Add an allocator for the palette compressed chunk data.

src/main.zig

@@ -576,6 +576,9 @@ pub fn main() void { // MARK: main()
 	audio.init() catch std.log.err("Failed to initialize audio. Continuing the game without sounds.", .{});
 	defer audio.deinit();
 
+	utils.initDynamicIntArrayStorage();
+	defer utils.deinitDynamicIntArrayStorage();
+
 	chunk.init();
 	defer chunk.deinit();
 

src/utils.zig

@@ -777,25 +777,36 @@ pub const ThreadPool = struct { // MARK: ThreadPool
 	}
 };
 
+var dynamicIntArrayAllocator: main.heap.PowerOfTwoPoolAllocator(main.chunk.chunkVolume/@bitSizeOf(u8), main.chunk.chunkVolume*@sizeOf(u16), 64) = undefined;
+
+pub fn initDynamicIntArrayStorage() void {
+	dynamicIntArrayAllocator = .init(main.globalAllocator);
+}
+
+pub fn deinitDynamicIntArrayStorage() void {
+	dynamicIntArrayAllocator.deinit();
+}
+
 /// An packed array of integers with dynamic bit size.
 /// The bit size can be changed using the `resize` function.
 pub fn DynamicPackedIntArray(size: comptime_int) type { // MARK: DynamicPackedIntArray
+	std.debug.assert(std.math.isPowerOfTwo(size));
 	return struct {
 		data: []align(64) u32 = &.{},
 		bitSize: u5 = 0,
 
 		const Self = @This();
 
-		pub fn initCapacity(allocator: main.heap.NeverFailingAllocator, bitSize: u5) Self {
+		pub fn initCapacity(bitSize: u5) Self {
 			std.debug.assert(bitSize == 0 or bitSize & bitSize - 1 == 0); // Must be a power of 2
 			return .{
-				.data = allocator.alignedAlloc(u32, 64, @as(usize, @divExact(size, @bitSizeOf(u32)))*bitSize),
+				.data = dynamicIntArrayAllocator.allocator().alignedAlloc(u32, 64, @as(usize, @divExact(size, @bitSizeOf(u32)))*bitSize),
 				.bitSize = bitSize,
 			};
 		}
 
-		pub fn deinit(self: *Self, allocator: main.heap.NeverFailingAllocator) void {
+		pub fn deinit(self: *Self) void {
-			allocator.free(self.data);
+			dynamicIntArrayAllocator.allocator().free(self.data);
 			self.* = .{};
 		}
 
@@ -808,9 +819,9 @@ pub fn DynamicPackedIntArray(size: comptime_int) type { // MARK: DynamicPackedIn
 			return result;
 		}
 
-		pub fn resizeOnce(self: *Self, allocator: main.heap.NeverFailingAllocator) void {
+		pub fn resizeOnce(self: *Self) void {
 			const newBitSize = if(self.bitSize != 0) self.bitSize*2 else 1;
-			var newSelf = Self.initCapacity(allocator, newBitSize);
+			var newSelf = Self.initCapacity(newBitSize);
 
 			switch(self.bitSize) {
 				0 => @memset(newSelf.data, 0),
@@ -823,7 +834,7 @@ pub fn DynamicPackedIntArray(size: comptime_int) type { // MARK: DynamicPackedIn
 				},
 				else => unreachable,
 			}
-			allocator.free(self.data);
+			dynamicIntArrayAllocator.allocator().free(self.data);
 			self.* = newSelf;
 		}
 
@@ -889,13 +900,10 @@ pub fn PaletteCompressedRegion(T: type, size: comptime_int) type { // MARK: Pale
 		}
 
 		pub fn initCopy(self: *Self, template: *const Self) void {
-			const dataDupe = main.globalAllocator.alignedAlloc(u32, 64, template.data.data.len);
+			const dataDupe = DynamicPackedIntArray(size).initCapacity(template.data.bitSize);
-			@memcpy(dataDupe, template.data.data);
+			@memcpy(dataDupe.data, template.data.data);
 			self.* = .{
-				.data = .{
 				.data = dataDupe,
-					.bitSize = template.data.bitSize,
-				},
 				.palette = main.globalAllocator.dupe(T, template.palette),
 				.paletteOccupancy = main.globalAllocator.dupe(u32, template.paletteOccupancy),
 				.paletteLength = template.paletteLength,
@@ -908,7 +916,7 @@ pub fn PaletteCompressedRegion(T: type, size: comptime_int) type { // MARK: Pale
 			const bitSize: u5 = getTargetBitSize(paletteLength);
 			const bufferLength = @as(u32, 1) << bitSize;
 			self.* = .{
-				.data = DynamicPackedIntArray(size).initCapacity(main.globalAllocator, bitSize),
+				.data = DynamicPackedIntArray(size).initCapacity(bitSize),
 				.palette = main.globalAllocator.alloc(T, bufferLength),
 				.paletteOccupancy = main.globalAllocator.alloc(u32, bufferLength),
 				.paletteLength = paletteLength,
@@ -919,7 +927,7 @@ pub fn PaletteCompressedRegion(T: type, size: comptime_int) type { // MARK: Pale
 		}
 
