|
| 1 | +package handler |
| 2 | + |
| 3 | +import ( |
| 4 | + "database/sql" |
| 5 | + "encoding/json" |
| 6 | + "fmt" |
| 7 | + "io/ioutil" |
| 8 | + "net/http" |
| 9 | + "strings" |
| 10 | + |
| 11 | + "github.com/src-d/gitbase-playground/server/serializer" |
| 12 | + "gopkg.in/bblfsh/sdk.v1/uast" |
| 13 | + |
| 14 | + "github.com/go-sql-driver/mysql" |
| 15 | +) |
| 16 | + |
| 17 | +type queryRequest struct { |
| 18 | + Query string `json:"query"` |
| 19 | + Limit int `json:"limit,omitempty"` |
| 20 | +} |
| 21 | + |
| 22 | +// genericVals returns a slice of interface{}, each one a pointer to the proper |
| 23 | +// type for each column |
| 24 | +func genericVals(colTypes []string) []interface{} { |
| 25 | + columnValsPtr := make([]interface{}, len(colTypes)) |
| 26 | + |
| 27 | + for i, colType := range colTypes { |
| 28 | + switch colType { |
| 29 | + case "BIT": |
| 30 | + columnValsPtr[i] = new(sql.NullBool) |
| 31 | + case "TIMESTAMP", "DATE", "DATETIME": |
| 32 | + columnValsPtr[i] = new(mysql.NullTime) |
| 33 | + case "INT", "MEDIUMINT", "BIGINT", "SMALLINT", "TINYINT": |
| 34 | + columnValsPtr[i] = new(sql.NullInt64) |
| 35 | + case "DOUBLE", "FLOAT": |
| 36 | + columnValsPtr[i] = new(sql.NullFloat64) |
| 37 | + case "JSON": |
| 38 | + columnValsPtr[i] = new([]byte) |
| 39 | + default: // All the text and binary variations |
| 40 | + columnValsPtr[i] = new(sql.NullString) |
| 41 | + } |
| 42 | + } |
| 43 | + |
| 44 | + return columnValsPtr |
| 45 | +} |
| 46 | + |
| 47 | +// Query returns a function that forwards an SQL query to gitbase and returns |
| 48 | +// the rows as JSON |
| 49 | +func Query(db *sql.DB) RequestProcessFunc { |
| 50 | + return func(r *http.Request) (*serializer.Response, error) { |
| 51 | + var queryRequest queryRequest |
| 52 | + body, err := ioutil.ReadAll(r.Body) |
| 53 | + if err != nil { |
| 54 | + return nil, err |
| 55 | + } |
| 56 | + |
| 57 | + err = json.Unmarshal(body, &queryRequest) |
| 58 | + if err != nil { |
| 59 | + return nil, serializer.NewHTTPError(http.StatusBadRequest, |
| 60 | + `Bad Request. Expected body: { "query": "SQL statement", "limit": 1234 }`) |
| 61 | + } |
| 62 | + |
| 63 | + query := addLimit(queryRequest.Query, queryRequest.Limit) |
| 64 | + rows, err := db.Query(query) |
| 65 | + if err != nil { |
| 66 | + if mysqlErr, ok := err.(*mysql.MySQLError); ok { |
| 67 | + return nil, serializer.NewMySQLError( |
| 68 | + http.StatusBadRequest, |
| 69 | + mysqlErr.Number, |
| 70 | + mysqlErr.Message) |
| 71 | + } |
| 72 | + |
| 73 | + return nil, serializer.NewHTTPError(http.StatusBadRequest, err.Error()) |
| 74 | + } |
| 75 | + defer rows.Close() |
| 76 | + |
| 77 | + columnNames, columnTypes, err := columnsInfo(rows) |
| 78 | + if err != nil { |
| 79 | + return nil, err |
| 80 | + } |
| 81 | + |
| 82 | + columnValsPtr := genericVals(columnTypes) |
| 83 | + |
| 84 | + tableData := make([]map[string]interface{}, 0) |
| 85 | + |
| 86 | + for rows.Next() { |
| 87 | + if err := rows.Scan(columnValsPtr...); err != nil { |
| 88 | + return nil, err |
| 89 | + } |
| 90 | + |
| 91 | + colData := make(map[string]interface{}, len(columnTypes)) |
| 92 | + |
| 93 | + for i, val := range columnValsPtr { |
| 94 | + colData[columnNames[i]] = nil |
| 95 | + |
| 96 | + switch val.(type) { |
| 97 | + case *sql.NullBool: |
| 98 | + sqlVal, _ := val.(*sql.NullBool) |
| 99 | + if sqlVal.Valid { |
