libs/androidfw/LocaleData.cpp - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2016 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <array>
 #include <cstdint>
 #include <cstdlib>
 #include <cstring>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>

 #include <androidfw/LocaleData.h>

 namespace android {

 #include "LocaleDataTables.cpp"

 inline uint32_t packLocale(const char* language, const char* region) {
     return (((uint8_t) language[0]) << 24u) | (((uint8_t) language[1]) << 16u) |
            (((uint8_t) region[0]) << 8u) | ((uint8_t) region[1]);
 }

 inline uint32_t dropRegion(uint32_t packed_locale) {
     return packed_locale & 0xFFFF0000LU;
 }

 inline bool hasRegion(uint32_t packed_locale) {
     return (packed_locale & 0x0000FFFFLU) != 0;
 }

 const size_t SCRIPT_LENGTH = 4;
 const size_t SCRIPT_PARENTS_COUNT = sizeof(SCRIPT_PARENTS)/sizeof(SCRIPT_PARENTS[0]);
 const uint32_t PACKED_ROOT = 0; // to represent the root locale

 uint32_t findParent(uint32_t packed_locale, const char* script) {
     if (hasRegion(packed_locale)) {
         for (size_t i = 0; i < SCRIPT_PARENTS_COUNT; i++) {
             if (memcmp(script, SCRIPT_PARENTS[i].script, SCRIPT_LENGTH) == 0) {
                 auto map = SCRIPT_PARENTS[i].map;
                 auto lookup_result = map->find(packed_locale);
                 if (lookup_result != map->end()) {
                     return lookup_result->second;
                 }
                 break;
             }
         }
         return dropRegion(packed_locale);
     }
     return PACKED_ROOT;
 }

 // Find the ancestors of a locale, and fill 'out' with it (assumes out has enough
 // space). If any of the members of stop_list was seen, write it in the
 // output but stop afterwards.
 //
 // This also outputs the index of the last written ancestor in the stop_list
 // to stop_list_index, which will be -1 if it is not found in the stop_list.
 //
 // Returns the number of ancestors written in the output, which is always
 // at least one.
 //
 // (If 'out' is nullptr, we do everything the same way but we simply don't write
 // any results in 'out'.)
 size_t findAncestors(uint32_t* out, ssize_t* stop_list_index,
                      uint32_t packed_locale, const char* script,
                      const uint32_t* stop_list, size_t stop_set_length) {
     uint32_t ancestor = packed_locale;
     size_t count = 0;
     do {
         if (out != nullptr) out[count] = ancestor;
         count++;
         for (size_t i = 0; i < stop_set_length; i++) {
             if (stop_list[i] == ancestor) {
                 *stop_list_index = (ssize_t) i;
                 return count;
             }
         }
         ancestor = findParent(ancestor, script);
     } while (ancestor != PACKED_ROOT);
     *stop_list_index = (ssize_t) -1;
     return count;
 }

 size_t findDistance(uint32_t supported,
                     const char* script,
                     const uint32_t* request_ancestors,
                     size_t request_ancestors_count) {
     ssize_t request_ancestors_index;
     const size_t supported_ancestor_count = findAncestors(
             nullptr, &request_ancestors_index,
             supported, script,
             request_ancestors, request_ancestors_count);
     // Since both locales share the same root, there will always be a shared
     // ancestor, so the distance in the parent tree is the sum of the distance
     // of 'supported' to the lowest common ancestor (number of ancestors
     // written for 'supported' minus 1) plus the distance of 'request' to the
     // lowest common ancestor (the index of the ancestor in request_ancestors).
     return supported_ancestor_count + request_ancestors_index - 1;
 }

 inline bool isRepresentative(uint32_t language_and_region, const char* script) {
     const uint64_t packed_locale = (
             (((uint64_t) language_and_region) << 32u) |
             (((uint64_t) script[0]) << 24u) |
             (((uint64_t) script[1]) << 16u) |
             (((uint64_t) script[2]) <<  8u) |
             ((uint64_t) script[3]));

     return (REPRESENTATIVE_LOCALES.count(packed_locale) != 0);
 }

 const uint32_t US_SPANISH = 0x65735553LU; // es-US
 const uint32_t MEXICAN_SPANISH = 0x65734D58LU; // es-MX
 const uint32_t LATIN_AMERICAN_SPANISH = 0x6573A424LU; // es-419