 		pub fn deinit(self: *Self) void {
-			self.data.deinit(main.globalAllocator);
+			self.data.deinit();
 			main.globalAllocator.free(self.palette);
 			main.globalAllocator.free(self.paletteOccupancy);
 		}
@@ -945,7 +953,7 @@ pub fn PaletteCompressedRegion(T: type, size: comptime_int) type { // MARK: Pale
 			}
 			if(paletteIndex == self.paletteLength) {
 				if(self.paletteLength == self.palette.len) {
-					self.data.resizeOnce(main.globalAllocator);
+					self.data.resizeOnce();
 					self.palette = main.globalAllocator.realloc(self.palette, @as(usize, 1) << self.data.bitSize);
 					const oldLen = self.paletteOccupancy.len;
 					self.paletteOccupancy = main.globalAllocator.realloc(self.paletteOccupancy, @as(usize, 1) << self.data.bitSize);
@@ -1007,7 +1015,7 @@ pub fn PaletteCompressedRegion(T: type, size: comptime_int) type { // MARK: Pale
 			const newBitSize = getTargetBitSize(@intCast(self.activePaletteEntries));
 			if(self.data.bitSize == newBitSize) return;
 
-			var newData = main.utils.DynamicPackedIntArray(size).initCapacity(main.globalAllocator, newBitSize);
+			var newData = main.utils.DynamicPackedIntArray(size).initCapacity(newBitSize);
 			const paletteMap: []u32 = main.stackAllocator.alloc(u32, self.paletteLength);
 			defer main.stackAllocator.free(paletteMap);
 			{
@@ -1031,7 +1039,7 @@ pub fn PaletteCompressedRegion(T: type, size: comptime_int) type { // MARK: Pale
 			for(0..size) |i| {
 				newData.setValue(i, paletteMap[self.data.getValue(i)]);
 			}
-			self.data.deinit(main.globalAllocator);
+			self.data.deinit();
 			self.data = newData;
 			self.paletteLength = self.activePaletteEntries;
 			self.palette = main.globalAllocator.realloc(self.palette, @as(usize, 1) << self.data.bitSize);

src/utils/heap.zig

@@ -490,7 +490,7 @@ pub const NeverFailingArenaAllocator = struct { // MARK: NeverFailingArena
 };
 
 /// basically a copy of std.heap.MemoryPool, except it's thread-safe and has some more diagnostics.
-pub fn MemoryPool(Item: type) type {
+pub fn MemoryPool(Item: type) type { // MARK: MemoryPool
 	return struct {
 		const Pool = @This();
 
