Class Pbf

Protobuffer Reader and Writer

Description

Create a new PBF instance and either read or write to it. Follows the early Protobuf spec supporting various types of encoding including messages (which are usually representative of class objects).

Usage

Reading:

const data = fs.readFileSync(path);
const pbf = new Pbf(data);

Writing:

const pbf = new Pbf();
pbf.writeVarintField(1, 1);
// ...
const result = pbf.commit();

Hierarchy (View Summary)

PbfReader
- Pbf

Index

Constructors

constructor

Methods

commit destroy readBoolean readBytes readDouble readFields readFixed32 readFixed64 readFloat readMessage readPackedBoolean readPackedDouble readPackedFixed32 readPackedFixed64 readPackedFloat readPackedSFixed32 readPackedSFixed64 readPackedSVarint readPackedVarint readSFixed32 readSFixed64 readString readSVarint readTag readVarint readVarint64 realloc skip writeBoolean writeBooleanField writeBytes writeBytesField writeDouble writeDoubleField writeFixed32 writeFixed32Field writeFixed64 writeFixed64Field writeFloat writeFloatField writeMessage writePackedBoolean writePackedDouble writePackedFixed32 writePackedFixed64 writePackedFloat writePackedSFixed32 writePackedSFixed64 writePackedSVarint writePackedVarint writeRawMessage writeSFixed32 writeSFixed32Field writeSFixed64 writeSFixed64Field writeString writeStringField writeSVarint writeSVarintField writeTag writeVarint writeVarintField

Constructors

constructor

new Pbf(buf?: ArrayBuffer | Uint8Array): Pbf
Parameters
- buf: ArrayBuffer | Uint8Array = ...
  an optional Uint8Array to use for reading. otherwise defaults to an empty Uint8Array for writing
Returns Pbf
Inherited from PbfReader.constructor

Methods

commit

commit(): Uint8Array
Returns Uint8Array
- the entire written buffer

destroy

destroy(): void
Destroys the PBF instance. You can still use the Pbf instance after calling this method. However, the buffer will be emptied.

Returns void
Inherited from PbfReader.destroy

readBoolean

readBoolean(): boolean
Returns boolean
- parses the varint byte as a boolean expression
Inherited from PbfReader.readBoolean

readBytes

readBytes(): Uint8Array
NOTE: bytes is preceeded by a varint dscribing the length of the bytes. The bytes themselves are presumed to be u8s and therefore don't need to be decoded

Returns Uint8Array
- the decoded byte array
Inherited from PbfReader.readBytes

readDouble

readDouble(): number
Read in a 64-bit float from the buffer. There are no compression advantages with this type of encoding.

Returns number
- 64-bit float
Inherited from PbfReader.readDouble

readFields

readFields(readField: ReadFieldFunction, input: U, end: number): U
If you know you are reading a message, but have already read the length of the message OR you're reading fields of the top level data, then this method is the alternative. It's often used by sub-classes So that it can be instationated prior to reading the message.
Type Parameters
- U
Parameters
- readField: ReadFieldFunction
 user defined input function to parse the message fields
- input: U
 The class to mutate given field data
- end: number
 the end position of the message in the buffer
Returns U
- The class we mutated will be returned
See
readMessage.

Ex.
```
export class MapboxVectorLayer {
 constructor(pbf: Protobuf, end: number) {
 this.#pbf = pbf;
 pbf.readFields(this.#readLayer, this, end);
 }

 #readLayer(tag: number, layer: MapboxVectorLayer, pbf: Protobuf): void {
 if (tag === 15) layer.version = pbf.readVarint();
 else if (tag === 1) layer.name = pbf.readString();
 // ...
 }
}
```
Inherited from PbfReader.readFields

readFixed32

readFixed32(): number
Read in a 32-bit unsigned integer from the buffer. There are no compression advantages with this type of encoding.

Returns number
- 32-bit unsigned integer
Inherited from PbfReader.readFixed32

readFixed64

readFixed64(): number
Read in a 64-bit unsigned integer from the buffer. There are no compression advantages with this type of encoding.

Returns number
- 64-bit unsigned integer
Inherited from PbfReader.readFixed64

readFloat

readFloat(): number
Read in a 32-bit float from the buffer. There are no compression advantages with this type of encoding.

Returns number
- 32-bit float
Inherited from PbfReader.readFloat

readMessage

readMessage(readField: ReadFieldFunction, input: U): U
Reads a message from the buffer. Sometimes it's easier to manage sub structures so that the current method can build multiples of an entire structure/class. If you you are at the top level, or parsing the message inside a class, then
Type Parameters
- U
Parameters
- readField: ReadFieldFunction
 user defined input function
- input: U
 an instance of the class you are reading into
Returns U
- The class itself will be returned
See
readFields.

