Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/vendor/snap/src/varint.rs b/vendor/snap/src/varint.rs
new file mode 100644
index 000000000..d4a11384f
--- /dev/null
+++ b/vendor/snap/src/varint.rs
@@ -0,0 +1,31 @@
+/// https://developers.google.com/protocol-buffers/docs/encoding#varints
+pub fn write_varu64(data: &mut [u8], mut n: u64) -> usize {
+    let mut i = 0;
+    while n >= 0b1000_0000 {
+        data[i] = (n as u8) | 0b1000_0000;
+        n >>= 7;
+        i += 1;
+    }
+    data[i] = n as u8;
+    i + 1
+}
+
+/// https://developers.google.com/protocol-buffers/docs/encoding#varints
+pub fn read_varu64(data: &[u8]) -> (u64, usize) {
+    let mut n: u64 = 0;
+    let mut shift: u32 = 0;
+    for (i, &b) in data.iter().enumerate() {
+        if b < 0b1000_0000 {
+            return match (b as u64).checked_shl(shift) {
+                None => (0, 0),
+                Some(b) => (n | b, i + 1),
+            };
+        }
+        match ((b as u64) & 0b0111_1111).checked_shl(shift) {
+            None => return (0, 0),
+            Some(b) => n |= b,
+        }
+        shift += 7;
+    }
+    (0, 0)
+}