tiny.simd.Phast

1pub const Phast = struct {2    data: Data,3    hash: hash_mod.Triple32,45    const Self = @This();67    pub fn init(data: Data) PhastError!Self {8        if (data.isEmpty()) return error.BuildFailed;9        const num_buckets = data.config.numBuckets();10        const slice_length = data.config.placement.sliceLength();11        if (data.config.num_slots > std.math.maxInt(u32) or12            num_buckets > std.math.maxInt(u32) or13            !std.math.isPowerOfTwo(num_buckets) or14            data.seeds.words.len != data.config.seedWordsLen() or15            data.config.placement.num_slice_offsets == 0 or16            !std.math.isPowerOfTwo(slice_length) or17            slice_length > data.config.num_slots or18            data.config.placement.num_slice_offsets !=19                data.config.num_slots - slice_length + 1)20        {21            return error.InvalidData;22        }23        return .{24            .data = data,25            .hash = hash_mod.Triple32.initKey(data.config.hash_key),26        };27    }2829    pub fn index(self: Self, key: u32) u32 {30        const hash = self.hash.hash(key);31        const seed = self.data.seeds.get(hash & self.data.config.bucket_mask);32        return positionFromHashAndSeed(self.data.config.placement, hash, seed);33    }3435    pub fn twoVec(36        self: Self,37        comptime D: type,38        first_keys: D.Vector,39        second_keys: D.Vector,40    ) VectorPair(D) {41        requireTag(D);42        var first_hashes = first_keys;43        var second_hashes = second_keys;44        self.hash.twoVec(D, &first_hashes, &second_hashes);45        var first_seeds: D.Vector = undefined;46        var second_seeds: D.Vector = undefined;47        inline for (0..D.lane_count) |lane| {48            first_seeds[lane] = self.data.seeds.get(49                first_hashes[lane] & self.data.config.bucket_mask,50            );51            second_seeds[lane] = self.data.seeds.get(52                second_hashes[lane] & self.data.config.bucket_mask,53            );54        }55        return positionPairFromHashesAndSeeds(56            self.data.config.placement,57            D,58            first_hashes,59            second_hashes,60            first_seeds,61            second_seeds,62        );63    }6465    pub fn indexBatch(66        self: Self,67        comptime D: type,68        keys: []const u32,69        indices: []u32,70    ) PhastError!void {71        requireTag(D);72        if (indices.len != keys.len) return error.PlanMismatch;73        var offset: usize = 0;74        while (offset + 2 * D.lane_count <= keys.len) : (offset += 2 * D.lane_count) {75            const first: D.Vector = keys[offset..][0..D.lane_count].*;76            const second: D.Vector = keys[offset + D.lane_count ..][0..D.lane_count].*;77            const result = self.twoVec(D, first, second);78            const first_indices: [D.lane_count]u32 = result.first;79            const second_indices: [D.lane_count]u32 = result.second;80            @memcpy(indices[offset..][0..D.lane_count], &first_indices);81            @memcpy(indices[offset + D.lane_count ..][0..D.lane_count], &second_indices);82        }83        for (keys[offset..], indices[offset..]) |key, *output| output.* = self.index(key);84    }85};

1pub const Phast = phast.Phast;