Ex.
```
class Test {
 a: number = 0;

 static read(tag: number, test: Test, pbf: Protobuf): void {
 if (tag === 1) test.a = pbf.readVarint();
 // ...
 }
}

const pbf = new Pbf(data);
const t = new Test();
pbf3.readTag();
pbf3.readMessage(Test.read, t);
```
Inherited from PbfReader.readMessage

readPackedBoolean

readPackedBoolean(arr?: boolean[]): boolean[]
Parameters
- arr: boolean[] = []
  the array to write to
Returns boolean[]
- the arr input with the decoded boolean values is also returned
Inherited from PbfReader.readPackedBoolean

readPackedDouble

readPackedDouble(arr?: number[]): number[]
Parameters
- arr: number[] = []
  the array to write to
Returns number[]
- the arr input with the decoded doubles is also returned
Inherited from PbfReader.readPackedDouble

readPackedFixed32

readPackedFixed32(arr?: number[]): number[]
Parameters
- arr: number[] = []
  the array to write to
Returns number[]
- the arr input with the decoded unsigned integers is also returned
Inherited from PbfReader.readPackedFixed32

readPackedFixed64

readPackedFixed64(arr?: number[]): number[]
Parameters
- arr: number[] = []
  the array to write to
Returns number[]
- the arr input with the decoded unsigned 64-bit integers is also returned
Inherited from PbfReader.readPackedFixed64

readPackedFloat

readPackedFloat(arr?: number[]): number[]
Parameters
- arr: number[] = []
  the array to write to
Returns number[]
- the arr input with the decoded floats is also returned
Inherited from PbfReader.readPackedFloat

readPackedSFixed32

readPackedSFixed32(arr?: number[]): number[]
Parameters
- arr: number[] = []
  the array to write to
Returns number[]
- the arr input with the decoded signed integers is also returned
Inherited from PbfReader.readPackedSFixed32

readPackedSFixed64

readPackedSFixed64(arr?: number[]): number[]
Parameters
- arr: number[] = []
  the array to write to
Returns number[]
- the arr input with the decoded signed 64-bit integers is also returned
Inherited from PbfReader.readPackedSFixed64

readPackedSVarint

readPackedSVarint(arr?: number[]): number[]
Parameters
- arr: number[] = []
  the array to write to
Returns number[]
- the arr input with the decoded numbers is also returned
Inherited from PbfReader.readPackedSVarint

readPackedVarint

readPackedVarint(arr?: number[], isSigned?: boolean): number[]
Parameters
- arr: number[] = []
  the array to write to
- isSigned: boolean = false
  true if the numbers are signed
Returns number[]
- the arr input with the decoded numbers is also returned
Inherited from PbfReader.readPackedVarint

readSFixed32

readSFixed32(): number
Read in a 32-bit signed integer from the buffer. There are no compression advantages with this type of encoding.

Returns number
- 32-bit signed integer
Inherited from PbfReader.readSFixed32

readSFixed64

readSFixed64(): number
Read in a 64-bit signed integer from the buffer. There are no compression advantages with this type of encoding.

Returns number
- 64-bit signed integer
Inherited from PbfReader.readSFixed64

readString

readString(): string
Returns string
- the decoded string
Inherited from PbfReader.readString

readSVarint

readSVarint(): number
Returns number
- the decoded number as a signed number
Inherited from PbfReader.readSVarint

readTag

readTag(): Tag
Reads a tag from the buffer, pulls out the tag and type and returns it.

Returns Tag
- {tag: number, type: number}
Inherited from PbfReader.readTag

readVarint

readVarint(isSigned?: boolean): number
Parameters
- isSigned: boolean = false
  true if the number is signed
Returns number
- the decoded number
Inherited from PbfReader.readVarint

readVarint64

readVarint64(): number
Returns number
- the decoded number
See
readVarint for better performance

