152 lines
2.7 KiB
Go
152 lines
2.7 KiB
Go
// Package jsn provides fast and no-allocation functions to extract values and modify JSON data
|
|
package jsn
|
|
|
|
// Keys function fetches all the unique keys in the JSON data in order of their occurance
|
|
func Keys(b []byte) [][]byte {
|
|
res := make([][]byte, 0, 20)
|
|
|
|
s, e, d := 0, 0, 0
|
|
|
|
var k []byte
|
|
state := expectValue
|
|
|
|
st := newSkipInfoStack()
|
|
ae := 0
|
|
instr := false
|
|
slash := 0
|
|
|
|
for i := 0; i < len(b); i++ {
|
|
if instr && b[i] == '\\' {
|
|
slash++
|
|
continue
|
|
}
|
|
|
|
if b[i] == '"' && (slash%2 == 0) {
|
|
instr = !instr
|
|
}
|
|
|
|
if state == expectObjClose || state == expectListClose {
|
|
if !instr {
|
|
switch b[i] {
|
|
case '{', '[':
|
|
d++
|
|
case '}', ']':
|
|
d--
|
|
}
|
|
}
|
|
}
|
|
|
|
si := st.Peek()
|
|
|
|
switch {
|
|
case state == expectKey && si != nil && i >= si.ss:
|
|
i = si.se + 1
|
|
st.Pop()
|
|
|
|
case state == expectKey && b[i] == '{':
|
|
state = expectObjClose
|
|
s = i
|
|
d++
|
|
|
|
case state == expectObjClose && d == 0 && b[i] == '}':
|
|
state = expectKey
|
|
if ae != 0 {
|
|
st.Push(skipInfo{i, ae})
|
|
ae = 0
|
|
}
|
|
e = i
|
|
i = s
|
|
|
|
case state == expectKey && b[i] == '"':
|
|
state = expectKeyClose
|
|
s = i
|
|
|
|
case state == expectKeyClose && (b[i] == '"' && (slash%2 == 0)):
|
|
state = expectColon
|
|
k = b[(s + 1):i]
|
|
|
|
case state == expectColon && b[i] == ':':
|
|
state = expectValue
|
|
|
|
case state == expectValue && b[i] == '"':
|
|
state = expectString
|
|
s = i
|
|
|
|
case state == expectString && (b[i] == '"' && (slash%2 == 0)):
|
|
e = i
|
|
|
|
case state == expectValue && b[i] == '{':
|
|
state = expectObjClose
|
|
s = i
|
|
d++
|
|
|
|
case state == expectObjClose && d == 0 && b[i] == '}':
|
|
state = expectKey
|
|
e = i
|
|
i = s
|
|
|
|
case state == expectValue && b[i] == '[':
|
|
state = expectListClose
|
|
s = i
|
|
d++
|
|
|
|
case state == expectListClose && d == 0 && b[i] == ']':
|
|
state = expectKey
|
|
ae = i
|
|
e = i
|
|
i = s
|
|
|
|
case state == expectValue && (b[i] >= '0' && b[i] <= '9'):
|
|
state = expectNumClose
|
|
s = i
|
|
|
|
case state == expectNumClose &&
|
|
((b[i] < '0' || b[i] > '9') &&
|
|
(b[i] != '.' && b[i] != 'e' && b[i] != 'E' && b[i] != '+' && b[i] != '-')):
|
|
e = i - 1
|
|
|
|
case state == expectValue &&
|
|
(b[i] == 'f' || b[i] == 'F' || b[i] == 't' || b[i] == 'T'):
|
|
state = expectBoolClose
|
|
s = i
|
|
|
|
case state == expectBoolClose && (b[i] == 'e' || b[i] == 'E'):
|
|
e = i
|
|
|
|
case state == expectValue && b[i] == 'n':
|
|
state = expectNull
|
|
s = i
|
|
|
|
case state == expectNull && (b[i-1] == 'l' && b[i] == 'l'):
|
|
e = i
|
|
}
|
|
|
|
if e != 0 {
|
|
if k != nil {
|
|
res = append(res, k)
|
|
}
|
|
|
|
if state == expectListClose {
|
|
loop:
|
|
for j := i + 1; j < len(b); j++ {
|
|
switch b[j] {
|
|
case ' ', '\t', '\n':
|
|
continue
|
|
case '{':
|
|
break loop
|
|
}
|
|
i = e
|
|
break loop
|
|
}
|
|
}
|
|
state = expectKey
|
|
k = nil
|
|
e = 0
|
|
}
|
|
|
|
slash = 0
|
|
}
|
|
|
|
return res
|
|
}
|