durable_streams_server/transfer/
format.rs

1//! Serialisable types for the durable-streams export/import JSON format.
2//!
3//! The top-level [`ExportDocument`] wraps a versioned envelope around a list
4//! of [`ExportedStream`] entries, each containing stream metadata and the
5//! full message payload (base64-encoded for binary safety).
6
7use crate::storage::StreamConfig;
8use chrono::{DateTime, Utc};
9use serde::{Deserialize, Serialize};
10
11/// Current format version written by [`super::export::export_streams`].
12pub const FORMAT_VERSION: u32 = 1;
13
14/// Top-level envelope for an export/import JSON file.
15///
16/// The `format_version` field enables forward-compatible schema evolution:
17/// readers reject versions they do not understand.
18#[derive(Debug, Serialize, Deserialize)]
19pub struct ExportDocument {
20    /// Schema version (currently [`FORMAT_VERSION`]).
21    pub format_version: u32,
22    /// Timestamp when the export was created.
23    pub exported_at: DateTime<Utc>,
24    /// Server crate version that produced the export.
25    pub server_version: String,
26    /// Exported streams with their messages.
27    pub streams: Vec<ExportedStream>,
28}
29
30/// A single stream and all its messages within an [`ExportDocument`].
31#[derive(Debug, Serialize, Deserialize)]
32pub struct ExportedStream {
33    /// Stream name (path-style, e.g. `"events/clicks"`).
34    pub name: String,
35    /// Immutable configuration captured at create time.
36    pub config: StreamConfig,
37    /// Whether the stream was closed at export time.
38    pub closed: bool,
39    /// When the stream was originally created.
40    pub created_at: DateTime<Utc>,
41    /// When the stream was last modified (`None` for legacy data).
42    #[serde(default)]
43    pub updated_at: Option<DateTime<Utc>>,
44    /// Total payload bytes across all messages.
45    pub total_bytes: u64,
46    /// Number of messages in the stream.
47    pub message_count: u64,
48    /// Canonical next-offset string for reference; import generates fresh
49    /// offsets so this is informational only.
50    pub next_offset: String,
51    /// Ordered list of messages with base64-encoded payloads.
52    pub messages: Vec<ExportedMessage>,
53}
54
55/// A single message within an [`ExportedStream`].
56#[derive(Debug, Serialize, Deserialize)]
57pub struct ExportedMessage {
58    /// Original offset at export time (informational; import assigns new offsets).
59    pub offset: String,
60    /// Standard base64-encoded message payload.
61    pub data_base64: String,
62}
durable_streams_server/transfer/format.rs

durable_streams_server/transfer/
format.rs
