phundrak/lzw-assignment
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Merge branch 'master' of labs.phundrak.fr:phundrak/lzw-assignment

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This commit is contained in:
Phuntsok Drak-pa 2019-08-22 17:57:03 +02:00
commit bbfb669781
9 changed files with 50 additions and 40 deletions
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29
src/bitpack.cc
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@ -10,9 +10,9 @@ using vuint16 = vector<uint16_t>;
using vuchar = vector<uchar>;
using ustring = std::basic_string<unsigned char>;
int max(const int t_n) { return ipow(2, t_n) - 1; }
[[nodiscard]] int max(const int t_n) { return ipow(2, t_n) - 1; }
constexpr uint16_t mask_n(int t_nb_bits) {
[[nodiscard]] constexpr uint16_t mask_n(int t_nb_bits) {
if (t_nb_bits == 0) {
return 0;
}
@ -31,14 +31,14 @@ constexpr uint16_t masks[17] = {
// packing //
///////////////////////////////////////////////////////////////////////////////
vuchar pack(const vuint16 &t_input) {
[[nodiscard]] vuchar pack(const vuint16 &t_input) {
vuchar vec{};
return pack_n(t_input.begin(), t_input.end(), vec, 9);
}
vuchar pack_n(const vuint16::const_iterator t_input_begin,
const vuint16::const_iterator t_input_end, vuchar &t_res,
int t_n) {
[[nodiscard]] vuchar pack_n(const vuint16::const_iterator t_input_begin,
const vuint16::const_iterator t_input_end,
vuchar &t_res, int t_n) {
if (t_n == 16) {
return pack_16(t_input_begin, t_input_end, t_res);
}
@ -107,8 +107,9 @@ vuchar pack_n(const vuint16::const_iterator t_input_begin,
return t_res;
}
vuchar pack_16(const vuint16::const_iterator t_input_begin,
const vuint16::const_iterator t_input_end, vuchar &t_res) {
[[nodiscard]] vuchar pack_16(const vuint16::const_iterator t_input_begin,
const vuint16::const_iterator t_input_end,
vuchar &t_res) {
std::for_each(t_input_begin, t_input_end, [&t_res](const auto value) {
t_res.push_back(static_cast<uchar>(value >> 8 & 0xFFU));
t_res.push_back(static_cast<uchar>(value & 0xFFU));
@ -120,13 +121,14 @@ vuchar pack_16(const vuint16::const_iterator t_input_begin,
// unpacking //
///////////////////////////////////////////////////////////////////////////////
vuint16 unpack(ustring &&t_input) {
[[nodiscard]] vuint16 unpack(ustring &&t_input) {
vuint16 vec{};
return unpack_n(t_input.begin(), t_input.end(), vec, 9);
}
vuint16 unpack_n(const ustring::const_iterator t_begin,
const ustring::const_iterator t_end, vuint16 &t_res, int t_n) {
[[nodiscard]] vuint16 unpack_n(const ustring::const_iterator t_begin,
const ustring::const_iterator t_end,
vuint16 &t_res, int t_n) {
if (t_n == 16) {
return unpack_16(t_begin, t_end, t_res);
}
@ -165,8 +167,9 @@ vuint16 unpack_n(const ustring::const_iterator t_begin,
return t_res;
}
vuint16 unpack_16(const ustring::const_iterator t_begin,
const ustring::const_iterator t_end, vuint16 &t_res) {
[[nodiscard]] vuint16 unpack_16(const ustring::const_iterator t_begin,
const ustring::const_iterator t_end,
vuint16 &t_res) {
for (auto it = t_begin; it < t_end; ++it) {
t_res.push_back(static_cast<uint16_t>(*it << 8 | *++it));
}

20
src/bitpack.hh
View File

@ -5,24 +5,28 @@
#include <string>
#include <vector>
std::vector<unsigned char> pack(const std::vector<std::uint16_t> &);
[[nodiscard]] std::vector<unsigned char>
pack(const std::vector<std::uint16_t> &);
std::vector<unsigned char> pack_n(std::vector<std::uint16_t>::const_iterator,
std::vector<std::uint16_t>::const_iterator,
std::vector<unsigned char> &, int);
[[nodiscard]] std::vector<unsigned char>
pack_n(std::vector<std::uint16_t>::const_iterator,
std::vector<std::uint16_t>::const_iterator, std::vector<unsigned char> &,
int);
std::vector<unsigned char> pack_16(std::vector<std::uint16_t>::const_iterator,
[[nodiscard]] std::vector<unsigned char>
pack_16(std::vector<std::uint16_t>::const_iterator,
std::vector<std::uint16_t>::const_iterator,
std::vector<unsigned char> &);
std::vector<std::uint16_t> unpack(std::basic_string<unsigned char> &&);
[[nodiscard]] std::vector<std::uint16_t>
unpack(std::basic_string<unsigned char> &&);
std::vector<std::uint16_t>
[[nodiscard]] std::vector<std::uint16_t>
unpack_n(std::basic_string<unsigned char>::const_iterator t_begin,
std::basic_string<unsigned char>::const_iterator t_end,
std::vector<std::uint16_t> &, int t_n);
std::vector<std::uint16_t>
[[nodiscard]] std::vector<std::uint16_t>
unpack_16(std::basic_string<unsigned char>::const_iterator,
std::basic_string<unsigned char>::const_iterator,
std::vector<std::uint16_t> &);

