First commit of split-select tool

This tool emits a set of rules as JSON for when a Split APK
should match a target device.

Change-Id: I8bfbdfbdb51efcfc645889dd03e1961f16e39645
diff --git a/tools/split-select/Main.cpp b/tools/split-select/Main.cpp
new file mode 100644
index 0000000..d6251c3
--- /dev/null
+++ b/tools/split-select/Main.cpp
@@ -0,0 +1,314 @@
+/*
+ * Copyright (C) 2014 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 <algorithm>
+#include <cstdio>
+
+#include "aapt/AaptUtil.h"
+
+#include "Grouper.h"
+#include "Rule.h"
+#include "RuleGenerator.h"
+#include "SplitDescription.h"
+
+#include <androidfw/AssetManager.h>
+#include <androidfw/ResourceTypes.h>
+#include <utils/KeyedVector.h>
+#include <utils/Vector.h>
+
+using namespace android;
+
+namespace split {
+
+static void usage() {
+    fprintf(stderr,
+            "split-select --help\n"
+            "split-select --target <config> --split <path/to/apk> [--split <path/to/apk> [...]]\n"
+            "split-select --generate --split <path/to/apk> [--split <path/to/apk> [...]]\n"
+            "\n"
+            "  --help                   Displays more information about this program.\n"
+            "  --target <config>        Performs the Split APK selection on the given configuration.\n"
+            "  --generate               Generates the logic for selecting the Split APK, in JSON format.\n"
+            "  --split <path/to/apk>    Includes a Split APK in the selection process.\n"
+            "\n"
+            "  Where <config> is an extended AAPT resource qualifier of the form\n"
+            "  'resource-qualifiers:extended-qualifiers', where 'resource-qualifiers' is an AAPT resource\n"
+            "  qualifier (ex: en-rUS-sw600dp-xhdpi), and 'extended-qualifiers' is an ordered list of one\n"
+            "  qualifier (or none) from each category:\n"
+            "    Architecture: armeabi, armeabi-v7a, arm64-v8a, x86, x86_64, mips\n");
+}
+
+static void help() {
+    usage();
+    fprintf(stderr, "\n"
+            "  Generates the logic for selecting a Split APK given some target Android device configuration.\n"
+            "  Using the flag --generate will emit a JSON encoded tree of rules that must be satisfied in order\n"
+            "  to install the given Split APK. Using the flag --target along with the device configuration\n"
+            "  will emit the set of Split APKs to install, following the same logic that would have been emitted\n"
+            "  via JSON.\n");
+}
+
+class SplitSelector {
+public:
+    SplitSelector() = default;
+    SplitSelector(const Vector<SplitDescription>& splits);
+
+    Vector<SplitDescription> getBestSplits(const SplitDescription& target) const;
+
+    template <typename RuleGenerator>
+    KeyedVector<SplitDescription, sp<Rule> > getRules() const;
+
+private:
+    Vector<SortedVector<SplitDescription> > mGroups;
+};
+
+SplitSelector::SplitSelector(const Vector<SplitDescription>& splits)
+    : mGroups(groupByMutualExclusivity(splits)) {
+}
+
+static void selectBestFromGroup(const SortedVector<SplitDescription>& splits,
+        const SplitDescription& target, Vector<SplitDescription>& splitsOut) {
+    SplitDescription bestSplit;
+    bool isSet = false;
+    const size_t splitCount = splits.size();
+    for (size_t j = 0; j < splitCount; j++) {
+        const SplitDescription& thisSplit = splits[j];
+        if (!thisSplit.match(target)) {
+            continue;
+        }
+
+        if (!isSet || thisSplit.isBetterThan(bestSplit, target)) {
+            isSet = true;
+            bestSplit = thisSplit;
+        }
+    }
+
+    if (isSet) {
+        splitsOut.add(bestSplit);
+    }
+}
+
+Vector<SplitDescription> SplitSelector::getBestSplits(const SplitDescription& target) const {
+    Vector<SplitDescription> bestSplits;
+    const size_t groupCount = mGroups.size();
