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| 1 | +// Copyright 2019 PingCAP, Inc. |
| 2 | +// |
| 3 | +// Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | +// you may not use this file except in compliance with the License. |
| 5 | +// You may obtain a copy of the License at |
| 6 | +// |
| 7 | +// http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | +// |
| 9 | +// Unless required by applicable law or agreed to in writing, software |
| 10 | +// distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | +// See the License for the specific language governing permissions and |
| 13 | +// limitations under the License. |
| 14 | + |
| 15 | +package bindinfo |
| 16 | + |
| 17 | +import ( |
| 18 | + "time" |
| 19 | + "unsafe" |
| 20 | + |
| 21 | + "github.com/pingcap/tidb/pkg/parser" |
| 22 | + "github.com/pingcap/tidb/pkg/parser/ast" |
| 23 | + "github.com/pingcap/tidb/pkg/sessionctx" |
| 24 | + "github.com/pingcap/tidb/pkg/types" |
| 25 | + "github.com/pingcap/tidb/pkg/util/hint" |
| 26 | + "github.com/pkg/errors" |
| 27 | +) |
| 28 | + |
| 29 | +const ( |
| 30 | + // Enabled is the bind info's in enabled status. |
| 31 | + // It is the same as the previous 'Using' status. |
| 32 | + // Only use 'Enabled' status in the future, not the 'Using' status. |
| 33 | + // The 'Using' status is preserved for compatibility. |
| 34 | + Enabled = "enabled" |
| 35 | + // Disabled is the bind info's in disabled status. |
| 36 | + Disabled = "disabled" |
| 37 | + // Using is the bind info's in use status. |
| 38 | + // The 'Using' status is preserved for compatibility. |
| 39 | + Using = "using" |
| 40 | + // deleted is the bind info's deleted status. |
| 41 | + deleted = "deleted" |
| 42 | + // Invalid is the bind info's invalid status. |
| 43 | + Invalid = "invalid" |
| 44 | + // Manual indicates the binding is created by SQL like "create binding for ...". |
| 45 | + Manual = "manual" |
| 46 | + // Capture indicates the binding is captured by TiDB automatically. |
| 47 | + Capture = "capture" |
| 48 | + // Builtin indicates the binding is a builtin record for internal locking purpose. It is also the status for the builtin binding. |
| 49 | + Builtin = "builtin" |
| 50 | + // History indicate the binding is created from statement summary by plan digest |
| 51 | + History = "history" |
| 52 | +) |
| 53 | + |
| 54 | +// Binding stores the basic bind hint info. |
| 55 | +type Binding struct { |
| 56 | + OriginalSQL string |
| 57 | + Db string |
| 58 | + BindSQL string |
| 59 | + // Status represents the status of the binding. It can only be one of the following values: |
| 60 | + // 1. deleted: Bindings is deleted, can not be used anymore. |
| 61 | + // 2. enabled, using: Binding is in the normal active mode. |
| 62 | + Status string |
| 63 | + CreateTime types.Time |
| 64 | + UpdateTime types.Time |
| 65 | + Source string |
| 66 | + Charset string |
| 67 | + Collation string |
| 68 | + // Hint is the parsed hints, it is used to bind hints to stmt node. |
| 69 | + Hint *hint.HintsSet `json:"-"` |
| 70 | + // ID is the string form of Hint. It would be non-empty only when the status is `Using` or `PendingVerify`. |
| 71 | + ID string `json:"-"` |
| 72 | + SQLDigest string |
| 73 | + PlanDigest string |
| 74 | + |
| 75 | + // TableNames records all schema and table names in this binding statement, which are used for fuzzy matching. |
| 76 | + TableNames []*ast.TableName `json:"-"` |
| 77 | +} |
| 78 | + |
| 79 | +func (b *Binding) isSame(rb *Binding) bool { |
| 80 | + if b.ID != "" && rb.ID != "" { |
| 81 | + return b.ID == rb.ID |
| 82 | + } |
| 83 | + // Sometimes we cannot construct `ID` because of the changed schema, so we need to compare by bind sql. |
| 84 | + return b.BindSQL == rb.BindSQL |
| 85 | +} |
| 86 | + |
| 87 | +// IsBindingEnabled returns whether the binding is enabled. |
| 88 | +func (b *Binding) IsBindingEnabled() bool { |
| 89 | + return b.Status == Enabled || b.Status == Using |
| 90 | +} |
| 91 | + |
| 92 | +// IsBindingAvailable returns whether the binding is available. |
| 93 | +// The available means the binding can be used or can be converted into a usable status. |
| 94 | +// It includes the 'Enabled', 'Using' and 'Disabled' status. |
| 95 | +func (b *Binding) IsBindingAvailable() bool { |
| 96 | + return b.IsBindingEnabled() || b.Status == Disabled |
| 97 | +} |
| 98 | + |
| 99 | +// SinceUpdateTime returns the duration since last update time. Export for test. |
| 100 | +func (b *Binding) SinceUpdateTime() (time.Duration, error) { |
| 101 | + updateTime, err := b.UpdateTime.GoTime(time.Local) |
| 102 | + if err != nil { |
| 103 | + return 0, err |
| 104 | + } |
| 105 | + return time.Since(updateTime), nil |
| 106 | +} |
| 107 | + |
| 108 | +// Bindings represents a sql bind record retrieved from the storage. |
| 109 | +type Bindings []Binding |
