array_list.zig:
- adds ArrayList.initCapacity(*Allocator,usize) to allow preallocation of a block at initialization to reduce future allocations.
- adds a test for ArrayList.initCapacity() that ensures ArrayList.len() is unchanged and that at least the requested amount is allocated for.
buffer.zig:
- adds Buffer.initCapacity(*Allocator,usize), based off of ArrayList.initCapacity(), to preallocate a buffer before use.
note: contrary to Buffer.initSize(0) and then Buffer.list.ensureCapacity(200) (the presumed current method), this only allocates once instead of twice.
- adds Buffer.capacity to check usable allocated space, not including the null byte.
note: returns 0 when Buffer has only a null byte or when initNull() was used before without resize()/replaceContents().
- adds a test "Buffer.initCapacity" which ensures that Buffer.append()'s with [added size <= Buffer.capacity()-Buffer.len()] do not cause a reallocation to occur.
- adds a test "Buffer.initSize" which ensures that Buffer.initSize() behaves as expected, also combined with Buffer.append().
- adds a doc comment to Buffer.initSize() that makes its function and distinction from Buffer.initCapacity() clearer.
Added Buffer.initCapcity() to buffer to allow preallocation of a block of memory to reduce future allocations. Uses the added ArrayList.initCapacity() function to achieve this.
Added Buffer.capacity() to track current usable allocation size, not counting null byte, and returning 0 if empty or created with Buffer.initNull()
Added a test for initCapacity() that shows that no further allocation is performed for an append of size smaller than or equal to capacity when initCapacity is used.
Added a test for initSize(), since it did not exist already.
Also added a comment to better explain the difference between initSize() and initCapacity()
note: forgot in the first commit but thanks to mikdusan for helping me brainstorm, through the process, and for drawing up a draft diff which I tweaked.
Added ArrayList.initCapcity() as a way to preallocate a block of memory to reduce future allocations.
Added a test "std.ArrayList.initCapacity" that ensures initCapacity adds no elements and increases capacity by at least the requested amount
Show differing pointer values when comparing pointers instead of the
content they point to.
It's confusing for a test to say "expected S{.x = 1}, found S{.x = 1}"
as illustrated below when it was the pointers that differed.
There seems to be different rules for when a pointer is dereferenced by
the printing routine depending on its type. I don't fully grok this but
it's also illustrated below.
const std = @import("std");
const S = struct { x: u32 };
// before: ...expected S{ .x = 1 }, found S{ .x = 1 }
// after: ...expected S@7ffcd20b7798, found S@7ffcd20b7790
test "compare_ptr_to_struct" {
var a = S{.x = 1};
var b = S{.x = 1};
std.testing.expectEqual(&a, &b);
}
// before: ...expected u32@7fff316ba31c, found u32@7fff316ba318
// after: ...expected u32@7ffecec622dc, found u32@7ffecec622d8
test "compare_ptr_to_scalar" {
var a: u32 = 1;
var b: u32 = 1;
std.testing.expectEqual(&a, &b);
}
This removes the remaining hack in the implementation of anonymous
struct literals, and they can now therefore now have greater than 16
fields/elements.
