bit-buffer-ts v0.8.1
@ntrip/bit-buffer
Modification of the original bit-buffer by inolen, changing to TypeScript and modifying methods relating to buffer/string reading/writing.
BitBuffer provides two objects, BitView and BitStream. BitView is a wrapper for ArrayBuffers with support for bit-level reads and writes. BitStream is a wrapper for a BitView used to help maintain your current buffer position.
Class: BitView
Wrapper for ArrayBuffers with support for bit-level reads and writes.
Similar to JavaScript's DataView.
Constructors
constructor
+ new BitView(buffer: Uint8Array, byteOffset: number, byteLength: number): BitView
Parameters:
| Name | Type | Default |
|---|---|---|
buffer | Uint8Array | - |
byteOffset | number | 0 |
byteLength | number | buffer.length - byteOffset |
Returns: BitView
Properties
Readonly bitLength: number
Length of this view (in bits) from the start of its buffer.
Readonly buffer: Uint8Array
Underlying buffer which this view accesses.
Readonly byteLength: number
Length of this view (in bytes) from the start of its buffer.
Methods
getBit(offset: number): 1 | 0
Returns the bit value at the specified bit offset.
getBits(offset: number, bits: number, signed: boolean): number
Returns a bits long value at the specified bit offset.
getBitArray(offset: number, bits: number): boolean[]
Returns a bits long array of bit values at the specified bit offset.
readBuffer(offset: number, byteLength: number): Uint8Array
Returns a buffer containing the bytes at the specified bit offset.
readString(offset: number, byteLength: number, decoder?: undefined | TextDecoder): string
Returns a string decoded from the bytes at the specified bit offset.
setBit(offset: number, value: 1 | 0): void
Writes the bit value at the specified bit offset.
setBits(offset: number, value: number, bits: number): void
Writes a bits long value at the specified bit offset.
remarks There is no difference between signed and unsigned values when storing.
setBitArray(offset: number, value: boolean[], bits: number): void
Writes a bits long array of bit values at the specified bit offset.
writeBuffer(offset: number, buffer: Uint8Array): number
Writes the contents of a buffer at the specified bit offset.
Returns: The number of bytes written.
writeString(offset: number, string: string, byteLength?: undefined | number, encoder?: undefined | TextEncoder): number
Writes an encoded form of a string to the bytes at the specified bit offset.
remarks If the encoded string length is less than byteLength, the remainder is filled with 0s.
remarks If the encoded string length is longer than byteLength, it is truncated.
Returns: The number of bytes written (may be different from the string length).
getBoolean, getInt8, getInt16, getInt32, getUint8, getUint16, getUint32, setBoolean, setInt8, setInt16, setInt32, setUint8, setUint16, setUint32
Helper methods, see getBits and setBits.
Class: BitStream
Wrapper for BitViews that maintains an index while reading/writing sequential data.
Constructors
constructor
+ new BitStream(source: BitView): BitStream
Parameters:
| Name | Type |
|---|---|
source | BitView |
Returns: BitStream
+ new BitStream(source: Buffer, byteOffset?: undefined | number, byteLength?: undefined | number): BitStream
Parameters:
| Name | Type |
|---|---|
source | Buffer |
byteOffset? | undefined | number |
byteLength? | undefined | number |
Returns: BitStream
Properties
bitIndex: number
Current position of this stream (in bits) from/to which data is read/written.
Readonly bitLength: number
Length of this stream (in bits) from the start of its buffer.
Readonly buffer: Uint8Array
Underlying buffer which this stream accesses.
Readonly byteLength: number
Length of this stream (in bytes) from the start of its buffer.
Readonly view: BitView
Underlying view which this stream accesses.
Accessors
bitsLeft
• get bitsLeft(): number
Number of bits remaining in this stream's underlying buffer from the current position.
Returns: number
byteIndex
• get byteIndex(): number
Current position of this stream (in bytes) from/to which data is read/written.
Returns: number
• set byteIndex(val: number): void
Current position of this stream (in bytes) from/to which data is read/written.
Parameters:
| Name | Type |
|---|---|
val | number |
Returns: void
index
Alias for bitIndex
Parameters:
| Name | Type |
|---|---|
val | number |
Returns: void
Methods
readBit(): 1 | 0
readBits(bits: number, signed: boolean): number
readBitArray(bits: number): boolean[]
readBuffer(byteLength: number): Uint8Array
readString(byteLength: number, decoder?: undefined | TextDecoder): string
writeBit(value: 1 | 0): void
writeBits(value: number, bits: number): void
writeBitArray(value: boolean[], bits: number): void
writeBuffer(buffer: Uint8Array): number
writeString(string: string, byteLength?: undefined | number, encoder?: undefined | TextEncoder): number
readBoolean, readInt8, readInt16, readInt32, readUint8, readUint16, readUint32, writeBoolean, writeInt8, writeInt16, writeInt32, writeUint8, writeUint16, writeUint32
Helper methods, see readBits and writeBits.