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#pragma once
namespace nall::Encode {
template<u32 S = 1, u32 M = 4 / S> //S = word size; M = match length
inline auto RLE(array_view<u8> input) -> vector<u8> {
vector<u8> output;
for(u32 byte : range(8)) output.append(input.size() >> byte * 8);
u32 base = 0;
u32 skip = 0;
auto load = [&](u32 offset) -> u8 {
return input(offset);
};
auto read = [&](u32 offset) -> u64 {
u64 value = 0;
for(u32 byte : range(S)) value |= load(offset + byte) << byte * 8;
return value;
};
auto write = [&](u64 value) -> void {
for(u32 byte : range(S)) output.append(value >> byte * 8);
};
auto flush = [&] {
output.append(skip - 1);
do {
write(read(base));
base += S;
} while(--skip);
};
while(base + S * skip < input.size()) {
u32 same = 1;
for(u32 offset = base + S * (skip + 1); offset < input.size(); offset += S) {
if(read(offset) != read(base + S * skip)) break;
if(++same == 127 + M) break;
}
if(same < M) {
if(++skip == 128) flush();
} else {
if(skip) flush();
output.append(128 | same - M);
write(read(base));
base += S * same;
}
}
if(skip) flush();
return output;
}
}
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