rdkafka/
config.rs

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
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
//! Producer and consumer configuration.
//!
//! ## C library configuration
//!
//! The Rust library will forward all the configuration to the C library. The
//! most frequently used parameters are listed here.
//!
//! ### Frequently used parameters
//!
//! For producer-specific and consumer-specific parameters check the producer
//! and consumer modules documentation. The full list of available parameters is
//! available in the [librdkafka documentation][librdkafka-config].
//!
//! - `client.id`: Client identifier. Default: `rdkafka`.
//! - `bootstrap.servers`: Initial list of brokers as a CSV list of broker host
//!    or host:port. Default: empty.
//! - `message.max.bytes`: Maximum message size. Default: 1000000.
//! - `debug`: A comma-separated list of debug contexts to enable. Use 'all' to
//!    print all the debugging information. Default: empty (off).
//! - `statistics.interval.ms`: how often the statistic callback
//!    specified in the [`ClientContext`] will be called. Default: 0 (disabled).
//!
//! [librdkafka-config]: https://github.com/edenhill/librdkafka/blob/master/CONFIGURATION.md

use std::collections::HashMap;
use std::ffi::{CStr, CString};
use std::iter::FromIterator;
use std::os::raw::c_char;
use std::ptr;

use rdkafka_sys as rdsys;
use rdkafka_sys::types::*;

use crate::client::ClientContext;
use crate::error::{IsError, KafkaError, KafkaResult};
use crate::log::{log_enabled, DEBUG, INFO, WARN};
use crate::util::{ErrBuf, KafkaDrop, NativePtr};

/// The log levels supported by librdkafka.
#[derive(Copy, Clone, Debug)]
pub enum RDKafkaLogLevel {
    /// Higher priority then [`Level::Error`](log::Level::Error) from the log
    /// crate.
    Emerg = 0,
    /// Higher priority then [`Level::Error`](log::Level::Error) from the log
    /// crate.
    Alert = 1,
    /// Higher priority then [`Level::Error`](log::Level::Error) from the log
    /// crate.
    Critical = 2,
    /// Equivalent to [`Level::Error`](log::Level::Error) from the log crate.
    Error = 3,
    /// Equivalent to [`Level::Warn`](log::Level::Warn) from the log crate.
    Warning = 4,
    /// Higher priority then [`Level::Info`](log::Level::Info) from the log
    /// crate.
    Notice = 5,
    /// Equivalent to [`Level::Info`](log::Level::Info) from the log crate.
    Info = 6,
    /// Equivalent to [`Level::Debug`](log::Level::Debug) from the log crate.
    Debug = 7,
}

impl RDKafkaLogLevel {
    pub(crate) fn from_int(level: i32) -> RDKafkaLogLevel {
        match level {
            0 => RDKafkaLogLevel::Emerg,
            1 => RDKafkaLogLevel::Alert,
            2 => RDKafkaLogLevel::Critical,
            3 => RDKafkaLogLevel::Error,
            4 => RDKafkaLogLevel::Warning,
            5 => RDKafkaLogLevel::Notice,
            6 => RDKafkaLogLevel::Info,
            _ => RDKafkaLogLevel::Debug,
        }
    }
}

//
// ********** CLIENT CONFIG **********
//

/// A native rdkafka-sys client config.
pub struct NativeClientConfig {
    ptr: NativePtr<RDKafkaConf>,
}

unsafe impl KafkaDrop for RDKafkaConf {
    const TYPE: &'static str = "client config";
    const DROP: unsafe extern "C" fn(*mut Self) = rdsys::rd_kafka_conf_destroy;
}

impl NativeClientConfig {
    /// Wraps a pointer to an `RDKafkaConfig` object and returns a new `NativeClientConfig`.
    pub(crate) unsafe fn from_ptr(ptr: *mut RDKafkaConf) -> NativeClientConfig {
        NativeClientConfig {
            ptr: NativePtr::from_ptr(ptr).unwrap(),
        }
    }

    /// Returns the pointer to the librdkafka RDKafkaConf structure.
    pub fn ptr(&self) -> *mut RDKafkaConf {
        self.ptr.ptr()
    }

    /// Gets the value of a parameter in the configuration.
    ///
    /// This method reflects librdkafka's view of the current value of the
    /// parameter. If the parameter was overridden by the user, it returns the
    /// user-specified value. Otherwise, it returns librdkafka's default value
    /// for the parameter.
    pub fn get(&self, key: &str) -> KafkaResult<String> {
        let make_err = |res| {
            KafkaError::ClientConfig(
                res,
                match res {
                    RDKafkaConfRes::RD_KAFKA_CONF_UNKNOWN => "Unknown configuration name",
                    RDKafkaConfRes::RD_KAFKA_CONF_INVALID => "Invalid configuration value",
                    RDKafkaConfRes::RD_KAFKA_CONF_OK => "OK",
                }
                .into(),
                key.into(),
                "".into(),
            )
        };
        let key_c = CString::new(key.to_string())?;

        // Call with a `NULL` buffer to determine the size of the string.
        let mut size = 0_usize;
        let res = unsafe {
            rdsys::rd_kafka_conf_get(self.ptr(), key_c.as_ptr(), ptr::null_mut(), &mut size)
        };
        if res.is_error() {
            return Err(make_err(res));
        }

        // Allocate a buffer of that size and call again to get the actual
        // string.
        let mut buf = vec![0_u8; size];
        let res = unsafe {
            rdsys::rd_kafka_conf_get(
                self.ptr(),
                key_c.as_ptr(),
                buf.as_mut_ptr() as *mut c_char,
                &mut size,
            )
        };
        if res.is_error() {
            return Err(make_err(res));
        }

