From 10ee2acdd26a7f1298c6f6d6b7af9b469fe29b87 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sat, 4 May 2024 14:41:41 +0200
Subject: Merging upstream version 1.70.0+dfsg2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 vendor/gix-pack/src/verify.rs | 64 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 vendor/gix-pack/src/verify.rs

(limited to 'vendor/gix-pack/src/verify.rs')

diff --git a/vendor/gix-pack/src/verify.rs b/vendor/gix-pack/src/verify.rs
new file mode 100644
index 000000000..f985c8657
--- /dev/null
+++ b/vendor/gix-pack/src/verify.rs
@@ -0,0 +1,64 @@
+use std::{path::Path, sync::atomic::AtomicBool};
+
+use gix_features::progress::Progress;
+
+///
+pub mod checksum {
+    /// Returned by various methods to verify the checksum of a memory mapped file that might also exist on disk.
+    #[derive(thiserror::Error, Debug)]
+    #[allow(missing_docs)]
+    pub enum Error {
+        #[error("Interrupted by user")]
+        Interrupted,
+        #[error("index checksum mismatch: expected {expected}, got {actual}")]
+        Mismatch {
+            expected: gix_hash::ObjectId,
+            actual: gix_hash::ObjectId,
+        },
+    }
+}
+
+/// Returns the `index` at which the following `index + 1` value is not an increment over the value at `index`.
+pub fn fan(data: &[u32]) -> Option<usize> {
+    data.windows(2)
+        .enumerate()
+        .find_map(|(win_index, v)| (v[0] > v[1]).then_some(win_index))
+}
+
+/// Calculate the hash of the given kind by trying to read the file from disk at `data_path` or falling back on the mapped content in `data`.
+/// `Ok(desired_hash)` or `Err(Some(actual_hash))` is returned if the hash matches or mismatches.
+/// If the `Err(None)` is returned, the operation was interrupted.
+pub fn checksum_on_disk_or_mmap(
+    data_path: &Path,
+    data: &[u8],
+    expected: gix_hash::ObjectId,
+    object_hash: gix_hash::Kind,
+    mut progress: impl Progress,
+    should_interrupt: &AtomicBool,
+) -> Result<gix_hash::ObjectId, checksum::Error> {
+    let data_len_without_trailer = data.len() - object_hash.len_in_bytes();
+    let actual = match gix_features::hash::bytes_of_file(
+        data_path,
+        data_len_without_trailer,
+        object_hash,
+        &mut progress,
+        should_interrupt,
+    ) {
+        Ok(id) => id,
+        Err(err) if err.kind() == std::io::ErrorKind::Interrupted => return Err(checksum::Error::Interrupted),
+        Err(_io_err) => {
+            let start = std::time::Instant::now();
+            let mut hasher = gix_features::hash::hasher(object_hash);
+            hasher.update(&data[..data_len_without_trailer]);
+            progress.inc_by(data_len_without_trailer);
+            progress.show_throughput(start);
+            gix_hash::ObjectId::from(hasher.digest())
+        }
+    };
+
+    if actual == expected {
+        Ok(actual)
+    } else {
+        Err(checksum::Error::Mismatch { actual, expected })
+    }
+}
-- 
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