+    for (size_t i = 0; i < groupCount; i++) {
+        selectBestFromGroup(mGroups[i], target, bestSplits);
+    }
+    return bestSplits;
+}
+
+template <typename RuleGenerator>
+KeyedVector<SplitDescription, sp<Rule> > SplitSelector::getRules() const {
+    KeyedVector<SplitDescription, sp<Rule> > rules;
+
+    const size_t groupCount = mGroups.size();
+    for (size_t i = 0; i < groupCount; i++) {
+        const SortedVector<SplitDescription>& splits = mGroups[i];
+        const size_t splitCount = splits.size();
+        for (size_t j = 0; j < splitCount; j++) {
+            sp<Rule> rule = Rule::simplify(RuleGenerator::generate(splits, j));
+            if (rule != NULL) {
+                rules.add(splits[j], rule);
+            }
+        }
+    }
+    return rules;
+}
+
+Vector<SplitDescription> select(const SplitDescription& target, const Vector<SplitDescription>& splits) {
+    const SplitSelector selector(splits);
+    return selector.getBestSplits(target);
+}
+
+void generate(const KeyedVector<String8, Vector<SplitDescription> >& splits) {
+    Vector<SplitDescription> allSplits;
+    const size_t apkSplitCount = splits.size();
+    for (size_t i = 0; i < apkSplitCount; i++) {
+        allSplits.appendVector(splits[i]);
+    }
+    const SplitSelector selector(allSplits);
+    KeyedVector<SplitDescription, sp<Rule> > rules(selector.getRules<RuleGenerator>());
+
+    fprintf(stdout, "[\n");
+    for (size_t i = 0; i < apkSplitCount; i++) {
+        sp<Rule> masterRule = new Rule();
+        masterRule->op = Rule::OR_SUBRULES;
+        const Vector<SplitDescription>& splitDescriptions = splits[i];
+        const size_t splitDescriptionCount = splitDescriptions.size();
+        for (size_t j = 0; j < splitDescriptionCount; j++) {
+            masterRule->subrules.add(rules.valueFor(splitDescriptions[j]));
+        }
+        masterRule = Rule::simplify(masterRule);
+        fprintf(stdout, "  {\n    \"path\": \"%s\",\n    \"rules\": %s\n  }%s\n",
+                splits.keyAt(i).string(),
+                masterRule->toJson(2).string(),
+                i < apkSplitCount - 1 ? "," : "");
+    }
+    fprintf(stdout, "]\n");
+}
+
+static void removeRuntimeQualifiers(ConfigDescription* outConfig) {
+    outConfig->imsi = 0;
+    outConfig->orientation = ResTable_config::ORIENTATION_ANY;
+    outConfig->screenWidth = ResTable_config::SCREENWIDTH_ANY;
+    outConfig->screenHeight = ResTable_config::SCREENHEIGHT_ANY;
+    outConfig->uiMode &= ResTable_config::UI_MODE_NIGHT_ANY;
+}
+
+static Vector<SplitDescription> extractSplitDescriptionsFromApk(const String8& path) {
+    AssetManager assetManager;
+    Vector<SplitDescription> splits;
+    int32_t cookie = 0;
+    if (!assetManager.addAssetPath(path, &cookie)) {
+        return splits;
+    }
+
+    const ResTable& res = assetManager.getResources(false);
+    if (res.getError() == NO_ERROR) {
+        Vector<ResTable_config> configs;
+        res.getConfigurations(&configs);
+        const size_t configCount = configs.size();
+        for (size_t i = 0; i < configCount; i++) {
+            splits.add();
+            splits.editTop().config = configs[i];
+        }
+    }
+
+    AssetDir* dir = assetManager.openNonAssetDir(cookie, "lib");
+    if (dir != NULL) {
+        const size_t fileCount = dir->getFileCount();
+        for (size_t i = 0; i < fileCount; i++) {
+            splits.add();
+            Vector<String8> parts = AaptUtil::splitAndLowerCase(dir->getFileName(i), '-');
+            if (parseAbi(parts, 0, &splits.editTop()) < 0) {
+                fprintf(stderr, "Malformed library %s\n", dir->getFileName(i).string());
+                splits.pop();
+            }
+        }
+        delete dir;
+    }
+    return splits;
+}
+
+static int main(int argc, char** argv) {
+    // Skip over the first argument.
