| // Copyright 2015 The Chromium 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 "base/macros.h" |
| #include "uri_encoder.h" |
| |
| using base::StringPiece; |
| |
| namespace { |
| |
| struct expansion { |
| uint8_t code; |
| const char* value; |
| }; |
| |
| // The two following data structures are the expansions code tables for URI |
| // encoding described in the following specification: |
| // https://github.com/google/uribeacon/blob/master/specification/AdvertisingMode.md |
| |
| // For the prefix of the URI. |
| struct expansion prefix_expansions_list[] = { |
| {0, "http://www."}, |
| {1, "https://www."}, |
| {2, "http://"}, |
| {3, "https://"}, |
| {4, "urn:uuid:"}, |
| }; |
| |
| // For the remaining part of the URI. |
| struct expansion expansions_list[] = { |
| {0, ".com/"}, |
| {1, ".org/"}, |
| {2, ".edu/"}, |
| {3, ".net/"}, |
| {4, ".info/"}, |
| {5, ".biz/"}, |
| {6, ".gov/"}, |
| {7, ".com"}, |
| {8, ".org"}, |
| {9, ".edu"}, |
| {10, ".net"}, |
| {11, ".info"}, |
| {12, ".biz"}, |
| {13, ".gov"}, |
| }; |
| |
| struct expansion* CommonLookupExpansionByValue(struct expansion* table, |
| int table_length, |
| const std::string& input, |
| int input_index) { |
| int found = -1; |
| int found_length = -1; |
| |
| for (int k = 0; k < table_length; k++) { |
| const char* value = table[k].value; |
| int len = static_cast<int>(strlen(table[k].value)); |
| if (input_index + len <= static_cast<int>(input.size())) { |
| if (len > found_length && strncmp(&input[input_index], value, len) == 0) { |
| found = k; |
| found_length = len; |
| } |
| } |
| } |
| if (found == -1) |
| return NULL; |
| return &table[found]; |
| } |
| |
| struct expansion* LookupExpansionByValue(const std::string& input, |
| int input_index) { |
| return CommonLookupExpansionByValue( |
| expansions_list, arraysize(expansions_list), input, input_index); |
| } |
| |
| struct expansion* LookupPrefixExpansionByValue(const std::string& input, |
| int input_index) { |
| return CommonLookupExpansionByValue(prefix_expansions_list, |
| arraysize(prefix_expansions_list), input, |
| input_index); |
| } |
| |
| struct expansion* LookupExpansionByCode(const std::vector<uint8_t>& input, |
| int input_index) { |
| if (input[input_index] >= arraysize(expansions_list)) |
| return NULL; |
| return &expansions_list[input[input_index]]; |
| } |
| |
| struct expansion* LookupPrefixExpansionByCode(const std::vector<uint8_t>& input, |
| int input_index) { |
| if (input[input_index] >= arraysize(prefix_expansions_list)) |
| return NULL; |
| return &prefix_expansions_list[input[input_index]]; |
| } |
| |
| } // namespace |
| |
| void device::EncodeUriBeaconUri(const std::string& input, |
| std::vector<uint8_t>& output) { |
| int i = 0; |
| while (i < static_cast<int>(input.size())) { |
| struct expansion* exp; |
| if (i == 0) |
| exp = LookupPrefixExpansionByValue(input, i); |
| else |
| exp = LookupExpansionByValue(input, i); |
| if (exp == NULL) { |
| output.push_back(static_cast<uint8_t>(input[i])); |
| i++; |
| } else { |
| output.push_back(exp->code); |
| i += static_cast<int>(strlen(exp->value)); |
| } |
| } |
| } |
| |
| void device::DecodeUriBeaconUri(const std::vector<uint8_t>& input, |
| std::string& output) { |
| int length = static_cast<int>(input.size()); |
| for (int i = 0; i < length; i++) { |
| struct expansion* exp; |
| if (i == 0) |
| exp = LookupPrefixExpansionByCode(input, i); |
| else |
| exp = LookupExpansionByCode(input, i); |
| if (exp == NULL) |
| output.push_back(static_cast<char>(input[i])); |
| else |
| output.append(exp->value); |
| } |
| } |