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jackz's Avatar jackz revised this gist 1 year ago. Go to revision

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jackz's Avatar Jackz revised this gist 2 years ago. Go to revision

1 file changed, 91 insertions, 44 deletions

BufferReader.ts

@@ -2,25 +2,33 @@ export default class BufferReader {
2 2 #buffer: Buffer
3 3 #offset: number
4 4 #length = 0
5 -
6 - static *getBuffers(data: Buffer) {
7 - let i = 0
8 - let reader = new BufferReader(data)
9 - yield reader
10 - while(reader.nextBuffer != null) {
11 - console.log(i++, "got next buffer", reader.nextBuffer.toString('hex'))
12 - reader = new BufferReader(reader.nextBuffer)
13 - yield reader
14 - }
15 - return null
5 +
6 + /// Yields BufferReaders, splitting when it hits newline
7 + static *getPackets(data: Buffer) {
8 + let reader = new BufferReader(data)
9 + yield reader
10 + // while(reader.nextBuffer != null) {
11 + // reader = new BufferReader(reader.nextBuffer)
12 + // yield reader
13 + // }
14 + return null
15 + }
16 +
17 + static new(size: number) {
18 + return new BufferReader(Buffer.alloc(size))
16 19 }
17 20
18 21 constructor(data: Buffer) {
19 22 if(!data) throw new Error("buffer is null or undefined")
20 - console.log(data.toString('hex'))
23 + // console.log(data.byteLength, data.length, data.toString('hex'))
21 24 this.#buffer = data
22 25 this.#offset = 0
23 26 this.#length = data.byteLength
27 +
28 + }
29 +
30 + get buffer() {
31 + return this.#buffer.subarray()
24 32 }
25 33
26 34 get offset() {
@@ -75,43 +83,82 @@ export default class BufferReader {
75 83 return value
76 84 }
77 85
78 - readString(length: number): string {
79 - const slice = this.#buffer.subarray(this.#offset, this.#offset + length)
80 - this.#offset += length
81 - return slice.toString().split("\0").shift();
82 - }
83 -
84 - readVarString(): string {
85 - let length = this.readShort()
86 - return this.readString(length)
86 + readString(): string {
87 + let start = this.#offset
88 + // Read until null term
89 + while(this.#offset < this.#length) {
90 + if(this.#curChar === 0x0) {
91 + return this.#buffer.subarray(start, this.#offset++).toString()
92 + }
93 + this.#offset++
94 + }
95 + throw new Error("No null term found")
87 96 }
88 -
89 - *readRecord() {
90 - let recordStart: number = null
97 +
98 + /// Yields a BufferReader for every record in a packet
99 + *readRecords() {
91 100 while(!this.isEOF) {
92 - if(this.IsRecordSeparator) {
93 - if(recordStart != null) {
94 - // End of record
95 - yield this.#buffer.subarray(recordStart, this.#offset)
96 - }
97 - recordStart = this.#offset + 1
98 - }
99 - this.#offset++;
100 - }
101 - // Check to see that we have seen the \n(0xa) character at the end, otherwise this record got truncated:
102 - if(recordStart != null && this.#curChar == 0xa) {
103 - yield this.#buffer.subarray(recordStart, this.#offset)
101 + const length = this.readByte()
102 + const endRecord = this.#offset + length
103 + yield new BufferReader(this.#buffer.subarray(this.#offset, endRecord))
104 + this.#offset = endRecord + 1
104 105 }
105 106 return null
106 107 }
107 108
108 - get nextBuffer() {
109 - if(this.#curChar == 0xa && this.#offset + 1 < this.#buffer.length) {
110 - return this.#buffer.subarray(this.#offset + 1)
111 - } else {
112 - return null
113 - }
114 - }
109 + #expand(newSize?: number) {
110 + if(!newSize) newSize = 2 * this.buffer.length
111 + if(newSize < this.#buffer.length) throw new Error("new size must be greater than the current size")
112 + const newBuffer = Buffer.alloc(newSize)
113 + this.buffer.copy(newBuffer, 0, 0, this.buffer.length)
114 + this.#buffer = newBuffer
115 + this.#length = newSize
116 + }
117 +
118 +
119 + writeByte(value: number) {
120 + if(this.#offset + 1 >= this.#length) this.#expand()
121 + this.#buffer.writeInt8(value, this.#offset)
122 + this.#offset++
123 + return this
124 + }
125 +
126 + writeShort(value: number) {
127 + if(this.#offset + 2 >= this.#length) this.#expand()
128 + this.#buffer.writeInt16LE(value, this.#offset)
129 + this.#offset += 2
130 + return this
131 + }
132 +
133 + writeInt(value: number) {
134 + if(this.#offset + 4 >= this.#length) this.#expand()
135 + this.#buffer.writeInt32LE(value, this.#offset)
136 + this.#offset += 4
137 + return this
138 + }
139 +
140 + writeFloat(value: number) {
141 + if(this.#offset + 4 >= this.#length) this.#expand()
142 + this.#buffer.writeFloatLE(value, this.#offset)
143 + this.#offset += 4
144 + return this
145 + }
146 +
147 + writeString(value: string) {
148 + if(this.#offset + value.length + 1 >= this.#length) this.#expand(this.#length + value.length + 1)
149 + if(value == undefined) value = ""
150 + this.#buffer.write(value + "\0", this.#offset, "ascii")
151 + this.#offset += value.length + 1
152 + return this
153 + }
154 +
155 + // get nextBuffer() {
156 + // if(this.#curChar == 0xa && this.#offset + 1 < this.#buffer.length) {
157 + // return this.#buffer.subarray(this.#offset + 1)
158 + // } else {
159 + // return null
160 + // }
161 + // }
115 162
116 163 at(i: number): number {
117 164 return this.#buffer.at(i)
@@ -121,4 +168,4 @@ export default class BufferReader {
121 168 if(this.#offset == this.#length) return null
122 169 return this.readByte()
123 170 }
124 - }
171 + }

