eventdbx 1.14.2

An event-sourced, key-value, write-side database system.
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
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
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
use std::{
    collections::BTreeMap,
    env,
    path::{Path, PathBuf},
    process::Stdio,
    sync::Arc,
};

use anyhow::{Context, Result, anyhow};
use capnp::message::ReaderOptions;
use capnp::serialize::{OwnedSegments, write_message_to_words};
use capnp_futures::serialize::{read_message, try_read_message};
use futures::AsyncWriteExt;
use serde_json::{self, Value};
use tokio::{
    net::{TcpListener, TcpStream},
    process::Command,
    task::JoinHandle,
};
use tokio_util::compat::{TokioAsyncReadCompatExt, TokioAsyncWriteCompatExt};
use tracing::{debug, info, warn};

use crate::{
    cli_capnp::{cli_request, cli_response},
    replication_capnp::{
        replication_hello, replication_hello_response, replication_request, replication_response,
    },
    replication_capnp_client::REPLICATION_PROTOCOL_VERSION,
    schema::{AggregateSchema, SchemaManager},
    store::{AggregatePositionEntry, EventMetadata, EventRecord, EventStore},
};

#[derive(Debug, Clone)]
pub struct CliCommandResult {
    pub exit_code: i32,
    pub stdout: String,
    pub stderr: String,
}

struct SerializedEvent {
    aggregate_type: String,
    aggregate_id: String,
    event_type: String,
    version: u64,
    merkle_root: String,
    hash: String,
    payload: Vec<u8>,
    metadata: Vec<u8>,
}

enum ReplicationReply {
    Positions(Vec<AggregatePositionEntry>),
    Events(Vec<SerializedEvent>),
    ApplyEvents { applied_sequence: u64 },
    PullSchemas { schemas_json: Vec<u8> },
    ApplySchemas { aggregate_count: u32 },
}

pub async fn start(
    bind_addr: &str,
    config_path: Arc<PathBuf>,
    store: Arc<EventStore>,
    schemas: Arc<SchemaManager>,
    local_public_key: Arc<Vec<u8>>,
) -> Result<JoinHandle<()>> {
    let listener = TcpListener::bind(bind_addr)
        .await
        .with_context(|| format!("failed to bind CLI Cap'n Proto listener on {bind_addr}"))?;
    let display_addr = listener
        .local_addr()
        .map(|addr| addr.to_string())
        .unwrap_or_else(|_| bind_addr.to_string());
    info!("CLI Cap'n Proto server listening on {}", display_addr);

    let handle = tokio::spawn(async move {
        if let Err(err) = serve(listener, config_path, store, schemas, local_public_key).await {
            warn!("CLI proxy server terminated: {err:?}");
        }
    });
    Ok(handle)
}

async fn serve(
    listener: TcpListener,
    config_path: Arc<PathBuf>,
    store: Arc<EventStore>,
    schemas: Arc<SchemaManager>,
    local_public_key: Arc<Vec<u8>>,
) -> Result<()> {
    loop {
        let (stream, peer) = listener
            .accept()
            .await
            .context("failed to accept CLI proxy connection")?;
        let config_path = Arc::clone(&config_path);
        let store = Arc::clone(&store);
        let schemas = Arc::clone(&schemas);
        let local_public_key = Arc::clone(&local_public_key);
        tokio::spawn(async move {
            if let Err(err) =
                handle_connection(stream, config_path, store, schemas, local_public_key).await
            {
                warn!(target: "cli_proxy", peer = %peer, "CLI proxy connection error: {err:?}");
            }
        });
    }
}

async fn handle_connection(
    stream: TcpStream,
    config_path: Arc<PathBuf>,
    store: Arc<EventStore>,
    schemas: Arc<SchemaManager>,
    local_public_key: Arc<Vec<u8>>,
) -> Result<()> {
    let (reader, writer) = stream.into_split();
    let mut reader = reader.compat();
    let mut writer = writer.compat_write();

    let first_message = match try_read_message(&mut reader, ReaderOptions::new()).await {
        Ok(Some(message)) => message,
        Ok(None) => return Ok(()),
        Err(err) => {
            return Err(anyhow::Error::new(err).context("failed to read initial message"));
        }
    };

    let is_cli_request = first_message
        .get_root::<cli_request::Reader>()
        .and_then(|request| request.get_args())
        .is_ok();

    if is_cli_request {
        handle_cli_loop(
            Some(first_message),
            &mut reader,
            &mut writer,
            Arc::clone(&config_path),
        )
        .await?;
    } else {
        handle_replication_session(
            first_message,
            &mut reader,
            &mut writer,
            store,
            schemas,
            local_public_key,
        )
        .await?;
    }

