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collations: Refactor to separate basic collation information from data #13868

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merged 1 commit into from
Aug 29, 2023
Merged

collations: Refactor to separate basic collation information from data #13868

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16 changes: 8 additions & 8 deletions go.mod
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -72,15 +72,15 @@ require (
go.etcd.io/etcd/client/pkg/v3 v3.5.8
go.etcd.io/etcd/client/v3 v3.5.8
go.uber.org/mock v0.2.0
golang.org/x/crypto v0.8.0 // indirect
golang.org/x/mod v0.11.0 // indirect
golang.org/x/net v0.9.0
golang.org/x/crypto v0.12.0 // indirect
golang.org/x/mod v0.12.0 // indirect
golang.org/x/net v0.14.0
golang.org/x/oauth2 v0.7.0
golang.org/x/sys v0.8.0 // indirect
golang.org/x/term v0.8.0
golang.org/x/text v0.9.0
golang.org/x/sys v0.11.0 // indirect
golang.org/x/term v0.11.0
golang.org/x/text v0.12.0
golang.org/x/time v0.3.0
golang.org/x/tools v0.8.0
golang.org/x/tools v0.12.1-0.20230815132531-74c255bcf846
google.golang.org/api v0.121.0
google.golang.org/genproto v0.0.0-20230410155749-daa745c078e1 // indirect
google.golang.org/grpc v1.55.0-dev
Expand All @@ -107,7 +107,7 @@ require (
github.com/spf13/jwalterweatherman v1.1.0
github.com/xlab/treeprint v1.2.0
go.uber.org/goleak v1.2.1
golang.org/x/sync v0.1.0
golang.org/x/sync v0.3.0
modernc.org/sqlite v1.20.3
)

Expand Down
31 changes: 16 additions & 15 deletions go.sum
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -667,8 +667,8 @@ golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5y
golang.org/x/crypto v0.0.0-20211108221036-ceb1ce70b4fa/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
golang.org/x/crypto v0.0.0-20211117183948-ae814b36b871/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
golang.org/x/crypto v0.0.0-20220314234659-1baeb1ce4c0b/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
golang.org/x/crypto v0.8.0 h1:pd9TJtTueMTVQXzk8E2XESSMQDj/U7OUu0PqJqPXQjQ=
golang.org/x/crypto v0.8.0/go.mod h1:mRqEX+O9/h5TFCrQhkgjo2yKi0yYA+9ecGkdQoHrywE=
golang.org/x/crypto v0.12.0 h1:tFM/ta59kqch6LlvYnPa0yx5a83cL2nHflFhYKvv9Yk=
golang.org/x/crypto v0.12.0/go.mod h1:NF0Gs7EO5K4qLn+Ylc+fih8BSTeIjAP05siRnAh98yw=
golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
Expand Down Expand Up @@ -705,8 +705,8 @@ golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
golang.org/x/mod v0.7.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
golang.org/x/mod v0.11.0 h1:bUO06HqtnRcc/7l71XBe4WcqTZ+3AH1J59zWDDwLKgU=
golang.org/x/mod v0.11.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
golang.org/x/mod v0.12.0 h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
golang.org/x/net v0.0.0-20180218175443-cbe0f9307d01/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
Expand Down Expand Up @@ -759,8 +759,8 @@ golang.org/x/net v0.0.0-20220127200216-cd36cc0744dd/go.mod h1:CfG3xpIq0wQ8r1q4Su
golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
golang.org/x/net v0.1.0/go.mod h1:Cx3nUiGt4eDBEyega/BKRp+/AlGL8hYe7U9odMt2Cco=
golang.org/x/net v0.3.0/go.mod h1:MBQ8lrhLObU/6UmLb4fmbmk5OcyYmqtbGd/9yIeKjEE=
golang.org/x/net v0.9.0 h1:aWJ/m6xSmxWBx+V0XRHTlrYrPG56jKsLdTFmsSsCzOM=
golang.org/x/net v0.9.0/go.mod h1:d48xBJpPfHeWQsugry2m+kC02ZBRGRgulfHnEXEuWns=
golang.org/x/net v0.14.0 h1:BONx9s002vGdD9umnlX1Po8vOZmrgH34qlHcD1MfK14=
golang.org/x/net v0.14.0/go.mod h1:PpSgVXXLK0OxS0F31C1/tv6XNguvCrnXIDrFMspZIUI=
golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
Expand All @@ -784,8 +784,9 @@ golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJ
golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
golang.org/x/sync v0.3.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
golang.org/x/sys v0.0.0-20180823144017-11551d06cbcc/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
Expand Down Expand Up @@ -856,14 +857,14 @@ golang.org/x/sys v0.0.0-20220908164124-27713097b956/go.mod h1:oPkhp1MJrh7nUepCBc
golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/sys v0.11.0 h1:eG7RXZHdqOJ1i+0lgLgCpSXAp6M3LYlAo6osgSi0xOM=
golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
golang.org/x/term v0.1.0/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
golang.org/x/term v0.3.0/go.mod h1:q750SLmJuPmVoN1blW3UFBPREJfb1KmY3vwxfr+nFDA=
golang.org/x/term v0.8.0 h1:n5xxQn2i3PC0yLAbjTpNT85q/Kgzcr2gIoX9OrJUols=
golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
golang.org/x/term v0.11.0 h1:F9tnn/DA/Im8nCwm+fX+1/eBwi4qFjRT++MhtVC4ZX0=
golang.org/x/term v0.11.0/go.mod h1:zC9APTIj3jG3FdV/Ons+XE1riIZXG4aZ4GTHiPZJPIU=
golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
Expand All @@ -875,8 +876,8 @@ golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
golang.org/x/text v0.3.8/go.mod h1:E6s5w1FMmriuDzIBO73fBruAKo1PCIq6d2Q6DHfQ8WQ=
golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
golang.org/x/text v0.5.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
golang.org/x/text v0.9.0 h1:2sjJmO8cDvYveuX97RDLsxlyUxLl+GHoLxBiRdHllBE=
golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
golang.org/x/text v0.12.0 h1:k+n5B8goJNdU7hSvEtMUz3d1Q6D/XW4COJSJR6fN0mc=
golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
Expand Down Expand Up @@ -936,8 +937,8 @@ golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
golang.org/x/tools v0.1.1/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
golang.org/x/tools v0.4.0/go.mod h1:UE5sM2OK9E/d67R0ANs2xJizIymRP5gJU295PvKXxjQ=
golang.org/x/tools v0.8.0 h1:vSDcovVPld282ceKgDimkRSC8kpaH1dgyc9UMzlt84Y=
golang.org/x/tools v0.8.0/go.mod h1:JxBZ99ISMI5ViVkT1tr6tdNmXeTrcpVSD3vZ1RsRdN4=
golang.org/x/tools v0.12.1-0.20230815132531-74c255bcf846 h1:Vve/L0v7CXXuxUmaMGIEK/dEeq7uiqb5qBgQrZzIE7E=
golang.org/x/tools v0.12.1-0.20230815132531-74c255bcf846/go.mod h1:Sc0INKfu04TlqNoRA1hgpFZbhYXHPr4V5DzpSBTPqQM=
golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
Expand Down
212 changes: 5 additions & 207 deletions go/mysql/collations/coercion.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,8 +19,6 @@ package collations
import (
"fmt"
"unsafe"

