Further work on getting everything working again

Mainly working on decompression interface

src/decomp/zlib.zig

@@ -0,0 +1,55 @@
+const std = @import("std");
+const Reader = std.Io.Reader;
+const flate = std.compress.flate;
+
+const Decompressor = @import("../util/decompressor.zig");
+const Error = Decompressor.Error;
+
+pub fn Zlib(stateless: bool) type {
+    return if (stateless)
+        struct {
+            const Self = @This();
+
+            interface: Decompressor = .{ .decomp_fn = decomp },
+
+            const init: Self = .{};
+
+            fn decomp(_: *?Decompressor, alloc: std.mem.Allocator, in: []u8, out: []u8) Error!usize {
+                const buf = try alloc.alloc(u8, in.len * 2);
+                defer alloc.free(buf);
+                return zlibDecomp(buf, in, out);
+            }
+        }
+    else
+        struct {
+            const Self = @This();
+
+            interface: Decompressor = .{ .decomp_fn = decomp },
+
+            alloc: std.mem.Allocator,
+
+            block_size: u32,
+            buffers: std.ArrayList([]u8),
+            buffer_queue: std.SinglyLinkedList,
+
+            pub fn init(alloc: std.mem.Allocator, block_size: u32) !Self {
+                return .{
+                    .alloc = alloc,
+
+                    .block_size = block_size,
+                    .buffers = try .initCapacity(alloc, 20),
+                };
+            }
+            pub fn deinit(self: Self) void {
+                for (self.buffers) |buf|
+                    self.alloc.free(buf);
+            }
+        };
+}
+
+inline fn zlibDecomp(buffer: []u8, in: []u8, out: []u8) !usize {
+    var rdr: Reader = .fixed(in);
+    var decomp = flate.Decompress.init(&rdr, .zlib, buffer);
+
+    return decomp.reader.readSliceShort(out);
+}