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|
//! `GET /admin/document`: the local document as Automerge bytes, for backups and as
//! input to an `import` remake.
//!
//! The whole document is saved: history, and protocol data under `_continuum`. Where
//! it came from is in headers: `X-Continuum-Swarm`, `X-Continuum-Epoch`
//! (`<generation>:<id hex>`) and `X-Continuum-Heads` (hex, comma-separated).
use axum::{
extract::State,
http::{HeaderName, HeaderValue, StatusCode, header},
response::{IntoResponse, Response},
};
use tokio::time::Instant;
use tracing::{info, warn};
use crate::state::AppState;
pub(crate) async fn get_document(State(state): State<AppState>) -> Response {
if !state.is_ready().await {
return (StatusCode::SERVICE_UNAVAILABLE, "node is not ready\n").into_response();
}
let swarm_id = state.swarm_id().await.unwrap_or_default();
let start = Instant::now();
let doc = std::sync::Arc::clone(&state.doc);
// Both steps take time proportional to the document: off the async threads, and
// the lock only for the copy.
let saved = tokio::task::spawn_blocking(move || {
let (mut copy, epoch) = {
let replica = doc.blocking_read();
(replica.doc.clone(), replica.epoch)
};
let heads = copy.get_heads();
(copy.save(), heads, epoch)
})
.await;
let (bytes, heads, epoch) = match saved {
Ok(saved) => saved,
Err(error) => {
warn!(error = %error, "Saving the document for export failed");
return (StatusCode::INTERNAL_SERVER_ERROR, "saving failed\n").into_response();
}
};
let took = start.elapsed();
state.stats.saved_size_measured(bytes.len() as u64, took);
info!(
bytes = bytes.len(),
took_ms = took.as_millis() as u64,
"Exported the document"
);
let heads = heads
.iter()
.map(|head| head.to_string())
.collect::<Vec<_>>()
.join(",");
let filename = format!(
"attachment; filename=\"continuum-{swarm_id}-{}.automerge\"",
epoch.generation
);
let mut response = bytes.into_response();
let headers = response.headers_mut();
let mut set = |name: HeaderName, value: String| {
if let Ok(value) = HeaderValue::from_str(&value) {
headers.insert(name, value);
}
};
set(header::CONTENT_TYPE, "application/octet-stream".to_owned());
set(header::CONTENT_DISPOSITION, filename);
set(HeaderName::from_static("x-continuum-swarm"), swarm_id);
set(
HeaderName::from_static("x-continuum-epoch"),
format!("{}:{}", epoch.generation, epoch.id_hex()),
);
set(HeaderName::from_static("x-continuum-heads"), heads);
response
}
|
