gosora/query_gen/lib/utils.go

418 lines
12 KiB
Go

/* WIP Under Construction */
package qgen
//import "fmt"
import "strings"
import "os"
func _process_columns(colstr string) (columns []DB_Column) {
if colstr == "" {
return columns
}
colstr = strings.Replace(colstr, " as ", " AS ", -1)
for _, segment := range strings.Split(colstr, ",") {
var outcol DB_Column
dothalves := strings.Split(strings.TrimSpace(segment), ".")
var halves []string
if len(dothalves) == 2 {
outcol.Table = dothalves[0]
halves = strings.Split(dothalves[1], " AS ")
} else {
halves = strings.Split(dothalves[0], " AS ")
}
halves[0] = strings.TrimSpace(halves[0])
if len(halves) == 2 {
outcol.Alias = strings.TrimSpace(halves[1])
}
if halves[0][len(halves[0])-1] == ')' {
outcol.Type = "function"
} else if halves[0] == "?" {
outcol.Type = "substitute"
} else {
outcol.Type = "column"
}
outcol.Left = halves[0]
columns = append(columns, outcol)
}
return columns
}
func _process_orderby(orderstr string) (order []DB_Order) {
if orderstr == "" {
return order
}
for _, segment := range strings.Split(orderstr, ",") {
var outorder DB_Order
halves := strings.Split(strings.TrimSpace(segment), " ")
if len(halves) != 2 {
continue
}
outorder.Column = halves[0]
outorder.Order = strings.ToLower(halves[1])
order = append(order, outorder)
}
return order
}
func _processJoiner(joinstr string) (joiner []DB_Joiner) {
if joinstr == "" {
return joiner
}
joinstr = strings.Replace(joinstr, " on ", " ON ", -1)
joinstr = strings.Replace(joinstr, " and ", " AND ", -1)
for _, segment := range strings.Split(joinstr, " AND ") {
var outjoin DB_Joiner
var parseOffset int
var left, right string
left, parseOffset = _getIdentifier(segment, parseOffset)
outjoin.Operator, parseOffset = _getOperator(segment, parseOffset+1)
right, parseOffset = _getIdentifier(segment, parseOffset+1)
left_column := strings.Split(left, ".")
right_column := strings.Split(right, ".")
outjoin.LeftTable = strings.TrimSpace(left_column[0])
outjoin.RightTable = strings.TrimSpace(right_column[0])
outjoin.LeftColumn = strings.TrimSpace(left_column[1])
outjoin.RightColumn = strings.TrimSpace(right_column[1])
joiner = append(joiner, outjoin)
}
return joiner
}
func _processWhere(wherestr string) (where []DB_Where) {
if wherestr == "" {
return where
}
wherestr = strings.Replace(wherestr, " and ", " AND ", -1)
var buffer string
var optype int // 0: None, 1: Number, 2: Column, 3: Function, 4: String, 5: Operator
for _, segment := range strings.Split(wherestr, " AND ") {
var tmp_where DB_Where
segment += ")"
for i := 0; i < len(segment); i++ {
char := segment[i]
//fmt.Println("optype",optype)
switch optype {
case 0: // unknown
//fmt.Println("case 0:",char,string(char))
if '0' <= char && char <= '9' {
optype = 1
buffer = string(char)
} else if ('a' <= char && char <= 'z') || ('A' <= char && char <= 'Z') || char == '_' {
optype = 2
buffer = string(char)
} else if char == '\'' {
optype = 4
buffer = ""
} else if _is_op_byte(char) {
optype = 5
buffer = string(char)
} else if char == '?' {
//fmt.Println("Expr:","?")
