| Conditions | 22 |
| Total Lines | 86 |
| Code Lines | 54 |
| Lines | 0 |
| Ratio | 0 % |
| Changes | 0 | ||
Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.
For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.
Commonly applied refactorings include:
If many parameters/temporary variables are present:
Complex classes like mysql.*mysqlConn.handleInFileRequest often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
| 1 | // Go MySQL Driver - A MySQL-Driver for Go's database/sql package |
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| 96 | func (mc *mysqlConn) handleInFileRequest(name string) (err error) { |
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| 97 | var rdr io.Reader |
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| 98 | var data []byte |
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| 99 | packetSize := 16 * 1024 // 16KB is small enough for disk readahead and large enough for TCP |
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| 100 | if mc.maxWriteSize < packetSize { |
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| 101 | packetSize = mc.maxWriteSize |
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| 102 | } |
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| 103 | |||
| 104 | if idx := strings.Index(name, "Reader::"); idx == 0 || (idx > 0 && name[idx-1] == '/') { // io.Reader |
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| 105 | // The server might return an an absolute path. See issue #355. |
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| 106 | name = name[idx+8:] |
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| 107 | |||
| 108 | readerRegisterLock.RLock() |
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| 109 | handler, inMap := readerRegister[name] |
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| 110 | readerRegisterLock.RUnlock() |
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| 111 | |||
| 112 | if inMap { |
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| 113 | rdr = handler() |
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| 114 | if rdr != nil { |
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| 115 | if cl, ok := rdr.(io.Closer); ok { |
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| 116 | defer deferredClose(&err, cl) |
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| 117 | } |
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| 118 | } else { |
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| 119 | err = fmt.Errorf("Reader '%s' is <nil>", name) |
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| 120 | } |
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| 121 | } else { |
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| 122 | err = fmt.Errorf("Reader '%s' is not registered", name) |
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| 123 | } |
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| 124 | } else { // File |
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| 125 | name = strings.Trim(name, `"`) |
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| 126 | fileRegisterLock.RLock() |
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| 127 | fr := fileRegister[name] |
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| 128 | fileRegisterLock.RUnlock() |
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| 129 | if mc.cfg.AllowAllFiles || fr { |
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| 130 | var file *os.File |
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| 131 | var fi os.FileInfo |
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| 132 | |||
| 133 | if file, err = os.Open(name); err == nil { |
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| 134 | defer deferredClose(&err, file) |
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| 135 | |||
| 136 | // get file size |
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| 137 | if fi, err = file.Stat(); err == nil { |
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| 138 | rdr = file |
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| 139 | if fileSize := int(fi.Size()); fileSize < packetSize { |
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| 140 | packetSize = fileSize |
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| 141 | } |
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| 142 | } |
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| 143 | } |
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| 144 | } else { |
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| 145 | err = fmt.Errorf("local file '%s' is not registered", name) |
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| 146 | } |
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| 147 | } |
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| 148 | |||
| 149 | // send content packets |
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| 150 | // if packetSize == 0, the Reader contains no data |
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| 151 | if err == nil && packetSize > 0 { |
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| 152 | data := make([]byte, 4+packetSize) |
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| 153 | var n int |
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| 154 | for err == nil { |
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| 155 | n, err = rdr.Read(data[4:]) |
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| 156 | if n > 0 { |
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| 157 | if ioErr := mc.writePacket(data[:4+n]); ioErr != nil { |
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| 158 | return ioErr |
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| 159 | } |
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| 160 | } |
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| 161 | } |
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| 162 | if err == io.EOF { |
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| 163 | err = nil |
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| 164 | } |
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| 165 | } |
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| 166 | |||
| 167 | // send empty packet (termination) |
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| 168 | if data == nil { |
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| 169 | data = make([]byte, 4) |
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| 170 | } |
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| 171 | if ioErr := mc.writePacket(data[:4]); ioErr != nil { |
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| 172 | return ioErr |
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| 173 | } |
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| 174 | |||
| 175 | // read OK packet |
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| 176 | if err == nil { |
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| 177 | return mc.readResultOK() |
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| 178 | } |
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| 179 | |||
| 180 | mc.readPacket() |
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| 181 | return err |
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| 182 | } |
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| 183 |