refactor(tvix/nix-compat): move narinfo into separate mod r/7039

Change-Id: Id85f979e46946da0345483cbbc6de3dd29c94c63
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10077
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>

1 files changed, 629 insertions, 0 deletions

diff --git a/tvix/nix-compat/src/narinfo/mod.rs b/tvix/nix-compat/src/narinfo/mod.rs
new file mode 100644
index 000000000000..2392b89737d4
--- /dev/null
+++ b/tvix/nix-compat/src/narinfo/mod.rs
@@ -0,0 +1,629 @@
+//! NAR info files describe a store path in a traditional Nix binary cache.
+//! Over the wire, they are formatted as "Key: value" pairs separated by newlines.
+//!
+//! It contains four kinds of information:
+//! 1. the description of the store path itself
+//!    * store path prefix, digest, and name
+//!    * NAR hash and size
+//!    * references
+//! 2. authenticity information
+//!    * zero or more signatures over that description
+//!    * an optional [CAHash] for content-addressed paths (fixed outputs, sources, and derivations)
+//! 3. derivation metadata
+//!    * deriver (the derivation that produced this path)
+//!    * system (the system value of that derivation)
+//! 4. cache-specific information
+//!    * URL of the compressed NAR, relative to the NAR info file
+//!    * compression algorithm used for the NAR
+//!    * hash and size of the compressed NAR
+
+use bitflags::bitflags;
+use data_encoding::{BASE64, HEXLOWER};
+use std::{
+    fmt::{self, Display},
+    mem,
+};
+
+use crate::{
+    nixbase32,
+    nixhash::{CAHash, NixHash},
+    store_path::StorePathRef,
+};
+
+#[derive(Debug)]
+pub struct NarInfo<'a> {
+    pub flags: Flags,
+    // core (authenticated, but unverified here)
+    /// Store path described by this [NarInfo]
+    pub store_path: StorePathRef<'a>,
+    /// SHA-256 digest of the NAR file
+    pub nar_hash: [u8; 32],
+    /// Size of the NAR file in bytes
+    pub nar_size: u64,
+    /// Store paths known to be referenced by the contents
+    pub references: Vec<StorePathRef<'a>>,
+    // authenticity
+    /// Ed25519 signature over the path fingerprint
+    pub signatures: Vec<Signature<'a>>,
+    /// Content address (for content-defined paths)
+    pub ca: Option<CAHash>,
+    // derivation metadata
+    /// Nix system triple of [deriver]
+    pub system: Option<&'a str>,
+    /// Store path of the derivation that produced this
+    pub deriver: Option<StorePathRef<'a>>,
+    // cache-specific untrusted metadata
+    /// Relative URL of the compressed NAR file
+    pub url: &'a str,
+    /// Compression method of the NAR file
+    /// `None` means `Compression: none`.
+    ///
+    /// Nix interprets a missing `Compression` field as `Some("bzip2")`,
+    /// so we do as well. We haven't found any examples of this in the
+    /// wild, not even in the cache.nixos.org dataset.