 // The two locales es-US and es-MX are treated as special fallbacks for es-419.
 // If there is no es-419, they are considered its equivalent.
 inline bool isSpecialSpanish(uint32_t language_and_region) {
     return (language_and_region == US_SPANISH || language_and_region == MEXICAN_SPANISH);
 }

 int localeDataCompareRegions(
         const char* left_region, const char* right_region,
         const char* requested_language, const char* requested_script,
         const char* requested_region) {

     if (left_region[0] == right_region[0] && left_region[1] == right_region[1]) {
         return 0;
     }
     uint32_t left = packLocale(requested_language, left_region);
     uint32_t right = packLocale(requested_language, right_region);
     const uint32_t request = packLocale(requested_language, requested_region);

     // If one and only one of the two locales is a special Spanish locale, we
     // replace it with es-419. We don't do the replacement if the other locale
     // is already es-419, or both locales are special Spanish locales (when
     // es-US is being compared to es-MX).
     const bool leftIsSpecialSpanish = isSpecialSpanish(left);
     const bool rightIsSpecialSpanish = isSpecialSpanish(right);
     if (leftIsSpecialSpanish && !rightIsSpecialSpanish && right != LATIN_AMERICAN_SPANISH) {
         left = LATIN_AMERICAN_SPANISH;
     } else if (rightIsSpecialSpanish && !leftIsSpecialSpanish && left != LATIN_AMERICAN_SPANISH) {
         right = LATIN_AMERICAN_SPANISH;
     }

     uint32_t request_ancestors[MAX_PARENT_DEPTH+1];
     ssize_t left_right_index;
     // Find the parents of the request, but stop as soon as we saw left or right
     const std::array<uint32_t, 2> left_and_right = {{left, right}};
     const size_t ancestor_count = findAncestors(
             request_ancestors, &left_right_index,
             request, requested_script,
             left_and_right.data(), left_and_right.size());
     if (left_right_index == 0) { // We saw left earlier
         return 1;
     }
     if (left_right_index == 1) { // We saw right earlier
         return -1;
     }

     // If we are here, neither left nor right are an ancestor of the
     // request. This means that all the ancestors have been computed and
     // the last ancestor is just the language by itself. We will use the
     // distance in the parent tree for determining the better match.
     const size_t left_distance = findDistance(
             left, requested_script, request_ancestors, ancestor_count);
     const size_t right_distance = findDistance(
             right, requested_script, request_ancestors, ancestor_count);
     if (left_distance != right_distance) {
         return (int) right_distance - (int) left_distance; // smaller distance is better
     }

     // If we are here, left and right are equidistant from the request. We will
     // try and see if any of them is a representative locale.
     const bool left_is_representative = isRepresentative(left, requested_script);
     const bool right_is_representative = isRepresentative(right, requested_script);
     if (left_is_representative != right_is_representative) {
         return (int) left_is_representative - (int) right_is_representative;
     }

     // We have no way of figuring out which locale is a better match. For
     // the sake of stability, we consider the locale with the lower region
     // code (in dictionary order) better, with two-letter codes before
     // three-digit codes (since two-letter codes are more specific).
     return (int64_t) right - (int64_t) left;
 }

 void localeDataComputeScript(char out[4], const char* language, const char* region) {
     if (language[0] == '\0') {
         memset(out, '\0', SCRIPT_LENGTH);
         return;
     }
     uint32_t lookup_key = packLocale(language, region);
     auto lookup_result = LIKELY_SCRIPTS.find(lookup_key);
     if (lookup_result == LIKELY_SCRIPTS.end()) {
         // We couldn't find the locale. Let's try without the region
         if (region[0] != '\0') {
             lookup_key = dropRegion(lookup_key);
             lookup_result = LIKELY_SCRIPTS.find(lookup_key);
             if (lookup_result != LIKELY_SCRIPTS.end()) {
                 memcpy(out, SCRIPT_CODES[lookup_result->second], SCRIPT_LENGTH);
                 return;
             }
         }
         // We don't know anything about the locale
         memset(out, '\0', SCRIPT_LENGTH);
         return;
     } else {
         // We found the locale.
         memcpy(out, SCRIPT_CODES[lookup_result->second], SCRIPT_LENGTH);
     }
 }

 const uint32_t ENGLISH_STOP_LIST[2] = {
     0x656E0000LU, // en
     0x656E8400LU, // en-001
 };
 const char ENGLISH_CHARS[2] = {'e', 'n'};
 const char LATIN_CHARS[4] = {'L', 'a', 't', 'n'};

 bool localeDataIsCloseToUsEnglish(const char* region) {
     const uint32_t locale = packLocale(ENGLISH_CHARS, region);
     ssize_t stop_list_index;
     findAncestors(nullptr, &stop_list_index, locale, LATIN_CHARS, ENGLISH_STOP_LIST, 2);
     // A locale is like US English if we see "en" before "en-001" in its ancestor list.
     return stop_list_index == 0; // 'en' is first in ENGLISH_STOP_LIST
 }