tmp_where.Expr = append(tmp_where.Expr, DB_Token{"?", "substitute"})
}
case 1: // number
if '0' <= char && char <= '9' {
buffer += string(char)
} else {
optype = 0
i--
//fmt.Println("Expr:",buffer)
tmp_where.Expr = append(tmp_where.Expr, DB_Token{buffer, "number"})
}
case 2: // column
if ('a' <= char && char <= 'z') || ('A' <= char && char <= 'Z') || char == '.' || char == '_' {
buffer += string(char)
} else if char == '(' {
optype = 3
i--
} else {
optype = 0
i--
//fmt.Println("Expr:",buffer)
tmp_where.Expr = append(tmp_where.Expr, DB_Token{buffer, "column"})
}
case 3: // function
var preI = i
//fmt.Println("buffer",buffer)
//fmt.Println("len(halves)",len(halves[1]))
//fmt.Println("preI",string(halves[1][preI]))
//fmt.Println("msg prior to preI",halves[1][0:preI])
i = _skipFunctionCall(segment, i-1)
//fmt.Println("i",i)
//fmt.Println("msg prior to i-1",halves[1][0:i-1])
//fmt.Println("string(i-1)",string(halves[1][i-1]))
//fmt.Println("string(i)",string(halves[1][i]))
buffer += segment[preI:i] + string(segment[i])
//fmt.Println("Expr:",buffer)
tmp_where.Expr = append(tmp_where.Expr, DB_Token{buffer, "function"})
optype = 0
case 4: // string
if char != '\'' {
buffer += string(char)
} else {
optype = 0
//fmt.Println("Expr:",buffer)
tmp_where.Expr = append(tmp_where.Expr, DB_Token{buffer, "string"})
}
case 5: // operator
if _is_op_byte(char) {
buffer += string(char)
} else {
optype = 0
i--
//fmt.Println("Expr:",buffer)
tmp_where.Expr = append(tmp_where.Expr, DB_Token{buffer, "operator"})
}
default:
panic("Bad optype in _process_where")
}
}
where = append(where, tmp_where)
}
return where
}
func _process_set(setstr string) (setter []DB_Setter) {
if setstr == "" {
return setter
}
//fmt.Println("setstr",setstr)
// First pass, splitting the string by commas while ignoring the innards of functions
var setset []string
var buffer string
var lastItem int
setstr += ","
for i := 0; i < len(setstr); i++ {
if setstr[i] == '(' {
i = _skipFunctionCall(setstr, i-1)
setset = append(setset, setstr[lastItem:i+1])
buffer = ""
lastItem = i + 2
} else if setstr[i] == ',' && buffer != "" {
setset = append(setset, buffer)
buffer = ""
lastItem = i + 1
} else if (setstr[i] > 32) && setstr[i] != ',' && setstr[i] != ')' {
buffer += string(setstr[i])
}
}
// Second pass. Break this setitem into manageable chunks
buffer = ""
for _, setitem := range setset {
var tmp_setter DB_Setter
halves := strings.Split(setitem, "=")
if len(halves) != 2 {
continue
}
tmp_setter.Column = strings.TrimSpace(halves[0])
halves[1] += ")"
var optype int // 0: None, 1: Number, 2: Column, 3: Function, 4: String, 5: Operator
//fmt.Println("halves[1]",halves[1])
for i := 0; i < len(halves[1]); i++ {
char := halves[1][i]
//fmt.Println("optype",optype)
switch optype {
case 0: // unknown
if '0' <= char && char <= '9' {
optype = 1
buffer = string(char)
} else if ('a' <= char && char <= 'z') || ('A' <= char && char <= 'Z') || char == '_' {
optype = 2
buffer = string(char)
} else if char == '\'' {
optype = 4
buffer = ""
} else if _is_op_byte(char) {
optype = 5
buffer = string(char)
} else if char == '?' {
//fmt.Println("Expr:","?")
