By David F. Gleich, based on TypedBytes for python by Klaas Bosteels, and typedbytes in Hadoop by Brandyn White.
This library implements readers and writers for the TypedBytes codes in C++. It was originally developed for the mrtsqr project, but should be independently useful.
Let's suppose we have a typed bytes file has an integer for a header, a sequence of strings, and a map of strings to integers. For fun, let's pretend the sequence has a list of directory names, and the map is a list of filenames and their filesizes.
FILE* f = fopen("myfile.tb","r")
TypedBytesInFile tb(f);
assert(tb.next_type() == TypedBytesInteger)
int header = tb.read_int();
assert(tb.next_type() == TypedBytesList);
while (tb.next_type() != TypedBytesListEnd) {
std::string dirname;
// we already read the typecode, so use lastcode here instead
assert(tb.lastcode == TypedBytesString);
tb.read_string(&dirname);
}
// notice that we already read the typecode
assert(tb.lastcode == TypedBytesMap)
int maplen = tb.read_typedbytes_sequence_length();
for (int i=0; i<maplen; ++i) {
assert(tb.next_type() == TypedBytesString)
std::string filename;
tb.read_string(&filename);
// allow promotion of bool, char, and integers to full ints
assert(tb.can_be_int(tb.next_type()));
int size = tb.convert_int();
}
The makefile is setup to build libtypedbytes.a
If you just have a simple script, then the typedbytes.hpp include
will package everything together for you. Just include this file,
and you are ready to go!