vindexes: Efficient unicode hashing (#14395)

Signed-off-by: Vicent Marti <vmg@strn.cat>
Signed-off-by: Dirkjan Bussink <d.bussink@gmail.com>
Co-authored-by: Dirkjan Bussink <d.bussink@gmail.com>

go.mod

@@ -77,7 +77,7 @@ require (
 	golang.org/x/oauth2 v0.7.0
 	golang.org/x/sys v0.13.0
 	golang.org/x/term v0.13.0
-	golang.org/x/text v0.13.0
+	golang.org/x/text v0.13.0 // indirect
 	golang.org/x/time v0.3.0
 	golang.org/x/tools v0.12.1-0.20230815132531-74c255bcf846
 	google.golang.org/api v0.121.0

go/mysql/collations/colldata/golden_test.go

@@ -25,7 +25,7 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"vitess.io/vitess/go/mysql/collations/charset"
-	"vitess.io/vitess/go/mysql/collations/internal/testutil"
+	"vitess.io/vitess/go/mysql/collations/testutil"
 )
 
 func TestGoldenWeights(t *testing.T) {

go/mysql/collations/integration/collations_test.go

@@ -20,16 +20,17 @@ import (
 	"bufio"
 	"bytes"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"os"
 	"path"
 	"path/filepath"
 	"strings"
 	"testing"
+	"unicode/utf8"
 
 	"github.com/spf13/pflag"
 	"github.com/stretchr/testify/require"
-	"golang.org/x/text/encoding/unicode/utf32"
 
 	"vitess.io/vitess/go/mysql/collations/colldata"
 
@@ -95,16 +96,29 @@ type uca900CollationTest struct {
 	collation string
 }
 
-var defaultUtf32 = utf32.UTF32(utf32.BigEndian, utf32.IgnoreBOM)
+func decodeUtf32(dst, src []byte) ([]byte, error) {
+	for len(src) >= 4 {
+		r := rune(uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3]))
+		dst = utf8.AppendRune(dst, r)
+		src = src[4:]
+	}
+	if len(src) != 0 {
+		return nil, errors.New("short src")
+	}
+	return dst, nil
+}
 
 func parseUtf32cp(b []byte) []byte {
 	var hexbuf [16]byte
 	c, err := hex.Decode(hexbuf[:], b)
 	if err != nil {
 		return nil
 	}
-	utf8, _ := defaultUtf32.NewDecoder().Bytes(hexbuf[:c])
-	return utf8
+	dst, err := decodeUtf32(nil, hexbuf[:c])
+	if err != nil {
+		panic("failed to decode utf32")
+	}
+	return dst
 }
 
 func parseWeightString(b []byte) []byte {

go/mysql/collations/integration/weight_string_test.go

@@ -26,8 +26,8 @@ import (
 	"vitess.io/vitess/go/mysql/collations"
 	"vitess.io/vitess/go/mysql/collations/charset"
 	"vitess.io/vitess/go/mysql/collations/colldata"
-	"vitess.io/vitess/go/mysql/collations/internal/testutil"
 	"vitess.io/vitess/go/mysql/collations/remote"
+	"vitess.io/vitess/go/mysql/collations/testutil"
 )
 
 func TestFastIterators(t *testing.T) {

go/mysql/collations/tools/maketestdata/maketestdata.go

@@ -31,11 +31,11 @@ import (
 	"github.com/spf13/pflag"
 
 	"vitess.io/vitess/go/mysql/collations/colldata"
+	"vitess.io/vitess/go/mysql/collations/testutil"
 
 	"vitess.io/vitess/go/internal/flag"
 	"vitess.io/vitess/go/mysql/collations"
 	"vitess.io/vitess/go/mysql/collations/charset"
-	"vitess.io/vitess/go/mysql/collations/internal/testutil"
 )
 
 func wikiRequest(lang testutil.Lang, args map[string]string, output any) error {

go/mysql/collations/vindex/.gitignore

@@ -0,0 +1,6 @@
+# Add no patterns to .gitignore except for files generated by the build.
+last-change
+/DATA
+# This file is rather large and the tests really only need to be run
+# after generation.
+/unicode/norm/data_test.go