 } // namespace android
	/*
	* Copyright (C) 2016 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <array>
	#include <cstdint>
	#include <cstdlib>
	#include <cstring>
	#include <string>
	#include <unordered_map>
	#include <unordered_set>

	#include <androidfw/LocaleData.h>

	namespace android {

	#include "LocaleDataTables.cpp"

	inline uint32_t packLocale(const char* language, const char* region) {
	return (((uint8_t) language[0]) << 24u) \| (((uint8_t) language[1]) << 16u) \|
	(((uint8_t) region[0]) << 8u) \| ((uint8_t) region[1]);
	}

	inline uint32_t dropRegion(uint32_t packed_locale) {
	return packed_locale & 0xFFFF0000LU;
	}

	inline bool hasRegion(uint32_t packed_locale) {
	return (packed_locale & 0x0000FFFFLU) != 0;
	}

	const size_t SCRIPT_LENGTH = 4;
	const size_t SCRIPT_PARENTS_COUNT = sizeof(SCRIPT_PARENTS)/sizeof(SCRIPT_PARENTS[0]);
	const uint32_t PACKED_ROOT = 0; // to represent the root locale

	uint32_t findParent(uint32_t packed_locale, const char* script) {
	if (hasRegion(packed_locale)) {
	for (size_t i = 0; i < SCRIPT_PARENTS_COUNT; i++) {
	if (memcmp(script, SCRIPT_PARENTS[i].script, SCRIPT_LENGTH) == 0) {
	auto map = SCRIPT_PARENTS[i].map;
	auto lookup_result = map->find(packed_locale);
	if (lookup_result != map->end()) {
	return lookup_result->second;
	}
	break;
	}
	}
	return dropRegion(packed_locale);
	}
	return PACKED_ROOT;
	}

	// Find the ancestors of a locale, and fill 'out' with it (assumes out has enough
	// space). If any of the members of stop_list was seen, write it in the
	// output but stop afterwards.
	//
	// This also outputs the index of the last written ancestor in the stop_list
	// to stop_list_index, which will be -1 if it is not found in the stop_list.
	//
	// Returns the number of ancestors written in the output, which is always
	// at least one.
	//
	// (If 'out' is nullptr, we do everything the same way but we simply don't write
	// any results in 'out'.)
	size_t findAncestors(uint32_t* out, ssize_t* stop_list_index,
	uint32_t packed_locale, const char* script,
	const uint32_t* stop_list, size_t stop_set_length) {
	uint32_t ancestor = packed_locale;
	size_t count = 0;
	do {
	if (out != nullptr) out[count] = ancestor;
	count++;
	for (size_t i = 0; i < stop_set_length; i++) {
	if (stop_list[i] == ancestor) {
	*stop_list_index = (ssize_t) i;
	return count;
	}
	}
	ancestor = findParent(ancestor, script);
	} while (ancestor != PACKED_ROOT);
	*stop_list_index = (ssize_t) -1;
	return count;
	}

	size_t findDistance(uint32_t supported,
	const char* script,
	const uint32_t* request_ancestors,
	size_t request_ancestors_count) {
	ssize_t request_ancestors_index;
	const size_t supported_ancestor_count = findAncestors(
	nullptr, &request_ancestors_index,
	supported, script,
	request_ancestors, request_ancestors_count);
	// Since both locales share the same root, there will always be a shared
	// ancestor, so the distance in the parent tree is the sum of the distance
	// of 'supported' to the lowest common ancestor (number of ancestors
	// written for 'supported' minus 1) plus the distance of 'request' to the
	// lowest common ancestor (the index of the ancestor in request_ancestors).
	return supported_ancestor_count + request_ancestors_index - 1;
	}

	inline bool isRepresentative(uint32_t language_and_region, const char* script) {
	const uint64_t packed_locale = (
	(((uint64_t) language_and_region) << 32u) \|
	(((uint64_t) script[0]) << 24u) \|
	(((uint64_t) script[1]) << 16u) \|
	(((uint64_t) script[2]) << 8u) \|
	((uint64_t) script[3]));

	return (REPRESENTATIVE_LOCALES.count(packed_locale) != 0);
	}

	const uint32_t US_SPANISH = 0x65735553LU; // es-US
	const uint32_t MEXICAN_SPANISH = 0x65734D58LU; // es-MX
	const uint32_t LATIN_AMERICAN_SPANISH = 0x6573A424LU; // es-419

