Start to implement time zones

teavm-classlib/pom.xml

@@ -69,6 +69,11 @@
       <artifactId>jzlib</artifactId>
       <version>1.1.3</version>
     </dependency>
+    <dependency>
+      <groupId>joda-time</groupId>
+      <artifactId>joda-time</artifactId>
+      <version>2.7</version>
+    </dependency>
   </dependencies>
 
   <build>

teavm-classlib/src/main/java/org/teavm/classlib/impl/Base46.java

@@ -0,0 +1,125 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  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.
+ */
+package org.teavm.classlib.impl;
+
+/**
+ * <p>Base47 encoding is best fit for encoding varible length numbers in JavaScript strings.</p>
+ *
+ * <p>47 = (int)(93 / 2), where 94 is the number of ASCII characters representable in JavaScript string
+ * without escaping. These characters are encoded by one byte in UTF-8 charset. All other character require
+ * either escaping or two or more bytes in UTF-8.</p>
+ *
+ * <p>We divide 93 by 2 for the following trick. Representing integers takes 5 bytes in Base93. However,
+ * we often need smaller integers that might be represented by one or two bytes. By each Base93 digit we
+ * can encode both part of the number and a flag indicating whether the number contains one more digit.</p>
+ *
+ * @author Alexey Andreev
+ */
+public class Base46 {
+    public static void encodeUnsigned(StringBuilder sb, int number) {
+        boolean hasMore;
+        do {
+            int digit = number % 46;
+            number /= 46;
+            hasMore = number > 0;
+            digit = digit * 2 + (hasMore ? 1 : 0);
+            sb.append(encodeDigit(digit));
+        } while (hasMore);
+    }
+
+    public static void encode(StringBuilder sb, int number) {
+        encodeUnsigned(sb, Math.abs(number) * 2 + (number >= 0 ? 0 : 1));
+    }
+
+    public static void encodeUnsigned(StringBuilder sb, long number) {
+        boolean hasMore;
+        do {
+            int digit = (int)(number % 46);
+            number /= 46;
+            hasMore = number > 0;
+            digit = digit * 2 + (hasMore ? 1 : 0);
+            sb.append(encodeDigit(digit));
+        } while (hasMore);
+    }
+
+    public static void encode(StringBuilder sb, long number) {
+        encodeUnsigned(sb, Math.abs(number) * 2 + (number >= 0 ? 0 : 1));
+    }
+
+    public static int decodeUnsigned(CharFlow seq) {
+        int number = 0;
+        int pos = 1;
+        boolean hasMore;
+        do {
+            int digit = decodeDigit(seq.characters[seq.pointer++]);
+            hasMore = digit % 2 == 1;
+            number += pos * (digit / 2);
+            pos *= 46;
+        } while (hasMore);
+        return number;
+    }
+
+    public static int decode(CharFlow seq) {
+        int number = decodeUnsigned(seq);
+        int result = number / 2;
+        if (number % 2 != 0) {
+            result = -result;
+        }
+        return result;
+    }
+
+    public static long decodeUnsignedLong(CharFlow seq) {
+        long number = 0;
+        long pos = 1;
+        boolean hasMore;
+        do {
+            int digit = decodeDigit(seq.characters[seq.pointer++]);
+            hasMore = digit % 2 == 1;
+            number += pos * (digit / 2);
+            pos *= 46;
+        } while (hasMore);
+        return number;
+    }
+
+    public static long decodeLong(CharFlow seq) {
+        long number = decodeUnsigned(seq);
+        long result = number / 2;
+        if (number % 2 != 0) {
+            result = -result;
+        }
+        return result;
+    }
+
+    public static char encodeDigit(int digit) {
+        if (digit < 2) {
+            return (char)(digit + ' ');
+        } else if (digit < 59) {
+            return (char)(digit + 1 + ' ');
+        } else {
+            return (char)(digit + 2 + ' ');
+        }
+    }
+
+    public static int decodeDigit(char c) {
+        if (c < '"') {
+            return c - ' ';
+        } else if (c < '\\') {
+            return c - ' ' - 1;
+        } else {
+            return c - ' ' - 2;
+        }
+    }
+}

teavm-classlib/src/main/java/org/teavm/classlib/impl/CharFlow.java

@@ -0,0 +1,29 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  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.
+ */
+package org.teavm.classlib.impl;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class CharFlow {
+    public final char[] characters;
+    public int pointer;
+
+    public CharFlow(char[] characters) {
+        this.characters = characters;
+    }
+}