+    pub compression: Option<&'a str>,
+    /// SHA-256 digest of the file at `url`
+    pub file_hash: Option<[u8; 32]>,
+    /// Size of the file at `url` in bytes
+    pub file_size: Option<u64>,
+}
+
+bitflags! {
+    /// TODO(edef): be conscious of these when roundtripping
+    #[derive(Debug, Copy, Clone)]
+    pub struct Flags: u8 {
+        const UNKNOWN_FIELD = 1 << 0;
+        const COMPRESSION_DEFAULT = 1 << 1;
+        // Format quirks encountered in the cache.nixos.org dataset
+        const REFERENCES_OUT_OF_ORDER = 1 << 2;
+        const NAR_HASH_HEX = 1 << 3;
+    }
+}
+
+impl<'a> NarInfo<'a> {
+    pub fn parse(input: &'a str) -> Result<Self, Error> {
+        let mut flags = Flags::empty();
+        let mut store_path = None;
+        let mut url = None;
+        let mut compression = None;
+        let mut file_hash = None;
+        let mut file_size = None;
+        let mut nar_hash = None;
+        let mut nar_size = None;
+        let mut references = None;
+        let mut system = None;
+        let mut deriver = None;
+        let mut signatures = vec![];
+        let mut ca = None;
+
+        for line in input.lines() {
+            let (tag, val) = line
+                .split_once(':')
+                .ok_or_else(|| Error::InvalidLine(line.to_string()))?;
+
+            let val = val
+                .strip_prefix(' ')
+                .ok_or_else(|| Error::InvalidLine(line.to_string()))?;
+
+            match tag {
+                "StorePath" => {
+                    let val = val
+                        .strip_prefix("/nix/store/")
+                        .ok_or(Error::InvalidStorePath(
+                            crate::store_path::Error::MissingStoreDir,
+                        ))?;
+                    let val = StorePathRef::from_bytes(val.as_bytes())
+                        .map_err(Error::InvalidStorePath)?;
+
+                    if store_path.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "URL" => {
+                    if val.is_empty() {
+                        return Err(Error::EmptyField(tag.to_string()));
+                    }
+
+                    if url.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "Compression" => {
+                    if val.is_empty() {
+                        return Err(Error::EmptyField(tag.to_string()));
+                    }
+
+                    if compression.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "FileHash" => {
+                    let val = val
+                        .strip_prefix("sha256:")
+                        .ok_or_else(|| Error::MissingPrefixForHash(tag.to_string()))?;
+                    let val = nixbase32::decode_fixed::<32>(val)
+                        .map_err(|e| Error::UnableToDecodeHash(tag.to_string(), e))?;
+
+                    if file_hash.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "FileSize" => {
+                    let val = val
+                        .parse::<u64>()
+                        .map_err(|_| Error::UnableToParseSize(tag.to_string(), val.to_string()))?;
+
+                    if file_size.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "NarHash" => {
+                    let val = val
+                        .strip_prefix("sha256:")
+                        .ok_or_else(|| Error::MissingPrefixForHash(tag.to_string()))?;
+
+                    let val = if val.len() != HEXLOWER.encode_len(32) {
+                        nixbase32::decode_fixed::<32>(val)
+                    } else {
+                        flags |= Flags::NAR_HASH_HEX;
+
+                        let val = val.as_bytes();
+                        let mut buf = [0u8; 32];
+
+                        HEXLOWER
+                            .decode_mut(val, &mut buf)
+                            .map_err(|e| e.error)
+                            .map(|_| buf)
+                    };
+
+                    let val = val.map_err(|e| Error::UnableToDecodeHash(tag.to_string(), e))?;
+
+                    if nar_hash.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "NarSize" => {
+                    let val = val
+                        .parse::<u64>()
+                        .map_err(|_| Error::UnableToParseSize(tag.to_string(), val.to_string()))?;
+
+                    if nar_size.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "References" => {
+                    let val: Vec<StorePathRef> = if !val.is_empty() {
+                        let mut prev = "";
+                        val.split(' ')
+                            .enumerate()
+                            .map(|(i, s)| {
+                                // TODO(edef): track *duplicates* if this occurs
+                                if mem::replace(&mut prev, s) >= s {
+                                    flags |= Flags::REFERENCES_OUT_OF_ORDER;
+                                }
+
+                                StorePathRef::from_bytes(s.as_bytes())
+                                    .map_err(|err| Error::InvalidReference(i, err))
+                            })
+                            .collect::<Result<_, _>>()?