go/mysql/collations/vindex/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

go/mysql/collations/vindex/PATENTS

@@ -0,0 +1,22 @@
+Additional IP Rights Grant (Patents)
+
+"This implementation" means the copyrightable works distributed by
+Google as part of the Go project.
+
+Google hereby grants to You a perpetual, worldwide, non-exclusive,
+no-charge, royalty-free, irrevocable (except as stated in this section)
+patent license to make, have made, use, offer to sell, sell, import,
+transfer and otherwise run, modify and propagate the contents of this
+implementation of Go, where such license applies only to those patent
+claims, both currently owned or controlled by Google and acquired in
+the future, licensable by Google that are necessarily infringed by this
+implementation of Go.  This grant does not include claims that would be
+infringed only as a consequence of further modification of this
+implementation.  If you or your agent or exclusive licensee institute or
+order or agree to the institution of patent litigation against any
+entity (including a cross-claim or counterclaim in a lawsuit) alleging
+that this implementation of Go or any code incorporated within this
+implementation of Go constitutes direct or contributory patent
+infringement, or inducement of patent infringement, then any patent
+rights granted to you under this License for this implementation of Go
+shall terminate as of the date such litigation is filed.

go/mysql/collations/vindex/collate/collate.go

@@ -0,0 +1,68 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// TODO: remove hard-coded versions when we have implemented fractional weights.
+// The current implementation is incompatible with later CLDR versions.
+//go:generate go run maketables.go -cldr=23 -unicode=6.2.0
+
+// Package collate contains types for comparing and sorting Unicode strings
+// according to a given collation order.
+package collate // import "vitess.io/vitess/go/mysql/collations/vindex/collate"
+
+import (
+	"hash"
+
+	"vitess.io/vitess/go/mysql/collations/vindex/internal/colltab"
+)
+
+type Hasher struct {
+	iter    colltab.Iter
+	hash    hash.Hash
+	scratch [32]colltab.Elem
+}
+
+// New returns a new Hasher initialized for the given hash function
+func New(h hash.Hash) *Hasher {
+	c := &Hasher{}
+	c.iter.Weighter = getTable(tableIndex{0x15, 0x0})
+	c.iter.Elems = c.scratch[:0]
+	c.hash = h
+	return c
+}
+
+func (c *Hasher) Hash(str []byte) []byte {
+	c.hash.Reset()
+	c.iter.SetInput(str)
+
+	var scratch [64]byte
+	var pos int
+
+	for c.iter.Next() {
+		for n := 0; n < c.iter.N; n++ {
+			if w := c.iter.Elems[n].Primary(); w > 0 {
+				if w <= 0x7FFF {
+					if len(scratch)-pos < 2 {
+						c.hash.Write(scratch[:pos])
+						pos = 0
+					}
+					scratch[pos+0] = uint8(w >> 8)
+					scratch[pos+1] = uint8(w)
+					pos += 2
+				} else {
+					if len(scratch)-pos < 3 {
+						c.hash.Write(scratch[:pos])
+						pos = 0
+					}
+					scratch[pos+0] = uint8(w>>16) | 0x80
+					scratch[pos+1] = uint8(w >> 8)
+					scratch[pos+2] = uint8(w)
+					pos += 3
+				}
+			}
+		}
+		c.iter.Discard()
+	}
+	c.hash.Write(scratch[:pos])
+	return c.hash.Sum(nil)
+}

go/mysql/collations/vindex/collate/index.go

@@ -0,0 +1,30 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package collate
+
+import "vitess.io/vitess/go/mysql/collations/vindex/internal/colltab"
+
+const blockSize = 64
+
+func getTable(t tableIndex) *colltab.Table {
+	return &colltab.Table{
+		Index: colltab.Trie{
+			Index0:  mainLookup[:][blockSize*t.lookupOffset:],
+			Values0: mainValues[:][blockSize*t.valuesOffset:],
+			Index:   mainLookup[:],
+			Values:  mainValues[:],
+		},
+		ExpandElem:    mainExpandElem[:],
+		ContractTries: mainCTEntries[:],
+		ContractElem:  mainContractElem[:],
+	}
+}
+
+// tableIndex holds information for constructing a table
+// for a certain locale based on the main table.
+type tableIndex struct {
+	lookupOffset uint32
+	valuesOffset uint32
+}