teavm-classlib/src/main/java/org/teavm/classlib/impl/tz/TimeZoneGenerator.java

@@ -0,0 +1,125 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  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.
+ */
+package org.teavm.classlib.impl.tz;
+
+import org.joda.time.DateTimeZone;
+import org.teavm.classlib.impl.Base46;
+import org.teavm.model.MethodReference;
+import org.teavm.platform.metadata.MetadataGenerator;
+import org.teavm.platform.metadata.MetadataGeneratorContext;
+import org.teavm.platform.metadata.ResourceMap;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class TimeZoneGenerator implements MetadataGenerator {
+    private static int[] divisors = { 60_000, 300_000, 1800_000, 3600_000 };
+    public static int RESOLUTION_MINUTE = 0;
+    public static int RESOLUTION_5_MINUTES = 1;
+    public static int RESOLUTION_HALF_HOUR = 2;
+    public static int RESOLUTION_HOUR = 3;
+
+
+    @Override
+    public ResourceMap<ResourceMap<TimeZoneResource>> generateMetadata(
+            MetadataGeneratorContext context, MethodReference method) {
+        ResourceMap<ResourceMap<TimeZoneResource>> result = context.createResourceMap();
+        for (String id : DateTimeZone.getAvailableIDs()) {
+            int sepIndex = id.indexOf('/');
+            String areaName = id.substring(0, sepIndex);
+            String locationName = id.substring(sepIndex + 1);
+            ResourceMap<TimeZoneResource> area = result.get(areaName);
+            if (area == null) {
+                area = context.createResourceMap();
+                result.put(areaName, area);
+            }
+
+            DateTimeZone tz = DateTimeZone.forID(id);
+            TimeZoneResource tzRes = context.createResource(TimeZoneResource.class);
+            tzRes.setAbbreviation(locationName);
+            tzRes.setData(encodeData(tz));
+            area.put(locationName, tzRes);
+        }
+
+        return result;
+    }
+
+    public String encodeData(DateTimeZone tz) {
+        // Find resolution
+        int resolution = RESOLUTION_HOUR;
+        long current = 0;
+        long offset = tz.getOffset(0);
+        while (true) {
+            long next = tz.nextTransition(current);
+            if (next == current) {
+                break;
+            }
+            current = next;
+
+            int nextOffset = tz.getOffset(next);
+            if (nextOffset == offset) {
+                continue;
+            }
+
+            offset = nextOffset;
+            resolution = getResolution(resolution, current);
+            resolution = getResolution(resolution, offset);
+            if (resolution == 0) {
+                break;
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+        Base46.encode(sb, resolution);
+
+        current = 0;
+        offset = tz.getOffset(0);
+        int divisor = divisors[resolution];
+        long last = 0;
+        long lastOffset = offset / divisor;
+        Base46.encode(sb, lastOffset);
+        while (true) {
+            long next = tz.nextTransition(current);
+            if (next == current) {
+                break;
+            }
+            current = next;
+
+            int nextOffset = tz.getOffset(next);
+            if (nextOffset == offset) {
+                continue;
+            }
+
+            offset = nextOffset;
+            long newTime = current / divisor;
+            long newOffset = offset / divisor;
+            Base46.encodeUnsigned(sb, newTime - last);
+            Base46.encode(sb, newOffset - lastOffset);
+            last = newTime;
+            lastOffset = newOffset;
+        }
+
+        return sb.toString();
+    }
+
+    private int getResolution(int currentResolution, long value) {
+        while (currentResolution > 0 && value % divisors[currentResolution] != 0) {
+            --currentResolution;
+        }
+        return currentResolution;
+    }
+}

teavm-classlib/src/main/java/org/teavm/classlib/impl/tz/TimeZoneResource.java

@@ -0,0 +1,32 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  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.
+ */
+package org.teavm.classlib.impl.tz;
+
+import org.teavm.platform.metadata.Resource;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public interface TimeZoneResource extends Resource {
+    String getAbbreviation();
+
+    void setAbbreviation(String abbreviation);
+
+    String getData();
+
+    void setData(String data);
+}

teavm-classlib/src/main/java/org/teavm/classlib/impl/tz/TimeZoneResourceProvider.java

@@ -0,0 +1,39 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  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.
+ */
+package org.teavm.classlib.impl.tz;
+
+import org.teavm.platform.metadata.MetadataProvider;
+import org.teavm.platform.metadata.ResourceMap;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class TimeZoneResourceProvider {
+    public static TimeZoneResource getTimeZone(String id) {
+        int sepIndex = id.indexOf('/');
+        String areaName = id.substring(0, sepIndex);
+        String locationName = id.substring(sepIndex + 1);
+        ResourceMap<TimeZoneResource> area = getResource().get(areaName);
+        if (area == null) {
+            return null;
+        }
+        return area.get(locationName);
+    }
+
+    @MetadataProvider(TimeZoneGenerator.class)
+    private static native ResourceMap<ResourceMap<TimeZoneResource>> getResource();
+}

teavm-classlib/src/test/java/org/teavm/classlib/impl/Base46Test.java

@@ -0,0 +1,38 @@
+/*
+ *  Copyright 2015 Alexey Andreev.
+ *
+ *  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.
+ */
+package org.teavm.classlib.impl;
+
+import static org.junit.Assert.*;
+import org.junit.Test;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class Base46Test {
+    @Test
+    public void encode() {
+        StringBuilder sb = new StringBuilder();
+        for (int i = -65536; i <= 65536; ++i) {
+            sb.setLength(0);
+            Base46.encode(sb, i);
+            System.out.println(i + " - " + sb);
+            CharFlow flow = new CharFlow(sb.toString().toCharArray());
+            int num = Base46.decode(flow);
+            assertEquals(i, num);
+        }
+    }
+}

teavm-tests/src/test/java/org/teavm/classlib/java/util/TimeZoneTest.java

@@ -0,0 +1,16 @@
+package org.teavm.classlib.java.util;
+
+import static org.junit.Assert.*;
+import org.junit.Test;
+import org.teavm.classlib.impl.tz.TimeZoneResourceProvider;
+
+/**
+ *
+ * @author Alexey Andreev
+ */
+public class TimeZoneTest {
+    @Test
+    public void resourceProvided() {
+        assertNotNull(TimeZoneResourceProvider.getTimeZone("Europe/Moscow"));
+    }
+}