| 110 | + |
| 111 | +// Copy get the copy of bindings |
| 112 | +func (br Bindings) Copy() Bindings { |
| 113 | + nbr := append(make(Bindings, 0, len(br)), br...) |
| 114 | + return nbr |
| 115 | +} |
| 116 | + |
| 117 | +// HasAvailableBinding checks if there are any available bindings in bind record. |
| 118 | +// The available means the binding can be used or can be converted into a usable status. |
| 119 | +// It includes the 'Enabled', 'Using' and 'Disabled' status. |
| 120 | +func HasAvailableBinding(br Bindings) bool { |
| 121 | + if br == nil { |
| 122 | + return false |
| 123 | + } |
| 124 | + for _, binding := range br { |
| 125 | + if binding.IsBindingAvailable() { |
| 126 | + return true |
| 127 | + } |
| 128 | + } |
| 129 | + return false |
| 130 | +} |
| 131 | + |
| 132 | +// prepareHints builds ID and Hint for Bindings. If sctx is not nil, we check if |
| 133 | +// the BindSQL is still valid. |
| 134 | +func prepareHints(sctx sessionctx.Context, binding *Binding) (rerr error) { |
| 135 | + defer func() { |
| 136 | + if r := recover(); r != nil { |
| 137 | + rerr = errors.Errorf("panic when preparing hints for binding %v, panic: %v", binding.BindSQL, r) |
| 138 | + } |
| 139 | + }() |
| 140 | + |
| 141 | + p := parser.New() |
| 142 | + if (binding.Hint != nil && binding.ID != "") || binding.Status == deleted { |
| 143 | + return nil |
| 144 | + } |
| 145 | + dbName := binding.Db |
| 146 | + bindingStmt, err := p.ParseOneStmt(binding.BindSQL, binding.Charset, binding.Collation) |
| 147 | + if err != nil { |
| 148 | + return err |
| 149 | + } |
| 150 | + tableNames := CollectTableNames(bindingStmt) |
| 151 | + isFuzzy := isFuzzyBinding(bindingStmt) |
| 152 | + if isFuzzy { |
| 153 | + dbName = "*" // ues '*' for universal bindings |
| 154 | + } |
| 155 | + |
| 156 | + hintsSet, stmt, warns, err := hint.ParseHintsSet(p, binding.BindSQL, binding.Charset, binding.Collation, dbName) |
| 157 | + if err != nil { |
| 158 | + return err |
| 159 | + } |
| 160 | + if sctx != nil && !isFuzzy { |
| 161 | + paramChecker := ¶mMarkerChecker{} |
| 162 | + stmt.Accept(paramChecker) |
| 163 | + if !paramChecker.hasParamMarker { |
| 164 | + _, err = getHintsForSQL(sctx, binding.BindSQL) |
| 165 | + if err != nil { |
| 166 | + return err |
| 167 | + } |
| 168 | + } |
| 169 | + } |
| 170 | + hintsStr, err := hintsSet.Restore() |
| 171 | + if err != nil { |
| 172 | + return err |
| 173 | + } |
| 174 | + // For `create global binding for select * from t using select * from t`, we allow it though hintsStr is empty. |
| 175 | + // For `create global binding for select * from t using select /*+ non_exist_hint() */ * from t`, |
| 176 | + // the hint is totally invalid, we escalate warning to error. |
| 177 | + if hintsStr == "" && len(warns) > 0 { |
| 178 | + return warns[0] |
| 179 | + } |
| 180 | + binding.Hint = hintsSet |
| 181 | + binding.ID = hintsStr |
| 182 | + binding.TableNames = tableNames |
| 183 | + return nil |
| 184 | +} |
| 185 | + |
| 186 | +// `merge` merges two Bindings. It will replace old bindings with new bindings if there are new updates. |
| 187 | +func merge(lBindings, rBindings Bindings) Bindings { |
| 188 | + if lBindings == nil { |
| 189 | + return rBindings |
| 190 | + } |
| 191 | + if rBindings == nil { |
| 192 | + return lBindings |
| 193 | + } |
| 194 | + result := lBindings.Copy() |
| 195 | + for i := range rBindings { |
| 196 | + rbind := rBindings[i] |
| 197 | + found := false |
| 198 | + for j, lbind := range lBindings { |
| 199 | + if lbind.isSame(&rbind) { |
| 200 | + found = true |
| 201 | + if rbind.UpdateTime.Compare(lbind.UpdateTime) >= 0 { |
| 202 | + result[j] = rbind |
| 203 | + } |
| 204 | + break |
| 205 | + } |
| 206 | + } |
| 207 | + if !found { |
| 208 | + result = append(result, rbind) |
| 209 | + } |
| 210 | + } |
| 211 | + return result |
| 212 | +} |
| 213 | + |
| 214 | +func removeDeletedBindings(br Bindings) Bindings { |
| 215 | + result := make(Bindings, 0, len(br)) |
| 216 | + for _, binding := range br { |
| 217 | + if binding.Status != deleted { |
| 218 | + result = append(result, binding) |
| 219 | + } |
| 220 | + } |
| 221 | + return result |
| 222 | +} |
| 223 | + |
| 224 | +// size calculates the memory size of a Bindings. |
| 225 | +func (br Bindings) size() float64 { |
| 226 | + mem := float64(0) |
| 227 | + for _, binding := range br { |
| 228 | + mem += binding.size() |
| 229 | + } |
| 230 | + return mem |
| 231 | +} |
| 232 | + |
| 233 | +// size calculates the memory size of a bind info. |
| 234 | +func (b *Binding) size() float64 { |
| 235 | + res := len(b.OriginalSQL) + len(b.Db) + len(b.BindSQL) + len(b.Status) + 2*int(unsafe.Sizeof(b.CreateTime)) + len(b.Charset) + len(b.Collation) + len(b.ID) |
| 236 | + return float64(res) |
| 237 | +} |
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