;
            TaggedFields::decode(buf)?; // per-result tagged fields

            results.push(CreatePartitionsTopicResult {
                name,
                error_code,
                error_message,
            });
        }

        TaggedFields::decode(buf)?; // top-level tagged fields
        Ok(Self {
            throttle_time_ms,
            results,
        })
    }
}

impl VersionedEncode for CreatePartitionsRequest {
    fn encode_versioned(&self, version: i16, buf: &mut impl BufMut) -> Result<()> {
        match version {
            0 | 1 => self.encode_v0(buf)?,
            2 | 3 => self.encode_v2(buf)?,
            _ => return unsupported_encode!("CreatePartitionsRequest", version),
        }
        Ok(())
    }
}

impl VersionedDecode for CreatePartitionsResponse {
    fn decode_versioned(version: i16, buf: &mut impl Buf) -> Result<Self> {
        match version {
            0 | 1 => Self::decode_v0(buf),
            2 | 3 => Self::decode_v2(buf),
            _ => unsupported_decode!("CreatePartitionsResponse", version),
        }
    }
}

#[cfg(test)]
#[allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
mod tests {
    use super::*;

    use bytes::BytesMut;

    #[test]
    fn test_create_partitions_v1_same_as_v0() {
        let request = CreatePartitionsRequest::new("test", 6, std::time::Duration::from_secs(30));
        let mut v0 = BytesMut::new();
        request.encode_versioned(0, &mut v0).unwrap();
        let mut v1 = BytesMut::new();
        request.encode_versioned(1, &mut v1).unwrap();
        assert_eq!(v0, v1);
    }

    #[test]
    fn test_create_partitions_v2_flexible() {
        let request = CreatePartitionsRequest::new("test", 6, std::time::Duration::from_secs(30));
        let mut v0 = BytesMut::new();
        request.encode_v0(&mut v0).unwrap();
        let mut v2 = BytesMut::new();
        request.encode_v2(&mut v2).unwrap();
        assert_ne!(v0.len(), v2.len());
        // v2 and v3 same wire
        let mut v3 = BytesMut::new();
        request.encode_versioned(3, &mut v3).unwrap();
        assert_eq!(v2, v3);
    }

    #[test]
    fn test_create_partitions_response_v2_roundtrip() {
        let mut buf = BytesMut::new();
        buf.put_i32(0); // throttle_time_ms
        buf.put_u8(2); // results: compact array count=1+1=2
        buf.put_u8(5); // name: compact string "test"
        buf.put_slice(b"test");
        buf.put_i16(0); // error_code
        buf.put_u8(0); // error_message: compact null
        buf.put_u8(0); // per-result tagged fields
        buf.put_u8(0); // top-level tagged fields

        let mut frozen = buf.freeze();
        let resp = CreatePartitionsResponse::decode_v2(&mut frozen).unwrap();
        assert_eq!(resp.results.len(), 1);
        assert_eq!(resp.results[0].name, "test");
        assert!(resp.results[0].error_code.is_ok());
    }
}