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// Copyright 2014 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <brillo/url_utils.h>
#include <algorithm>
namespace {
// Given a URL string, determine where the query string starts and ends.
// URLs have schema, domain and path (along with possible user name, password
// and port number which are of no interest for us here) which could optionally
// have a query string that is separated from the path by '?'. Finally, the URL
// could also have a '#'-separated URL fragment which is usually used by the
// browser as a bookmark element. So, for example:
// http://server.com/path/to/object?k=v&foo=bar#fragment
// Here:
// http://server.com/path/to/object - is the URL of the object,
// ?k=v&foo=bar - URL query string
// #fragment - URL fragment string
// If |exclude_fragment| is true, the function returns the start character and
// the length of the query string alone. If it is false, the query string length
// will include both the query string and the fragment.
bool GetQueryStringPos(const std::string& url,
bool exclude_fragment,
size_t* query_pos,
size_t* query_len) {
size_t query_start = url.find_first_of("?#");
if (query_start == std::string::npos) {
*query_pos = url.size();
if (query_len)
*query_len = 0;
return false;
}
*query_pos = query_start;
if (query_len) {
size_t query_end = url.size();
if (exclude_fragment) {
if (url[query_start] == '?') {
size_t pos_fragment = url.find('#', query_start);
if (pos_fragment != std::string::npos)
query_end = pos_fragment;
} else {
query_end = query_start;
}
}
*query_len = query_end - query_start;
}
return true;
}
} // anonymous namespace
namespace brillo {
std::string url::TrimOffQueryString(std::string* url) {
size_t query_pos;
if (!GetQueryStringPos(*url, false, &query_pos, nullptr))
return std::string();
std::string query_string = url->substr(query_pos);
url->resize(query_pos);
return query_string;
}
std::string url::Combine(const std::string& url, const std::string& subpath) {
return CombineMultiple(url, {subpath});
}
std::string url::CombineMultiple(const std::string& url,
const std::vector<std::string>& parts) {
std::string result = url;
if (!parts.empty()) {
std::string query_string = TrimOffQueryString(&result);
for (const auto& part : parts) {
if (!part.empty()) {
if (!result.empty() && result.back() != '/')
result += '/';
size_t non_slash_pos = part.find_first_not_of('/');
if (non_slash_pos != std::string::npos)
result += part.substr(non_slash_pos);
}
}
result += query_string;
}
return result;
}
std::string url::GetQueryString(const std::string& url, bool remove_fragment) {
std::string query_string;
size_t query_pos, query_len;
if (GetQueryStringPos(url, remove_fragment, &query_pos, &query_len)) {
query_string = url.substr(query_pos, query_len);
}
return query_string;
}
data_encoding::WebParamList url::GetQueryStringParameters(
const std::string& url) {
// Extract the query string and remove the leading '?'.
std::string query_string = GetQueryString(url, true);
if (!query_string.empty() && query_string.front() == '?')
query_string.erase(query_string.begin());
return data_encoding::WebParamsDecode(query_string);
}
std::string url::GetQueryStringValue(const std::string& url,
const std::string& name) {
return GetQueryStringValue(GetQueryStringParameters(url), name);
}
std::string url::GetQueryStringValue(const data_encoding::WebParamList& params,
const std::string& name) {
for (const auto& pair : params) {
if (name.compare(pair.first) == 0)
return pair.second;
}
return std::string();
}
std::string url::RemoveQueryString(const std::string& url,
bool remove_fragment_too) {
size_t query_pos, query_len;
if (!GetQueryStringPos(url, !remove_fragment_too, &query_pos, &query_len))
return url;
std::string result = url.substr(0, query_pos);
size_t fragment_pos = query_pos + query_len;
if (fragment_pos < url.size()) {
result += url.substr(fragment_pos);
}
return result;
}
std::string url::AppendQueryParam(const std::string& url,
const std::string& name,
const std::string& value) {
return AppendQueryParams(url, {{name, value}});
}
std::string url::AppendQueryParams(const std::string& url,
const data_encoding::WebParamList& params) {
if (params.empty())
return url;
size_t query_pos, query_len;
GetQueryStringPos(url, true, &query_pos, &query_len);
size_t fragment_pos = query_pos + query_len;
std::string result = url.substr(0, fragment_pos);
if (query_len == 0) {
result += '?';
} else if (query_len > 1) {
result += '&';
}
result += data_encoding::WebParamsEncode(params);
if (fragment_pos < url.size()) {
result += url.substr(fragment_pos);
}
return result;
}
bool url::HasQueryString(const std::string& url) {
size_t query_pos, query_len;
GetQueryStringPos(url, true, &query_pos, &query_len);
return (query_len > 0);
}
} // namespace brillo