nix-super/src/libstore/fetchers/parse.cc
Eelco Dolstra 9f4d8c6170 Pluggable fetchers
Flakes are now fetched using an extensible mechanism. Also lots of
other flake cleanups.
2020-01-21 22:56:04 +01:00

129 lines
3.3 KiB
C++

#include "parse.hh"
#include "util.hh"
#include "regex.hh"
namespace nix::fetchers {
std::regex refRegex(refRegexS, std::regex::ECMAScript);
std::regex revRegex(revRegexS, std::regex::ECMAScript);
ParsedURL parseURL(const std::string & url)
{
static std::regex uriRegex(
"(((" + schemeRegex + "):"
+ "(//(" + authorityRegex + "))?"
+ "(" + pathRegex + "))"
+ "(?:\\?(" + queryRegex + "))?"
+ "(?:#(" + queryRegex + "))?"
+ ")",
std::regex::ECMAScript);
std::smatch match;
if (std::regex_match(url, match, uriRegex)) {
auto & base = match[2];
std::string scheme = match[3];
auto authority = match[4].matched
? std::optional<std::string>(match[5]) : std::nullopt;
std::string path = match[6];
auto & query = match[7];
auto & fragment = match[8];
auto isFile = scheme.find("file") != std::string::npos;
if (authority && *authority != "" && isFile)
throw Error("file:// URL '%s' has unexpected authority '%s'",
url, *authority);
if (isFile && path.empty())
path = "/";
return ParsedURL{
.url = url,
.base = base,
.scheme = scheme,
.authority = authority,
.path = path,
.query = decodeQuery(query),
.fragment = percentDecode(std::string(fragment))
};
}
else
throw BadURL("'%s' is not a valid URL", url);
}
std::string percentDecode(std::string_view in)
{
std::string decoded;
for (size_t i = 0; i < in.size(); ) {
if (in[i] == '%') {
if (i + 2 >= in.size())
throw BadURL("invalid URI parameter '%s'", in);
try {
decoded += std::stoul(std::string(in, i + 1, 2), 0, 16);
i += 3;
} catch (...) {
throw BadURL("invalid URI parameter '%s'", in);
}
} else
decoded += in[i++];
}
return decoded;
}
std::map<std::string, std::string> decodeQuery(const std::string & query)
{
std::map<std::string, std::string> result;
for (auto s : tokenizeString<Strings>(query, "&")) {
auto e = s.find('=');
if (e != std::string::npos)
result.emplace(
s.substr(0, e),
percentDecode(std::string_view(s).substr(e + 1)));
}
return result;
}
std::string percentEncode(std::string_view s)
{
std::string res;
for (auto & c : s)
if ((c >= 'a' && c <= 'z')
|| (c >= 'A' && c <= 'Z')
|| (c >= '0' && c <= '9')
|| strchr("-._~!$&'()*+,;=:@", c))
res += c;
else
res += fmt("%%%02x", (unsigned int) c);
return res;
}
std::string encodeQuery(const std::map<std::string, std::string> & ss)
{
std::string res;
bool first = true;
for (auto & [name, value] : ss) {
if (!first) res += '&';
first = false;
res += percentEncode(name);
res += '=';
res += percentEncode(value);
}
return res;
}
std::string ParsedURL::to_string() const
{
return
scheme
+ ":"
+ (authority ? "//" + *authority : "")
+ path
+ (query.empty() ? "" : "?" + encodeQuery(query))
+ (fragment.empty() ? "" : "#" + percentEncode(fragment));
}
}