Add hex_display utility crate

4 files changed, 132 insertions, 0 deletions

diff --git a/utils/hex_display/Cargo.toml b/utils/hex_display/Cargo.toml
new file mode 100644
index 0000000..0e096d7
--- /dev/null
+++ b/utils/hex_display/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "hex_display"
+edition = "2024"
+version.workspace = true
+
+[dependencies]
diff --git a/utils/hex_display/src/lib.rs b/utils/hex_display/src/lib.rs
new file mode 100644
index 0000000..833ab22
--- /dev/null
+++ b/utils/hex_display/src/lib.rs
@@ -0,0 +1,96 @@
+pub mod macros;
+pub mod test;
+
+/// Format a byte slice into a hex display string
+pub fn hex_display_slice(slice: &[u8]) -> String {
+    let mut result = String::new();
+
+    for (chunk_index, chunk) in slice.chunks(16).enumerate() {
+        draw_range(&mut result, chunk_index * 16, chunk);
+    }
+
+    // Remove trailing newline
+    if result.ends_with('\n') {
+        result.pop();
+    }
+
+    result
+}
+
+/// Format a byte vector into a hex display string
+pub fn hex_display_vec(vec: Vec<u8>) -> String {
+    hex_display_slice(&vec)
+}
+
+/// Draw one line of hex display
+fn draw_range(result: &mut String, offset: usize, chunk: &[u8]) {
+    write_offset(result, offset);
+    write_data(result, chunk);
+    write_ascii(result, chunk);
+    result.push('\n');
+}
+
+/// Write the offset part
+fn write_offset(result: &mut String, offset: usize) {
+    result.push_str(&format!("{:08x}  ", offset));
+}
+
+/// Write the hex data part
+fn write_data(result: &mut String, chunk: &[u8]) {
+    for (i, &byte) in chunk.iter().enumerate() {
+        result.push_str(&format!("{:02x}", byte));
+
+        if i < 15 {
+            result.push(' ');
+        }
+
+        if i == 7 {
+            result.push(' ');
+        }
+    }
+
+    if chunk.len() < 16 {
+        pad_data(result, chunk.len());
+    }
+}
+
+/// Pad missing hex data
+fn pad_data(result: &mut String, actual_len: usize) {
+    let missing = 16 - actual_len;
+
+    for i in 0..missing {
+        result.push_str("   ");
+
+        if actual_len + i == 7 {
+            result.push(' ');
+        }
+    }
+
+    if result.ends_with(' ') {
+        result.pop();
+    }
+}
+
+/// Write the ASCII representation part
+fn write_ascii(result: &mut String, chunk: &[u8]) {
+    result.push_str("  |");
+
+    for &byte in chunk {
+        if byte >= 32 && byte <= 126 {
+            result.push(byte as char);
+        } else {
+            result.push('.');
+        }
+    }
+
+    pad_ascii(result, chunk.len());
+
+    result.push('|');
+}
+
+/// Pad the ASCII part to a fixed width
+fn pad_ascii(result: &mut String, actual_len: usize) {
+    for _ in actual_len..16 {
+        result.push(' ');
+    }
+}
diff --git a/utils/hex_display/src/macros.rs b/utils/hex_display/src/macros.rs
new file mode 100644
index 0000000..77f9d43
--- /dev/null
+++ b/utils/hex_display/src/macros.rs
@@ -0,0 +1,9 @@
+#[macro_export]
+macro_rules! hex_display {
+    ($slice:expr) => {
+        hex_display::hex_display_slice($slice)
+    };
+    ($vec:expr) => {
+        hex_display::hex_display_vec($vec)
+    };
+}
diff --git a/utils/hex_display/src/test.rs b/utils/hex_display/src/test.rs
new file mode 100644
index 0000000..d68cebe
--- /dev/null
+++ b/utils/hex_display/src/test.rs
@@ -0,0 +1,21 @@
+#[cfg(test)]
+mod tests {
+    use crate::hex_display_slice;
+
+    #[test]
+    fn test_hex_display_slice() {
+        const RAW_DATA: [u8; 64] = [
+            0x01, 0x02, 0x00, 0x00, 0x00, 0x02, 0x00, 0x1b, 0x00, 0x00, 0x00, 0x0f, 0x00, 0x00,
+            0x00, 0x02, 0x00, 0x00, 0x00, 0x02, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x0d,
+            0x01, 0x05, 0x00, 0x00, 0x64, 0x69, 0x72, 0x2f, 0x66, 0x69, 0x6c, 0x65, 0x32, 0x2e,
+            0x74, 0x78, 0x74, 0x6f, 0x74, 0x68, 0x65, 0x72, 0x09, 0x00, 0x00, 0x01, 0x00, 0x66,
+            0x69, 0x6c, 0x65, 0x31, 0x2e, 0x74, 0x78, 0x74,
+        ];
+        let expected = "\
+00000000  01 02 00 00 00 02 00 1b  00 00 00 0f 00 00 00 02  |................|
+00000010  00 00 00 02 00 01 00 00  00 01 00 0d 01 05 00 00  |................|
+00000020  64 69 72 2f 66 69 6c 65  32 2e 74 78 74 6f 74 68  |dir/file2.txtoth|
+00000030  65 72 09 00 00 01 00 66  69 6c 65 31 2e 74 78 74  |er.....file1.txt|";
+        assert_eq!(hex_display_slice(&RAW_DATA), expected);
+    }
+}