+                    } else {
+                        vec![]
+                    };
+
+                    if references.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "System" => {
+                    if val.is_empty() {
+                        return Err(Error::EmptyField(tag.to_string()));
+                    }
+
+                    if system.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "Deriver" => {
+                    let val = StorePathRef::from_bytes(val.as_bytes())
+                        .map_err(Error::InvalidDeriverStorePath)?;
+
+                    if !val.name().ends_with(".drv") {
+                        return Err(Error::InvalidDeriverStorePathMissingSuffix);
+                    }
+
+                    if deriver.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                "Sig" => {
+                    let val = Signature::parse(val)
+                        .map_err(|e| Error::UnableToParseSignature(signatures.len(), e))?;
+
+                    signatures.push(val);
+                }
+                "CA" => {
+                    let val =
+                        parse_ca(val).ok_or_else(|| Error::UnableToParseCA(val.to_string()))?;
+
+                    if ca.replace(val).is_some() {
+                        return Err(Error::DuplicateField(tag.to_string()));
+                    }
+                }
+                _ => {
+                    flags |= Flags::UNKNOWN_FIELD;
+                }
+            }
+        }
+
+        Ok(NarInfo {
+            store_path: store_path.ok_or(Error::MissingField("StorePath"))?,
+            nar_hash: nar_hash.ok_or(Error::MissingField("NarHash"))?,
+            nar_size: nar_size.ok_or(Error::MissingField("NarSize"))?,
+            references: references.ok_or(Error::MissingField("References"))?,
+            signatures,
+            ca,
+            system,
+            deriver,
+            url: url.ok_or(Error::MissingField("URL"))?,
+            compression: match compression {
+                Some("none") => None,
+                None => {
+                    flags |= Flags::COMPRESSION_DEFAULT;
+                    Some("bzip2")
+                }
+                _ => compression,
+            },
+            file_hash,
+            file_size,
+            flags,
+        })
+    }
+}
+
+impl Display for NarInfo<'_> {
+    fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result {
+        writeln!(w, "StorePath: /nix/store/{}", self.store_path)?;
+        writeln!(w, "URL: {}", self.url)?;
+
+        if let Some(compression) = self.compression {
+            writeln!(w, "Compression: {compression}")?;
+        }
+
+        if let Some(file_hash) = self.file_hash {
+            writeln!(w, "FileHash: {}", fmt_hash(&NixHash::Sha256(file_hash)))?;
+        }
+
+        if let Some(file_size) = self.file_size {
+            writeln!(w, "FileSize: {file_size}")?;
+        }
+
+        writeln!(w, "NarHash: {}", fmt_hash(&NixHash::Sha256(self.nar_hash)))?;
+        writeln!(w, "NarSize: {}", self.nar_size)?;
+
+        write!(w, "References:")?;
