refactor: add digest_file for hashing file content

[hanabi1224]

Summary of changes

Changes introduced in this pull request:

Reference issue to close (if applicable)

Closes

Other information and links

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

Outside contributions

• I have read and agree to the CONTRIBUTING document.
• I have read and agree to the AI Policy document. I understand that failure to comply with the guidelines will lead to rejection of the pull request.

[coderabbitai]

Walkthrough

The PR introduces streaming hash utility functions in a new utils::hash module and migrates existing hashing code to use them. Dependencies for digest, md-5, and sha2 are upgraded to version 0.11 to support the streaming approach via the new digest-io dependency.

Changes

Cohort / File(s)	Summary
Dependency Ecosystem Upgrade Cargo.toml	Added digest = "0.11" and digest-io = "0.1" dependencies. Bumped md-5 from 0.10 to 0.11 and sha2 from 0.10 to 0.11 (keeping default-features = false).
Streaming Hash Utilities src/utils/hash/mod.rs, src/utils/mod.rs	Introduced new public module with digest_stream<H, R> and digest_file<H> functions for streaming hash computation using digest_io::IoWrapper. Added module export in utils.
Hash Call Site Migrations src/state_manager/utils.rs, src/utils/io/writer_checksum.rs, src/utils/net/download_file.rs, src/utils/proofs_api/parameters.rs	Updated hashing logic across multiple files to use new streaming utilities. Changed error handling in download_file.rs from Option to Result and updated checksum formatting in tests. Refactored BufReader initialization in parameters.rs.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• refactor: simplify hasher usage #6812: Modifies hashing call sites and switches to streaming digest approaches across tests and download/proofs code, directly related to this refactoring pattern.
• chore(deps): favor re-exported digest crate #6603: Affects digest crate usage and digest-related imports in overlapping files like src/state_manager/utils.rs, sharing dependency and API changes.

Suggested reviewers

• akaladarshi
• sudo-shashank
• LesnyRumcajs

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 75.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main refactoring: introducing a digest_file function for hashing file content, which is the primary addition across all changed files.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch hm/digest-file

✨ Simplify code

• Create PR with simplified code
• Commit simplified code in branch hm/digest-file

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[coderabbitai]

🧹 Nitpick comments (2)

src/utils/hash/mod.rs (2)

14-15: Minor: H: Update bound may be redundant.

In digest 0.11, the Digest trait already requires Update, so H: Digest alone should suffice. This is a very minor nit and doesn't affect correctness.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@src/utils/hash/mod.rs` around lines 14 - 15, The generic bound on H in the
function/impl (the clause "where H: Digest + Update") is redundant because the
Digest trait already requires Update in digest 0.11; remove the explicit
"Update" bound and leave "where H: Digest" (update any occurrences of that
where-clause on the functions/impls referencing H such as the Digest-related
function signatures) to simplify the constraints.

---

12-30: Consider adding doc comments for public functions.

These functions are pub and will be part of the module's API. Adding brief doc comments would improve discoverability and maintainability.

📝 Suggested doc comments

+/// Computes the digest of data read from a stream.
+///
+/// Reads from `reader` until EOF, feeding all bytes into the hasher `H`,
+/// and returns the finalized digest.
 #[allow(dead_code)]
 pub fn digest_stream<H, R>(reader: &mut R) -> std::io::Result<Output<H>>
 where
     H: Digest + Update,
     R: Read,
 {
     let mut hasher = IoWrapper(H::new());
     std::io::copy(reader, &mut hasher)?;
     Ok(hasher.0.finalize())
 }

+/// Computes the digest of a file's contents.
+///
+/// Opens the file at `path`, reads it through a buffered reader,
+/// and returns the finalized digest.
 #[allow(dead_code)]
 pub fn digest_file<H>(path: impl AsRef<Path>) -> std::io::Result<Output<H>>
 where
     H: Digest + Update,
 {
     let mut reader = BufReader::new(File::open(path)?);
     digest_stream::<H, _>(&mut reader)
 }

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@src/utils/hash/mod.rs` around lines 12 - 30, Add brief doc comments for the
public functions to document their purpose, parameters and return value: add a
doc comment above pub fn digest_stream<H, R>(reader: &mut R) describing that it
reads from the given reader, computes and returns the digest Output<H> and may
return std::io::Error, and add a doc comment above pub fn digest_file<H>(path:
impl AsRef<Path>) describing that it opens the file at path, wraps it in a
BufReader, and returns the computed digest via digest_stream; mention trait
bounds (H: Digest + Update) and the possible I/O errors in both comments.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@src/utils/hash/mod.rs`:
- Around line 14-15: The generic bound on H in the function/impl (the clause
"where H: Digest + Update") is redundant because the Digest trait already
requires Update in digest 0.11; remove the explicit "Update" bound and leave
"where H: Digest" (update any occurrences of that where-clause on the
functions/impls referencing H such as the Digest-related function signatures) to
simplify the constraints.
- Around line 12-30: Add brief doc comments for the public functions to document
their purpose, parameters and return value: add a doc comment above pub fn
digest_stream<H, R>(reader: &mut R) describing that it reads from the given
reader, computes and returns the digest Output<H> and may return std::io::Error,
and add a doc comment above pub fn digest_file<H>(path: impl AsRef<Path>)
describing that it opens the file at path, wraps it in a BufReader, and returns
the computed digest via digest_stream; mention trait bounds (H: Digest + Update)
and the possible I/O errors in both comments.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: fb8162e2-4755-43d8-9cdd-5a2f50e75a55

📥 Commits

Reviewing files that changed from the base of the PR and between 45f66c3 and c4b99ca.

⛔ Files ignored due to path filters (1)

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

📒 Files selected for processing (7)

• Cargo.toml
• src/state_manager/utils.rs
• src/utils/hash/mod.rs
• src/utils/io/writer_checksum.rs
• src/utils/mod.rs
• src/utils/net/download_file.rs
• src/utils/proofs_api/parameters.rs

[codecov]

Codecov Report

❌ Patch coverage is 84.37500% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 63.95%. Comparing base (d0dc5b8) to head (d650268).
⚠️ Report is 3 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/utils/hash/mod.rs	85.71%	0 Missing and 2 partials ⚠️
src/utils/net/download_file.rs	81.81%	0 Missing and 2 partials ⚠️
src/state_manager/utils.rs	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
src/utils/io/writer_checksum.rs	82.40% <100.00%> (-0.17%)	⬇️
src/utils/mod.rs	82.45% <ø> (ø)
src/utils/proofs_api/parameters.rs	83.56% <100.00%> (-0.23%)	⬇️
src/state_manager/utils.rs	79.80% <0.00%> (ø)
src/utils/hash/mod.rs	85.71% <85.71%> (ø)
src/utils/net/download_file.rs	80.68% <81.81%> (-0.14%)	⬇️

... and 5 files with indirect coverage changes

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