| 100 | + colData[columnNames[i]] = sqlVal.Bool |
| 101 | + } |
| 102 | + case *mysql.NullTime: |
| 103 | + sqlVal, _ := val.(*mysql.NullTime) |
| 104 | + if sqlVal.Valid { |
| 105 | + colData[columnNames[i]] = sqlVal.Time |
| 106 | + } |
| 107 | + case *sql.NullInt64: |
| 108 | + sqlVal, _ := val.(*sql.NullInt64) |
| 109 | + if sqlVal.Valid { |
| 110 | + colData[columnNames[i]] = sqlVal.Int64 |
| 111 | + } |
| 112 | + case *sql.NullString: |
| 113 | + sqlVal, _ := val.(*sql.NullString) |
| 114 | + if sqlVal.Valid { |
| 115 | + colData[columnNames[i]] = sqlVal.String |
| 116 | + } |
| 117 | + case *[]byte: |
| 118 | + // DatabaseTypeName JSON is used for arrays of uast nodes and |
| 119 | + // arrays of strings, but we don't know the exact type. |
| 120 | + // We try with arry of uast nodes first and any JSON later |
| 121 | + nodes, err := unmarshallUAST(val) |
| 122 | + if err == nil { |
| 123 | + colData[columnNames[i]] = nodes |
| 124 | + } else { |
| 125 | + var data interface{} |
| 126 | + |
| 127 | + if err := json.Unmarshal(*val.(*[]byte), &data); err != nil { |
| 128 | + return nil, err |
| 129 | + } |
| 130 | + colData[columnNames[i]] = data |
| 131 | + } |
| 132 | + } |
| 133 | + } |
| 134 | + |
| 135 | + tableData = append(tableData, colData) |
| 136 | + } |
| 137 | + |
| 138 | + if err := rows.Err(); err != nil { |
| 139 | + return nil, err |
| 140 | + } |
| 141 | + |
| 142 | + return serializer.NewQueryResponse(tableData, columnNames, columnTypes), nil |
| 143 | + } |
| 144 | +} |
| 145 | + |
| 146 | +// columnsInfo returns the column names and column types, or error |
| 147 | +func columnsInfo(rows *sql.Rows) ([]string, []string, error) { |
| 148 | + names, err := rows.Columns() |
| 149 | + if err != nil { |
| 150 | + return nil, nil, err |
| 151 | + } |
| 152 | + |
| 153 | + types, err := rows.ColumnTypes() |
| 154 | + if err != nil { |
| 155 | + return nil, nil, err |
| 156 | + } |
| 157 | + |
| 158 | + typesStr := make([]string, len(types)) |
| 159 | + for i, colType := range types { |
| 160 | + typesStr[i] = colType.DatabaseTypeName() |
| 161 | + } |
| 162 | + |
| 163 | + return names, typesStr, nil |
| 164 | +} |
| 165 | + |
| 166 | +// unmarshallUAST tries to cast data as [][]byte and unmarshall uast nodes |
| 167 | +func unmarshallUAST(data interface{}) ([]*uast.Node, error) { |
| 168 | + var protobufs [][]byte |
| 169 | + if err := json.Unmarshal(*data.(*[]byte), &protobufs); err != nil { |
| 170 | + return nil, err |
| 171 | + } |
| 172 | + |
| 173 | + nodes := make([]*uast.Node, len(protobufs)) |
| 174 | + |
| 175 | + for i, v := range protobufs { |
| 176 | + node := uast.NewNode() |
| 177 | + if err := node.Unmarshal(v); err != nil { |
| 178 | + return nil, err |
| 179 | + } |
| 180 | + nodes[i] = node |
| 181 | + } |
| 182 | + |
| 183 | + return nodes, nil |
| 184 | +} |
| 185 | + |
| 186 | +// addLimit adds LIMIT to the query if it's a SELECT, avoiding '; limit' |
| 187 | +func addLimit(query string, limit int) string { |
| 188 | + if limit <= 0 { |
| 189 | + return query |
| 190 | + } |
| 191 | + |
| 192 | + query = strings.TrimRight(strings.TrimSpace(query), ";") |
| 193 | + if strings.HasPrefix(strings.ToUpper(query), "SELECT") { |
| 194 | + return fmt.Sprintf("%s LIMIT %d", query, limit) |
| 195 | + } |
| 196 | + |
| 197 | + return query |
| 198 | +} |
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