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GeezerVison is showing github.com — sqlparser/comments.go at master · simake2017/sqlparser Expand file tree/ Copy pathcomments.goMore file actions 293 lines (251 loc) · 7.48 KB / Copy pathcomments.goFile metadata and controls293 lines (251 loc) · 7.48 KB 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 /* Copyright 2017 Google Inc. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package sqlparser import ( "strconv" "strings" "unicode" ) const ( // DirectiveMultiShardAutocommit is the query comment directive to allow // single round trip autocommit with a multi-shard statement. DirectiveMultiShardAutocommit = "MULTI_SHARD_AUTOCOMMIT" // DirectiveSkipQueryPlanCache skips query plan cache when set. DirectiveSkipQueryPlanCache = "SKIP_QUERY_PLAN_CACHE" // DirectiveQueryTimeout sets a query timeout in vtgate. Only supported for SELECTS. DirectiveQueryTimeout = "QUERY_TIMEOUT_MS" ) func isNonSpace(r rune) bool { return !unicode.IsSpace(r) } // leadingCommentEnd returns the first index after all leading comments, or // 0 if there are no leading comments. func leadingCommentEnd(text string) (end int) { hasComment := false pos := 0 for pos < len(text) { // Eat up any whitespace. Trailing whitespace will be considered part of // the leading comments. nextVisibleOffset := strings.IndexFunc(text[pos:], isNonSpace) if nextVisibleOffset < 0 { break } pos += nextVisibleOffset remainingText := text[pos:] // Found visible characters. Look for '/*' at the beginning // and '*/' somewhere after that. if len(remainingText) < 4 || remainingText[:2] != "/*" { break } commentLength := 4 + strings.Index(remainingText[2:], "*/") if commentLength < 4 { // Missing end comment :/ break } hasComment = true pos += commentLength } if hasComment { return pos } return 0 } // trailingCommentStart returns the first index of trailing comments. // If there are no trailing comments, returns the length of the input string. func trailingCommentStart(text string) (start int) { hasComment := false reducedLen := len(text) for reducedLen > 0 { // Eat up any whitespace. Leading whitespace will be considered part of // the trailing comments. nextReducedLen := strings.LastIndexFunc(text[:reducedLen], isNonSpace) + 1 if nextReducedLen == 0 { break } reducedLen = nextReducedLen if reducedLen < 4 || text[reducedLen-2:reducedLen] != "*/" { break } // Find the beginning of the comment startCommentPos := strings.LastIndex(text[:reducedLen-2], "/*") if startCommentPos < 0 { // Badly formatted sql :/ break } hasComment = true reducedLen = startCommentPos } if hasComment { return reducedLen } return len(text) } // MarginComments holds the leading and trailing comments that surround a query. type MarginComments struct { Leading string Trailing string } // SplitMarginComments pulls out any leading or trailing comments from a raw sql query. // This function also trims leading (if there's a comment) and trailing whitespace. func SplitMarginComments(sql string) (query string, comments MarginComments) { trailingStart := trailingCommentStart(sql) leadingEnd := leadingCommentEnd(sql[:trailingStart]) comments = MarginComments{ Leading: strings.TrimLeftFunc(sql[:leadingEnd], unicode.IsSpace), Trailing: strings.TrimRightFunc(sql[trailingStart:], unicode.IsSpace), } return strings.TrimFunc(sql[leadingEnd:trailingStart], unicode.IsSpace), comments } // StripLeadingComments trims the SQL string and removes any leading comments func StripLeadingComments(sql string) string { sql = strings.TrimFunc(sql, unicode.IsSpace) for hasCommentPrefix(sql) { switch sql[0] { case '/': // Multi line comment index := strings.Index(sql, "*/") if index <= 1 { return sql } // don't strip /*! ... */ or /*!50700 ... */ if len(sql) > 2 && sql[2] == '!' { return sql } sql = sql[index+2:] case '-': // Single line comment index := strings.Index(sql, "\n") if index == -1 { return sql } sql = sql[index+1:] } sql = strings.TrimFunc(sql, unicode.IsSpace) } return sql } func hasCommentPrefix(sql string) bool { return len(sql) > 1 && ((sql[0] == '/' && sql[1] == '*') || (sql[0] == '-' && sql[1] == '-')) } // ExtractMysqlComment extracts the version and SQL from a comment-only query // such as /*!50708 sql here */ func ExtractMysqlComment(sql string) (version string, innerSQL string) { sql = sql[3 : len(sql)-2] digitCount := 0 endOfVersionIndex := strings.IndexFunc(sql, func(c rune) bool { digitCount++ return !unicode.IsDigit(c) || digitCount == 6 }) version = sql[0:endOfVersionIndex] innerSQL = strings.TrimFunc(sql[endOfVersionIndex:], unicode.IsSpace) return version, innerSQL } const commentDirectivePreamble = "/*vt+" // CommentDirectives is the parsed representation for execution directives // conveyed in query comments type CommentDirectives map[string]interface{} // ExtractCommentDirectives parses the comment list for any execution directives // of the form: // // /*vt+ OPTION_ONE=1 OPTION_TWO OPTION_THREE=abcd */ // // It returns the map of the directive values or nil if there aren't any. func ExtractCommentDirectives(comments Comments) CommentDirectives { if comments == nil { return nil } var vals map[string]interface{} for _, comment := range comments { commentStr := string(comment) if commentStr[0:5] != commentDirectivePreamble { continue } if vals == nil { vals = make(map[string]interface{}) } // Split on whitespace and ignore the first and last directive // since they contain the comment start/end directives := strings.Fields(commentStr) for i := 1; i < len(directives)-1; i++ { directive := directives[i] sep := strings.IndexByte(directive, '=') // No value is equivalent to a true boolean if sep == -1 { vals[directive] = true continue } strVal := directive[sep+1:] directive = directive[:sep] intVal, err := strconv.Atoi(strVal) if err == nil { vals[directive] = intVal continue } boolVal, err := strconv.ParseBool(strVal) if err == nil { vals[directive] = boolVal continue } vals[directive] = strVal } } return vals } // IsSet checks the directive map for the named directive and returns // true if the directive is set and has a true/false or 0/1 value func (d CommentDirectives) IsSet(key string) bool { if d == nil { return false } val, ok := d[key] if !ok { return false } boolVal, ok := val.(bool) if ok { return boolVal } intVal, ok := val.(int) if ok { return intVal == 1 } return false } // SkipQueryPlanCacheDirective returns true if skip query plan cache directive is set to true in query. func SkipQueryPlanCacheDirective(stmt Statement) bool { switch stmt := stmt.(type) { case *Select: directives := ExtractCommentDirectives(stmt.Comments) if directives.IsSet(DirectiveSkipQueryPlanCache) { return true } case *Insert: directives := ExtractCommentDirectives(stmt.Comments) if directives.IsSet(DirectiveSkipQueryPlanCache) { return true } case *Update: directives := ExtractCommentDirectives(stmt.Comments) if directives.IsSet(DirectiveSkipQueryPlanCache) { return true } case *Delete: directives := ExtractCommentDirectives(stmt.Comments) if directives.IsSet(DirectiveSkipQueryPlanCache) { return true } default: return false } return false } |
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