Fix uninitialized memory access

Author: lalinsky

src/MultiIndex.zig

@@ -80,7 +80,7 @@ pub fn acquireIndex(self: *Self, id: u8, create: bool) !*IndexRef {
         return err;
     };
 
-    result.value_ptr.references += 1;
+    result.value_ptr.references = 1;
     result.value_ptr.last_used_at = std.time.timestamp();
     return result.value_ptr;
 }

src/filefmt.zig

@@ -223,10 +223,7 @@ test "writeBlock/readBlock/readFirstItemFromBlock" {
 }
 
 // "SGM1"
-const header_magic_v1 = 0x53474d31;
-
-// "1SGM"
-const footer_magic_v1 = 0x3153474d;
+const header_magic_v1 = 0x31474d53;
 
 pub const Header = packed struct {
     magic: u32 = header_magic_v1,
@@ -428,20 +425,21 @@ test "writeFile/readFile" {
     }
 }
 
-// "IDX1"
-const index_header_magic_v1: u32 = 0x49445831;
+const index_header_magic_v1: u32 = 0x31584449; // "IDX1"
 
 const IndexHeader = packed struct {
     magic: u32,
     version: u32,
     num_segments: u32,
+    reserved: u32,
 };
 
 pub fn writeIndexFile(writer: anytype, segments: std.ArrayList(SegmentVersion)) !void {
     const header = IndexHeader{
         .magic = index_header_magic_v1,
         .version = 1,
         .num_segments = @intCast(segments.items.len),
+        .reserved = 0,
     };
     try writer.writeStructEndian(header, .little);
     for (segments.items) |segment| {

src/main.zig

@@ -16,7 +16,7 @@ pub fn main() !void {
     defer args.deinit();
 
     const dir_path = args.get("dir") orelse ".";
-    const dir = try std.fs.cwd().openDir(dir_path, .{});
+    const dir = try std.fs.cwd().makeOpenPath(dir_path, .{ .iterate = true });
 
     const address = args.get("address") orelse "127.0.0.1";