Inherited from PbfReader.readVarint64

realloc

realloc(min: number): void
Allocate more space in the buffer
Parameters
- min: number
  the minimum number of bytes to allocate
Returns void

skip

skip(val: number): void
Skip a value we are not interested in parsing
Parameters
- val: number
  the type to skip
Returns void
Inherited from PbfReader.skip

writeBoolean

writeBoolean(val: number | boolean): void
Write a boolean value. Can also be a number, in which case it will be converted to a boolean. 0 is false, anything else is true.
Parameters
- val: number | boolean
  the boolean to write.
Returns void

writeBooleanField

writeBooleanField(tag: number, val: number | boolean): void
Write a packed repeated boolean array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- val: number | boolean
  the boolean to write.
Returns void

writeBytes

writeBytes(inBuf: ArrayBuffer | Uint8Array | Buffer): void
Write a byte array
Parameters
- inBuf: ArrayBuffer | Uint8Array | Buffer
  a Buffer to write. Will write the length of the buffer first. After that, the buffer will be written byte by byte.
Returns void

writeBytesField

writeBytesField(tag: number, buffer: ArrayBuffer | Uint8Array | Buffer): void
Write a packed repeated byte array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- buffer: ArrayBuffer | Uint8Array | Buffer
  the buffer of bytes to write.
Returns void

writeDouble

writeDouble(val: number): void
Write a 64-bit floating point number
Parameters
- val: number
  a 64-bit floating point number to write
Returns void

writeDoubleField

writeDoubleField(tag: number, val: number): void
Write a packed repeated double array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- val: number
  the double to write.
Returns void

writeFixed32

writeFixed32(val: number): void
Write a 32-bit unsigned integer
Parameters
- val: number
  the 32-bit unsigned integer to write
Returns void

writeFixed32Field

writeFixed32Field(tag: number, val: number): void
write a packed repeated fixed 32-bit integer array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- val: number
  the unsigned 32-bit integer to write.
Returns void

writeFixed64

writeFixed64(val: number): void
Write a 64-bit unsigned integer
Parameters
- val: number
  the 64-bit unsigned integer to write
Returns void

writeFixed64Field

writeFixed64Field(tag: number, val: number): void
Write a packed repeated unsigned 64-bit integer array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- val: number
  the unsigned 64-bit integer to write.
Returns void

writeFloat

writeFloat(val: number): void
Write a 32-bit floating point number
Parameters
- val: number
  a 32-bit floating point number to write
Returns void

writeFloatField

writeFloatField(tag: number, val: number): void
Write a packed repeated float array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- val: number
  the float to write.
Returns void

writeMessage

writeMessage<T>(tag: number, fn: (obj: T, pbf: Pbf) => void, obj: T): void
Write a message to the buffer. Allows you to pass in an object with a write function to define how the message should be written. A good tool to abstract away storing classes or sub-classes.
Type Parameters
- T
Parameters
- tag: number
  the tag to write to associate with the message. This will help track how to read following data.
- fn: (obj: T, pbf: Pbf) => void
  user defined function to call to manually define how to write the object
- obj: T
  the object to pass to the user defined function
Returns void

writePackedBoolean

writePackedBoolean(tag: number, arr: (number | boolean)[]): void
Write a packed repeated boolean array to the buffer. Supports numbers: 0 is false, everything else is true.
Parameters
- tag: number
  the tag to write to associate with the value.
- arr: (number | boolean)[]
  the array of booleans to write.
Returns void

writePackedDouble

writePackedDouble(tag: number, arr: number[]): void
Write a packed repeated 64-bit double array to the buffer.
Parameters
- tag: number
  the tag to write to associate with the value.
- arr: number[]
  the array of doubles to write.
Returns void

writePackedFixed32

writePackedFixed32(tag: number, arr: number[]): void
Write a packed repeated 32-bit unsigned integer array to the buffer.
Parameters
- tag: number
  the tag to write to associate with the value.
- arr: number[]
  the array of unsigned 32-bit numbers to write.
Returns void

writePackedFixed64

writePackedFixed64(tag: number, arr: number[]): void
Write a packed repeated 64-bit unsigned integer array to the buffer.
Parameters
- tag: number
  the tag to write to associate with the value.
- arr: number[]
  the array of unsigned 64-bit numbers to write.
Returns void

writePackedFloat

writePackedFloat(tag: number, arr: number[]): void
Write a packed repeated 32-bit float array to the buffer.
Parameters
- tag: number
  the tag to write to associate with the value.
- arr: number[]
  the array of floats to write.
Returns void

writePackedSFixed32

writePackedSFixed32(tag: number, arr: number[]): void
Write a packed repeated 32-bit signed integer array to the buffer.
Parameters
- tag: number
  the tag to write to associate with the value.
- arr: number[]
  the array of signed 32-bit numbers to write.
Returns void

