path: root/tvix/castore/protos/castore.proto

// SPDX-FileCopyrightText: edef <edef@unfathomable.blue>
// SPDX-License-Identifier: OSL-3.0 OR MIT OR Apache-2.0

syntax = "proto3";

package tvix.castore.v1;

option go_package = "code.tvl.fyi/tvix/castore-go;castorev1";

// A Directory can contain Directory, File or Symlink nodes.
// Each of these nodes have a name attribute, which is the basename in that directory
// and node type specific attributes.
// The name attribute:
//  - MUST not contain slashes or null bytes
//  - MUST not be '.' or '..'
//  - MUST be unique across all three lists
// Elements in each list need to be lexicographically ordered by the name
// attribute.
message Directory {
    repeated DirectoryNode directories = 1;
    repeated FileNode files = 2;
    repeated SymlinkNode symlinks = 3;
}

// A DirectoryNode represents a directory in a Directory.
message DirectoryNode {
    // The (base)name of the directory
    bytes name = 1;
    // The blake3 hash of a Directory message, serialized in protobuf canonical form.
    bytes digest = 2;
    // Number of child elements in the Directory referred to by `digest`.
    // Calculated by summing up the numbers of `directories`, `files` and
    // `symlinks`, and for each directory, its size field. Used for inode
    // number calculation.
    // This field is precisely as verifiable as any other Merkle tree edge.
    // Resolve `digest`, and you can compute it incrementally. Resolve the
    // entire tree, and you can fully compute it from scratch.
    // A credulous implementation won't reject an excessive size, but this is
    // harmless: you'll have some ordinals without nodes. Undersizing is
    // obvious and easy to reject: you won't have an ordinal for some nodes.
    uint32 size = 3;
}

// A FileNode represents a regular or executable file in a Directory.
message FileNode {
    // The (base)name of the file
    bytes name = 1;
    // The blake3 digest of the file contents
    bytes digest = 2;
    // The file content size
    uint32 size = 3;
    // Whether the file is executable
    bool executable = 4;
}

// A SymlinkNode represents a symbolic link in a Directory.
message SymlinkNode {
    // The (base)name of the symlink
    bytes name = 1;
    // The target of the symlink.
    bytes target = 2;
}

// A Node is either a DirectoryNode, FileNode or SymlinkNode.
message Node {
    oneof node {
        DirectoryNode directory = 1;
        FileNode file = 2;
        SymlinkNode symlink = 3;
    }
}