jackz's Avatar Jackz revised this gist 2 years ago. Go to revision

1 file changed, 124 insertions

BufferReader.ts(file created)

@@ -0,0 +1,124 @@
1 + export default class BufferReader {
2 + #buffer: Buffer
3 + #offset: number
4 + #length = 0
5 +
6 + static *getBuffers(data: Buffer) {
7 + let i = 0
8 + let reader = new BufferReader(data)
9 + yield reader
10 + while(reader.nextBuffer != null) {
11 + console.log(i++, "got next buffer", reader.nextBuffer.toString('hex'))
12 + reader = new BufferReader(reader.nextBuffer)
13 + yield reader
14 + }
15 + return null
16 + }
17 +
18 + constructor(data: Buffer) {
19 + if(!data) throw new Error("buffer is null or undefined")
20 + console.log(data.toString('hex'))
21 + this.#buffer = data
22 + this.#offset = 0
23 + this.#length = data.byteLength
24 + }
25 +
26 + get offset() {
27 + return this.#offset
28 + }
29 +
30 + get length() {
31 + return this.#length
32 + }
33 +
34 + get isEOF() {
35 + return this.#offset >= this.#length || this.#curChar == 0xa // new line
36 + }
37 +
38 + get IsRecordSeparator() {
39 + return this.#curChar === BufferReader.RecordSeparator
40 + }
41 +
42 + get #curChar() {
43 + return this.#buffer.at(this.#offset)
44 + }
45 +
46 + static get RecordSeparator() {
47 + return 0x1e
48 + }
49 +
50 + peekByte(): number {
51 + return this.#buffer.readInt8(this.#offset)
52 + }
53 +
54 + readByte(): number {
55 + const value = this.#buffer.readInt8(this.#offset)
56 + this.#offset += 1
57 + return value
58 + }
59 +
60 + readShort(): number {
61 + const value = this.#buffer.readInt16LE(this.#offset)
62 + this.#offset += 2
63 + return value
64 + }
65 +
66 + readInt(): number {
67 + const value = this.#buffer.readInt32LE(this.#offset)
68 + this.#offset += 4
69 + return value
70 + }
71 +
72 + readFloat(): number {
73 + const value = this.#buffer.readFloatLE(this.#offset)
74 + this.#offset += 4
75 + return value
76 + }
77 +
78 + readString(length: number): string {
79 + const slice = this.#buffer.subarray(this.#offset, this.#offset + length)
80 + this.#offset += length
81 + return slice.toString().split("\0").shift();
82 + }
83 +
84 + readVarString(): string {
85 + let length = this.readShort()
86 + return this.readString(length)
87 + }
88 +
89 + *readRecord() {
90 + let recordStart: number = null
91 + while(!this.isEOF) {
92 + if(this.IsRecordSeparator) {
93 + if(recordStart != null) {
94 + // End of record
95 + yield this.#buffer.subarray(recordStart, this.#offset)
96 + }
97 + recordStart = this.#offset + 1
98 + }
99 + this.#offset++;
100 + }
101 + // Check to see that we have seen the \n(0xa) character at the end, otherwise this record got truncated:
102 + if(recordStart != null && this.#curChar == 0xa) {
103 + yield this.#buffer.subarray(recordStart, this.#offset)
104 + }
105 + return null
106 + }
107 +
108 + get nextBuffer() {
109 + if(this.#curChar == 0xa && this.#offset + 1 < this.#buffer.length) {
110 + return this.#buffer.subarray(this.#offset + 1)
111 + } else {
112 + return null
113 + }
114 + }
115 +
116 + at(i: number): number {
117 + return this.#buffer.at(i)
118 + }
119 +
120 + next(): number | null {
121 + if(this.#offset == this.#length) return null
122 + return this.readByte()
123 + }
124 + }
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