	// The two locales es-US and es-MX are treated as special fallbacks for es-419.
	// If there is no es-419, they are considered its equivalent.
	inline bool isSpecialSpanish(uint32_t language_and_region) {
	return (language_and_region == US_SPANISH \|\| language_and_region == MEXICAN_SPANISH);
	}

	int localeDataCompareRegions(
	const char* left_region, const char* right_region,
	const char* requested_language, const char* requested_script,
	const char* requested_region) {

	if (left_region[0] == right_region[0] && left_region[1] == right_region[1]) {
	return 0;
	}
	uint32_t left = packLocale(requested_language, left_region);
	uint32_t right = packLocale(requested_language, right_region);
	const uint32_t request = packLocale(requested_language, requested_region);

	// If one and only one of the two locales is a special Spanish locale, we
	// replace it with es-419. We don't do the replacement if the other locale
	// is already es-419, or both locales are special Spanish locales (when
	// es-US is being compared to es-MX).
	const bool leftIsSpecialSpanish = isSpecialSpanish(left);
	const bool rightIsSpecialSpanish = isSpecialSpanish(right);
	if (leftIsSpecialSpanish && !rightIsSpecialSpanish && right != LATIN_AMERICAN_SPANISH) {
	left = LATIN_AMERICAN_SPANISH;
	} else if (rightIsSpecialSpanish && !leftIsSpecialSpanish && left != LATIN_AMERICAN_SPANISH) {
	right = LATIN_AMERICAN_SPANISH;
	}

	uint32_t request_ancestors[MAX_PARENT_DEPTH+1];
	ssize_t left_right_index;
	// Find the parents of the request, but stop as soon as we saw left or right
	const std::array<uint32_t, 2> left_and_right = {{left, right}};
	const size_t ancestor_count = findAncestors(
	request_ancestors, &left_right_index,
	request, requested_script,
	left_and_right.data(), left_and_right.size());
	if (left_right_index == 0) { // We saw left earlier
	return 1;
	}
	if (left_right_index == 1) { // We saw right earlier
	return -1;
	}

	// If we are here, neither left nor right are an ancestor of the
	// request. This means that all the ancestors have been computed and
	// the last ancestor is just the language by itself. We will use the
	// distance in the parent tree for determining the better match.
	const size_t left_distance = findDistance(
	left, requested_script, request_ancestors, ancestor_count);
	const size_t right_distance = findDistance(
	right, requested_script, request_ancestors, ancestor_count);
	if (left_distance != right_distance) {
	return (int) right_distance - (int) left_distance; // smaller distance is better
	}

	// If we are here, left and right are equidistant from the request. We will
	// try and see if any of them is a representative locale.
	const bool left_is_representative = isRepresentative(left, requested_script);
	const bool right_is_representative = isRepresentative(right, requested_script);
	if (left_is_representative != right_is_representative) {
	return (int) left_is_representative - (int) right_is_representative;
	}

	// We have no way of figuring out which locale is a better match. For
	// the sake of stability, we consider the locale with the lower region
	// code (in dictionary order) better, with two-letter codes before
	// three-digit codes (since two-letter codes are more specific).
	return (int64_t) right - (int64_t) left;
	}

	void localeDataComputeScript(char out[4], const char* language, const char* region) {
	if (language[0] == '\0') {
	memset(out, '\0', SCRIPT_LENGTH);
	return;
	}
	uint32_t lookup_key = packLocale(language, region);
	auto lookup_result = LIKELY_SCRIPTS.find(lookup_key);
	if (lookup_result == LIKELY_SCRIPTS.end()) {
	// We couldn't find the locale. Let's try without the region
	if (region[0] != '\0') {
	lookup_key = dropRegion(lookup_key);
	lookup_result = LIKELY_SCRIPTS.find(lookup_key);
	if (lookup_result != LIKELY_SCRIPTS.end()) {
	memcpy(out, SCRIPT_CODES[lookup_result->second], SCRIPT_LENGTH);
	return;
	}
	}
	// We don't know anything about the locale
	memset(out, '\0', SCRIPT_LENGTH);
	return;
	} else {
	// We found the locale.
	memcpy(out, SCRIPT_CODES[lookup_result->second], SCRIPT_LENGTH);
	}
	}

	const uint32_t ENGLISH_STOP_LIST[2] = {
	0x656E0000LU, // en
	0x656E8400LU, // en-001
	};
	const char ENGLISH_CHARS[2] = {'e', 'n'};
	const char LATIN_CHARS[4] = {'L', 'a', 't', 'n'};

	bool localeDataIsCloseToUsEnglish(const char* region) {
	const uint32_t locale = packLocale(ENGLISH_CHARS, region);
	ssize_t stop_list_index;
	findAncestors(nullptr, &stop_list_index, locale, LATIN_CHARS, ENGLISH_STOP_LIST, 2);
	// A locale is like US English if we see "en" before "en-001" in its ancestor list.
	return stop_list_index == 0; // 'en' is first in ENGLISH_STOP_LIST
	}

	} // namespace android