diff options
author | Unknwon <u@gogs.io> | 2017-02-13 20:52:35 -0500 |
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committer | Unknwon <u@gogs.io> | 2017-02-13 20:52:35 -0500 |
commit | f967e9d02114553535a267d076df37201f74ddf5 (patch) | |
tree | 9c3032f722a2523e153a69c5c02b6dc3ad4345af /vendor/github.com/denisenkom/go-mssqldb/parser.go | |
parent | 5179063e71d7234250209389e6f69db1cd6f0caa (diff) |
vendor: add new dependency (#3772)
Diffstat (limited to 'vendor/github.com/denisenkom/go-mssqldb/parser.go')
-rw-r--r-- | vendor/github.com/denisenkom/go-mssqldb/parser.go | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/vendor/github.com/denisenkom/go-mssqldb/parser.go b/vendor/github.com/denisenkom/go-mssqldb/parser.go new file mode 100644 index 00000000..4eb0d00c --- /dev/null +++ b/vendor/github.com/denisenkom/go-mssqldb/parser.go @@ -0,0 +1,257 @@ +package mssql + +import ( + "bytes" + "io" + "strconv" +) + +type parser struct { + r *bytes.Reader + w bytes.Buffer + paramCount int + paramMax int + + // using map as a set + namedParams map [string]bool +} + +func (p *parser) next() (rune, bool) { + ch, _, err := p.r.ReadRune() + if err != nil { + if err != io.EOF { + panic(err) + } + return 0, false + } + return ch, true +} + +func (p *parser) unread() { + err := p.r.UnreadRune() + if err != nil { + panic(err) + } +} + +func (p *parser) write(ch rune) { + p.w.WriteRune(ch) +} + +type stateFunc func(*parser) stateFunc + +func parseParams(query string) (string, int) { + p := &parser{ + r: bytes.NewReader([]byte(query)), + namedParams: map [string]bool{}, + } + state := parseNormal + for state != nil { + state = state(p) + } + return p.w.String(), p.paramMax + len(p.namedParams) +} + +func parseNormal(p *parser) stateFunc { + for { + ch, ok := p.next() + if !ok { + return nil + } + if ch == '?' { + return parseOrdinalParameter + } else if ch == '$' || ch == ':' { + ch2, ok := p.next() + if !ok { + p.write(ch) + return nil + } + p.unread() + if ch2 >= '0' && ch2 <= '9' { + return parseOrdinalParameter + } else if 'a' <= ch2 && ch2 <= 'z' || 'A' <= ch2 && ch2 <= 'Z' { + return parseNamedParameter + } + } + p.write(ch) + switch ch { + case '\'': + return parseQuote + case '"': + return parseDoubleQuote + case '[': + return parseBracket + case '-': + return parseLineComment + case '/': + return parseComment + } + } +} + +func parseOrdinalParameter(p *parser) stateFunc { + var paramN int + var ok bool + for { + var ch rune + ch, ok = p.next() + if ok && ch >= '0' && ch <= '9' { + paramN = paramN*10 + int(ch-'0') + } else { + break + } + } + if ok { + p.unread() + } + if paramN == 0 { + p.paramCount++ + paramN = p.paramCount + } + if paramN > p.paramMax { + p.paramMax = paramN + } + p.w.WriteString("@p") + p.w.WriteString(strconv.Itoa(paramN)) + if !ok { + return nil + } + return parseNormal +} + +func parseNamedParameter(p *parser) stateFunc { + var paramName string + var ok bool + for { + var ch rune + ch, ok = p.next() + if ok && (ch >= '0' && ch <= '9' || 'a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z') { + paramName = paramName + string(ch) + } else { + break + } + } + if ok { + p.unread() + } + p.namedParams[paramName] = true + p.w.WriteString("@") + p.w.WriteString(paramName) + if !ok { + return nil + } + return parseNormal +} + +func parseQuote(p *parser) stateFunc { + for { + ch, ok := p.next() + if !ok { + return nil + } + p.write(ch) + if ch == '\'' { + return parseNormal + } + } +} + +func parseDoubleQuote(p *parser) stateFunc { + for { + ch, ok := p.next() + if !ok { + return nil + } + p.write(ch) + if ch == '"' { + return parseNormal + } + } +} + +func parseBracket(p *parser) stateFunc { + for { + ch, ok := p.next() + if !ok { + return nil + } + p.write(ch) + if ch == ']' { + ch, ok = p.next() + if !ok { + return nil + } + if ch != ']' { + p.unread() + return parseNormal + } + p.write(ch) + } + } +} + +func parseLineComment(p *parser) stateFunc { + ch, ok := p.next() + if !ok { + return nil + } + if ch != '-' { + p.unread() + return parseNormal + } + p.write(ch) + for { + ch, ok = p.next() + if !ok { + return nil + } + p.write(ch) + if ch == '\n' { + return parseNormal + } + } +} + +func parseComment(p *parser) stateFunc { + var nested int + ch, ok := p.next() + if !ok { + return nil + } + if ch != '*' { + p.unread() + return parseNormal + } + p.write(ch) + for { + ch, ok = p.next() + if !ok { + return nil + } + p.write(ch) + for ch == '*' { + ch, ok = p.next() + if !ok { + return nil + } + p.write(ch) + if ch == '/' { + if nested == 0 { + return parseNormal + } else { + nested-- + } + } + } + for ch == '/' { + ch, ok = p.next() + if !ok { + return nil + } + p.write(ch) + if ch == '*' { + nested++ + } + } + } +} |