remove libipld dependency

[vmx]

libipld is deprecated. There wasn't really any IPLD used, but just some underlying Multiformats. Hence use cid directly.

Summary by CodeRabbit

• Refactor

  • Reworked internal hashing implementation to use direct SHA-256 with multihash wrapping while preserving existing behavior.
  • No changes to the public API.

• Chores

  • Updated dependencies to support the new hashing approach (added required crates, removed an outdated one).

• Impact

  • No user-facing changes; existing functionality and outputs remain consistent.

[coderabbitai]

Walkthrough

Replaces libipld-based multihash computation with direct sha2 hashing and cid’s Multihash wrapper. Updates Cargo.toml to add cid and sha2 dependencies and remove libipld. Oid public API remains unchanged; only internal hashing/Multihash construction is modified.

Changes

Cohort / File(s)	Summary
Dependencies update Cargo.toml	Added cid = "0.11.1" and sha2 = "0.10.9"; removed libipld = "0.16".
OID hashing implementation src/oid.rs	Replaced libipld multihash usage with sha2::Sha256::digest and cid::multihash::Multihash::wrap using constant MULTIHASH_SHA2_256 = 0x12; imports updated; Oid public API unchanged.

Sequence Diagram(s)

sequenceDiagram
  autonumber
  actor Caller
  participant O as Oid::new
  participant H as sha2::Sha256
  participant M as cid::multihash::Multihash

  Caller->>O: new(bytes)
  O->>H: digest(bytes)
  H-->>O: sha256_digest
  O->>M: wrap(0x12, sha256_digest)
  M-->>O: multihash
  O-->>Caller: Oid (with multihash)
  
  note over O,M: 0x12 = MULTIHASH_SHA2_256

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Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Pre-merge checks (3 passed)

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The title "remove libipld dependency" is concise and directly reflects the primary change in the PR (removing libipld and switching to cid/sha2), so it clearly communicates the main intent to reviewers scanning history.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

Poem

I nibble bytes with careful chew,
Swap fields of hash for something new—
A 0x12 to guide my hop,
Through sha2 lanes I never stop.
With cid crumbs I trace the trail,
My Oid is crisp, I thump my tail. 🥕🐇

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Actionable comments posted: 0

🧹 Nitpick comments (3)

Cargo.toml (1)

19-19: Prefer cid/multihash’s Code::Sha2_256 over a direct sha2 dependency.

You can drop the sha2 crate and compute the digest via multihash, simplifying deps and avoiding hard-coded multihash codes in src/oid.rs. If you keep sha2, consider default-features = false to minimize features.

Cargo diff (only if switching to multihash digest):

 [dependencies]
 base64 = "0.22"
 brotli = "6.0"
 cid = "0.11.1"
 cjson = "0.1"
 embed-doc-image = "0.1"
 multibase = "0.9"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-sha2 = "0.10.9"

Also applies to: 25-25

src/oid.rs (2)

1-2: Use multihash Code instead of manual sha2 + numeric code.

This lets you remove the sha2 import and the 0x12 constant; the multihash crate ensures length/algorithm correctness.

-use cid::{multihash::Multihash, Cid};
-use sha2::{Digest, Sha256};
+use cid::Cid;
+use cid::multihash::{Code, MultihashDigest};
@@
-const MULTIHASH_SHA2_256: u64 = 0x12;

Additionally, the doc still references “libipld”. Consider updating it to “cid crate”.

/// `Oid` is a struct that represents an object identifier (OID) backed by a `Cid` from the `cid` crate.

Also applies to: 5-6

---

34-36: Simplify digest construction; avoid hard-coded multihash code.

Leverage Code::Sha2_256.digest(bytes); no error path needed here.

-        let digest = Sha256::digest(bytes);
-        let hash = Multihash::wrap(MULTIHASH_SHA2_256, &digest)?;
-        let cid = Cid::new_v1(0x55, hash); // 0x55 is the code for raw codec
+        let hash = Code::Sha2_256.digest(bytes);
+        let cid = Cid::new_v1(0x55, hash); // raw codec

Optional: avoid the magic number by using the typed multicodec if available:

use cid::multicodec::Code as Codec;
// ...
let cid = Cid::new_v1(Codec::Raw.into(), hash);

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 9f06fef and c03467b.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (2)

• Cargo.toml (1 hunks)
• src/oid.rs (2 hunks)