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|
use super::RenderError;
use crate::{
blobservice::BlobService,
directoryservice::DirectoryService,
proto::{self, NamedNode},
};
use count_write::CountWrite;
use nix_compat::nar;
use sha2::{Digest, Sha256};
use std::{
io::{self, BufReader},
sync::Arc,
};
use tracing::warn;
/// Invoke [write_nar], and return the size and sha256 digest of the produced
/// NAR output.
pub fn calculate_size_and_sha256(
root_node: &proto::node::Node,
blob_service: Arc<dyn BlobService>,
directory_service: Arc<dyn DirectoryService>,
) -> Result<(u64, [u8; 32]), RenderError> {
let h = Sha256::new();
let mut cw = CountWrite::from(h);
write_nar(&mut cw, root_node, blob_service, directory_service)?;
Ok((cw.count(), cw.into_inner().finalize().into()))
}
/// Accepts a [proto::node::Node] pointing to the root of a (store) path,
/// and uses the passed blob_service and directory_service to
/// perform the necessary lookups as it traverses the structure.
/// The contents in NAR serialization are writen to the passed [std::io::Write].
pub fn write_nar<W: std::io::Write>(
w: &mut W,
proto_root_node: &proto::node::Node,
blob_service: Arc<dyn BlobService>,
directory_service: Arc<dyn DirectoryService>,
) -> Result<(), RenderError> {
// Initialize NAR writer
let nar_root_node = nar::writer::open(w).map_err(RenderError::NARWriterError)?;
walk_node(
nar_root_node,
proto_root_node,
blob_service,
directory_service,
)
}
/// Process an intermediate node in the structure.
/// This consumes the node.
fn walk_node(
nar_node: nar::writer::Node,
proto_node: &proto::node::Node,
blob_service: Arc<dyn BlobService>,
directory_service: Arc<dyn DirectoryService>,
) -> Result<(), RenderError> {
match proto_node {
proto::node::Node::Symlink(proto_symlink_node) => {
nar_node
.symlink(&proto_symlink_node.target)
.map_err(RenderError::NARWriterError)?;
}
proto::node::Node::File(proto_file_node) => {
let digest = proto_file_node.digest.clone().try_into().map_err(|_e| {
warn!(
file_node = ?proto_file_node,
"invalid digest length in file node",
);
RenderError::StoreError(crate::Error::StorageError(
"invalid digest len in file node".to_string(),
))
})?;
let mut blob_reader = match blob_service
.open_read(&digest)
.map_err(RenderError::StoreError)?
{
Some(blob_reader) => Ok(BufReader::new(blob_reader)),
None => Err(RenderError::NARWriterError(io::Error::new(
io::ErrorKind::NotFound,
format!("blob with digest {} not found", &digest),
))),
}?;
nar_node
.file(
proto_file_node.executable,
proto_file_node.size.into(),
&mut blob_reader,
)
.map_err(RenderError::NARWriterError)?;
}
proto::node::Node::Directory(proto_directory_node) => {
let digest = proto_directory_node
.digest
.clone()
.try_into()
.map_err(|_e| {
RenderError::StoreError(crate::Error::StorageError(
"invalid digest len in directory node".to_string(),
))
})?;
// look it up with the directory service
let resp = directory_service
.get(&digest)
.map_err(RenderError::StoreError)?;
match resp {
// if it's None, that's an error!
None => {
return Err(RenderError::DirectoryNotFound(
digest,
proto_directory_node.name.to_owned(),
))
}
Some(proto_directory) => {
// start a directory node
let mut nar_node_directory =
nar_node.directory().map_err(RenderError::NARWriterError)?;
// for each node in the directory, create a new entry with its name,
// and then invoke walk_node on that entry.
for proto_node in proto_directory.nodes() {
let child_node = nar_node_directory
.entry(proto_node.get_name())
.map_err(RenderError::NARWriterError)?;
walk_node(
child_node,
&proto_node,
blob_service.clone(),
directory_service.clone(),
)?;
}
// close the directory
nar_node_directory
.close()
.map_err(RenderError::NARWriterError)?;
}
}
}
}
Ok(())
}
|