+        if self.references.is_empty() {
+            write!(w, " ")?;
+        } else {
+            for path in &self.references {
+                write!(w, " {path}")?;
+            }
+        }
+        writeln!(w)?;
+
+        if let Some(deriver) = &self.deriver {
+            writeln!(w, "Deriver: {deriver}")?;
+        }
+
+        if let Some(system) = self.system {
+            writeln!(w, "System: {system}")?;
+        }
+
+        for sig in &self.signatures {
+            writeln!(w, "Sig: {sig}")?;
+        }
+
+        if let Some(ca) = &self.ca {
+            writeln!(w, "CA: {}", fmt_ca(ca))?;
+        }
+
+        Ok(())
+    }
+}
+
+#[derive(Debug)]
+pub struct Signature<'a> {
+    name: &'a str,
+    bytes: [u8; 64],
+}
+
+impl<'a> Signature<'a> {
+    pub fn parse(input: &'a str) -> Result<Signature<'a>, SignatureError> {
+        let (name, bytes64) = input
+            .split_once(':')
+            .ok_or(SignatureError::MissingSeparator)?;
+
+        let mut buf = [0; 66];
+        let mut bytes = [0; 64];
+        match BASE64.decode_mut(bytes64.as_bytes(), &mut buf) {
+            Ok(64) => {
+                bytes.copy_from_slice(&buf[..64]);
+            }
+            Ok(n) => return Err(SignatureError::InvalidSignatureLen(n)),
+            // keeping DecodePartial gets annoying lifetime-wise
+            Err(_) => return Err(SignatureError::DecodeError(input.to_string())),
+        }
+
+        Ok(Signature { name, bytes })
+    }
+
+    pub fn name(&self) -> &'a str {
+        self.name
+    }
+
+    pub fn bytes(&self) -> &[u8; 64] {
+        &self.bytes
+    }
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum SignatureError {
+    #[error("Missing separator")]
+    MissingSeparator,
+    #[error("Invalid signature len: {0}")]
+    InvalidSignatureLen(usize),
+    #[error("Unable to base64-decode signature: {0}")]
+    DecodeError(String),
+}
+
+impl Display for Signature<'_> {
+    fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result {
+        write!(w, "{}:{}", self.name, BASE64.encode(&self.bytes))
+    }
+}
+
+pub fn parse_ca(s: &str) -> Option<CAHash> {
+    let (tag, s) = s.split_once(':')?;
+
+    match tag {
+        "text" => {
+            let digest = s.strip_prefix("sha256:")?;
+            let digest = nixbase32::decode_fixed(digest).ok()?;
+            Some(CAHash::Text(digest))
+        }
+        "fixed" => {
+            if let Some(s) = s.strip_prefix("r:") {
+                parse_hash(s).map(CAHash::Nar)
+            } else {
+                parse_hash(s).map(CAHash::Flat)
+            }
+        }
+        _ => None,
+    }
+}
+
+#[allow(non_camel_case_types)]
+struct fmt_ca<'a>(&'a CAHash);
+
+impl Display for fmt_ca<'_> {
+    fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result {
+        match self.0 {
+            CAHash::Flat(h) => {
+                write!(w, "fixed:{}", fmt_hash(h))
+            }
+            &CAHash::Text(d) => {
+                write!(w, "text:{}", fmt_hash(&NixHash::Sha256(d)))
+            }
+            CAHash::Nar(h) => {
+                write!(w, "fixed:r:{}", fmt_hash(h))
