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const std = @import("std");
const builtin = @import("builtin");
const STATIC_MEMORY_SIZE = 256000;
pub var static_manager: ?std.heap.ArenaAllocator = null;
pub var root_manager: ?RootAlloc = null;
pub var needs_setup: bool = true;
pub var static: *std.mem.Allocator = undefined;
pub var dynamic: *std.mem.Allocator = undefined;
pub fn setup(root: *std.mem.Allocator) !void {
needs_setup = false;
static = root;
dynamic = root;
// static = @ptrCast(*std.mem.Allocator, &stat.allocator);
}
test "GlobalAllocator" {
try setup(std.heap.page_allocator);
var testType = try static.alloc(u8, 10);
testType[1] = 1;
}
pub const HunkSide = struct {
pub const VTable = struct {
alloc: fn (self: *Hunk, n: usize, alignment: u29) std.mem.Allocator.Error![]u8,
getMark: fn (self: *Hunk) usize,
freeToMark: fn (self: *Hunk, pos: usize) void,
};
hunk: *Hunk,
vtable: *const VTable,
allocator: std.mem.Allocator,
pub fn init(hunk: *Hunk, vtable: *const VTable) HunkSide {
return .{
.hunk = hunk,
.vtable = vtable,
.allocator = .{
.allocFn = allocFn,
.resizeFn = resizeFn,
},
};
}
pub fn getMark(self: HunkSide) usize {
return self.vtable.getMark(self.hunk);
}
pub fn freeToMark(self: HunkSide, pos: usize) void {
self.vtable.freeToMark(self.hunk, pos);
}
fn allocFn(allocator: *std.mem.Allocator, len: usize, ptr_align: u29, len_align: u29, ret_addr: usize) std.mem.Allocator.Error![]u8 {
const self = @fieldParentPtr(HunkSide, "allocator", allocator);
return try self.vtable.alloc(self.hunk, len, ptr_align);
}
fn resizeFn(allocator: *std.mem.Allocator, old_mem: []u8, old_align: u29, new_size: usize, len_align: u29, ret_addr: usize) std.mem.Allocator.Error!usize {
if (new_size > old_mem.len) {
return error.OutOfMemory;
}
if (new_size == 0) {
return 0;
}
return std.mem.alignAllocLen(old_mem.len, new_size, len_align);
}
};
pub const Hunk = struct {
low_used: usize,
high_used: usize,
buffer: []u8,
pub fn init(buffer: []u8) Hunk {
return .{
.low_used = 0,
.high_used = 0,
.buffer = buffer,
};
}
pub fn low(self: *Hunk) HunkSide {
const GlobalStorage = struct {
const vtable: HunkSide.VTable = .{
.alloc = allocLow,
.getMark = getLowMark,
.freeToMark = freeToLowMark,
};
};
return HunkSide.init(self, &GlobalStorage.vtable);
}
pub fn high(self: *Hunk) HunkSide {
const GlobalStorage = struct {
const vtable: HunkSide.VTable = .{
.alloc = allocHigh,
.getMark = getHighMark,
.freeToMark = freeToHighMark,
};
};
return HunkSide.init(self, &GlobalStorage.vtable);
}
pub fn allocLow(self: *Hunk, n: usize, alignment: u29) ![]u8 {
const start = @ptrToInt(self.buffer.ptr);
const adjusted_index = std.mem.alignForward(start + self.low_used, alignment) - start;
const new_low_used = adjusted_index + n;
if (new_low_used > self.buffer.len - self.high_used) {
return error.OutOfMemory;
}
const result = self.buffer[adjusted_index..new_low_used];
self.low_used = new_low_used;
return result;
}
pub fn allocHigh(self: *Hunk, n: usize, alignment: u29) ![]u8 {
const addr = @ptrToInt(self.buffer.ptr) + self.buffer.len - self.high_used;
const rem = @rem(addr, alignment);
const march_backward_bytes = rem;
const adjusted_index = self.high_used + march_backward_bytes;
const new_high_used = adjusted_index + n;
if (new_high_used > self.buffer.len - self.low_used) {
return error.OutOfMemory;
}
const start = self.buffer.len - adjusted_index - n;
const result = self.buffer[start .. start + n];
self.high_used = new_high_used;
return result;
}
pub fn getLowMark(self: *Hunk) usize {
return self.low_used;
}
pub fn getHighMark(self: *Hunk) usize {
return self.high_used;
}
pub fn freeToLowMark(self: *Hunk, pos: usize) void {
std.debug.assert(pos <= self.low_used);
if (pos < self.low_used) {
if (std.builtin.mode == std.builtin.Mode.Debug) {
std.mem.set(u8, self.buffer[pos..self.low_used], 0xcc);
}
self.low_used = pos;
}
}
pub fn freeToHighMark(self: *Hunk, pos: usize) void {
std.debug.assert(pos <= self.high_used);
if (pos < self.high_used) {
if (std.builtin.mode == std.builtin.Mode.Debug) {
const i = self.buffer.len - self.high_used;
const n = self.high_used - pos;
std.mem.set(u8, self.buffer[i .. i + n], 0xcc);
}
self.high_used = pos;
}
}
};
// WASM only
// test "Hunk" {
// // test a few random operations. very low coverage. write more later
// var buf: [100]u8 = undefined;
// var hunk = Hunk.init(buf[0..]);
// const high_mark = hunk.getHighMark();
// _ = try hunk.low().allocator.alloc(u8, 7);
// _ = try hunk.high().allocator.alloc(u8, 8);
// std.testing.expectEqual(@as(usize, 7), hunk.low_used);
// std.testing.expectEqual(@as(usize, 8), hunk.high_used);
// _ = try hunk.high().allocator.alloc(u8, 8);
// std.testing.expectEqual(@as(usize, 16), hunk.high_used);
// const low_mark = hunk.getLowMark();
// _ = try hunk.low().allocator.alloc(u8, 100 - 7 - 16);
// std.testing.expectEqual(@as(usize, 100 - 16), hunk.low_used);
// std.testing.expectError(error.OutOfMemory, hunk.high().allocator.alloc(u8, 1));
// hunk.freeToLowMark(low_mark);
// _ = try hunk.high().allocator.alloc(u8, 1);
// hunk.freeToHighMark(high_mark);
// std.testing.expectEqual(@as(usize, 0), hunk.high_used);
// }
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