    Ok(())
}

async fn handle_cli_loop<R, W>(
    mut pending: Option<capnp::message::Reader<OwnedSegments>>,
    reader: &mut R,
    writer: &mut W,
    config_path: Arc<PathBuf>,
) -> Result<()>
where
    R: futures::AsyncRead + Unpin,
    W: futures::AsyncWrite + Unpin,
{
    loop {
        let message = if let Some(message) = pending.take() {
            message
        } else {
            match try_read_message(&mut *reader, ReaderOptions::new()).await {
                Ok(Some(message)) => message,
                Ok(None) => break,
                Err(err) => {
                    return Err(anyhow::Error::new(err).context("failed to read CLI request"));
                }
            }
        };

        let response_result = process_request(message, Arc::clone(&config_path)).await;

        let response_bytes = {
            let mut response_message = capnp::message::Builder::new_default();
            {
                let mut response = response_message.init_root::<cli_response::Builder>();
                match response_result {
                    Ok(result) => {
                        response.set_exit_code(result.exit_code);
                        response.set_stdout(&result.stdout);
                        response.set_stderr(&result.stderr);
                    }
                    Err(err) => {
                        response.set_exit_code(-1);
                        response.set_stdout("");
                        response.set_stderr(&err.to_string());
                    }
                }
            }
            write_message_to_words(&response_message)
        };

        writer
            .write_all(&response_bytes)
            .await
            .context("failed to write CLI response")?;
        writer
            .flush()
            .await
            .context("failed to flush CLI response")?;
    }

    Ok(())
}

async fn handle_replication_session<R, W>(
    first_message: capnp::message::Reader<OwnedSegments>,
    reader: &mut R,
    writer: &mut W,
    store: Arc<EventStore>,
    schemas: Arc<SchemaManager>,
    local_public_key: Arc<Vec<u8>>,
) -> Result<()>
where
    R: futures::AsyncRead + Unpin,
    W: futures::AsyncWrite + Unpin,
{
    let hello = first_message
        .get_root::<replication_hello::Reader>()
        .context("failed to decode replication hello")?;
    let protocol_version = hello.get_protocol_version();
    let expected_key = hello
        .get_expected_public_key()
        .map_err(|err| anyhow!("failed to read handshake public key: {err}"))?
        .to_vec();

    let (accepted, response_text) = if protocol_version != REPLICATION_PROTOCOL_VERSION {
        (
            false,
            format!(
                "unsupported replication protocol version {}",
                protocol_version
            ),
        )
    } else if expected_key.is_empty() {
        (
            false,
            "missing expected public key in replication handshake".to_string(),
        )
    } else if expected_key != *local_public_key {
        warn!("replication handshake rejected due to pinned key mismatch");
        (false, "pinned public key mismatch".to_string())
    } else {
        (true, "ok".to_string())
    };

    let handshake_bytes = {
        let mut response_message = capnp::message::Builder::new_default();
        {
            let mut response = response_message.init_root::<replication_hello_response::Builder>();
            response.set_accepted(accepted);
            response.set_message(&response_text);
        }
        write_message_to_words(&response_message)
    };

    writer
        .write_all(&handshake_bytes)
        .await
        .context("failed to write replication hello response")?;
    writer
        .flush()
        .await
        .context("failed to flush replication hello response")?;

    if !accepted {
        return Ok(());
    }

    let store = Arc::clone(&store);
    let schemas = Arc::clone(&schemas);
    let mut last_sequence = 0u64;

    loop {
        let message = match try_read_message(&mut *reader, ReaderOptions::new()).await {
            Ok(Some(message)) => message,
            Ok(None) => break,
            Err(err) => {
                return Err(anyhow::Error::new(err).context("failed to read replication request"));
            }
        };