tmp_setter.Expr = append(tmp_setter.Expr, DB_Token{"?", "substitute"})
}
case 1: // number
if '0' <= char && char <= '9' {
buffer += string(char)
} else {
optype = 0
i--
//fmt.Println("Expr:",buffer)
tmp_setter.Expr = append(tmp_setter.Expr, DB_Token{buffer, "number"})
}
case 2: // column
if ('a' <= char && char <= 'z') || ('A' <= char && char <= 'Z') || char == '_' {
buffer += string(char)
} else if char == '(' {
optype = 3
i--
} else {
optype = 0
i--
//fmt.Println("Expr:",buffer)
tmp_setter.Expr = append(tmp_setter.Expr, DB_Token{buffer, "column"})
}
case 3: // function
var preI = i
//fmt.Println("buffer",buffer)
//fmt.Println("len(halves)",len(halves[1]))
//fmt.Println("preI",string(halves[1][preI]))
//fmt.Println("msg prior to preI",halves[1][0:preI])
i = _skipFunctionCall(halves[1], i-1)
//fmt.Println("i",i)
//fmt.Println("msg prior to i-1",halves[1][0:i-1])
//fmt.Println("string(i-1)",string(halves[1][i-1]))
//fmt.Println("string(i)",string(halves[1][i]))
buffer += halves[1][preI:i] + string(halves[1][i])
//fmt.Println("Expr:",buffer)
tmp_setter.Expr = append(tmp_setter.Expr, DB_Token{buffer, "function"})
optype = 0
case 4: // string
if char != '\'' {
buffer += string(char)
} else {
optype = 0
//fmt.Println("Expr:",buffer)
tmp_setter.Expr = append(tmp_setter.Expr, DB_Token{buffer, "string"})
}
case 5: // operator
if _is_op_byte(char) {
buffer += string(char)
} else {
optype = 0
i--
//fmt.Println("Expr:",buffer)
tmp_setter.Expr = append(tmp_setter.Expr, DB_Token{buffer, "operator"})
}
default:
panic("Bad optype in _process_set")
}
}
setter = append(setter, tmp_setter)
}
//fmt.Println("setter",setter)
return setter
}
func _processLimit(limitstr string) (limiter DB_Limit) {
halves := strings.Split(limitstr, ",")
if len(halves) == 2 {
limiter.Offset = halves[0]
limiter.MaxCount = halves[1]
} else {
limiter.MaxCount = halves[0]
}
return limiter
}
func _is_op_byte(char byte) bool {
return char == '<' || char == '>' || char == '=' || char == '!' || char == '*' || char == '%' || char == '+' || char == '-' || char == '/'
}
func _is_op_rune(char rune) bool {
return char == '<' || char == '>' || char == '=' || char == '!' || char == '*' || char == '%' || char == '+' || char == '-' || char == '/'
}
func _processFields(fieldstr string) (fields []DB_Field) {
if fieldstr == "" {
return fields
}
var buffer string
var lastItem int
fieldstr += ","
for i := 0; i < len(fieldstr); i++ {
if fieldstr[i] == '(' {
i = _skipFunctionCall(fieldstr, i-1)
fields = append(fields, DB_Field{Name: fieldstr[lastItem : i+1], Type: _getIdentifierType(fieldstr[lastItem : i+1])})
buffer = ""
lastItem = i + 2
} else if fieldstr[i] == ',' && buffer != "" {
fields = append(fields, DB_Field{Name: buffer, Type: _getIdentifierType(buffer)})
buffer = ""
lastItem = i + 1
} else if (fieldstr[i] > 32) && fieldstr[i] != ',' && fieldstr[i] != ')' {
buffer += string(fieldstr[i])
}
}
return fields
}
func _getIdentifierType(identifier string) string {
if ('a' <= identifier[0] && identifier[0] <= 'z') || ('A' <= identifier[0] && identifier[0] <= 'Z') {
if identifier[len(identifier)-1] == ')' {
return "function"
}
return "column"
}
if identifier[0] == '\'' || identifier[0] == '"' {
return "string"
}
return "literal"
}
func _getIdentifier(segment string, startOffset int) (out string, i int) {
segment = strings.TrimSpace(segment)
segment += " " // Avoid overflow bugs with slicing
for i = startOffset; i < len(segment); i++ {
if segment[i] == '(' {
i = _skipFunctionCall(segment, i)
return strings.TrimSpace(segment[startOffset:i]), (i - 1)
}
if (segment[i] == ' ' || _is_op_byte(segment[i])) && i != startOffset {
return strings.TrimSpace(segment[startOffset:i]), (i - 1)
}
}
return strings.TrimSpace(segment[startOffset:]), (i - 1)
}
func _getOperator(segment string, startOffset int) (out string, i int) {
segment = strings.TrimSpace(segment)
segment += " " // Avoid overflow bugs with slicing
for i = startOffset; i < len(segment); i++ {
if !_is_op_byte(segment[i]) && i != startOffset {
return strings.TrimSpace(segment[startOffset:i]), (i - 1)
}
}
return strings.TrimSpace(segment[startOffset:]), (i - 1)
}
func _skipFunctionCall(data string, index int) int {
var braceCount int
for ; index < len(data); index++ {
char := data[index]
if char == '(' {
braceCount++
} else if char == ')' {
braceCount--
if braceCount == 0 {
return index
}
}
}
return index
}
func writeFile(name string, content string) (err error) {
f, err := os.Create(name)
if err != nil {
return err
}
_, err = f.WriteString(content)
if err != nil {
return err
}
err = f.Sync()
if err != nil {
return err
}
return f.Close()
}