zig/lib/std/heap/logging_allocator.zig

54 lines
2.1 KiB
Zig

const std = @import("../std.zig");
const Allocator = std.mem.Allocator;
const AnyErrorOutStream = std.io.OutStream(anyerror);
/// This allocator is used in front of another allocator and logs to the provided stream
/// on every call to the allocator. Stream errors are ignored.
/// If https://github.com/ziglang/zig/issues/2586 is implemented, this API can be improved.
pub const LoggingAllocator = struct {
allocator: Allocator,
parent_allocator: *Allocator,
out_stream: *AnyErrorOutStream,
const Self = @This();
pub fn init(parent_allocator: *Allocator, out_stream: *AnyErrorOutStream) Self {
return Self{
.allocator = Allocator{
.reallocFn = realloc,
.shrinkFn = shrink,
},
.parent_allocator = parent_allocator,
.out_stream = out_stream,
};
}
fn realloc(allocator: *Allocator, old_mem: []u8, old_align: u29, new_size: usize, new_align: u29) ![]u8 {
const self = @fieldParentPtr(Self, "allocator", allocator);
if (old_mem.len == 0) {
self.out_stream.print("allocation of {} ", new_size) catch {};
} else {
self.out_stream.print("resize from {} to {} ", old_mem.len, new_size) catch {};
}
const result = self.parent_allocator.reallocFn(self.parent_allocator, old_mem, old_align, new_size, new_align);
if (result) |buff| {
self.out_stream.print("success!\n") catch {};
} else |err| {
self.out_stream.print("failure!\n") catch {};
}
return result;
}
fn shrink(allocator: *Allocator, old_mem: []u8, old_align: u29, new_size: usize, new_align: u29) []u8 {
const self = @fieldParentPtr(Self, "allocator", allocator);
const result = self.parent_allocator.shrinkFn(self.parent_allocator, old_mem, old_align, new_size, new_align);
if (new_size == 0) {
self.out_stream.print("free of {} bytes success!\n", old_mem.len) catch {};
} else {
self.out_stream.print("shrink from {} bytes to {} bytes success!\n", old_mem.len, new_size) catch {};
}
return result;
}
};