        let response_bytes = {
            let mut response_message = capnp::message::Builder::new_default();
            let mut response_root = response_message.init_root::<replication_response::Builder>();

            let result = message
                .get_root::<replication_request::Reader>()
                .map_err(|err| anyhow!("failed to decode replication request: {err}"))
                .and_then(|request| {
                    process_replication_request(request, &store, &schemas, &mut last_sequence)
                })
                .and_then(|reply| populate_replication_response(&mut response_root, reply));

            if let Err(err) = result {
                let mut error = response_root.init_error();
                error.set_message(&err.to_string());
            }

            write_message_to_words(&response_message)
        };
        writer
            .write_all(&response_bytes)
            .await
            .context("failed to write replication response")?;
        writer
            .flush()
            .await
            .context("failed to flush replication response")?;
    }

    Ok(())
}

fn process_replication_request(
    request: replication_request::Reader<'_>,
    store: &EventStore,
    schemas: &SchemaManager,
    last_sequence: &mut u64,
) -> Result<ReplicationReply> {
    use replication_request::Which;

    match request.which()? {
        Which::ListPositions(()) => {
            let positions = store.aggregate_positions()?;
            Ok(ReplicationReply::Positions(positions))
        }
        Which::PullEvents(req) => {
            let req = req.map_err(|err| anyhow!("failed to read pullEvents request: {err}"))?;
            let aggregate_type = read_text_field(req.get_aggregate_type(), "aggregate type")?;
            let aggregate_id = read_text_field(req.get_aggregate_id(), "aggregate id")?;
            let from_version = req.get_from_version();
            let limit = req.get_limit();
            let limit = if limit == 0 {
                None
            } else {
                Some(limit as usize)
            };

            let events = store.events_after(&aggregate_type, &aggregate_id, from_version, limit)?;
            let mut serialized = Vec::with_capacity(events.len());
            for event in events {
                let payload = serde_json::to_vec(&event.payload)
                    .map_err(|err| anyhow!("failed to encode event payload: {err}"))?;
                let metadata = serde_json::to_vec(&event.metadata)
                    .map_err(|err| anyhow!("failed to encode event metadata: {err}"))?;
                serialized.push(SerializedEvent {
                    aggregate_type: event.aggregate_type,
                    aggregate_id: event.aggregate_id,
                    event_type: event.event_type,
                    version: event.version,
                    merkle_root: event.merkle_root,
                    hash: event.hash,
                    payload,
                    metadata,
                });
            }

            Ok(ReplicationReply::Events(serialized))
        }
        Which::ApplyEvents(req) => {
            let req = req.map_err(|err| anyhow!("failed to read applyEvents request: {err}"))?;
            let sequence = req.get_sequence();
            let events = req
                .get_events()
                .map_err(|err| anyhow!("failed to access applyEvents list: {err}"))?;

            for event_reader in events.iter() {
                let record = decode_capnp_event(event_reader)?;
                store.append_replica(record)?;
            }

            *last_sequence = sequence;
            Ok(ReplicationReply::ApplyEvents {
                applied_sequence: *last_sequence,
            })
        }
        Which::PullSchemas(()) => {
            let snapshot = schemas.snapshot();
            let payload = serde_json::to_vec(&snapshot)
                .map_err(|err| anyhow!("failed to encode schema snapshot: {err}"))?;
            Ok(ReplicationReply::PullSchemas {
                schemas_json: payload,
            })
        }
        Which::ApplySchemas(req) => {
            let req = req.map_err(|err| anyhow!("failed to read applySchemas request: {err}"))?;
            let data = req
                .get_schemas_json()
                .map_err(|err| anyhow!("failed to read applySchemas payload: {err}"))?;
            let map: BTreeMap<String, AggregateSchema> = if data.is_empty() {
                BTreeMap::new()
            } else {
                serde_json::from_slice(data)
                    .map_err(|err| anyhow!("failed to decode schema payload: {err}"))?
            };

            let aggregate_count = map.len() as u32;
            schemas
                .replace_all(map)
                .map_err(|err| anyhow!("failed to apply schema updates: {err}"))?;
            Ok(ReplicationReply::ApplySchemas { aggregate_count })
        }
    }
}

