47 lines
1.5 KiB
Zig
47 lines
1.5 KiB
Zig
const assert = @import("debug.zig").assert;
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const math = @import("math.zig");
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const os = @import("os.zig");
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const io = @import("io.zig");
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pub error NoMem;
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pub type Context = u8;
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pub struct Allocator {
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alloc_fn: fn (self: &Allocator, n: usize) -> %[]u8,
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realloc_fn: fn (self: &Allocator, old_mem: []u8, new_size: usize) -> %[]u8,
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free_fn: fn (self: &Allocator, mem: []u8),
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context: ?&Context,
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/// Aborts the program if an allocation fails.
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fn checked_alloc(self: &Allocator, inline T: type, n: usize) -> []T {
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alloc(self, T, n) %% |err| {
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// TODO var args printf
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%%io.stderr.write("allocation failure: ");
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%%io.stderr.write(@err_name(err));
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%%io.stderr.printf("\n");
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os.abort()
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}
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}
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fn alloc(self: &Allocator, inline T: type, n: usize) -> %[]T {
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const byte_count = %return math.mul_overflow(usize, @sizeof(T), n);
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([]T)(%return self.alloc_fn(self, byte_count))
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}
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fn realloc(self: &Allocator, inline T: type, old_mem: []T, n: usize) -> %[]T {
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const byte_count = %return math.mul_overflow(usize, @sizeof(T), n);
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([]T)(%return self.realloc_fn(self, ([]u8)(old_mem), byte_count))
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}
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fn free(self: &Allocator, inline T: type, mem: []T) {
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self.free_fn(self, ([]u8)(mem));
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}
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}
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/// Copy all of source into dest at position 0.
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/// dest.len must be >= source.len.
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pub fn copy(inline T: type, dest: []T, source: []T) {
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assert(dest.len >= source.len);
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@memcpy(dest.ptr, source.ptr, @sizeof(T) * source.len);
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}
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