+    argc--;
+    argv++;
+
+    bool generateFlag = false;
+    String8 targetConfigStr;
+    Vector<String8> splitApkPaths;
+    while (argc > 0) {
+        const String8 arg(*argv);
+        if (arg == "--target") {
+            argc--;
+            argv++;
+            if (argc < 1) {
+                fprintf(stderr, "Missing parameter for --split.\n");
+                usage();
+                return 1;
+            }
+            targetConfigStr.setTo(*argv);
+        } else if (arg == "--split") {
+            argc--;
+            argv++;
+            if (argc < 1) {
+                fprintf(stderr, "Missing parameter for --split.\n");
+                usage();
+                return 1;
+            }
+            splitApkPaths.add(String8(*argv));
+        } else if (arg == "--generate") {
+            generateFlag = true;
+        } else if (arg == "--help") {
+            help();
+            return 0;
+        } else {
+            fprintf(stderr, "Unknown argument '%s'\n", arg.string());
+            usage();
+            return 1;
+        }
+        argc--;
+        argv++;
+    }
+
+    if (!generateFlag && targetConfigStr == "") {
+        usage();
+        return 1;
+    }
+
+    if (splitApkPaths.size() == 0) {
+        usage();
+        return 1;
+    }
+
+    SplitDescription targetSplit;
+    if (!generateFlag) {
+        if (!SplitDescription::parse(targetConfigStr, &targetSplit)) {
+            fprintf(stderr, "Invalid --target config: '%s'\n",
+                    targetConfigStr.string());
+            usage();
+            return 1;
+        }
+
+        // We don't want to match on things that will change at run-time
+        // (orientation, w/h, etc.).
+        removeRuntimeQualifiers(&targetSplit.config);
+    }
+
+    KeyedVector<String8, Vector<SplitDescription> > apkPathSplitMap;
+    KeyedVector<SplitDescription, String8> splitApkPathMap;
+    Vector<SplitDescription> splitConfigs;
+    const size_t splitCount = splitApkPaths.size();
+    for (size_t i = 0; i < splitCount; i++) {
+        Vector<SplitDescription> splits = extractSplitDescriptionsFromApk(splitApkPaths[i]);
+        if (splits.isEmpty()) {
+            fprintf(stderr, "Invalid --split path: '%s'. No splits found.\n",
+                    splitApkPaths[i].string());
+            usage();
+            return 1;
+        }
+        apkPathSplitMap.replaceValueFor(splitApkPaths[i], splits);
+        const size_t apkSplitDescriptionCount = splits.size();
+        for (size_t j = 0; j < apkSplitDescriptionCount; j++) {
+            splitApkPathMap.replaceValueFor(splits[j], splitApkPaths[i]);
+        }
+        splitConfigs.appendVector(splits);
+    }
+
+    if (!generateFlag) {
+        Vector<SplitDescription> matchingConfigs = select(targetSplit, splitConfigs);
+        const size_t matchingConfigCount = matchingConfigs.size();
+        SortedVector<String8> matchingSplitPaths;
+        for (size_t i = 0; i < matchingConfigCount; i++) {
+            matchingSplitPaths.add(splitApkPathMap.valueFor(matchingConfigs[i]));
+        }
+
+        const size_t matchingSplitApkPathCount = matchingSplitPaths.size();
+        for (size_t i = 0; i < matchingSplitApkPathCount; i++) {
+            fprintf(stderr, "%s\n", matchingSplitPaths[i].string());
+        }
+    } else {
+        generate(apkPathSplitMap);
+    }
+    return 0;
+}
+
+} // namespace split
+
+int main(int argc, char** argv) {
+    return split::main(argc, argv);
+}