65 lines
2.3 KiB
Zig
65 lines
2.3 KiB
Zig
const std = @import("../index.zig");
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const mem = std.mem;
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/// Allocator that fails after N allocations, useful for making sure out of
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/// memory conditions are handled correctly.
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pub const FailingAllocator = struct {
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allocator: mem.Allocator,
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index: usize,
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fail_index: usize,
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internal_allocator: *mem.Allocator,
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allocated_bytes: usize,
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freed_bytes: usize,
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deallocations: usize,
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pub fn init(allocator: *mem.Allocator, fail_index: usize) FailingAllocator {
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return FailingAllocator{
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.internal_allocator = allocator,
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.fail_index = fail_index,
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.index = 0,
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.allocated_bytes = 0,
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.freed_bytes = 0,
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.deallocations = 0,
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.allocator = mem.Allocator{
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.allocFn = alloc,
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.reallocFn = realloc,
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.freeFn = free,
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},
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};
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}
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fn alloc(allocator: *mem.Allocator, n: usize, alignment: u29) ![]u8 {
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const self = @fieldParentPtr(FailingAllocator, "allocator", allocator);
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if (self.index == self.fail_index) {
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return error.OutOfMemory;
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}
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const result = try self.internal_allocator.allocFn(self.internal_allocator, n, alignment);
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self.allocated_bytes += result.len;
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self.index += 1;
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return result;
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}
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fn realloc(allocator: *mem.Allocator, old_mem: []u8, new_size: usize, alignment: u29) ![]u8 {
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const self = @fieldParentPtr(FailingAllocator, "allocator", allocator);
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if (new_size <= old_mem.len) {
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self.freed_bytes += old_mem.len - new_size;
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return self.internal_allocator.reallocFn(self.internal_allocator, old_mem, new_size, alignment);
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}
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if (self.index == self.fail_index) {
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return error.OutOfMemory;
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}
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const result = try self.internal_allocator.reallocFn(self.internal_allocator, old_mem, new_size, alignment);
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self.allocated_bytes += new_size - old_mem.len;
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self.deallocations += 1;
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self.index += 1;
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return result;
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}
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fn free(allocator: *mem.Allocator, bytes: []u8) void {
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const self = @fieldParentPtr(FailingAllocator, "allocator", allocator);
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self.freed_bytes += bytes.len;
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self.deallocations += 1;
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return self.internal_allocator.freeFn(self.internal_allocator, bytes);
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}
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};
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