        // Convert the C string to a Rust string.
        Ok(CStr::from_bytes_with_nul(&buf)
            .unwrap()
            .to_string_lossy()
            .into())
    }
}

/// Client configuration.
#[derive(Clone, Debug)]
pub struct ClientConfig {
    conf_map: HashMap<String, String>,
    /// The librdkafka logging level. Refer to [`RDKafkaLogLevel`] for the list
    /// of available levels.
    pub log_level: RDKafkaLogLevel,
}

impl Default for ClientConfig {
    fn default() -> Self {
        Self::new()
    }
}

impl ClientConfig {
    /// Creates a new empty configuration.
    pub fn new() -> ClientConfig {
        ClientConfig {
            conf_map: HashMap::new(),
            log_level: log_level_from_global_config(),
        }
    }

    /// Gets the value of a parameter in the configuration.
    ///
    /// Returns the current value set for `key`, or `None` if no value for `key`
    /// exists.
    ///
    /// Note that this method will only ever return values that were installed
    /// by a call to [`ClientConfig::set`]. To retrieve librdkafka's default
    /// value for a parameter, build a [`NativeClientConfig`] and then call
    /// [`NativeClientConfig::get`] on the resulting object.
    pub fn get(&self, key: &str) -> Option<&str> {
        self.conf_map.get(key).map(|val| val.as_str())
    }

    /// Sets a parameter in the configuration.
    ///
    /// If there is an existing value for `key` in the configuration, it is
    /// overridden with the new `value`.
    pub fn set<K, V>(&mut self, key: K, value: V) -> &mut ClientConfig
    where
        K: Into<String>,
        V: Into<String>,
    {
        self.conf_map.insert(key.into(), value.into());
        self
    }

    /// Removes a parameter from the configuration.
    pub fn remove<'a>(&'a mut self, key: &str) -> &'a mut ClientConfig {
        self.conf_map.remove(key);
        self
    }

    /// Sets the log level of the client. If not specified, the log level will be calculated based
    /// on the global log level of the log crate.
    pub fn set_log_level(&mut self, log_level: RDKafkaLogLevel) -> &mut ClientConfig {
        self.log_level = log_level;
        self
    }

    /// Builds a native librdkafka configuration.
    pub fn create_native_config(&self) -> KafkaResult<NativeClientConfig> {
        let conf = unsafe { NativeClientConfig::from_ptr(rdsys::rd_kafka_conf_new()) };
        let mut err_buf = ErrBuf::new();
        for (key, value) in &self.conf_map {
            let key_c = CString::new(key.to_string())?;
            let value_c = CString::new(value.to_string())?;
            let ret = unsafe {
                rdsys::rd_kafka_conf_set(
                    conf.ptr(),
                    key_c.as_ptr(),
                    value_c.as_ptr(),
                    err_buf.as_mut_ptr(),
                    err_buf.capacity(),
                )
            };
            if ret.is_error() {
                return Err(KafkaError::ClientConfig(
                    ret,
                    err_buf.to_string(),
                    key.to_string(),
                    value.to_string(),
                ));
            }
        }
        Ok(conf)
    }

    /// Uses the current configuration to create a new Consumer or Producer.
    pub fn create<T: FromClientConfig>(&self) -> KafkaResult<T> {
        T::from_config(self)
    }

    /// Uses the current configuration and the provided context to create a new Consumer or Producer.
    pub fn create_with_context<C, T>(&self, context: C) -> KafkaResult<T>
    where
        C: ClientContext,
        T: FromClientConfigAndContext<C>,
    {
        T::from_config_and_context(self, context)
    }
}

impl FromIterator<(String, String)> for ClientConfig {
    fn from_iter<I>(iter: I) -> ClientConfig
    where
        I: IntoIterator<Item = (String, String)>,
    {
        let mut config = ClientConfig::new();
        config.extend(iter);
        config
    }
}

impl Extend<(String, String)> for ClientConfig {
    fn extend<I>(&mut self, iter: I)
    where
        I: IntoIterator<Item = (String, String)>,
    {
        self.conf_map.extend(iter)
    }
}

/// Return the log level
fn log_level_from_global_config() -> RDKafkaLogLevel {
    if log_enabled!(target: "librdkafka", DEBUG) {
        RDKafkaLogLevel::Debug
    } else if log_enabled!(target: "librdkafka", INFO) {
        RDKafkaLogLevel::Info
    } else if log_enabled!(target: "librdkafka", WARN) {
        RDKafkaLogLevel::Warning
    } else {
        RDKafkaLogLevel::Error
    }
}

/// Create a new client based on the provided configuration.
pub trait FromClientConfig: Sized {
    /// Creates a client from a client configuration. The default client context
    /// will be used.
    fn from_config(_: &ClientConfig) -> KafkaResult<Self>;
}

/// Create a new client based on the provided configuration and context.
pub trait FromClientConfigAndContext<C: ClientContext>: Sized {
    /// Creates a client from a client configuration and a client context.
    fn from_config_and_context(_: &ClientConfig, _: C) -> KafkaResult<Self>;
}

#[cfg(test)]
mod tests {
    use super::ClientConfig;

    #[test]
    fn test_client_config_set_map() {
        let mut config: ClientConfig = vec![("a".into(), "1".into()), ("b".into(), "1".into())]
            .into_iter()
            .collect();
        config.extend([("b".into(), "2".into()), ("c".into(), "3".into())]);

        assert_eq!(config.get("a").unwrap(), "1");
        assert_eq!(config.get("b").unwrap(), "2");
        assert_eq!(config.get("c").unwrap(), "3");
    }
}