writePackedSFixed64

writePackedSFixed64(tag: number, arr: number[]): void
Write a packed repeated 64-bit signed integer array to the buffer.
Parameters
- tag: number
  the tag to write to associate with the value.
- arr: number[]
  the array of signed 64-bit numbers to write.
Returns void

writePackedSVarint

writePackedSVarint(tag: number, arr: number[]): void
Write a packed repeated signed whole number array to the buffer.
Parameters
- tag: number
  the tag to write to associate with the value.
- arr: number[]
  the array of signed whole numbers to write.
Returns void

writePackedVarint

writePackedVarint(tag: number, arr: number[]): void
Write a packed repeated unsigned whole number array to the buffer.
Parameters
- tag: number
  the tag to write to associate with the value.
- arr: number[]
  the array of unsigned whole numbers to write.
Returns void

writeRawMessage

writeRawMessage<T>(fn: (obj: T, pbf: Pbf) => void, obj: T): void
Write a message to the buffer. Allows you to pass in an object with a write function to define how the message should be written. A good tool to abstract away storing classes or sub-classes.
Type Parameters
- T
Parameters
- fn: (obj: T, pbf: Pbf) => void
  the user defined function to call to write the message
- obj: T
  the object to pass to the user defined function
Returns void

writeSFixed32

writeSFixed32(val: number): void
Write a 32-bit signed integer
Parameters
- val: number
  the 32-bit signed integer to write
Returns void

writeSFixed32Field

writeSFixed32Field(tag: number, val: number): void
Write a packed repeated signed 32-bit integer array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- val: number
  the signed 32-bit integer to write.
Returns void

writeSFixed64

writeSFixed64(val: number): void
Write a 64-bit signed integer
Parameters
- val: number
  the 64-bit signed integer to write
Returns void

writeSFixed64Field

writeSFixed64Field(tag: number, val: number): void
Write a packed repeated signed 64-bit integer array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- val: number
  the signed 64-bit integer to write.
Returns void

writeString

writeString(str: string): void
Write a string. Strings larger then 128 bytes will be written in chunks of 128 bytes and are slightly less efficient.
Parameters
- str: string
  the string to write
Returns void

writeStringField

writeStringField(tag: number, str: string): void
Write a packed repeated string array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- str: string
  the string to write.
Returns void

writeSVarint

writeSVarint(val: number): void
Write a signed varint. Can be max 64-bits. Numbers can be negative but must still be a while number.
Parameters
- val: number
  any whole signed number. It's usually best practice to not use this function directly unless you know what you're doing.
Returns void

writeSVarintField

writeSVarintField(tag: number, val: number): void
Write a packed repeated signed integer array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- val: number
  the signed number to write.
Returns void

writeTag

writeTag(tag: number, type: number): void
Write a tag and its associated type
Parameters
- tag: number
  the tag to write
- type: number
  the type to write (will never be greater than 3 bits)
Returns void

writeVarint

writeVarint(val: number): void
Write a varint. Can be max 64-bits. Numbers are coerced to an unsigned while number before using this function.
Parameters
- val: number
  any whole unsigned number. It's usually best practice to not use this function directly unless you know what you're doing.
Returns void

writeVarintField

writeVarintField(tag: number, val: number): void
Write a packed repeated unsigned integer array to the buffer with an associated tag.
Parameters
- tag: number
  the tag to write to associate with the value.
- val: number
  the unsigned number to write.
Returns void

Class Pbf

Protobuffer Reader and Writer

Description

Usage

Reading:

Writing:

Hierarchy (View Summary)

Index

Constructors

Methods

Constructors

constructor

Parameters

Returns Pbf

Methods

commit

Returns Uint8Array

destroy

Returns void

readBoolean

Returns boolean

readBytes

Returns Uint8Array

readDouble

Returns number

readFields

Type Parameters

Parameters

Returns U

See

readFixed32

Returns number

readFixed64

Returns number

readFloat

Returns number

readMessage

Type Parameters

Parameters

Returns U

See

readPackedBoolean

Parameters

Returns boolean[]

readPackedDouble

Parameters

Returns number[]

readPackedFixed32

Parameters

Returns number[]

readPackedFixed64

Parameters

Returns number[]

readPackedFloat

Parameters

Returns number[]

readPackedSFixed32

Parameters

Returns number[]

readPackedSFixed64

Parameters

Returns number[]

readPackedSVarint

Parameters

Returns number[]

readPackedVarint

Parameters

Returns number[]

readSFixed32

Returns number

readSFixed64

Returns number

readString

Returns string

readSVarint

Returns number

readTag

Returns Tag

readVarint

Parameters