From df78a4d24ee88289d979c2068ddf59d949c41004 Mon Sep 17 00:00:00 2001 From: John Ericson Date: Thu, 30 Mar 2023 17:30:28 -0400 Subject: refactor(tvix/nix-compat): Inline `texthash` mod It is moved into `store_path::utils` with the other path builders. Change-Id: I3257170e442af5d83bcf79e63fa7387dd914597c Reviewed-on: https://cl.tvl.fyi/c/depot/+/8410 Reviewed-by: flokli Tested-by: BuildkiteCI --- tvix/nix-compat/src/store_path/utils.rs | 41 ++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) (limited to 'tvix/nix-compat/src/store_path') diff --git a/tvix/nix-compat/src/store_path/utils.rs b/tvix/nix-compat/src/store_path/utils.rs index 0d96414a21..4491177172 100644 --- a/tvix/nix-compat/src/store_path/utils.rs +++ b/tvix/nix-compat/src/store_path/utils.rs @@ -1,6 +1,6 @@ use crate::nixbase32; +use crate::nixhash::NixHash; use crate::store_path::StorePath; -use crate::texthash::text_hash_string; use sha2::{Digest, Sha256}; use super::Error; @@ -60,6 +60,45 @@ pub fn build_store_path_from_fingerprint( StorePath::from_string(format!("{}-{}", nixbase32::encode(&compressed), name).as_str()) } +/// This contains the Nix logic to create "text hash strings", which are used +/// in `builtins.toFile`, as well as in Derivation Path calculation. +/// +/// A text hash is calculated by concatenating the following fields, separated by a `:`: +/// +/// - text +/// - references, individually joined by `:` +/// - the nix_hash_string representation of the sha256 digest of some contents +/// - the value of `storeDir` +/// - the name +pub fn text_hash_string, I: IntoIterator, C: AsRef<[u8]>>( + name: &str, + content: C, + references: I, +) -> String { + let mut s = String::from("text:"); + + for reference in references { + s.push_str(reference.as_ref()); + s.push(':'); + } + + // the nix_hash_string representation of the sha256 digest of some contents + s.push_str( + &{ + let content_digest = { + let hasher = Sha256::new_with_prefix(content); + hasher.finalize() + }; + NixHash::new(crate::nixhash::HashAlgo::Sha256, content_digest.to_vec()) + } + .to_nix_hash_string(), + ); + + s.push_str(&format!(":{}:{}", crate::store_path::STORE_DIR, name)); + + s +} + /// Nix placeholders (i.e. values returned by `builtins.placeholder`) /// are used to populate outputs with paths that must be /// string-replaced with the actual placeholders later, at runtime. -- cgit 1.4.1