+            }
+        }
+    }
+}
+
+fn parse_hash(s: &str) -> Option<NixHash> {
+    let (tag, digest) = s.split_once(':')?;
+
+    (match tag {
+        "md5" => nixbase32::decode_fixed(digest).map(NixHash::Md5),
+        "sha1" => nixbase32::decode_fixed(digest).map(NixHash::Sha1),
+        "sha256" => nixbase32::decode_fixed(digest).map(NixHash::Sha256),
+        "sha512" => nixbase32::decode_fixed(digest)
+            .map(Box::new)
+            .map(NixHash::Sha512),
+        _ => return None,
+    })
+    .ok()
+}
+
+#[allow(non_camel_case_types)]
+struct fmt_hash<'a>(&'a NixHash);
+
+impl Display for fmt_hash<'_> {
+    fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result {
+        let (tag, digest) = match self.0 {
+            NixHash::Md5(d) => ("md5", &d[..]),
+            NixHash::Sha1(d) => ("sha1", &d[..]),
+            NixHash::Sha256(d) => ("sha256", &d[..]),
+            NixHash::Sha512(d) => ("sha512", &d[..]),
+        };
+
+        write!(w, "{tag}:{}", nixbase32::encode(digest))
+    }
+}
+
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error("duplicate field: {0}")]
+    DuplicateField(String),
+
+    #[error("missing field: {0}")]
+    MissingField(&'static str),
+
+    #[error("invalid line: {0}")]
+    InvalidLine(String),
+
+    #[error("invalid StorePath: {0}")]
+    InvalidStorePath(crate::store_path::Error),
+
+    #[error("field {0} may not be empty string")]
+    EmptyField(String),
+
+    #[error("invalid {0}: {1}")]
+    UnableToParseSize(String, String),
+
+    #[error("unable to parse #{0} reference: {1}")]
+    InvalidReference(usize, crate::store_path::Error),
+
+    #[error("invalid Deriver store path: {0}")]
+    InvalidDeriverStorePath(crate::store_path::Error),
+
+    #[error("invalid Deriver store path, must end with .drv")]
+    InvalidDeriverStorePathMissingSuffix,
+
+    #[error("missing prefix for {0}")]
+    MissingPrefixForHash(String),
+
+    #[error("unable to decode {0}: {1}")]
+    UnableToDecodeHash(String, data_encoding::DecodeError),
+
+    #[error("unable to parse signature #{0}: {1}")]
+    UnableToParseSignature(usize, SignatureError),
+
+    #[error("unable to parse CA field: {0}")]
+    UnableToParseCA(String),
+}
+
+#[cfg(test)]
+mod test {
+    use hex_literal::hex;
+    use lazy_static::lazy_static;
+    use pretty_assertions::assert_eq;
+    use std::{io, str};
+
+    use crate::{
+        nixhash::{CAHash, NixHash},
+        store_path::StorePathRef,
+    };
+
+    use super::{Flags, NarInfo};
+
+    lazy_static! {
+        static ref CASES: &'static [&'static str] = {
+            let data = zstd::decode_all(io::Cursor::new(include_bytes!(
+                "../../testdata/narinfo.zst"
+            )))
+            .unwrap();
+            let data = str::from_utf8(Vec::leak(data)).unwrap();
+            Vec::leak(
+                data.split_inclusive("\n\n")
+                    .map(|s| s.strip_suffix('\n').unwrap())
+                    .collect::<Vec<_>>(),
+            )
+        };
+    }
+
+    #[test]
+    fn roundtrip() {
+        for &input in *CASES {
