move netsurf and mimalloc into modules

src/mimalloc/mimalloc.zig

@@ -0,0 +1,76 @@
+// Copyright (C) 2023-2024  Lightpanda (Selecy SAS)
+//
+// Francis Bouvier <francis@lightpanda.io>
+// Pierre Tachoire <pierre@lightpanda.io>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+// This file makes the glue between mimalloc heap allocation and libdom memory
+// management.
+// We replace the libdom default usage of allocations with mimalloc heap
+// allocation to be able to free all memory used at once, like an arena usage.
+
+const std = @import("std");
+const c = @cImport({
+    @cInclude("mimalloc.h");
+});
+
+const Error = error{
+    HeapNotNull,
+    HeapNull,
+};
+
+var heap: ?*c.mi_heap_t = null;
+
+pub fn create() Error!void {
+    if (heap != null) return Error.HeapNotNull;
+    heap = c.mi_heap_new();
+    if (heap == null) return Error.HeapNull;
+}
+
+pub fn destroy() void {
+    if (heap == null) return;
+    c.mi_heap_destroy(heap.?);
+    heap = null;
+}
+
+pub export fn m_alloc(size: usize) callconv(.C) ?*anyopaque {
+    if (heap == null) return null;
+    return c.mi_heap_malloc(heap.?, size);
+}
+
+pub export fn re_alloc(ptr: ?*anyopaque, size: usize) callconv(.C) ?*anyopaque {
+    if (heap == null) return null;
+    return c.mi_heap_realloc(heap.?, ptr, size);
+}
+
+pub export fn c_alloc(nmemb: usize, size: usize) callconv(.C) ?*anyopaque {
+    if (heap == null) return null;
+    return c.mi_heap_calloc(heap.?, nmemb, size);
+}
+
+pub export fn str_dup(s: [*c]const u8) callconv(.C) [*c]u8 {
+    if (heap == null) return null;
+    return c.mi_heap_strdup(heap.?, s);
+}
+
+pub export fn strn_dup(s: [*c]const u8, size: usize) callconv(.C) [*c]u8 {
+    if (heap == null) return null;
+    return c.mi_heap_strndup(heap.?, s, size);
+}
+
+// NOOP, use destroy to clear all the memory allocated at once.
+pub export fn f_ree(_: ?*anyopaque) callconv(.C) void {
+    return;
+}