124 lines
2.2 KiB
Go
124 lines
2.2 KiB
Go
package jsn
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import (
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"bytes"
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)
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// Strip function strips out all values from the JSON data expect for the provided path
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func Strip(b []byte, path [][]byte) []byte {
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s, e, d := 0, 0, 0
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ob := b
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pi := 0
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pm := false
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state := expectKey
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instr := false
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slash := 0
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for i := 0; i < len(b); i++ {
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if instr && b[i] == '\\' {
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slash++
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continue
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}
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if b[i] == '"' && (slash%2 == 0) {
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instr = !instr
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}
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if state == expectObjClose || state == expectListClose {
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if !instr {
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switch b[i] {
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case '{', '[':
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d++
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case '}', ']':
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d--
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}
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}
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}
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switch {
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case state == expectKey && b[i] == '"':
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state = expectKeyClose
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s = i
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case state == expectKeyClose && (b[i] == '"' && (slash%2 == 0)):
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state = expectColon
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if pi == len(path) {
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pi = 0
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}
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pm = bytes.Equal(b[(s+1):i], path[pi])
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if pm {
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pi++
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}
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case state == expectColon && b[i] == ':':
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state = expectValue
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case state == expectValue && b[i] == '"':
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state = expectString
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s = i
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case state == expectString && (b[i] == '"' && (slash%2 == 0)):
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e = i
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case state == expectValue && b[i] == '[':
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state = expectListClose
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s = i
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d++
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case state == expectListClose && d == 0 && b[i] == ']':
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e = i
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case state == expectValue && b[i] == '{':
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state = expectObjClose
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s = i
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d++
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case state == expectObjClose && d == 0 && b[i] == '}':
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e = i
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case state == expectValue && (b[i] >= '0' && b[i] <= '9'):
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state = expectNumClose
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s = i
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case state == expectNumClose &&
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((b[i] < '0' || b[i] > '9') &&
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(b[i] != '.' && b[i] != 'e' && b[i] != 'E' && b[i] != '+' && b[i] != '-')):
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e = i - 1
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case state == expectValue &&
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(b[i] == 'f' || b[i] == 'F' || b[i] == 't' || b[i] == 'T'):
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state = expectBoolClose
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s = i
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case state == expectBoolClose && (b[i] == 'e' || b[i] == 'E'):
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e = i
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case state == expectValue && b[i] == 'n':
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state = expectNull
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s = i
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case state == expectNull && (b[i-1] == 'l' && b[i] == 'l'):
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e = i
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}
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if e != 0 {
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if pm && (b[s] == '[' || b[s] == '{') {
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b = b[s:(e + 1)]
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i = 0
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if pi == len(path) {
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return b
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}
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}
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state = expectKey
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e = 0
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}
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slash = 0
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}
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return ob
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}
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