cse100-sm14 / pa2

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Commit dcc4520eaae826baf04cd5883ffa721ebe56eb6d

Authored by Zack Grannan
1 parent 1629dd754a
Exists in master

Added BitInputStream + BitOutputStream

Showing 2 changed files with 104 additions and 0 deletions Side-by-side Diff

BitInputStream.hpp View file @ dcc4520
  1 +#ifndef BITINPUTSTREAM_HPP
  2 +#define BITINPUTSTREAM_HPP
  3 +
  4 +#include <iostream>
  5 +#include <bitset>
  6 +
  7 +using namespace std;
  8 +
  9 +/** A class for reading bits (and ints) from an istream
  10 + */
  11 +class BitInputStream {
  12 +private:
  13 + istream& in; // the istream to delegate to
  14 + char buf; // the buffer of bits
  15 + //bitset<8> buf;
  16 + int bufi; // the bit buffer index
  17 +
  18 +public:
  19 + /** Initialize a BitInputStream object, given an istream.
  20 + */
  21 + BitInputStream(istream& s) : in(s), buf(0), bufi(8) { }
  22 + // BitInputStream(istream& s) : in(s), bufi(8) { }
  23 +
  24 + /** Read the next bit from the bit buffer.
  25 + * If the bit buffer is currently empty,
  26 + * fill the bit buffer by reading a char from the istream first.
  27 + * Return the bit read as the least signficant bit of an int.
  28 + * Return -1 on EOF.
  29 + * This must be consistent with BitOutputStream::writeBit(), in terms
  30 + * of ordering of bits in the stream.
  31 + */
  32 + int readBit();
  33 +
  34 + /** Read a byte from the ostream.
  35 + * Return -1 on EOF.
  36 + * This function doesn't touch the bit buffer.
  37 + * The client has to manage interaction between reading bits
  38 + * and reading bytes.
  39 + */
  40 + int readByte();
  41 +
  42 + /** Read a non-negative int from the ostream.
  43 + * Return -1 on EOF.
  44 + * This function doesn't touch the bit buffer.
  45 + * The client has to manage interaction between reading bits
  46 + * and reading ints.
  47 + */
  48 + int readInt();
  49 +
  50 +
  51 +};
  52 +
  53 +#endif // BITINPUTSTREAM_HPP
BitOutputStream.hpp View file @ dcc4520
  1 +#ifndef BITOUTPUTSTREAM_HPP
  2 +#define BITOUTPUTSTREAM_HPP
  3 +
  4 +#include <iostream>
  5 +#include <bitset>
  6 +
  7 +using namespace std;
  8 +
  9 +/** A class for writing bits (and chars and ints) to an ostream
  10 + */
  11 +class BitOutputStream {
  12 +
  13 +private:
  14 + ostream& out; // the ostream to delegate to
  15 + char buf; // the buffer of bits
  16 + // bitset<8> buf; // the buffer of bits
  17 + int bufi; // the bit buffer index
  18 +
  19 +public:
  20 + BitOutputStream(ostream& s) : out(s), buf(0), bufi(0) { }
  21 + // BitOutputStream(ostream& s) : out(s), bufi(0) { }
  22 +
  23 + /** Write the least significant bit of the argument into
  24 + * the bit buffer, and increment the bit buffer index.
  25 + * Flush to the ostream first if the bit buffer is full.
  26 + * This must be consistent with BitInputStream::readBit().
  27 + */
  28 + void writeBit(int bit);
  29 +
  30 + /** Write the least significant byte of the argument to the ostream.
  31 + * This function doesn't touch the bit buffer.
  32 + * The client has to manage interaction between writing bits
  33 + * and writing bytes.
  34 + */
  35 + void writeByte(int b);
  36 +
  37 + /** Write the argument to the ostream.
  38 + * This function doesn't touch the bit buffer.
  39 + * The client has to manage interaction between writing bits
  40 + * and writing ints.
  41 + */
  42 + void writeInt(int i);
  43 +
  44 + /** If the bit buffer contains any bits, flush the bit buffer to the ostream,
  45 + * clear the bit buffer, and set the bit buffer index to 0.
  46 + * Also flush the ostream itself.
  47 + */
  48 + void flush();
  49 +};
  50 +
  51 +#endif // BITOUTPUTSTREAM_HPP