bionic/libc/tools/zoneinfo/ZoneInfo.java

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/*
* Copyright (C) 2007 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.
*/
import java.io.IOException;
import java.util.Arrays;
import java.util.Date;
import java.util.TimeZone;
/**
* Copied from ZoneInfo and ZoneInfoDB in dalvik.
* {@hide}
*/
public class ZoneInfo extends TimeZone {
private static final long MILLISECONDS_PER_DAY = 24 * 60 * 60 * 1000;
private static final long MILLISECONDS_PER_400_YEARS =
MILLISECONDS_PER_DAY * (400 * 365 + 100 - 3);
private static final long UNIX_OFFSET = 62167219200000L;
private static final int[] NORMAL = new int[] {
0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334,
};
private static final int[] LEAP = new int[] {
0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335,
};
private static String nullName(byte[] data, int where, int off) {
if (off < 0)
return null;
int end = where + off;
while (end < data.length && data[end] != '\0')
end++;
return new String(data, where + off, end - (where + off));
}
public static ZoneInfo make(String name, byte[] data) {
int ntransition = read4(data, 32);
int ngmtoff = read4(data, 36);
int base = 44;
int[] transitions = new int[ntransition];
for (int i = 0; i < ntransition; i++)
transitions[i] = read4(data, base + 4 * i);
base += 4 * ntransition;
byte[] type = new byte[ntransition];
for (int i = 0; i < ntransition; i++)
type[i] = data[base + i];
base += ntransition;
int[] gmtoff = new int[ngmtoff];
byte[] isdst = new byte[ngmtoff];
byte[] abbrev = new byte[ngmtoff];
for (int i = 0; i < ngmtoff; i++) {
gmtoff[i] = read4(data, base + 6 * i);
isdst[i] = data[base + 6 * i + 4];
abbrev[i] = data[base + 6 * i + 5];
}
base += 6 * ngmtoff;
return new ZoneInfo(name, transitions, type, gmtoff, isdst, abbrev, data, base);
}
private static int read4(byte[] data, int off) {
return ((data[off ] & 0xFF) << 24) |
((data[off + 1] & 0xFF) << 16) |
((data[off + 2] & 0xFF) << 8) |
((data[off + 3] & 0xFF) << 0);
}
/*package*/ ZoneInfo(String name, int[] transitions, byte[] type,
int[] gmtoff, byte[] isdst, byte[] abbrev,
byte[] data, int abbrevoff) {
mTransitions = transitions;
mTypes = type;
mGmtOffs = gmtoff;
mIsDsts = isdst;
mUseDst = false;
setID(name);
// Find the latest GMT and non-GMT offsets for their abbreviations
int lastdst;
for (lastdst = mTransitions.length - 1; lastdst >= 0; lastdst--) {
if (mIsDsts[mTypes[lastdst] & 0xFF] != 0)
break;
}
int laststd;
for (laststd = mTransitions.length - 1; laststd >= 0; laststd--) {
if (mIsDsts[mTypes[laststd] & 0xFF] == 0)
break;
}
if (lastdst >= 0) {
mDaylightName = nullName(data, abbrevoff,
abbrev[mTypes[lastdst] & 0xFF]);
}
if (laststd >= 0) {
mStandardName = nullName(data, abbrevoff,
abbrev[mTypes[laststd] & 0xFF]);
}
// Use the latest non-DST offset if any as the raw offset
if (laststd < 0) {
laststd = 0;
}
if (laststd >= mTypes.length) {
mRawOffset = mGmtOffs[0];
} else {
mRawOffset = mGmtOffs[mTypes[laststd] & 0xFF];
}
// Subtract the raw offset from all offsets so it can be changed
// and affect them too.
// Find whether there exist any observances of DST.
for (int i = 0; i < mGmtOffs.length; i++) {
mGmtOffs[i] -= mRawOffset;
if (mIsDsts[i] != 0) {
mUseDst = true;
}
}
mRawOffset *= 1000;
}
@Override
public int getOffset(@SuppressWarnings("unused") int era,
int year, int month, int day,
@SuppressWarnings("unused") int dayOfWeek,
int millis) {
// XXX This assumes Gregorian always; Calendar switches from
// Julian to Gregorian in 1582. What calendar system are the
// arguments supposed to come from?
long calc = (year / 400) * MILLISECONDS_PER_400_YEARS;
year %= 400;
calc += year * (365 * MILLISECONDS_PER_DAY);
calc += ((year + 3) / 4) * MILLISECONDS_PER_DAY;
if (year > 0)
calc -= ((year - 1) / 100) * MILLISECONDS_PER_DAY;
boolean isLeap = (year == 0 || (year % 4 == 0 && year % 100 != 0));
int[] mlen = isLeap ? LEAP : NORMAL;
calc += mlen[month] * MILLISECONDS_PER_DAY;
calc += (day - 1) * MILLISECONDS_PER_DAY;
calc += millis;
calc -= mRawOffset;
calc -= UNIX_OFFSET;
return getOffset(calc);
}
@Override
public int getOffset(long when) {
int unix = (int) (when / 1000);
int trans = Arrays.binarySearch(mTransitions, unix);
if (trans == ~0) {
return mGmtOffs[0] * 1000 + mRawOffset;
}
if (trans < 0) {
trans = ~trans - 1;
}
return mGmtOffs[mTypes[trans] & 0xFF] * 1000 + mRawOffset;
}
@Override
public int getRawOffset() {
return mRawOffset;
}
@Override
public void setRawOffset(int off) {
mRawOffset = off;
}
@Override
public boolean inDaylightTime(Date when) {
int unix = (int) (when.getTime() / 1000);
int trans = Arrays.binarySearch(mTransitions, unix);
if (trans == ~0) {
return mIsDsts[0] != 0;
}
if (trans < 0) {
trans = ~trans - 1;
}
return mIsDsts[mTypes[trans] & 0xFF] != 0;
}
@Override
public boolean useDaylightTime() {
return mUseDst;
}
private int mRawOffset;
private int[] mTransitions;
private int[] mGmtOffs;
private byte[] mTypes;
private byte[] mIsDsts;
private boolean mUseDst;
private String mDaylightName;
private String mStandardName;
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof ZoneInfo)) {
return false;
}
ZoneInfo other = (ZoneInfo) obj;
return mUseDst == other.mUseDst
&& (mDaylightName == null ? other.mDaylightName == null :
mDaylightName.equals(other.mDaylightName))
&& (mStandardName == null ? other.mStandardName == null :
mStandardName.equals(other.mStandardName))
&& mRawOffset == other.mRawOffset
// Arrays.equals returns true if both arrays are null
&& Arrays.equals(mGmtOffs, other.mGmtOffs)
&& Arrays.equals(mIsDsts, other.mIsDsts)
&& Arrays.equals(mTypes, other.mTypes)
&& Arrays.equals(mTransitions, other.mTransitions);
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((mDaylightName == null) ? 0 :
mDaylightName.hashCode());
result = prime * result + Arrays.hashCode(mGmtOffs);
result = prime * result + Arrays.hashCode(mIsDsts);
result = prime * result + mRawOffset;
result = prime * result + ((mStandardName == null) ? 0 :
mStandardName.hashCode());
result = prime * result + Arrays.hashCode(mTransitions);
result = prime * result + Arrays.hashCode(mTypes);
result = prime * result + (mUseDst ? 1231 : 1237);
return result;
}
}