Commit 44db92d1ca90c9cfdfb29fe46f04ff8f11c80901 | zig

author	Travis Staloch <twostepted@gmail.com> 2024-04-30 17:21:44-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2024-05-02 22:09:03-07:00
log	44db92d1ca90c9cfdfb29fe46f04ff8f11c80901
tree	713c0d3e47f69e9b4979c396934a5c4783f29901
parent	ea9d817a905ae19dcf27db4f380270485f9e26d2

std.StaticStringMap: bump eval branch quota

closes #19803 by changing quota from (30 * N) to (10 * N * log2(N)) where
N = kvs_list.len

* adds reported adversarial test case
* update doc comment of getLongestPrefix()

1 files changed, 39 insertions(+), 4 deletions(-)

lib
- std
  - static_string_map.zig

lib/std/static_string_map.zig+39-4

...	@@ -70,11 +70,15 @@ pub fn StaticStringMapWithEql(	...	@@ -70,11 +70,15 @@ pub fn StaticStringMapWithEql(
70	/// (only keys) tuples if `V` is `void`.	70	/// (only keys) tuples if `V` is `void`.
71	pub inline fn initComptime(comptime kvs_list: anytype) Self {	71	pub inline fn initComptime(comptime kvs_list: anytype) Self {
72	comptime {	72	comptime {
73	@setEvalBranchQuota(30 * kvs_list.len);
74	var self = Self{};	73	var self = Self{};
75	if (kvs_list.len == 0)	74	if (kvs_list.len == 0)
76	return self;	75	return self;
77		76
		77	// Since the KVs are sorted, a linearly-growing bound will never
		78	// be sufficient for extreme cases. So we grow proportional to
		79	// N*log2(N).
		80	@setEvalBranchQuota(10 * kvs_list.len * std.math.log2_int_ceil(usize, kvs_list.len));
		81
78	var sorted_keys: [kvs_list.len][]const u8 = undefined;	82	var sorted_keys: [kvs_list.len][]const u8 = undefined;
79	var sorted_vals: [kvs_list.len]V = undefined;	83	var sorted_vals: [kvs_list.len]V = undefined;
80		84
...	@@ -212,8 +216,12 @@ pub fn StaticStringMapWithEql(	...	@@ -212,8 +216,12 @@ pub fn StaticStringMapWithEql(
212	}	216	}
213	}	217	}
214		218
215	/// Returns the longest key, value pair where key is a prefix of `str`	219	/// Returns the key-value pair where key is the longest prefix of `str`
216	/// else null.	220	/// else null.
		221	///
		222	/// This is effectively an O(N) algorithm which loops from `max_len` to
		223	/// `min_len` and calls `getIndex()` to check all keys with the given
		224	/// len.
217	pub fn getLongestPrefix(self: Self, str: []const u8) ?KV {	225	pub fn getLongestPrefix(self: Self, str: []const u8) ?KV {
218	if (self.kvs.len == 0)	226	if (self.kvs.len == 0)
219	return null;	227	return null;
...	@@ -497,6 +505,33 @@ test "getLongestPrefix2" {	...	@@ -497,6 +505,33 @@ test "getLongestPrefix2" {
497	try testing.expectEqual(null, map.getLongestPrefix("xxx"));	505	try testing.expectEqual(null, map.getLongestPrefix("xxx"));
498	}	506	}
499		507
500	test "long kvs_list doesn't exceed @setEvalBranchQuota" {	508	test "sorting kvs doesn't exceed eval branch quota" {
501	_ = TestMapVoid.initComptime([1]TestKVVoid{.{"x"}} ** 1_000);	509	// from https://github.com/ziglang/zig/issues/19803
		510	const TypeToByteSizeLUT = std.StaticStringMap(u32).initComptime(.{
		511	.{ "bool", 0 },
		512	.{ "c_int", 0 },
		513	.{ "c_long", 0 },
		514	.{ "c_longdouble", 0 },
		515	.{ "t20", 0 },
		516	.{ "t19", 0 },
		517	.{ "t18", 0 },
		518	.{ "t17", 0 },
		519	.{ "t16", 0 },
		520	.{ "t15", 0 },
		521	.{ "t14", 0 },
		522	.{ "t13", 0 },
		523	.{ "t12", 0 },
		524	.{ "t11", 0 },
		525	.{ "t10", 0 },
		526	.{ "t9", 0 },
		527	.{ "t8", 0 },
		528	.{ "t7", 0 },
		529	.{ "t6", 0 },
		530	.{ "t5", 0 },
		531	.{ "t4", 0 },
		532	.{ "t3", 0 },
		533	.{ "t2", 0 },
		534	.{ "t1", 1 },
		535	});
		536	try testing.expectEqual(1, TypeToByteSizeLUT.get("t1"));
502	}	537	}