+            let parsed = NarInfo::parse(input).expect("should parse");
+            let output = format!("{parsed}");
+            assert_eq!(input, output, "should roundtrip");
+        }
+    }
+
+    #[test]
+    fn references_out_of_order() {
+        let parsed = NarInfo::parse(
+            r#"StorePath: /nix/store/xi429w4ddvb1r77978hm7jfb2jsn559r-gcc-3.4.6
+URL: nar/1hr09cgkyw1hcsfkv5qp5jlpmf2mqrkrqs3xj5zklq9c1h9544ff.nar.bz2
+Compression: bzip2
+FileHash: sha256:1hr09cgkyw1hcsfkv5qp5jlpmf2mqrkrqs3xj5zklq9c1h9544ff
+FileSize: 4006
+NarHash: sha256:0ik9mpqxpd9hv325hdblj2nawqj5w7951qdyy8ikxgwr6fq7m11c
+NarSize: 21264
+References: a8922c0h87iilxzzvwn2hmv8x210aqb9-glibc-2.7 7w2acjgalb0cm7b3bg8yswza4l7iil9y-binutils-2.18 mm631h09mj964hm9q04l5fd8vw12j1mm-bash-3.2-p39 nx2zs2qd6snfcpzw4a0jnh26z9m0yihz-gcc-3.4.6 xi429w4ddvb1r77978hm7jfb2jsn559r-gcc-3.4.6
+Deriver: 2dzpn70c1hawczwhg9aavqk18zp9zsva-gcc-3.4.6.drv
+Sig: cache.nixos.org-1:o1DTsjCz0PofLJ216P2RBuSulI8BAb6zHxWE4N+tzlcELk5Uk/GO2SCxWTRN5wJutLZZ+cHTMdWqOHF88KGQDg==
+"#).expect("should parse");
+
+        assert!(parsed.flags.contains(Flags::REFERENCES_OUT_OF_ORDER));
+        assert_eq!(
+            vec![
+                "a8922c0h87iilxzzvwn2hmv8x210aqb9-glibc-2.7",
+                "7w2acjgalb0cm7b3bg8yswza4l7iil9y-binutils-2.18",
+                "mm631h09mj964hm9q04l5fd8vw12j1mm-bash-3.2-p39",
+                "nx2zs2qd6snfcpzw4a0jnh26z9m0yihz-gcc-3.4.6",
+                "xi429w4ddvb1r77978hm7jfb2jsn559r-gcc-3.4.6"
+            ],
+            parsed
+                .references
+                .iter()
+                .map(StorePathRef::to_string)
+                .collect::<Vec<_>>(),
+        );
+    }
+
+    #[test]
+    fn ca_nar_hash_sha1() {
+        let parsed = NarInfo::parse(
+            r#"StorePath: /nix/store/k20pahypzvr49fy82cw5sx72hdfg3qcr-texlive-hyphenex-37354
+URL: nar/0i5biw0g01514llhfswxy6xfav8lxxdq1xg6ik7hgsqbpw0f06yi.nar.xz
+Compression: xz
+FileHash: sha256:0i5biw0g01514llhfswxy6xfav8lxxdq1xg6ik7hgsqbpw0f06yi
+FileSize: 7120
+NarHash: sha256:0h1bm4sj1cnfkxgyhvgi8df1qavnnv94sd0v09wcrm971602shfg
+NarSize: 22552
+References: 
+Sig: cache.nixos.org-1:u01BybwQhyI5H1bW1EIWXssMDhDDIvXOG5uh8Qzgdyjz6U1qg6DHhMAvXZOUStIj6X5t4/ufFgR8i3fjf0bMAw==
+CA: fixed:r:sha1:1ak1ymbmsfx7z8kh09jzkr3a4dvkrfjw
+"#).expect("should parse");
+
+        assert_eq!(
+            parsed.ca,
+            Some(CAHash::Nar(NixHash::Sha1(hex!(
+                "5cba3c77236ae4f9650270a27fbad375551fa60a"
+            ))))
+        );
+    }
+
+    #[test]
+    fn compression_default() {
+        // This doesn't exist as such in cache.nixos.org.
+        // We explicitly removed the compression field for the sake of this test.
+        let parsed = NarInfo::parse(r#"StorePath: /nix/store/a1jjalr4csx9hcga7fnm122aqabrjnch-digikam-2.6.0
+URL: nar/1fzimfnvq2k8b40n4g54abmncpx2ddckh6qlb77pgq6xiysyil69.nar.bz2
+FileHash: sha256:1fzimfnvq2k8b40n4g54abmncpx2ddckh6qlb77pgq6xiysyil69
+FileSize: 43503778
+NarHash: sha256:0zpbbwipqzr5p8mlpag9wrsp5hlaxkq7gax5jj0hg3vvdziypcw5
+NarSize: 100658640
