mu/102persist.cc

119 lines
3.7 KiB
C++

//: Dead simple persistence.
//: 'restore' - reads string from a file
//: 'save' - writes string to a file
:(before "End Primitive Recipe Declarations")
RESTORE,
:(before "End Primitive Recipe Numbers")
put(Recipe_ordinal, "restore", RESTORE);
:(before "End Primitive Recipe Checks")
case RESTORE: {
if (SIZE(inst.ingredients) != 1) {
raise << maybe(get(Recipe, r).name) << "'restore' requires exactly one ingredient, but got '" << inst.original_string << "'\n" << end();
break;
}
string filename;
if (is_literal_text(inst.ingredients.at(0))) {
;
}
else if (is_mu_text(inst.ingredients.at(0))) {
;
}
else {
raise << maybe(get(Recipe, r).name) << "first ingredient of 'restore' should be a string, but got '" << to_string(inst.ingredients.at(0)) << "'\n" << end();
break;
}
break;
}
:(before "End Primitive Recipe Implementations")
case RESTORE: {
string filename;
if (is_literal_text(current_instruction().ingredients.at(0))) {
filename = current_instruction().ingredients.at(0).name;
}
else if (is_mu_text(current_instruction().ingredients.at(0))) {
filename = read_mu_text(ingredients.at(0).at(0));
}
if (Current_scenario) {
// do nothing in tests
products.resize(1);
products.at(0).push_back(0);
break;
}
string contents = slurp("lesson/"+filename);
products.resize(1);
if (contents.empty())
products.at(0).push_back(0);
else
products.at(0).push_back(new_mu_text(contents));
break;
}
:(code)
// http://cpp.indi.frih.net/blog/2014/09/how-to-read-an-entire-file-into-memory-in-cpp
string slurp(const string& filename) {
ifstream fin(filename.c_str());
fin.peek();
if (!fin) return ""; // don't bother checking errno
ostringstream result;
result << fin.rdbuf();
fin.close();
return result.str();
}
:(before "End Primitive Recipe Declarations")
SAVE,
:(before "End Primitive Recipe Numbers")
put(Recipe_ordinal, "save", SAVE);
:(before "End Primitive Recipe Checks")
case SAVE: {
if (SIZE(inst.ingredients) != 2) {
raise << maybe(get(Recipe, r).name) << "'save' requires exactly two ingredients, but got '" << inst.original_string << "'\n" << end();
break;
}
if (is_literal_text(inst.ingredients.at(0))) {
;
}
else if (is_mu_text(inst.ingredients.at(0))) {
;
}
else {
raise << maybe(get(Recipe, r).name) << "first ingredient of 'save' should be a string, but got '" << to_string(inst.ingredients.at(0)) << "'\n" << end();
break;
}
if (!is_mu_text(inst.ingredients.at(1))) {
raise << maybe(get(Recipe, r).name) << "second ingredient of 'save' should be an address:@:char, but got '" << to_string(inst.ingredients.at(1)) << "'\n" << end();
break;
}
break;
}
:(before "End Primitive Recipe Implementations")
case SAVE: {
if (Current_scenario) break; // do nothing in tests
string filename;
if (is_literal_text(current_instruction().ingredients.at(0))) {
filename = current_instruction().ingredients.at(0).name;
}
else if (is_mu_text(current_instruction().ingredients.at(0))) {
filename = read_mu_text(ingredients.at(0).at(0));
}
ofstream fout(("lesson/"+filename).c_str());
if (!fout) break;
string contents = read_mu_text(ingredients.at(1).at(0));
fout << contents;
fout.close();
if (!exists("lesson/.git")) break;
// bug in git: git diff -q messes up --exit-code
// explicitly say '--all' for git 1.9
int status = system("cd lesson; git add --all .; git diff HEAD --exit-code >/dev/null || git commit -a -m . >/dev/null");
if (status != 0)
raise << "error in commit: contents " << contents << '\n' << end();
break;
}
:(code)
bool exists(const string& filename) {
struct stat dummy;
return 0 == stat(filename.c_str(), &dummy);
}