fn populate_replication_response(
    response: &mut replication_response::Builder<'_>,
    payload: ReplicationReply,
) -> Result<()> {
    match payload {
        ReplicationReply::Positions(positions) => {
            let mut list = response.reborrow().init_list_positions();
            let mut builder = list.reborrow().init_positions(positions.len() as u32);
            for (idx, entry) in positions.into_iter().enumerate() {
                let mut position = builder.reborrow().get(idx as u32);
                position.set_aggregate_type(&entry.aggregate_type);
                position.set_aggregate_id(&entry.aggregate_id);
                position.set_version(entry.version);
            }
        }
        ReplicationReply::Events(events) => {
            let mut pull = response.reborrow().init_pull_events();
            let mut builder = pull.reborrow().init_events(events.len() as u32);
            for (idx, event) in events.into_iter().enumerate() {
                let mut record = builder.reborrow().get(idx as u32);
                record.set_aggregate_type(&event.aggregate_type);
                record.set_aggregate_id(&event.aggregate_id);
                record.set_event_type(&event.event_type);
                record.set_version(event.version);
                record.set_merkle_root(&event.merkle_root);
                record.set_hash(&event.hash);
                record.set_payload(&event.payload);
                record.set_metadata(&event.metadata);
            }
        }
        ReplicationReply::ApplyEvents { applied_sequence } => {
            let mut apply = response.reborrow().init_apply_events();
            apply.set_applied_sequence(applied_sequence);
        }
        ReplicationReply::PullSchemas { schemas_json } => {
            let mut pull = response.reborrow().init_pull_schemas();
            pull.set_schemas_json(&schemas_json);
        }
        ReplicationReply::ApplySchemas { aggregate_count } => {
            let mut apply = response.reborrow().init_apply_schemas();
            apply.set_aggregate_count(aggregate_count);
        }
    }
    Ok(())
}

fn decode_capnp_event(
    reader: crate::replication_capnp::event_record::Reader<'_>,
) -> Result<EventRecord> {
    let aggregate_type = read_text_field(reader.get_aggregate_type(), "event aggregate type")?;
    let aggregate_id = read_text_field(reader.get_aggregate_id(), "event aggregate id")?;
    let event_type = read_text_field(reader.get_event_type(), "event type")?;
    let version = reader.get_version();
    let merkle_root = read_text_field(reader.get_merkle_root(), "event merkle root")?;
    let hash = read_text_field(reader.get_hash(), "event hash")?;
    let payload_bytes = reader
        .get_payload()
        .map_err(|err| anyhow!("failed to read event payload: {err}"))?;
    let metadata_bytes = reader
        .get_metadata()
        .map_err(|err| anyhow!("failed to read event metadata: {err}"))?;

    let payload: Value = serde_json::from_slice(payload_bytes)
        .map_err(|err| anyhow!("failed to decode event payload: {err}"))?;
    let metadata: EventMetadata = serde_json::from_slice(metadata_bytes)
        .map_err(|err| anyhow!("failed to decode event metadata: {err}"))?;

    Ok(EventRecord {
        aggregate_type,
        aggregate_id,
        event_type,
        payload,
        metadata,
        version,
        hash,
        merkle_root,
    })
}

fn read_text_field(value: capnp::Result<capnp::text::Reader<'_>>, field: &str) -> Result<String> {
    let reader = value.map_err(|err| anyhow!("failed to read {field}: {err}"))?;
    reader
        .to_str()
        .map_err(|err| anyhow!("invalid UTF-8 in {field}: {err}"))
        .map(|s| s.to_string())
}

async fn process_request(
    message: capnp::message::Reader<OwnedSegments>,
    config_path: Arc<PathBuf>,
) -> Result<CliCommandResult> {
    let request = message
        .get_root::<cli_request::Reader>()
        .context("failed to decode CLI request")?;
    let args = {
        let args_reader = request
            .get_args()
            .context("failed to read CLI request arguments")?;

        let mut collected = Vec::with_capacity(args_reader.len() as usize);
        for arg in args_reader.iter() {
            let value = arg.context("failed to read CLI argument")?;
            collected.push(value.to_string()?);
        }
        collected
    };

