bit-io
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A library for reading/writing arbitrary length of bits.
bit-io
A library for reading/writing non octet aligned values such as 1-bit boolean or 17-bit unsigned int.
See bit-io2 for Java8+ flavored version.
Specifications
boolean
| type | size(min) | size(max) | notes |
|---|---|---|---|
boolean |
1 | 1 | readBoolean(), writeBoolean(boolean) |
numeric
integral
The size(min) is 1 and the size(max) is 2^e - (unsigned ? 1 : 0).
| type | e | size(min) | size(max) | notes |
|---|---|---|---|---|
byte |
3 | 1 | 7/8 | readByte(unsigned, size), writeByte(unsigned, size, byte) |
short |
4 | 1 | 15/16 | readShort(unsigned, size), writeShort(unsigned, size, short) |
int |
5 | 1 | 31/32 | readInt(unsigned, size), writeInt(unsigned, size, int) |
long |
6 | 1 | 63/64 | readLong(unsigned, size), writeLong(unsigned, size, long) |
char |
1 | 16 | readChar(size), writeChar(size, char) |
floating-point
No methods supplied for floating-point types.
Reading
- You need to prepare an instance of
ByteInputfor reading octets. - You can read bits from an instance of
BitInputwhich uses theByteInputinstance.
Preparing ByteInput
Prepare an instance of ByteInput from various sources.
new ArrayByteInput(byte[], int);
new BufferByteInput(java.nio.ByteBuffer);
new DataByteInput(java.io.DataInput);
new StreamByteInput(java.io.InputStream);
Creating BitInput
Using DefaultBitInput
Construct with an already existing ByteInput.
final BitInput bitInput = new DefalutBitInput(byteInput);
Reading values.
final BitInput input;
final boolean b = input.readBoolean(); // 1-bit boolean 1 1
final int ui6 = input.readInt(true, 6); // 6-bit unsigned int 6 7
final long sl47 = input.readLong(false, 47); // 47-bit signed long 47 54
final long discarded = input.align(1); // aligns to (1*8)-bit 2 56
assert discarded == 2L;
b llllllll llllllll llllllll llllllll llllllll llllll
iiiiiil dd
Writing
- You need to prepare an instance of
ByteOutputfor writing octets. - You can write bits to an instance of
BitInputwhich uses theByteOutputinstance.
Preparing ByteOutput
There are counter classes and contructors to ByteInput.
Creating BitOutput
There are also counter classes and constructors to BitInput.
Using DefalutBitOutput
Writing values.
final BitOutput output;
output.writeBoolean(false); // 1-bit boolean 1 1
output.writeInt(false, 9, -72); // 9-bit signed int 9 10
output.writeBoolean(true); // 1-bit boolean 1 11
output.writeLong(true, 33, 99L); // 33-bit unsigned long 33 44
final long padded = output.align(4); // aligns to (4*8)-bit 20 64
assert padded == 20L;
b b pppp pppppppp pppppppp
iiiiiii ii lllll llllllll llllllll llllllll llll
01101110 00100000 00000000 00000000 00000110 00110000 00000000 00000000
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