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stage2/utils/set.spl

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+// Expect retcode = 0
+
+// 开放寻址集合。键按字节复制到集合自己的存储中；集合只释放自身存储，
+// 不释放键值内部引用的资源。哈希与相等回调的约定和 Map 一致。
+type .{ .Status } = @import("error.spl");
+type .{ .Map, .LookupResult } = @import("map.spl");
+type .{ .ByteView } = @import("byte_view.spl");
+type .{ .hash_usize, .eq_usize, .hash_view, .eq_view } = @import("hash.spl");
+
+type Set = @self;
+
+map: Map,
+
+fn new(key_size: usize, key_align: usize,
+       hash_fn: fn(*u8): usize, eq_fn: fn(*u8, *u8): bool): Set {
+    ret Set {
+        .map = Map.new(key_size, key_align, 1, 1, hash_fn, eq_fn),
+    };
+}
+
+fn valid(self: Set): bool {
+    ret Map.valid(self.map) && self.map.val_size == 1;
+}
+
+fn size(self: Set): usize {
+    ret self.map.size;
+}
+
+fn capacity(self: Set): usize {
+    ret self.map.states.cap;
+}
+
+fn reserve(self: *Set, need: usize): Status {
+    ret Map.reserve(&self.map, need);
+}
+
+// 重复插入保持集合大小不变。
+fn insert(self: *Set, key: *u8): Status {
+    var marker: u8 = 1;
+    ret Map.put(&self.map, key, &marker);
+}
+
+fn find(self: *Set, key: *u8): LookupResult {
+    var marker: u8 = 0;
+    ret Map.get(&self.map, key, &marker);
+}
+
+fn remove(self: *Set, key: *u8): LookupResult {
+    ret Map.del(&self.map, key);
+}
+
+// 遍历 [0, slot_count)；仅 slot_occupied 为真时 key_at 有效。
+fn slot_count(self: Set): usize {
+    ret Map.slot_count(self.map);
+}
+
+fn slot_occupied(self: Set, index: usize): bool {
+    ret Map.slot_occupied(Map.slot_state(self.map, index));
+}
+
+fn key_at(self: *Set, index: usize): *u8 {
+    ret Map.key_at(&self.map, index);
+}
+
+fn clear(self: *Set) {
+    Map.clear(&self.map);
+}
+
+fn take(source: *Set): Set {
+    ret Set { .map = Map.take(&source.map) };
+}
+
+fn drop(self: *Set) {
+    Map.drop(&self.map);
+}
+
+// ---- 测试 ----
+
+fn expect_ok(result: Status) {
+    match result {
+        .Ok => {},
+        .Err(error) => { @assert(false, "unexpected Set error"); },
+    }
+}
+
+fn found(set: *Set, key: *u8): bool {
+    match find(set, key) {
+        .Found => { ret true; },
+        .NotFound => { ret false; },
+    }
+    ret false;
+}
+
+fn removed(set: *Set, key: *u8): bool {
+    match remove(set, key) {
+        .Found => { ret true; },
+        .NotFound => { ret false; },
+    }
+    ret false;
+}
+
+fn constant_hash(key: *u8): usize {
+    ret 3;
+}
+
+fn test_insert_find_remove() {
+    var set = new(@sizeof(usize), @alignof(usize), hash_usize, eq_usize);
+    defer { drop(&set); }
+    @assert(valid(set));
+    @assert(size(set) == 0 && capacity(set) == 0);
+
+    var i: usize = 0;
+    while i < 1000 {
+        expect_ok(insert(&set, &i as *u8));
+        i = i + 1;
+    }
+    @assert(size(set) == 1000, "all unique keys inserted");
+
+    i = 0;
+    while i < 1000 {
+        @assert(found(&set, &i as *u8), "key survives growth");
+        i = i + 1;
+    }
+
+    // 重复键不增加 size。
+    i = 0;
+    while i < 1000 {
+        expect_ok(insert(&set, &i as *u8));
+        i = i + 1;
+    }
+    @assert(size(set) == 1000, "duplicate insertion is idempotent");
+
+    i = 0;
+    while i < 1000 {
+        if i % 2 == 0 { @assert(removed(&set, &i as *u8)); }
+        i = i + 1;
+    }
+    @assert(size(set) == 500);
+
+    i = 0;
+    while i < 1000 {
+        @assert(found(&set, &i as *u8) == (i % 2 != 0), "removed membership");
+        i = i + 1;
+    }
+
+    i = 0;
+    while i < 1000 {
+        if i % 2 == 0 { expect_ok(insert(&set, &i as *u8)); }
+        i = i + 1;
+    }
+    @assert(size(set) == 1000, "removed keys can be reinserted");
+
+    var occupied: usize = 0;
+    i = 0;
+    while i < slot_count(set) {
+        if slot_occupied(set, i) {
+            var key = (key_at(&set, i) as *usize).*;
+            @assert(key < 1000, "iteration yields stored key");
+            occupied = occupied + 1;
+        }
+        i = i + 1;
+    }
+    @assert(occupied == size(set), "iteration visits each member once");
+
+    var missing: usize = 2000;
+    @assert(!removed(&set, &missing as *u8));
+    clear(&set);
+    @assert(size(set) == 0 && capacity(set) != 0, "clear retains allocation");
+}
+
+fn test_collisions_and_take() {
+    var set = new(@sizeof(usize), @alignof(usize), constant_hash, eq_usize);
+    defer { drop(&set); }
+
+    var i: usize = 0;
+    while i < 64 {
+        expect_ok(insert(&set, &i as *u8));
+        i = i + 1;
+    }
+    i = 0;
+    while i < 64 {
+        @assert(found(&set, &i as *u8), "collision chain lookup");
+        i = i + 1;
+    }
+
+    // 删除整条碰撞链后重新插入，验证墓碑会被复用且探测会终止。
+    i = 0;
+    while i < 64 {
+        @assert(removed(&set, &i as *u8));
+        i = i + 1;
+    }
+    @assert(size(set) == 0);
+    i = 64;
+    while i < 128 {
+        expect_ok(insert(&set, &i as *u8));
+        i = i + 1;
+    }
+    i = 64;
+    while i < 128 {
+        @assert(found(&set, &i as *u8), "tombstone collision chain reuse");
+        i = i + 1;
+    }
+
+    var moved = take(&set);
+    defer { drop(&moved); }
+    @assert(size(set) == 0 && capacity(set) == 0, "take clears source");
+    @assert(size(moved) == 64, "take preserves members");
+    i = 64;
+    while i < 128 {
+        @assert(found(&moved, &i as *u8));
+        i = i + 1;
+    }
+}
+
+fn test_byte_view_keys() {
+    var set = new(@sizeof(ByteView), @alignof(ByteView), hash_view, eq_view);
+    defer { drop(&set); }
+
+    var alpha = ByteView.from_slice("alpha");
+    var alpha_copy = ByteView.from_slice("alpha");
+    var beta = ByteView.from_slice("beta");
+    expect_ok(insert(&set, &alpha as *u8));
+    expect_ok(insert(&set, &alpha_copy as *u8));
+    expect_ok(insert(&set, &beta as *u8));
+    @assert(size(set) == 2, "ByteView keys compare by content");
+    @assert(found(&set, &alpha_copy as *u8));
+    @assert(removed(&set, &alpha_copy as *u8));
+    @assert(!found(&set, &alpha as *u8));
+}
+
+fn main() {
+    test_insert_find_remove();
+    test_collisions_and_take();
+    test_byte_view_keys();
+}