Implement smarter locale resource selection (b927c559) · Commits · e / os / android_frameworks_base

core/java/android/util/LocaleList.java

+11 −2

Original line number	Diff line number	Diff line
		@@ -301,10 +301,19 @@ public final class LocaleList implements Parcelable {
		// is a pseudo-locale. So this is not a match.
		return 0;
		}
		// There is no match if the two locales use different scripts. This will most imporantly
		// take care of traditional vs simplified Chinese.
		final String supportedScr = getLikelyScript(supported);
		if (supportedScr.isEmpty()) {
		// If we can't guess a script, we don't know enough about the locales' language to find
		// if the locales match. So we fall back to old behavior of matching, which considered
		// locales with different regions different.
		final String supportedRegion = supported.getCountry();
		return (supportedRegion.isEmpty() \|\|
		supportedRegion.equals(desired.getCountry()))
		? 1 : 0;
		}
		final String desiredScr = getLikelyScript(desired);
		// There is no match if the two locales use different scripts. This will most imporantly
		// take care of traditional vs simplified Chinese.
		return supportedScr.equals(desiredScr) ? 1 : 0;
		}

include/androidfw/LocaleData.h

0 → 100644

+34 −0

Original line number	Diff line number	Diff line
		/*
		* 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.
		*/

		#ifndef _LIBS_UTILS_LOCALE_DATA_H
		#define _LIBS_UTILS_LOCALE_DATA_H

		#include <stddef.h>
		#include <stdint.h>

		namespace android {

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

		void localeDataComputeScript(char out[4], const char* language, const char* region);

		} // namespace android

		#endif // _LIBS_UTILS_LOCALE_DATA_H

include/androidfw/ResourceTypes.h

+14 −1

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@
		#define _LIBS_UTILS_RESOURCE_TYPES_H

		#include <androidfw/Asset.h>
		#include <androidfw/LocaleData.h>
		#include <utils/ByteOrder.h>
		#include <utils/Errors.h>
		#include <utils/String16.h>
		@@ -1127,8 +1128,9 @@ struct ResTable_config
		// configuration. (eg. Hant, Latn, etc.). Interpreted in conjunction with
		// the locale field.
		char localeScript[4];
		bool localeScriptWasProvided;

		// A single BCP-47 variant subtag. Will vary in length between 5 and 8
		// A single BCP-47 variant subtag. Will vary in length between 4 and 8
		// chars. Interpreted in conjunction with the locale field.
		char localeVariant[8];

		@@ -1228,10 +1230,15 @@ struct ResTable_config

		inline void clearLocale() {
		locale = 0;
		localeScriptWasProvided = false;
		memset(localeScript, 0, sizeof(localeScript));
		memset(localeVariant, 0, sizeof(localeVariant));
		}

		inline void computeScript() {
		localeDataComputeScript(localeScript, language, country);
		}

		// Get the 2 or 3 letter language code of this configuration. Trailing
		// bytes are set to '\0'.
		size_t unpackLanguage(char language[4]) const;
		@@ -1255,6 +1262,12 @@ struct ResTable_config
		// and 0 if they're equally specific.
		int isLocaleMoreSpecificThan(const ResTable_config &o) const;

		// Return true if 'this' is a better locale match than 'o' for the
		// 'requested' configuration. Similar to isBetterThan(), this assumes that
		// match() has already been used to remove any configurations that don't
		// match the requested configuration at all.
		bool isLocaleBetterThan(const ResTable_config& o, const ResTable_config* requested) const;

		String8 toString() const;
		};

libs/androidfw/Android.mk

+1 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@ commonSources := \
		Asset.cpp \
		AssetDir.cpp \
		AssetManager.cpp \
		LocaleData.cpp \
		misc.cpp \
		ObbFile.cpp \
		ResourceTypes.cpp \

libs/androidfw/LocaleData.cpp

0 → 100644

+201 −0

Original line number	Diff line number	Diff line
		/*
		* 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 <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.
		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 {
		out[count++] = ancestor;
		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) {
		uint32_t supported_ancestors[MAX_PARENT_DEPTH+1];
		ssize_t request_ancestors_index;
		const size_t supported_ancestor_count = findAncestors(
		supported_ancestors, &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);
		}

		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;
		}
		const uint32_t left = packLocale(requested_language, left_region);
		const uint32_t right = packLocale(requested_language, right_region);
		const uint32_t request = packLocale(requested_language, requested_region);

		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 uint32_t left_and_right[] = {left, right};
		const size_t ancestor_count = findAncestors(
		request_ancestors, &left_right_index,
		request, requested_script,
		left_and_right, sizeof(left_and_right)/sizeof(left_and_right[0]));
		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);
		}
		}

		} // namespace android