@@ -526,8 +526,8 @@ pub fn MemoryPool(Item: type) type {
 		pub fn deinit(pool: *Pool) void {
 			if(pool.freeAllocations != pool.totalAllocations) {
 				std.log.err("Memory pool of type {s} leaked {} elements", .{@typeName(Item), pool.totalAllocations - pool.freeAllocations});
-			} else {
+			} else if(pool.totalAllocations != 0) {
-				std.log.info("Memory pool of type {s} contained a total of {} MiB ({} elements)", .{@typeName(Item), pool.totalAllocations*item_size >> 20, pool.totalAllocations});
+				std.log.info("{} MiB ({} elements) in {s} Memory pool", .{pool.totalAllocations*item_size >> 20, pool.totalAllocations, @typeName(Item)});
 			}
 			pool.arena.deinit();
 			pool.* = undefined;
@@ -572,3 +572,127 @@ pub fn MemoryPool(Item: type) type {
 		}
 	};
 }
+
+pub fn PowerOfTwoPoolAllocator(minSize: comptime_int, maxSize: comptime_int, maxAlignment: comptime_int) type { // MARK: PowerOfTwoPoolAllocator
+	std.debug.assert(std.math.isPowerOfTwo(minSize));
+	std.debug.assert(std.math.isPowerOfTwo(maxSize));
+	std.debug.assert(maxSize > minSize);
+	std.debug.assert(minSize >= maxAlignment);
+	std.debug.assert(minSize >= @sizeOf(usize));
+
+	const alignment = @max(maxAlignment, @sizeOf(usize));
+
+	const baseShift = std.math.log2_int(usize, minSize);
+	const bucketCount = std.math.log2_int(usize, maxSize) - baseShift + 1;
+	return struct {
+		const Self = @This();
+
+		const Node = struct {
+			next: ?*align(alignment) @This(),
+		};
+		const NodePtr = *align(alignment) Node;
+
+		const Bucket = struct {
+			freeLists: ?*align(alignment) Node = null,
+			freeAllocations: usize = 0,
+			totalAllocations: usize = 0,
+
+			pub fn deinit(self: *Bucket, size: usize) void {
+				if(self.freeAllocations != self.totalAllocations) {
+					std.log.err("PowerOfTwoPoolAllocator bucket of size {} leaked {} elements", .{size, self.totalAllocations - self.freeAllocations});
+				} else if(self.totalAllocations != 0) {
+					std.log.info("{} MiB ({} elements) in size {} PowerOfTwoPoolAllocator bucket", .{self.totalAllocations*size >> 20, self.totalAllocations, size});
+				}
+				self.* = undefined;
+			}
+
+			/// Creates a new item and adds it to the memory pool.
+			pub fn create(self: *Bucket, arena: NeverFailingAllocator, size: usize) [*]u8 {
+				const node = if(self.freeLists) |item| blk: {
+					self.freeLists = item.next;
+					break :blk item;
+				} else @as(NodePtr, @ptrCast(self.allocNew(arena, size)));
+
+				self.freeAllocations -= 1;
+				return @ptrCast(node);
+			}
+
+			/// Destroys a previously created item.
+			/// Only pass items to `ptr` that were previously created with `create()` of the same memory pool!
+			pub fn destroy(self: *Bucket, ptr: [*]u8) void {
+				const node = @as(NodePtr, @ptrCast(@alignCast(ptr)));
+				node.* = Node{
+					.next = self.freeLists,
+				};
+				self.freeLists = node;
+				self.freeAllocations += 1;
+			}
+
+			fn allocNew(self: *Bucket, arena: NeverFailingAllocator, size: usize) [*]align(alignment) u8 {
+				self.totalAllocations += 1;
+				self.freeAllocations += 1;
+				return arena.alignedAlloc(u8, alignment, size).ptr;
+			}
+		};
+
+		arena: NeverFailingArenaAllocator,
+		buckets: [bucketCount]Bucket = @splat(.{}),
+		mutex: std.Thread.Mutex = .{},
+
+		pub fn init(backingAllocator: NeverFailingAllocator) Self {
+			return .{.arena = .init(backingAllocator)};
+		}
+
+		pub fn deinit(self: *Self) void {
+			for(&self.buckets, 0..) |*bucket, i| {
+				bucket.deinit(@as(usize, minSize) << @intCast(i));
+			}
+			self.arena.deinit();
+		}
+
+		pub fn allocator(self: *Self) NeverFailingAllocator {
+			return .{
+				.allocator = .{
+					.vtable = &.{
+						.alloc = &alloc,
+						.resize = &resize,
+						.remap = &remap,
+						.free = &free,
+					},
+					.ptr = self,
+				},
+				.IAssertThatTheProvidedAllocatorCantFail = {},
+			};
+		}
+
+		fn alloc(ctx: *anyopaque, len: usize, _alignment: std.mem.Alignment, _: usize) ?[*]u8 {
+			std.debug.assert(@as(usize, 1) << @intFromEnum(_alignment) <= maxAlignment);
+			std.debug.assert(std.math.isPowerOfTwo(len));
+			std.debug.assert(len >= minSize);
+			std.debug.assert(len <= maxSize);
+			const self: *Self = @ptrCast(@alignCast(ctx));
+			const bucket = @ctz(len) - baseShift;
+			self.mutex.lock();
+			defer self.mutex.unlock();
+			return self.buckets[bucket].create(self.arena.allocator(), len);
+		}
+
+		fn resize(_: *anyopaque, _: []u8, _: std.mem.Alignment, _: usize, _: usize) bool {
+			return false;
+		}
+
+		fn remap(_: *anyopaque, _: []u8, _: std.mem.Alignment, _: usize, _: usize) ?[*]u8 {
+			return null;
+		}
+
+		fn free(ctx: *anyopaque, memory: []u8, _alignment: std.mem.Alignment, _: usize) void {
+			std.debug.assert(@as(usize, 1) << @intFromEnum(_alignment) <= maxAlignment);
+			std.debug.assert(std.math.isPowerOfTwo(memory.len));
+			const self: *Self = @ptrCast(@alignCast(ctx));
+			const bucket = @ctz(memory.len) - baseShift;
+			self.mutex.lock();
+			defer self.mutex.unlock();
+			self.buckets[bucket].destroy(memory.ptr);
+		}
+	};
+}