    execute_cli_command(args, &config_path).await
}

async fn execute_cli_command(args: Vec<String>, config_path: &PathBuf) -> Result<CliCommandResult> {
    let exe = resolve_cli_executable().context("failed to resolve CLI executable")?;

    let final_args = augment_args_with_config(args, config_path);

    let mut command = Command::new(exe);
    command.args(&final_args);
    command.stdout(Stdio::piped());
    command.stderr(Stdio::piped());

    let output = command
        .output()
        .await
        .context("failed to execute CLI command")?;

    let exit_code = output
        .status
        .code()
        .unwrap_or_else(|| if output.status.success() { 0 } else { -1 });

    let stdout = String::from_utf8_lossy(&output.stdout).into_owned();
    let stderr = String::from_utf8_lossy(&output.stderr).into_owned();

    debug!(
        target: "cli_proxy",
        args = ?final_args,
        exit_code,
        "CLI command executed"
    );

    Ok(CliCommandResult {
        exit_code,
        stdout,
        stderr,
    })
}

fn resolve_cli_executable() -> Result<PathBuf> {
    if let Ok(path) = env::var("EVENTDBX_CLI") {
        return Ok(PathBuf::from(path));
    }
    if let Ok(path) = env::var("CARGO_BIN_EXE_eventdbx") {
        return Ok(PathBuf::from(path));
    }
    let current = std::env::current_exe().context("failed to resolve current executable")?;
    if let Some(dir) = current.parent() {
        if let Some(candidate) = probe_dir_for_cli(dir) {
            return Ok(candidate);
        }
        if let Some(parent) = dir.parent() {
            if let Some(candidate) = probe_dir_for_cli(parent) {
                return Ok(candidate);
            }
        }
    }
    Ok(current)
}

fn probe_dir_for_cli(dir: &Path) -> Option<PathBuf> {
    let unix_path = dir.join("eventdbx");
    if unix_path.exists() {
        return Some(unix_path);
    }
    #[cfg(windows)]
    {
        let windows_path = dir.join("eventdbx.exe");
        if windows_path.exists() {
            return Some(windows_path);
        }
    }
    None
}

fn augment_args_with_config(mut args: Vec<String>, config_path: &PathBuf) -> Vec<String> {
    if has_config_arg(&args) {
        return args;
    }

    let mut final_args = Vec::with_capacity(args.len() + 2);
    final_args.push("--config".to_string());
    final_args.push(config_path.to_string_lossy().into_owned());
    final_args.extend(args.drain(..));
    final_args
}

fn has_config_arg(args: &[String]) -> bool {
    args.iter()
        .any(|arg| arg == "--config" || arg.starts_with("--config="))
}

pub async fn invoke(args: &[String], addr: &str) -> Result<CliCommandResult> {
    let stream = TcpStream::connect(addr)
        .await
        .with_context(|| format!("failed to connect to CLI proxy at {addr}"))?;
    let (reader, writer) = stream.into_split();
    let mut writer = writer.compat_write();
    let message_bytes = {
        let mut message = capnp::message::Builder::new_default();
        {
            let mut request = message.init_root::<cli_request::Builder>();
            let mut list = request.init_args(args.len() as u32);
            for (idx, arg) in args.iter().enumerate() {
                list.set(idx as u32, arg);
            }
        }
        write_message_to_words(&message)
    };

    writer
        .write_all(&message_bytes)
        .await
        .context("failed to send CLI request")?;
    writer
        .flush()
        .await
        .context("failed to flush CLI request")?;

    let mut reader = reader.compat();
    let response_message = read_message(&mut reader, ReaderOptions::new())
        .await
        .context("failed to read CLI response")?;
    let response = response_message
        .get_root::<cli_response::Reader>()
        .context("failed to decode CLI response")?;

    let stdout = response
        .get_stdout()
        .context("missing stdout field in CLI response")?
        .to_string()
        .map_err(|err| anyhow::Error::new(err).context("invalid UTF-8 in CLI stdout"))?;
    let stderr = response
        .get_stderr()
        .context("missing stderr field in CLI response")?
        .to_string()
        .map_err(|err| anyhow::Error::new(err).context("invalid UTF-8 in CLI stderr"))?;

    Ok(CliCommandResult {
        exit_code: response.get_exit_code(),
        stdout,
        stderr,
    })
}