refactor(tvix/nix-compat): move NixHashWithMode into separate file r/6055

… and keep the pub exports as is.

Change-Id: I9f89a738c508c478ddba61303c21ea294f01ee9f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8362
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>

1 files changed, 2 insertions, 108 deletions

diff --git a/tvix/nix-compat/src/nixhash.rs b/tvix/nix-compat/src/nixhash.rs
index 0da90fe4ccf5..69ed98ff962e 100644
--- a/tvix/nix-compat/src/nixhash.rs
+++ b/tvix/nix-compat/src/nixhash.rs
@@ -1,117 +1,11 @@
 use data_encoding::{BASE64, BASE64_NOPAD, HEXLOWER};
-use serde::ser::SerializeMap;
-use serde::{Deserialize, Deserializer, Serialize, Serializer};
+use serde::{Deserialize, Serialize};
 use std::fmt::Display;
 use thiserror::Error;
 
 use crate::nixbase32;
 
-/// A Nix Hash can either be flat or recursive.
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub enum NixHashWithMode {
-    Flat(NixHash),
-    Recursive(NixHash),
-}
-
-impl NixHashWithMode {
-    /// Formats a [NixHashWithMode] in the Nix default hash format,
-    /// which is the algo, followed by a colon, then the lower hex encoded digest.
-    /// In case the hash itself is recursive, a `r:` is added as prefix
-    pub fn to_nix_hash_string(&self) -> String {
-        match self {
-            NixHashWithMode::Flat(h) => h.to_nix_hash_string(),
-            NixHashWithMode::Recursive(h) => format!("r:{}", h.to_nix_hash_string()),
-        }
-    }
-}
-
-impl Serialize for NixHashWithMode {
-    /// map a NixHashWithMode into the serde data model.
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        let mut map = serializer.serialize_map(Some(2))?;
-        match self {
-            NixHashWithMode::Flat(h) => {
-                map.serialize_entry("hash", &nixbase32::encode(&h.digest))?;
-                map.serialize_entry("hashAlgo", &h.algo.to_string())?;
-            }
-            NixHashWithMode::Recursive(h) => {
-                map.serialize_entry("hash", &nixbase32::encode(&h.digest))?;
-                map.serialize_entry("hashAlgo", &format!("r:{}", &h.algo.to_string()))?;
-            }
-        };
-        map.end()
-    }
-}
-
-impl<'de> Deserialize<'de> for NixHashWithMode {
-    /// map the serde data model into a NixHashWithMode.
-    ///
-    /// The serde data model has a `hash` field (containing a digest in nixbase32),
-    /// and a `hashAlgo` field, containing the stringified hash algo.
-    /// In case the hash is recursive, hashAlgo also has a `r:` prefix.
-    ///
-    /// This is to match how `nix show-derivation` command shows them in JSON
-    /// representation.
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        // TODO: don't use serde_json here?
-        // TODO: serde seems to simply set `hash_with_mode` to None if hash
-        // and hashAlgo fail, but that should be a proper deserialization error
-        // that should be propagated to the user!
-
-        let json = serde_json::Value::deserialize(deserializer)?;
-        match json.as_object() {
-            None => Err(serde::de::Error::custom("couldn't parse as map"))?,
-            Some(map) => {
-                let digest: Vec<u8> = {
-                    if let Some(v) = map.get("hash") {
-                        if let Some(s) = v.as_str() {
-                            data_encoding::HEXLOWER
-                                .decode(s.as_bytes())
-                                .map_err(|e| serde::de::Error::custom(e.to_string()))?
-                        } else {
-                            return Err(serde::de::Error::custom(
-                                "couldn't parse 'hash' as string",
-                            ));
-                        }
-                    } else {
-                        return Err(serde::de::Error::custom("couldn't extract 'hash' key"));
-                    }
-                };
-
-                if let Some(v) = map.get("hashAlgo") {
-                    if let Some(s) = v.as_str() {
-                        match s.strip_prefix("r:") {
-                            Some(rest) => Ok(NixHashWithMode::Recursive(NixHash::new(
-                                HashAlgo::try_from(rest).map_err(|e| {
-                                    serde::de::Error::custom(format!("unable to parse algo: {}", e))
-                                })?,
-                                digest,
-                            ))),
-                            None => Ok(NixHashWithMode::Flat(NixHash::new(
-                                HashAlgo::try_from(s).map_err(|e| {
-                                    serde::de::Error::custom(format!("unable to parse algo: {}", e))
-                                })?,
-                                digest,
-                            ))),
-                        }
-                    } else {
-                        Err(serde::de::Error::custom(
-                            "couldn't parse 'hashAlgo' as string",
-                        ))
-                    }
-                } else {
-                    Err(serde::de::Error::custom("couldn't extract 'hashAlgo' key"))
-                }
-            }
-        }
-    }
-}
+pub use crate::nixhash_with_mode::NixHashWithMode;
 
 /// Nix allows specifying hashes in various encodings, and magically just
 /// derives the encoding.