"vitess.io/vitess/go/mysql/collations/charset"
)

func init() {
Expand Down Expand Up @@ -95,11 +93,6 @@ const (
RepertoireUnicode
)

// Coercion is a function that will transform either the given argument
// arguments of the function into a specific character set. The `dst` argument
// will be used as the destination of the coerced argument, but it can be nil.
type Coercion func(dst, in []byte) ([]byte, error)

// TypedCollation is the Collation of a SQL expression, including its coercibility
// and repertoire.
type TypedCollation struct {
Expand All @@ -112,208 +105,13 @@ func (tc TypedCollation) Valid() bool {
return tc.Collation != Unknown
}

func checkCompatibleCollations(
left Collation, leftCoercibility Coercibility, leftRepertoire Repertoire,
right Collation, rightCoercibility Coercibility, rightRepertoire Repertoire,
) bool {
leftCS := left.Charset()
rightCS := right.Charset()

switch leftCS.(type) {
case charset.Charset_utf8mb4:
if leftCoercibility <= rightCoercibility {
return true
}

case charset.Charset_utf32:
switch {
case leftCoercibility < rightCoercibility:
return true
case leftCoercibility == rightCoercibility:
if !charset.IsUnicode(rightCS) {
return true
}
if !left.IsBinary() {
return true
}
}

case charset.Charset_utf8mb3, charset.Charset_ucs2, charset.Charset_utf16, charset.Charset_utf16le:
switch {
case leftCoercibility < rightCoercibility:
return true
case leftCoercibility == rightCoercibility:
if !charset.IsUnicode(rightCS) {
return true
}
}
}

if rightRepertoire == RepertoireASCII {
switch {
case leftCoercibility < rightCoercibility:
return true
case leftCoercibility == rightCoercibility:
if leftRepertoire == RepertoireUnicode {
return true
}
}
}

return false
}

// CoercionOptions is used to configure how aggressive the algorithm can be
// when merging two different collations by transcoding them.
type CoercionOptions struct {
// ConvertToSuperset allows merging two different collations as long
// as the charset of one of them is a strict superset of the other. In
// order to operate on the two expressions, one of them will need to
// be transcoded. This transcoding will always be safe because the string
// with the smallest repertoire will be transcoded to its superset, which
// cannot fail.
ConvertToSuperset bool

// ConvertWithCoercion allows merging two different collations by forcing
// a coercion as long as the coercibility of the two sides is lax enough.
// This will force a transcoding of one of the expressions even if their
// respective charsets are not a strict superset, so the resulting transcoding
// CAN fail depending on the content of their strings.
ConvertWithCoercion bool
}

