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dcfc35316f
issue: https://github.com/milvus-io/milvus/issues/30721 Signed-off-by: longjiquan <jiquan.long@zilliz.com>
70 lines
1.4 KiB
Go
70 lines
1.4 KiB
Go
package planparserv2
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import (
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"github.com/milvus-io/milvus/internal/proto/planpb"
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)
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var wildcards = map[byte]struct{}{
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'_': {},
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'%': {},
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}
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var escapeCharacter byte = '\\'
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// hasWildcards returns true if pattern contains any wildcard.
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func hasWildcards(pattern string) bool {
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l := len(pattern)
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i := l - 1
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for ; i >= 0; i-- {
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_, ok := wildcards[pattern[i]]
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if ok {
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if i > 0 && pattern[i-1] == escapeCharacter {
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i--
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continue
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}
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return true
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}
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}
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return false
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}
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// findLastNotOfWildcards find the last location not of last wildcard.
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func findLastNotOfWildcards(pattern string) int {
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loc := len(pattern) - 1
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for ; loc >= 0; loc-- {
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_, ok := wildcards[pattern[loc]]
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if !ok {
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break
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}
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if ok {
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if loc > 0 && pattern[loc-1] == escapeCharacter {
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break
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}
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}
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}
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return loc
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}
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// translatePatternMatch translates pattern to related op type and operand.
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func translatePatternMatch(pattern string) (op planpb.OpType, operand string, err error) {
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l := len(pattern)
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loc := findLastNotOfWildcards(pattern)
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if loc < 0 {
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// always match.
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return planpb.OpType_PrefixMatch, "", nil
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}
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exist := hasWildcards(pattern[:loc+1])
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if loc >= l-1 && !exist {
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// equal match.
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return planpb.OpType_Equal, pattern, nil
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}
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if !exist {
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// prefix match.
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return planpb.OpType_PrefixMatch, pattern[:loc+1], nil
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}
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return planpb.OpType_Match, pattern, nil
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}
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