13
src/common.cc
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@ -6,7 +6,7 @@ using dic_comp_t = std::map<std::pair<uint16_t, uint8_t>, uint16_t>;
using ustring = std::basic_string<unsigned char>;
using p_ustring = std::shared_ptr<ustring>;
int ipow(int base, int exp) {
[[nodiscard]] int ipow(int base, int exp) {
int result = 1;
for (;;) {
if (exp & 1) {
@ -21,20 +21,21 @@ int ipow(int base, int exp) {
return result;
}
std::pair<bool, uint16_t> dico(dic_comp_t &t_dictionary,
const uint16_t t_nr_chaine, const uint8_t t_c) {
[[nodiscard]] std::pair<bool, uint16_t>
dico(dic_comp_t &t_dictionary, const uint16_t t_nr_chaine, const uint8_t t_c) {
if (t_nr_chaine == 0xFFFF) {
return std::make_pair(true, t_c);
}
auto &e = t_dictionary[std::make_pair(t_nr_chaine, t_c)];
if(e != 0)
if (e != 0)
return std::make_pair(true, e);
e = static_cast<uint16_t>(t_dictionary.size() + 255);
return std::make_pair(false, e);
}
ustring dico_uncompress(std::map<uint16_t, ustring> &t_dict,
const uint16_t t_code, const uint16_t t_old) {
[[nodiscard]] ustring dico_uncompress(std::map<uint16_t, ustring> &t_dict,
const uint16_t t_code,
const uint16_t t_old) {
// le code existe dans le dictionnaire s’il est < 256
if (t_code < 256) {
ustring e{static_cast<unsigned char>(t_code)};

6
src/common.hh
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@ -5,13 +5,13 @@
#include <map>
#include <memory>
int ipow(int, int);
[[nodiscard]] int ipow(int, int);
std::pair<bool, std::uint16_t>
[[nodiscard]] std::pair<bool, std::uint16_t>
dico(std::map<std::pair<std::uint16_t, std::uint8_t>, std::uint16_t> &,
const std::uint16_t, const std::uint8_t);
std::basic_string<unsigned char>
[[nodiscard]] std::basic_string<unsigned char>
dico_uncompress(std::map<std::uint16_t, std::basic_string<unsigned char>> &,
const std::uint16_t, const std::uint16_t);

4
src/compress.cc
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@ -17,7 +17,7 @@ using ustring = std::basic_string<unsigned char>;
using dict_t = std::map<std::pair<uint16_t, uint8_t>, uint16_t>;
using std::printf;
ustring read_file(const string &filename) {
[[nodiscard]] ustring read_file(const string &filename) {
std::ifstream file{filename, ios::binary};
assert(file);
file.unsetf(ios::skipws);
@ -32,7 +32,7 @@ ustring read_file(const string &filename) {
return res;
}
vvuint16 lzw_compress(ustring &&t_text) {
[[nodiscard]] vvuint16 lzw_compress(ustring &&t_text) {
vvuint16 res{};
const auto DICT_MAX = static_cast<size_t>(ipow(2, 14) - 256); /* 16 bits */
uint16_t w = 0xFFFF;

2
src/compress.hh
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@ -6,7 +6,7 @@
#include <thread>
#include <vector>
std::vector<std::vector<std::uint16_t>>
[[nodiscard]] std::vector<std::vector<std::uint16_t>>
lzw_compress(std::basic_string<unsigned char> &&);
void compress(const std::string &, const char *);

5
src/main.cc
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@ -37,7 +37,8 @@ Options available:\n\
\t\"_uncompresed\" will be added");
}
std::tuple<string, string, bool> process_args(int t_argc, char *t_argv[]) {
[[nodiscard]] std::tuple<string, string, bool> process_args(int t_argc,
char *t_argv[]) {
auto ret = std::make_tuple(string{}, string{}, true);
while (true) {
int option_index = 0;
@ -82,7 +83,7 @@ std::tuple<string, string, bool> process_args(int t_argc, char *t_argv[]) {
int main(int argc, char *argv[]) {
const auto [input_path, output_path, compressing] = process_args(argc, argv);
if(input_path.empty()) {
if (input_path.empty()) {
help();
return 0;
}

2
src/uncompress.cc
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@ -16,7 +16,7 @@ using std::vector;
using ustring = std::basic_string<unsigned char>;
using vuint16 = vector<uint16_t>;
ustring lzw_uncompress(vuint16 &&t_compressed) {
[[nodiscard]] ustring lzw_uncompress(vuint16 &&t_compressed) {
ustring ret{};
uint16_t old = 0;
std::map<uint16_t, ustring> dict{};

5
src/uncompress.hh
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@ -6,10 +6,11 @@
#include <string>
#include <vector>
std::basic_string<unsigned char> lzw_uncompress(std::vector<std::uint16_t> &&);
[[nodiscard]] std::basic_string<unsigned char>
lzw_uncompress(std::vector<std::uint16_t> &&);
void uncompress(const std::string &, const char *);
void uncompress_chunk(FILE *, std::ofstream&);
void uncompress_chunk(FILE *, std::ofstream &);
#endif /* LZW_SRC_UNCOMPRESS_H_ */