/
method_descriptor_parser.go
132 lines (118 loc) · 2.48 KB
/
method_descriptor_parser.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
package heap
import "strings"
type MethodDescriptorParser struct {
raw string
offset int
parsed *MethodDescriptor
}
func parseMethodDescriptor(descriptor string) *MethodDescriptor {
parser := &MethodDescriptorParser{}
return parser.parse(descriptor)
}
func (self *MethodDescriptorParser) parse(descriptor string) *MethodDescriptor {
self.raw = descriptor
self.parsed = &MethodDescriptor{}
self.startParams()
self.parseParamTypes()
self.endParams()
self.parseReturnType()
self.finish()
return self.parsed
}
func (self *MethodDescriptorParser) startParams() {
if self.readUint8() != '(' {
self.causePanic()
}
}
func (self *MethodDescriptorParser) endParams() {
if self.readUint8() != ')' {
self.causePanic()
}
}
func (self *MethodDescriptorParser) finish() {
if self.offset != len(self.raw) {
self.causePanic()
}
}
func (self *MethodDescriptorParser) causePanic() {
panic("BAD descriptor: " + self.raw)
}
func (self *MethodDescriptorParser) readUint8() uint8 {
b := self.raw[self.offset]
self.offset++
return b
}
func (self *MethodDescriptorParser) unreadUint8() {
self.offset--
}
func (self *MethodDescriptorParser) parseParamTypes() {
for {
t := self.parseFieldType()
if t != "" {
self.parsed.addParameterType(t)
} else {
break
}
}
}
func (self *MethodDescriptorParser) parseReturnType() {
if self.readUint8() == 'V' {
self.parsed.returnType = "V"
return
}
self.unreadUint8()
t := self.parseFieldType()
if t != "" {
self.parsed.returnType = t
return
}
self.causePanic()
}
func (self *MethodDescriptorParser) parseFieldType() string {
switch self.readUint8() {
case 'B':
return "B"
case 'C':
return "C"
case 'D':
return "D"
case 'F':
return "F"
case 'I':
return "I"
case 'J':
return "J"
case 'S':
return "S"
case 'Z':
return "Z"
case 'L':
return self.parseObjectType()
case '[':
return self.parseArrayType()
default:
self.unreadUint8()
return ""
}
}
func (self *MethodDescriptorParser) parseObjectType() string {
unread := self.raw[self.offset:]
semicolonIndex := strings.IndexRune(unread, ';')
if semicolonIndex == -1 {
self.causePanic()
return ""
} else {
objStart := self.offset - 1
objEnd := self.offset + semicolonIndex + 1
self.offset = objEnd
descriptor := self.raw[objStart:objEnd]
return descriptor
}
}
func (self *MethodDescriptorParser) parseArrayType() string {
arrStart := self.offset - 1
self.parseFieldType()
arrEnd := self.offset
descriptor := self.raw[arrStart:arrEnd]
return descriptor
}