+References: 0izkyk7bq2ag9393nvnhgm87p75cq09w-liblqr-1-0.4.1 1cslpgyb7vb30inj3210jv6agqv42jxz-qca-2.0.3 1sya3bwjxkzpkmwn67gfzp4gz4g62l36-libXrandr-1.3.1 26yxdaa9z0ma5sgw02i670rsqnl57crs-glib-2.30.3 27lnjh99236kmhbpc5747599zcymfzmg-qt-4.8.2 2v6x378vcfvyxilkvihs60zha54z2x2y-qjson-0.7.1 45hgr3fbnr45n795hn2x7hsymp0h2j2m-libjpeg-8c 4kw1b212s80ap2iyibxrimcqb5imhfj7-libkexiv2-4.7.4 7dvylm5crlc0sfafcc0n46mb5ch67q0j-glibc-2.13 a05cbh1awjbl1rbyb2ynyf4k42v5a9a7-boost-1.47.0 a1jjalr4csx9hcga7fnm122aqabrjnch-digikam-2.6.0 aav5ffg8wlnilgnvdb2jnrv2aam4zmmz-perl-5.14.2 ab0m9h30nsr13w48qriv0k350kmwx567-kdelibs-4.7.4 avffkd49cqvpwdkzry8bn69dkbw4cy29-lensfun-0.2.5 cy8rl8h4yp2j3h8987vkklg328q3wmjz-gcc-4.6.3 dmmh5ihyg1r2dm4azgsfj2kprj92czlg-libSM-1.2.0 fl56j5n4shfw9c0r6vs2i4f1h9zx5kac-soprano-2.7.6 g15cmvh15ggdjcwapskngv20q4yhix40-jasper-1.900.1 i04maxd0din6v92rnqcwl9yra0kl2vk5-marble-4.7.4 kqjjb3m26rdddwwwkk8v45821aps877k-libICE-1.0.7 lxz9r135wkndvi642z4bjgmvyypsgirb-libtiff-3.9.4 m9c8i0a6cl30lcqp654dqkbag3wjmd00-libX11-1.4.1 mpnj4k2ijrgyfkh48fg96nzcmklfh5pl-coreutils-8.15 nppljblap477s0893c151lyq7r7n5v1q-zlib-1.2.7 nw9mdbyp8kyn3v4vkdzq0gsnqbc4mnx3-expat-2.0.1 p1a0dn931mzdkvj6h5yzshbmgxba5r0z-libgphoto2-2.4.11 pvjj07xa1cfkad3gwk376nzdrgknbcqm-mesa-7.11.2 pzcxag98jqccp9ycbxknyh0w95pgnsk4-lcms-1.19 qfi5pgds33kg6vlnxsmj0hyl74vcmyiz-libpng-1.5.10 scm6bj86s3qh3s3x0b9ayjp6755p4q86-mysql-5.1.54 sd23qspcyg385va0lr35xgz3hvlqphg6-libkipi-4.7.4 svmbrhc6kzfzakv20a7zrfl6kbr5mfpq-kdepimlibs-4.7.4 v7kh3h7xfwjz4hgffg3gwrfzjff9bw9d-bash-4.2-p24 vi17f22064djgpk0w248da348q8gxkww-libkdcraw-4.7.4 wkjdzmj3z4dcbsc9f833zs6krdgg2krk-phonon-4.6.0 xf3i3awqi0035ixy2qyb6hk4c92r3vrn-opencv-2.4.2 y1vr0nz8i59x59501020nh2k1dw3bhwq-libusb-0.1.12 yf3hin2hb6i08n7zrk8g3acy54rhg9bp-libXext-1.2.0
+Deriver: la77dr44phk5m5jnl4dvk01cwpykyw9s-digikam-2.6.0.drv
+System: i686-linux
+Sig: cache.nixos.org-1:92fl0i5q7EyegCj5Yf4L0bENkWuVAtgveiRcTEEUH0P6HvCE1xFcPbz/0Pf6Np+K1LPzHK+s5RHOmVoxRsvsDg==
+"#).expect("should parse");
+
+        assert!(parsed.flags.contains(Flags::COMPRESSION_DEFAULT));
+        assert_eq!(parsed.compression, Some("bzip2"));
+    }
+
+    #[test]
+    fn nar_hash_hex() {
+        let parsed = NarInfo::parse(r#"StorePath: /nix/store/0vpqfxbkx0ffrnhbws6g9qwhmliksz7f-perl-HTTP-Cookies-6.01
+URL: nar/1rv1m9inydm1r4krw8hmwg1hs86d0nxddd1pbhihx7l7fycjvfk3.nar.xz
+Compression: xz
+FileHash: sha256:1rv1m9inydm1r4krw8hmwg1hs86d0nxddd1pbhihx7l7fycjvfk3
+FileSize: 19912
+NarHash: sha256:60adfd293a4d81ad7cd7e47263cbb3fc846309ef91b154a08ba672b558f94ff3
+NarSize: 45840
+References: 0vpqfxbkx0ffrnhbws6g9qwhmliksz7f-perl-HTTP-Cookies-6.01 9vrhbib2lxd9pjlg6fnl5b82gblidrcr-perl-HTTP-Message-6.06 wy20zslqxzxxfpzzk0rajh41d7a6mlnf-perl-HTTP-Date-6.02
+Deriver: fb4ihlq3psnsjq95mvvs49rwpplpc8zj-perl-HTTP-Cookies-6.01.drv
+Sig: cache.nixos.org-1:HhaiY36Uk3XV1JGe9d9xHnzAapqJXprU1YZZzSzxE97jCuO5RR7vlG2kF7MSC5thwRyxAtdghdSz3AqFi+QSCw==
+"#).expect("should parse");
+
+        assert!(parsed.flags.contains(Flags::NAR_HASH_HEX));
+        assert_eq!(
+            hex!("60adfd293a4d81ad7cd7e47263cbb3fc846309ef91b154a08ba672b558f94ff3"),
+            parsed.nar_hash,
+        );
+    }
+}