ona/src/oar.zig

const std = @import("std");
const sys = @import("./sys.zig");

///
/// An entry block of an Oar archive file.
///
/// Typically, following this block in memory is the file data it holds the meta-information for.
///
pub const Entry = extern struct {
    signature: [3]u8 = signature_magic,
    revision: u8,
    name_buffer: [255]u8 = std.mem.zeroes([255]u8),
    name_length: u8 = 0,
    file_size: u64,
    file_offset: u64,
    padding: [232]u8 = std.mem.zeroes([232]u8),

    comptime {
        const entry_size = @sizeOf(Entry);

        if (entry_size != 512)
            @compileError("Entry is " ++ std.fmt.comptimePrint("{d}", .{entry_size}) ++ " bytes");
    }

    ///
    /// [FindError.EntryNotFound] happens when an entry could not be found.
    ///
    pub const FindError = sys.FileAccess.Error || error {
        EntryNotFound,
    };

    ///
    ///
    ///
    pub fn find(file_access: sys.FileAccess, entry_name: []const u8) FindError!Entry {
        _ = file_access;
        _ = entry_name;

        return error.EntryNotFound;
    }

    ///
    /// Magic identifier used to validate [Entry] data.
    ///
    const signature_magic = [3]u8{'o', 'a', 'r'};
};