// MergeCollations returns a Coercion function for a pair of TypedCollation based
// on their coercibility.
//
// The function takes the typed collations for the two sides of a text operation
// (namely, a comparison or concatenation of two textual expressions). These typed
// collations includes the actual collation for the expression on each size, their
// coercibility values (see: Coercibility) and their respective repertoires,
// and returns the target collation (i.e. the collation into which the two expressions
// must be coerced, and a Coercion function. The Coercion function can be called repeatedly
// with the different values for the two expressions and will transcode either
// the left-hand or right-hand value to the appropriate charset so it can be
// collated against the other value.
//
// If the collations for both sides of the expressions are the same, the returned
// Coercion function will be a no-op. Likewise, if the two collations are not the same,
// but they are compatible and have the same charset, the Coercion function will also
// be a no-op.
//
// If the collations for both sides of the expression are not compatible, an error
// will be returned and the returned TypedCollation and Coercion will be nil.
func (env *Environment) MergeCollations(left, right TypedCollation, opt CoercionOptions) (TypedCollation, Coercion, Coercion, error) {
leftColl := left.Collation.Get()
rightColl := right.Collation.Get()
if leftColl == nil || rightColl == nil {
return TypedCollation{}, nil, nil, fmt.Errorf("unsupported TypeCollationID: %v / %v", left.Collation, right.Collation)
}

leftCS := leftColl.Charset()
rightCS := rightColl.Charset()

if left.Coercibility == CoerceExplicit && right.Coercibility == CoerceExplicit {
if left.Collation != right.Collation {
goto cannotCoerce
}
}

if leftCS.Name() == rightCS.Name() {
switch {
case left.Coercibility < right.Coercibility:
left.Repertoire |= right.Repertoire
return left, nil, nil, nil

case left.Coercibility > right.Coercibility:
right.Repertoire |= left.Repertoire
return right, nil, nil, nil

case left.Collation == right.Collation:
left.Repertoire |= right.Repertoire
return left, nil, nil, nil
}

if left.Coercibility == CoerceExplicit {
goto cannotCoerce
}

leftCsBin := leftColl.IsBinary()
rightCsBin := rightColl.IsBinary()

switch {
case leftCsBin && rightCsBin:
left.Coercibility = CoerceNone
return left, nil, nil, nil

case leftCsBin:
return left, nil, nil, nil

case rightCsBin:
return right, nil, nil, nil
}

defaults := env.byCharset[leftCS.Name()]
return TypedCollation{
Collation: defaults.Binary.ID(),
Coercibility: CoerceNone,
Repertoire: left.Repertoire | right.Repertoire,
}, nil, nil, nil
}

if _, leftIsBinary := leftColl.(*Collation_binary); leftIsBinary {
if left.Coercibility <= right.Coercibility {
return left, nil, nil, nil
}
goto coerceToRight
}
if _, rightIsBinary := rightColl.(*Collation_binary); rightIsBinary {
if left.Coercibility >= right.Coercibility {
return right, nil, nil, nil
}
goto coerceToLeft
}

if opt.ConvertToSuperset {
if checkCompatibleCollations(leftColl, left.Coercibility, left.Repertoire, rightColl, right.Coercibility, right.Repertoire) {
goto coerceToLeft
}
if checkCompatibleCollations(rightColl, right.Coercibility, right.Repertoire, leftColl, left.Coercibility, left.Repertoire) {
goto coerceToRight
}
}

if opt.ConvertWithCoercion {
if left.Coercibility < right.Coercibility && right.Coercibility > CoerceImplicit {
goto coerceToLeft
}
if right.Coercibility < left.Coercibility && left.Coercibility > CoerceImplicit {
goto coerceToRight
}
}

cannotCoerce:
return TypedCollation{}, nil, nil, fmt.Errorf("Illegal mix of collations (%s,%s) and (%s,%s)",
leftColl.Name(), left.Coercibility, rightColl.Name(), right.Coercibility)

coerceToLeft:
return left, nil,
func(dst, in []byte) ([]byte, error) {
return charset.Convert(dst, leftCS, in, rightCS)
}, nil

coerceToRight:
return right,
func(dst, in []byte) ([]byte, error) {
return charset.Convert(dst, rightCS, in, leftCS)
}, nil, nil
}

func (env *Environment) EnsureCollate(fromID, toID ID) error {
// these two lookups should never fail
from := fromID.Get()
to := toID.Get()
if from.Charset().Name() != to.Charset().Name() {
return fmt.Errorf("COLLATION '%s' is not valid for CHARACTER SET '%s'", to.Name(), from.Charset().Name())
fromCharsetName := env.LookupCharsetName(fromID)
toCharsetName := env.LookupCharsetName(toID)
if fromCharsetName != toCharsetName {
toCollName := env.LookupName(toID)
return fmt.Errorf("COLLATION '%s' is not valid for CHARACTER SET '%s'", toCollName, fromCharsetName)
}
return nil
}
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